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Energy efficiency upgrades � what is worth it?

Posted by Laura12 (My Page) on
Thu, Jan 31, 13 at 15:49

I'm trying to figure out which energy efficient upgrades are worth our money, by which I mean, which ones will have a reasonable return on investment, or on our comfort in our home. I live in the Northern California, away from the ocean, zone 3. We are building a 4400 sq ft home, mostly single story, but there is a large bonus room and spare bedroom upstairs. If we can get above 45% over California Title 24 requirements we could potentially get a $4000-$6000 rebate, and we are already 25% over without any of the below upgrades so some of the costs below would pay for themselves.

I'm also curious what other upgrades we could do that would be cost effective, increase the comfort of our home and help get us over the requirements (efficiency of the lighting can�t be considered, nor can adding solar).

Attic insulation - Upgrade from R 30 to R 38 for $600

AC Unites (two) - Upgrade from seer 13 to 16 for $1,500

Exterior Wall Insulation - Upgrade from R 13 to 21 for $2000 (we have 4x6 construction)

Windows - Upgrade all windows to argon filled windows with better solar co-efficient rates (Milgard Vinyl 3D with low e glazing vs Milgard Vinyl standard with low e glazing) $2400

Furnace - 95% efficiency included

Thanks!


Follow-Up Postings:

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RE: Energy efficiency upgrades � what is worth it?

I suggest you post this on the Renewable Energy forum.

Insulation for sure always pays...and i would look at the walls too, not just the attic. If you insulate the heck out of the attic, it won't help if the heat/cooling just escapes through the walls and windows.

You might look into geothermal heating/cooling as it is a big money saver. We have it and are very happy with it. I believe there is still a federal tax credit for it too...


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RE: Energy efficiency upgrades � what is worth it?

Not sure this works on the renewable energy forum since the question isn't really about renewable energy...

One of the options I mentioned was increasing the exterior wall insulation, so we are considering it. The problem is in our temperate area I'm not sure which of these items might just be overkill and which will pay for themselves.

Regarding geothermal, we REALLY did want to go that way, but it simply isn't common in our area and the costs were astronomical. We will be adding solar, though we don't know if we will be doing it now, or in a few years.

There are a few people I seen provide insulation advice on here, so I'd love some help on this one!


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RE: Energy efficiency upgrades � what is worth it?

I would do both insulation ones, no question. I am in Washington, Seattle area (so mild winters, milder summers) and for all of Washington, minimum code now is r38 in attic and R 21 in walls (I believe, maybe R30 for walls). In any case, being N California, I'd think you'd want similar minimums to Seattle.

I can't comment on Windows, per se. But, if it is only $2400 to upgrade all your windows, I'd probably do that. Where window loss is greatest, according to my research though, is between the actual glass/frame of the window and the framing of the house. You'll want to make sure they adequately insulate around those.

and, you'll want no can lights for best efficiency, or else ICAT cans (I know you said light upgrades don't count... but, for yourself...)

There is also a huge advantage to AC of 16 instead of 13. I'd do that option as well, likely. Esp if you have a lot of cooling days where you live.


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RE: Energy efficiency upgrades � what is worth it?

kirkhall, it is interesting that our minimum codes are so different. The minimum for us is only R 13 in the walls. We of course have much milder winters than you, but the daytime temperatures in the summer are high! :) Regularly over 100 F but then around but regularly around 60 F at night. Climate maps for my area don't make any sense to me, they clump the Silicon Valley area, my area south of that, Santa Cruz on the Ocean and SF all in the same zone, but the weather is substantially different!

As for lights, we will have a lot of can lights, and quite a few of those will be LEDs as well. There is a silly rule that you can't use your lighting efficiency toward the rebates unless you hire some sort of lighting consultant to do an assessment, which would cost more than the rebate!


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RE: Energy efficiency upgrades � what is worth it?

This IECC map details climate zones with much more precision than you may see elsewhere.

For economic levels of insulation you can use this calculator from the Oak Ridge National Laboratories.

Upgraded windows and attic insulation will likely yield you the greatest payback as they are the largest surfaces interfacing with the exterior.

The placement of the E-coating is dependent on the climate.

Where window loss is greatest, according to my research though, is between the actual glass/frame of the window and the framing of the house.

Are there still builders out there not insulating that space with low-expansion foam?

Here is a link that might be useful: Low-E Windows

This post was edited by worthy on Fri, Feb 1, 13 at 13:35


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RE: Energy efficiency upgrades � what is worth it?

Laura - as you know, this is always a very regional issue.

If you get to 100, you really want to work on a/c which is all about solar gain in the windows. $2400 sounds good but are they just making a 5% gain in SHGC? Are your windows already protected?

I mean if you have a wall of West windows and the gain is significant then $2400 is a good deal. If your majority windows are North or you have shade trees, then it isn't. Very tough questions.

I am guessing you have NG. I'd have to think that with Title 24 in your climate, your annual heating cost has to be below $200. Your wall upgrade primarily helps with heating - probably save $50 a year. What kind of ROI are you looking for? If you are trying to do your best to be sustainable, then a 40 year ROI isn't bad since walls should last 100 years (depending on fault lines....). The a/c savings is probably $10 a year even at Tier III.

Seattle the same climate as SF bay area - I don't know about that. Also WA reqs are on the extreme - like Title 24 but with different emphasis.

Geo makes zero sense in your area when you have NG. Makes even less sense in a tight new house.

Can you plug in your zip and get HDD and CDD. I'm always surprised how cold it gets where my father lives - hills of Berkeley. So I'm not entirely sure that even a zip code has a consistent climate in that area. What is your elevation? What is your average winter low and your winter design temp?

I'll always remember a conversation with a new transplant to Palo Alto (from Chicago) who was apologizing for the cold house in the morning. She said - you know - it is CA, we don't run the heat. Of course by mid morning, the house was toasty from the sun.

So the payback for a lot depends on your south windows and tolerance for cold temps in the morning. Like my NC climate, a lot of winter days have zero heat requirements because I don't mind 67 in the morning. The difference in window orientation can make a far greater difference than R13 or R21 in the walls.

With current PV prices and incentives, your best plan is to have a large area to put panels. They may payback faster than all your other options. They don't last forever and that is why wall insulation maybe more sustainable over the long haul. I built on the NC coast and had to have a realistic lifespan (I chose 20 years). The CA regulators have done a lot of payback analysis and they allow R-13 in the walls - that should tell you something....


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RE: Energy efficiency upgrades � what is worth it?

I would still cross post on renewable energy as you are discussing solar and potentially geothermal and the folks there spend all kinds of time looking at energy efficiency, insulation techniques, etc. That forum really encompasses all modes of energy efficiency and building green.

I'm surprised you say geothermal is astronomical...for us the only cost difference vs traditional heating and cooling was drilling the wells and the 30% tax credit more than covered the cost of that, so our system started paying back right away. And if AC is more a concern than heat in your area, most geothermal does AC even better than heat, IMO. And to have one unit vs 3 would seem to be a maintenance efficiency too.


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RE: Energy efficiency upgrades � what is worth it?

Agree with Annie on the geothermal. Seriously look at the actual cost before deciding. Even today when it was -15 degrees, our home is very comfortable. We do have a backup furnace, but have never used it. We also did all the insulation upgrades, and had the entire building envelope sealed. Our total utility bill including approx $80 for water conditioning is $250/mo. We are all electric except for our gas fireplace and cooktop. House is a 5200 sq ft ranch. Zone 3.

We have Milgard double hung windows, and I honestly wouldn't choose them again. I should have noticed this when we looked at them, but the "lip" to grab to move them up and down is on the upper pane. A real pain for those higher windows like over the sink. We also had a problem with a couple windows steaming up on the inside of the panes, but they replaced them immediately. But they are very easy to clean.


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RE: Energy efficiency upgrades � what is worth it?

Do solar water heaters not count either?

If you do get large solar gains on your windows (south facing) could automatic shades for them count to help?


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RE: Energy efficiency upgrades � what is worth it?

The two insulation upgrades are the most cost-effective.

See if that gets you into the rebate zone. If not, see what the windows will do.


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RE: Energy efficiency upgrades � what is worth it?

Wow! Thanks for all the suggestions!

Worthy,

According to that map we are in zone 3, but again, clumping in my area with San Francisco, and the coastal areas make no sense. While the winter temps may be similar (though, we have colder nights), the summer highs are entirely different.

Our summer averages are in the 90s, but it is also regularly over 100, and the summer nighttime lows are around 55 F. The daytime winter temps are around 60 F during the day and 35 at night. If you are somewhat familiar with the area, our weather has more in common with Napa/Sonoma than San Francisco.

Our elevation is 107, we are in a valley so the temps tend to be higher than average for the area during the summer days, and cooler at night

Both window options include low e glass, the upgraded price includes argon gas and some other energy features. I'll look at the differences between the solar heat gain and U ratings and post separately.

david_cary -

The regional variance makes it hard to get advice on so many things! :) There also seems to be very few people in California on this board which seems to double the problem! Additionally, the variability in weather in the bay area is an odd occurrence. Our house actually faces west (yes, unfortunate, but it is designed in such a way that there are limited windows on the west side. There is a small covered area in front of the kitchen windows to help with the sun there, and we will have solar shades on the windows in the Den. The other west windows are in the garage, the mudroom/laundry the master bedroom closet and the master bath. See floor plan below.

You mention insulation only helping with heating, does it not help as significantly with keeping the cool air inside in the summer as well? Our main goal is to create a comfortable home where we don't have to run the AC or heat that frequently. I wouldn't mind my house to be 67 in the morning without running the heater, currently we the heater is on from sundown to early morning throughout the winter just to keep our current house at 66 F (lately a bit warmer as we have a newborn), but we don't have ANY insulation in the walls!

To that end we are also putting in a whole house fan (for those unfamiliar it is a large fan that exchanges the air in your home for air outside rather quickly, beneficial in climates like min where the summer evening temperatures are cool, and the daytime temperatures very hot). I'd like to be able to run the whole house fan in the summer evenings to cool the house down, then close the windows up in the morning and keep it cool for most of the day without running the AC that often. Though, I don't know anyone who has a system like this, or a well sealed and insulated house to know whether it works well enough to not worry about increasing the efficiency of the AC.

What do you mean by HDD and CDD?

Annie & Joyce

David_cary is right, in our area geothermal makes little sense, especially considering we have natural gas. I priced it out geothermal when I didn't think we had access to NG and it would be around $50,000 for the system, not including the ductwork, and that is for a horizontal system not a vertical system. While we have 2.5 acres the county requires us to have TWO septic drainage fields, and we plan on putting in a pool and a large outdoor living area we don't know that we would have the space for the horizontal system. Compare all that to $20,000 for my HVAC system (including the ductwork) and it doesn't make sense.

What does make sense in our area is solar, it doesn't rain for 6 months of the year, and even in the winter we don't get very many cloudy days. My husband actually has the skills and experience to do most of the installation himself. Between the 30% tax credit and additional rebates for putting solar on new construction in California we would be crazy not to go that route. I expect we will only have to cover 25% of the cost ourselves.

We considered solar water, but decided against it.

Joyce - we are getting a combination of casement windows and sliders from the Milgard Tuscany line (though I'm looking into the price difference with their Style line.)

bdpeck_charlotte, automatic blinds don't count as they are removable.


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RE: Energy efficiency upgrades � what is worth it?

Geothermal on the West coast is no where near the prices seen on the East Coast. I have no idea why, but we considered Geo until we saw the costs--40k extra? no thanks.


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RE: Energy efficiency upgrades � what is worth it?

The local contractors tried to tell me that it was due to permitting, and the cost of shipping materials from east coast! Reasoning I find completely ludicrous.


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RE: Energy efficiency upgrades � what is worth it?

Attic insulation - Upgrade from R 30 to R 38 for $600

prior to insulating attic air sealing should be done, or
insulation performance is lessened to a great degree.
one point in case...recessed lights. not everything counts as $$ back. Insulation Contact recessed lights not only allow extreme attic temps into the house, but insulation is
installed next to the cans & the holes in the housing.
one IC can de-rates 1 sq ft of insulation around it to R-0
because of air infiltration through the insulation.
so, instead of IC lights, buy ICAT (insulation contact
air tight) and install them everywhere. including outside,
cause the electrician will mix IC & ICAT up when installing.
it is very cost effective to purchase ICAT as compared to the cost of installing air tight inserts & trim kits.
approx cost of inserts & trim kits are $17 PER light.

stopping air infiltration from the extreme attic temps
just makes common sense. but don't count on trades to do this. without you pushing air sealing..it won't get done.

AC Unites (two) - Upgrade from seer 13 to 16 for $1,500
I find that 15-17 SEER is a good investment. lower SEER
is not cost effective, nor is higher. without knowing if
you are all electric or a combo of elec w/gas furnace..
advice is general. if all electric Heat Pump.
if elec/gas then upgrade to higher efficiency gas furnace.
even in my hot humid climate people who understand that the efficiency cost is upfront are installing 96% gas furnaces.
works well for us, because we put our equipment & ductwork in the attic. so once furnace is upgraded,we can foam insulate the attic. this turns the attic into a semi conditioned space, allowing temps leaving equipment to remain same temp when entering the living space.
I don't recommend spray foam in walls, but if equipment
& ducts are in the attic..its a no brainer.
again...roi comes into this conversation. depending upon
size & pitch of roof your upgrade varies.
on an average 2500 sq ft house with a 10 on 12 roof
pitch, you are looking at an approx.8-10 year payback.
for walls...putting a 1" foam sheathing board on
exterior of walls works towards air tightness of wall &
adds R-7 in insulation value. then insulate with conventional insulation, and use an air tight drywall
approach to interior.

Exterior Wall Insulation - Upgrade from R 13 to 21 for $2000 (we have 4x6 construction) see above and don't you
mean 2x6?

Windows - Upgrade all windows to argon filled windows with better solar co-efficient rates (Milgard Vinyl 3D with low e glazing vs Milgard Vinyl standard with low e glazing) $2400
http://www.nfrc.org/Windowratings/The-NFRC-Label.html
learn what makes a window efficient. shop for windows
with this label. solar heat gain coefficients & ufactors
of .30 or less. low e and argon gas.
understand that the frame has a direct effect on the
glass. non conductive frames..vinyl, wood, metal exterior with wood interior all contribute to low shgc & ufactors.
metal windows conduct heat & cold. avoid metal even with thermal break.

Furnace - 95% efficiency included
see a/c

you can put the best hvac system,the best windows
and upgrade the insulation. but if the house is leaky
and the ducts are leaky...you'll never achieve the
efficiency you can with the attention to air sealing
& duct sealing.
in Ca. they do blower door testing & duct testing I believe.
these are important. a tight house is affordable
to heat & cool.
just because a house is new, does not mean that it is
tight. build tight, ventilate right.
if the house tests below .25 air changes..then you
add fresh air, as per ASHRAE's 62.2 ventilation strategy.

here is a link to the spec sheet that I give my clients.
note that it is for hot humid climate, so make allowences for your climate mandates.

http://ths.gardenweb.com/forums/load/build/msg0115070624800.html?4

best of luck


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RE: Energy efficiency upgrades � what is worth it?

Insulation still helps with a/c. It's just that the delta T is relatively small.

When it is 95 out and you want inside 78, that is only 17 degrees. Sure it gets hotter but not for very long (probably). If you are in the North, the temp goes down to 10 degrees for hours - a 60 degree delta T. That is where insulation really matters.

Now I don't know about the valley - that is a different thing all together. If a/c is a big issue, you really want to shade the windows. Upgrade the Seer and probably upgrade the windows. On my energy audit - a/c was 60% solar gain. And if you take away ducts, the windows were responsible for 80% of the a/c load. Sure you can upgrade the walls but you are chasing 10% (the other 10% is attic/crawl).

Geo does not help with a/c more than heat because of the same issue regarding delta T's. Air source heat pump (ie conventional a/c) has no problem dealing with 95 degrees. Heating when it is 10 degrees out is a problem - that is where geo shines. Now a/c really starts falling off in efficiency over 100 - I am guessing that is a 10 day a year problem - and again only for a few hours.

I am thinking very few "normal" people build houses in CA. Places like the SE are very difference where middle class people can build houses and the population is growing (unlike CA). Most new construction I've seen out there is tract houses and multi-million dollar houses. Here we have $200k builds that are custom...


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RE: Energy efficiency upgrades � what is worth it?

There's not much point in spending so much extra money on upgrading insulation values without air-tightness goals. What are you shooting for on your blower door test? Bringing down your ACH50 is usually more cost-effective than adding more insulation. Building air-tight allows insulation to do its job.

For the window comments on losing more energy to air leaks than window performance, I would agree even when a builder uses spray foam between the window frame and framing. We are extremely meticulous about sealing this location yet the blower door will usually reveal some spots that were missed. High grade tape or caulk with backing rod seems to do a better job in most cases.

Kudos for going casements. Double Hung and sliders are leaky from the beginning and get worse over time not to mention their other shortcomings.



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RE: Energy efficiency upgrades � what is worth it?

Here is the house - it faces west

Final plan main floor


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RE: Energy efficiency upgrades � what is worth it?

David_Cary - you are right that there isn't much "normal" people building homes in California. The population is still growing, but is mostly tract homes. The new homes tend to be on lots that cost 1 million + or complete teardowns where the owners are not concerned with market value or cost. That said, that does NOT describe us, we are far enough south that we could get land that wasn't too outrageous and our budget seems similar to many on here (700k consturction budget) and our land wasn't too ourtrageous, for this area anyways! :).

Your explanation of the benefits of insulation in regards to exterior and interior temperatures helps immensly. I don't know why I didn't see it that way before. The summer temps here are well above 100 for more than 10 days a year, so I think that helps me see the benefit a bit more!

Brian, I think it is about 50/50 casements and sliders.
I think it is sliders in the kids rooms, laundry room and den, and upstairs, and then the rest are casements. You can see that the plan really has a large proportion of sliding doors.

Also, while there are not plans to do a blower test (both the energy consultant and builder don't think it is worth it) we are paying attention to the building envelope, and part of this proces includes verifying: Duct Leakage HERS measure, verified Fan Watt Draw HERS measure & verified Cooling Coil Airflow HERS measure.

Energy_rater_la -

Great points about the lights!

Oh, we are electric + gas

The pitch of our roof id 5 on 10, and while long term spray foam is a good idea, that is outside the budget.

The plan is for a 5 ton system for downstairs, and a smaller system for upstairs. I'd really like a single system, but I'm being told that isn't possible.


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RE: Energy efficiency upgrades � what is worth it?

the tradeoff to building a tight well insulated
house..is smaller hvac system.
investing in a load calc..room by room load
calc instead of whole house calculation is the
best $$ you can spend.
avoiding the hvac companies that use rule
of thumb sizing will save you on equipment
costs, electrical consumption & not shorten
the life of the equipment.

where are you in your building process?
you say:"we are already 25% over"
over budget??
looking at things that cut costs would
be a big option to make efficiency more
affordable.

hopefully, I misunderstood that part of
your post.

best of luck


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RE: Energy efficiency upgrades � what is worth it?

I didn't say that we are 25% over budget, we are 25% over California Title 24 Energy Requirements, which is saying that we are 25% more efficient than the code requires us to be. If we get up to 45% over Title 24 Requirements the rebates we receive from the state go up, which basically cover the costs of the upgrades.

We are going to spend money on creating a tight envelope, and we hope to get through all of this without spray foaming the interior of the roof, as that upgrade is much more than the other items we are looking at. If we need it later can't we always do it at a later date?

if I want to consider an HVAC contractor other than the one my builder normally uses what questions would I ask them to ensure that they would do a room by room load calculation? Can another energy consultant do this?


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RE: Energy efficiency upgrades � what is worth it?

good..I thought I might have misunderstood that!
I've been working with builders to achieve 50% better
than our code..when you get to that level...everything
makes a difference!

as to foaming at later date...maybe. but
making the roof to attic floor at the eaves of
the house when attic has blown insulation can
be an issue. but when and if you decide to do the
foam...you can deal with it then.
some companies remove the insulation, which isn't a
bad thing, but making sure that this area
is insulation free and relatively dirt/dust free
is the only way to get a good air seal.

load calcs...talk to builder about another contractor.
when you call for bids, tell the companies that
you want a room by room load calc.
understand that they won't release the calcs to
you until you hire them. they don't want you shopping
their work(calcs) to various companies.
once you sign, they should give you a copy of the
load calc. plans should have all specifics of the
insulation, windows etc.

lots of independent people do load calcs.
you'd have to supply a set of plans...with specific
upgrades to them. then you could take the load
calc to the hvac companies.

this is one company that comes up when googling (sp??)
independent load calculations for hvac
I'm not recommending them...just suggesting you do
your own search in your area. although the load calc
can be done by anyone with access to heating & cooling
degree days & the know how.

http://acrightsize.com/

some energy raters do load calcs. not a lot...but
you could always ask.
www.resnet.us
our rating software does a load calc based on Elite
hvac load calc software.

best of luck


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RE: Energy efficiency upgrades � what is worth it?

We live in Los Angeles and have a whole house fan in a 10 year old house. We bought 2 years ago and it was one of the first things we added to the house. Coming from the Northeast, where many older homes have a WHF, it made so much sense to add one in this CA climate. In the Northeast they are only good in the spring/fall, once the humidity levels rise they don't help at all.


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RE: Energy efficiency upgrades � what is worth it?

Chispa - how much do you use your AC with the whole house fan?


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RE: Energy efficiency upgrades � what is worth it?

No blower test? I forgot that Title 24 didn't require one.

This is of course shocking to anyone in the biz from other parts of the country. More states require it now and I had one 4 years ago. GA (not exactly progressive nor cold) requires one. Energy star requires it (and ES is not strict at all - far less than Title 24 in general).

Most blower door tests are for certification and proof of a level of air tightness. While I'm sure you have requirements, without proof they are dubious. Of course your builder doesn't want to do it - it's a pain. The energy rater ... was he picked by the builder?

Gold standard is blower doors tests with remediation and is one of the most cost effective things to do during the build. But that doesn't help your original question. You are being pushed into less than cost effective upgrades by a rebate program. It seems to me that you should approach the upgrades with that in mind - what costs the least to get the most rebate. All things will help to varying degrees. Since you have an energy rater, they should be able to help you with this more than a forum can since they understand your local climate the best.

ERLA - I don't think you can compare LA code with Title 24 - they are probably as different as the tax structure between LA and CA. Going above Title 24 is pretty darn good - to the point of diminishing returns. While title 24 is strict, it isn't entirely rational either....


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RE: Energy efficiency upgrades � what is worth it?

I'm curious, on geothermal, do they not do vertical in CA? We have over 11 acres but went vertical anyway and drilling the wells took a single day so not a big deal or a big price....it's not like you're looking for water...you just want to get into the earth.


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RE: Energy efficiency upgrades � what is worth it?

Many feel that investing in the building envelope is better than mechanical systems. Although Geothermal generally has longer warranties, they still have a much shorter life than the building envelope. With a high performance envelope the payback can get as long as the expected system life. That being said, Iam still a fan.

I agree with David. Ive never heard of an energy consultant not recommending a blower door test. Its tough to pay attention to the building envelope without one.

My rater charges me 75$ for an EXTRA test. Its not a pain at all. I think its fun! Now a duct blaster test, thats a pain but still important of course.

Youre on the right track Laura. You are ahead of the game by even considering extra insulation. I think your home will turn out great but you should start to push for measurable airtightness.


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RE: Energy efficiency upgrades � what is worth it?

How much is a blower door test in other parts of the country? Brian, you mention $75 for an extra, but how much for the first?

The builder actually didn't say anything about not doing the blower door test, if I want to pay for it he will do it. The feedback regarding not doing is coming from the person who is doing the calculations of how energy efficient our home is, and she recommended a tester for the ducts and other items that are required.

Also, regarding foam insulation in the attic, am I wrong in thinking that costs more than all the other upgrades we are considering combined?

Annie, they do vertical for Geothermal here as well, however it is more expensive than a horizontal loop, and I only received pricing ballpark pricing for a horizontal loop. I see why you are such a proponent of Geo - it is a great system, it just doesn't make sense here. I can put in solar for less than half the cost, and twice the rebates. The solar will be enough to cover at least 80% of our electricity bills, so that will cover the AC bill, and then we have gas for heat, which as David explained will be a relatively small part of the equation here.

I'll look into getting load calcs to determine the size of the system. I'm going to push back on the builder regarding needing two AC systems and two furnaces, any other advice on the viability of this option? The main floor plan I posted is 3400 sq ft, and there is another 1000 upstairs, a large bonus room, media room, and spare bed/bath for guests.


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RE: Energy efficiency upgrades � what is worth it?

ERLA - I don't think you can compare LA code with Title 24 - they are probably as different as the tax structure between LA and CA. Going above Title 24 is pretty darn good - to the point of diminishing returns. While title 24 is strict, it isn't entirely rational either....

I agree. no comparism between La. code and Ca., wish
we would require folks to a higher standard!
but I did think that blower door & duct testing were
code in Ca.

Laura,
"The feedback regarding not doing is coming from the person who is doing the calculations of how energy efficient our home is, and she recommended a tester for the ducts and other items that are required."
so who is his person? energy rater..or auditor?
what background does she have to make the recommendations?

you asked about costs..prices vary as we are all independent.
for new homes I charge $550 for a average sized house
2500 sq ft with one hvac system. the larger the house with multiple hvac systems..prices increase.

this price includes an energy rating from plans..reports
one the explains amount of time for upgrades to pay for themselves, and another that shows what % of savings
for each upgrade. hvac sizing reports & various other
reports can be included.
also included is one intermediate inspection,and
final testing & verification. all paperwork is handled
by the rater.

once house is blacked in, thermal bypass inspection is
manditory. this is a walk thru inspection when insulation
is in walls..prior to sheetrock. without a visual inspection
the insulation grade is fail.
this timely inspection gives the rater a chance to verify
lots of things, how windows are flashed, how they are
sealed from inside, heating system is usually in place as
are ducts, so mastic seal of duct & heating model & serial
numbers are taken. window efficiency, insulation in walls etc. a blower door test can be done around
this time.that the trades people are still on site at this
time makes a world of difference. to try to get them
back once project is complete..is a pita.

I usually test when house is complete.
I can identify problem areas on intermediate inspection
so that these issues are addressed.(years of doing this)
final inspection is when house is complete.
condensing unit is in place and attic is insulated.
then the blower door & duct test is done.
sometimes if attic insulation is on the attic floor,
I'll test prior to insulation install. then come
back to verify R-values when insulation is installed.

to do additional blower door testing..I charge $100.
the builder is usually responsible as it is his lack
of doing what he was hired to do that is the reason
for additional testing. if it is an insulation
or hvac issue, these companies may assume the charge.

when called into just do a blower door & duct test
I charge more. in addition to the testing I give the
homeowner a written report of all leakage sites
& how to seal them, plus any issues that testing
showed. for this diagnostic on an average sized
house, I charge $250.
when I leave, the homeowner knows everything that
is done wrong & how to rectify the errors.

with testing ducts, the work is in the prep.
taping off all supplies & enough of the return
to set up duct blaster. I like to use the fan
to not only measure leakage amount, but then to
pressurize the duct sytem so that marking the
areas that leak in the attic (most of our ducts
and equipment are in the attic..worst place to put them)
that leak. I feel that knowing how much leakage
there is doesn't help unless you know where it
leaks. and then of course how to seal the leaks.

I usually work for the homeowner, not the builder.
in working for the builder, I find that it causes
conflict for me, as I am geared towards the homeowner's
needs. but that is a personal agenda. by working
for the homeowner I can be sure they get what they
pay for. as they are the ones who will live there,
and the builder will move on to the next project.

best of luck with your project.


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RE: Energy efficiency upgrades � what is worth it?

Energy Raters prices are a great value. My rater charges much more overall despite the slightly cheaper additional blower door test. Iam usually doing Energy Star which requires more paperwork and documentation. My poorly made point was that the blower door test is usually built into the services of a competent energy rater or "consultant" so it doesnt have a direct cost. Its just something you should do when you build a house these days.

Technically, the International Codes have minimum blower door test requirements in place. It is just now beginning to be enforced. In the very near future, you will not be able to legally build a home that is not blower door tested to a minimum level of airtightness.

2012 IECC says that Laura's home in Zone 3 should have a minimum ACH50 of 5. This sets a pathetically low bar in my opinion but at least its a wonderful step in the right direction. In Laura's position I would shoot for a 3 but most high performance builders are regularly achieving 1.5 and better. That is where you want to be if you're concerned with cost-effective energy efficiency.


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RE: Energy efficiency upgrades � what is worth it?

I find it shocking that there is something that TItle 24 doesn't require that is required in other areas! :) ha

I'll see if I can work it in, or talk to someone different to do the calculations. What is more surprising is that the my builder or the designer who did our plans haven't used blower door tests - ever!


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RE: Energy efficiency upgrades � what is worth it?

You know Laura, the issue in CA (mostly) is that it doesn't get that cold and infiltration is more of an issue for cold than heat. I think my baseline infiltration numbers were $10 a year for a/c and $80 for heat - this was average new house.

This is NC where most people think the summer is hotter than the winter is colder.

So I think that explains the blower test issue. But back to upgrades, the thought of doing R21 walls and not doing a blower door test makes little sense. When you are going to absolute best practices, you need a blower door test. I am not saying you "need" it but it is involved in best practices.

Like you have noticed - solar PV has a better payback than much of these things. A blower door test is not worth $500 for you. For me $800 or so covered the consultant and duct and blower door tests. If your rater doesn't routinely do it, I think you are out of luck for a cost effective option. Not a big deal really. Sealing a house is just super cheap compared to upping the wall r-value.


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RE: Energy efficiency upgrades � what is worth it?

so the efficiency upgrades came from the designer?
or who?

the whole pick a number of fresh air changes is
crazy. here in La. we were told to use .35 ach
as a tight house. in florida it was .25 ach.
much better is 1.5 ach, BUT when you tighten
to this level, there needs to be a fresh air
source for the whole house.

I lean towards whole house dehumdification
systems with fresh air intake, in my hot humid
climate. as I learn more, I see that these
systems are used in climates I wouldn't formerly
have thought it necessary.
there are multiple ways to address adding fresh/make
up air. ASHRAE 62.2 is a starting point.

what gets me is the 1200 cfm stove vents. talk
about putting a house under a negative pressure.

but folks do some crazy stuff!!


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RE: Energy efficiency upgrades � what is worth it?

You say you are in Zone 3 in Northern California. Is that Sunset zone 3. I checked the USDA plant hardiness zone map and can not find any zone 3 in CA.
I'm in northern WY a mile high in the Rocky Mtns and we are only a zone 4.


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RE: Energy efficiency upgrades � what is worth it?

The upgrade suggestions came from a separate energy consultant who is required to do an assessment on how we stack up against Title 24 requirements. Though, I've really been the one being proactive In learning more about the rebate options.

I agree that some of these upgrades in my climate don't have the best pay back, however with the rebates it makes sense. Actually we heard back today and it turns out that we have to do all the upgrades to qualify for the rebates. Before running the numbers she thought that ALL of them wouldn't be necessary to get the full among. That said with the rebate we should pretty much break even with all of this, or maybe be $1000 over which isn't a bad deal.

Creating a tight building is also important to us, so if we can get the blower test for a resonance amount we will, but if not we will just stress the importance of this with the builder.

There are also some pretty amazing rebates in California for solar on new construction, but they are confusing as hell! That is the next thing on the list!

Regarding our zone, the plant hardiness zones and energy efficiency zones are different (just to make life more confusing). For that measure we are in zone 9b.


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RE: Energy efficiency upgrades � what is worth it?

I was just looking at your OP - 4x6 construction?

Things like going from Seer 13 to Seer 16 almost always mean more than just efficiency. For instance, when I went from Seer 13 to Seer 15, my warranty went from 5 years to 10 years. They tend to use higher quality parts in the Seer 15 equipment. Given your temps and electric rates, this is a no brainer. $1500 is a great price. I paid $1000 for NC 2100 sqft - 2 units from 13 to 15.

The wall thickness matters and if you have 2x6 construction, you absolutely should fill the cavity with insulation. R13 would not be allowed by Energy Star in a 2x6 cavity. With fiberglass particularly, you want the cavity filled or you downgrade the R-value. Somehow I was thinking your were 2x4 and you were adding rigid foam panels which should be more expensive than your quote.

There are some issues with argon filled glass with cheaper windows with leakage down the road. Obviously all double panes can leak and get moisture in but I've heard (not substantiated) that the argon leaks out much earlier and downgrades the u-value of the window.

CDD=cooling degree days - a way of normalizing the a/c requirement between regions. HDD is the same idea.

Problem is that you might have a lot of CDD but with 60 degree dry nights, the a/c need is not as high as ours. You may peak higher 100 instead of 95 so it look like you need more a/c but we only go down to 75 and humid at night - so the house can't be opened up. When we have dry weather, we just open the house in the morning and cool it down where it stays all day without a/c. Something I am guessing you can do more than us.


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RE: Energy efficiency upgrades � what is worth it?

Eek - mistype 2x6! Ha... does 4x6 even exist? :)

The R13 in 2x6 walls did make zero sense to me, and I couldn't understand why the designer encourages 2x6 and then only included R13 walls, it seemed counter productive to me as well!

I don't know anyone who actually has a whole house fan to ask for advice, but I'm that also helps to decrease the amount we actually need to use the AC as well. It isn't suggested for use in the winter, but I wonder with our warm afternoon and cold nights in the winter if it could also work to pull warm air in?


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RE: Energy efficiency upgrades � what is worth it?

2x6 walls with conventional framing will average out very close to R13, especially with typical fiberglass batt installation.

You should consider having your home energy rated by a third party. They can provide certifications, energy modeling and diagnostic testing like the ductblaster and blower door tests. Voicing your concerns to a builder who has never done a blower door test is probably not going to accomplish any measurable results.

According to Wickipedia, Air infiltration accounts for 1/3 of HVAC energy use. I hope no one is making decisions that could have an impact for the next 100 years on anecdotal energy modeling outputs. Every house is different and the energy saving numbers put out by energy software programs are generally 25% underestimated to avoid conflict of promised returns.

If blower door testing is not worthwhile, then it wouldnt be written into the International Building codes. I can understand not doing it if will cost you 500$ but if you can get it included in the overall services of an energy rater then it would probably be money very well spent.

Remember that the costs of energy go FAR beyond the upfront costs. The entire community suffers from the what comes out of the smokestack and what goes into the ground to extract Natural Gas. The societal and environmental costs of our dirty energy use is tough to calculate.


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RE: Energy efficiency upgrades � what is worth it?

Thanks Brian!

My builder doesn't have a problem doing a blower door test at all. It was actually two seperate energy raters who are advising me on this, not the builder.

One individual is doing the calculations regarding the energy efficiency of our home, and the other will do the duct testing and fan watt testing. They are both familiar with blower door testing but don't feel it is necessary for us. I believe it would be in the $400-$500 range. I do have the freedom to get quotes from others, so I will still look into it.


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RE: Energy efficiency upgrades � what is worth it?

If you builder has never done a blower door test, how does he know he is building a tight house? I suppose he is just basing it on the building practices he uses, but does he have any data to show his houses really are tight?

I think the blower door test is a great tool to see how tight your house is and to see if there are any areas that could use some improvement. Of course I realize some people use them only to hit a certain number rather than to see where there is some leakage.


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RE: Energy efficiency upgrades � what is worth it?

2x6 is R-19
if you add the foam board R-7 to outside of
exterior walls, this brings wall R-value
up to R-26 and goes a long way to air seal
and thermal break of your R-5.5 studs.

I can't understand how an energy rater wouldn't
think that blower door testing is necessary.
unless they are just advising, and not
actually doing a rating.

the energy cost & features report lists each
upgrade that is recommended. code required is
in one column and your recommended upgrade in
another column.
each item is listed with % of savings it provides.
as you pick & chose upgrades, the report
is modified to reflect your choices.
I tell the homeowner that this is the blueprint
for efficiency of their specific house, as it
is detailed with your spec's, and unique to you.
its pretty cool actually. the software is RemRate
from architectural energy.
we are currently using version 12.93
versions change as they 'improve' the software.

if the report isn't with a current version of Remrate
then it is a big issue. this is one way to
determine if the rater is active or inactive
in the rating business.

in addition to the blower door test, you should
also have ductwork tested for leakage.

we haven't really discussed hvac. as this is
equipment that will keep you comfortable
you should be investigating it before hand
rather than later. its a whole different language.
so getting familiar with the terms used is a bonus.
there is a hvac forum here, and also another forum
where hvac pros answer homeowner questions.
www.hvac-talk.com no pricing, no diy on that site.

It is good to see homeowners investing the time
to educate themselves. good for you!

best of luck


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RE: Energy efficiency upgrades � what is worth it?

Ok - let's not pretend that Wickipedia number means anything. Any new house is far tighter than average housing stock. No CA is one of the mildest climates in the country.

I am not saying that infiltration doesn't matter. It absolutely does but that 1/3 number obviously comes from old houses in the NE and MW.

According to my audit, infiltration was about 10% on an average new house - no blower door test, bare minimum code. In the OP area it would probably be more like 5% and Title 24 probably does enough to get that to 3%.

No way is it worth an ERV/HRV and a really tight house in OP area. Of course saving energy is the goal but sometimes you can expend so much energy in doing so takes a long time to recover. Foam sheathing in a mild climate can take 50 years to recover the energy used to make it. And the foam was probably made using coal electricity and in 50 years, the energy source will be cleaner....

Using dollars as a proxy for energy is a fairly good estimate. Now a blower door test is labor and doesn't really apply. But when you spend $10 on foam and it saves you $.50 a year, then you can predict that it takes 20 years to recover the energy built into the foam. I foam sheathed my attic knee walls and I realize that 20 years is the energy payback time frame (and that is using my labor). Foam sheathing on top of a 2x6 wall in NoCa might be a 100 year payback... Hopefully we aren't using coal in 100 years. And to top it off OP is using the cleanest fuel available at 95% efficiency.


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RE: Energy efficiency upgrades � what is worth it?

I think Air Infiltation accounting for 1/3 HVAC energy use for new, average housing stock is in the ballpark, especially considering most new homes are not meeting minimimum building code aitightness requirements. I think most energy efficiency experts and building scientists would agree. The university study link I included suggests that controlling air infiltration can reduce heating costs by 50% and cooling costs by 22%.

Controlling Air infiltration for homes with higher cooling loads is more important in humid climates.

Sure CA can be mild but it still has building climate zones with energy code minimums. People should be trying to build above code especially when it comes to energy use. Will some of these practices not be cost-effective? Probably for the first homeowner but homes change hands many times over their lifetime which is the main reasons codes exist.

Energy audits are very helpful but it would be dangerous for readers to make important decisions based on a limited sampling of data. The outputs of energy software can be modified in a myriad of ways and its easy for individual components to appear cost-ineffective especially when the software is automatically trying to protect the rater's interests for promised energy returns.

I think the best thing readers can do is at least meet minimum codes even when they are not enforced. Building beyond code is helpful for the environment and future society.

Here is a link that might be useful: UT A&M study on air infiltration energy impacts


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RE: Energy efficiency upgrades � what is worth it?

Okay, I misspoke about my builder not having used a whole house fan, he has used it to test the air tightness of homes after the dry wall has been up, not to find leaks earlier in the process.

Brian, our home is in complete compliance with our local code, which in California is referred to as Title 24. Before considering any of these upgrades we were 25% over the requirements. It would easily qualify as an Energy Star home, but I don't see the purpose in doing so. Basically the only thing we would need for the Energy Star certification is to have the blower door test done to prove the amount of air infiltration. If I received a rebate or credit for the Energy Star status I would do this, :) but honestly in our case I agree with David_Carey, it is just throwing money out the window. There is some testing required, and that is:

- Duct Leakage HERS measure
- Verified Fan Watt Draw HERS measure
- Verified Cooling Coil Airflow HERS measure

We were considering additional upgrades because we want to make our home as energy efficient and comfortable as possible while not spending money that doesn't have a reasonable payoff, and also there are some substantial rebates available in California for having an efficient home, and these rebates increase incrementally as you get to be a higher % above code, maxing out at 45% over code. The individual doing our energy assessment (required here to be in your plans submitted to the county) suggested several options, and for each one I went back to the builder to get the costs, however we were not provided with a cost/benefit analysis in terms of payback. I'm sure that is something additional I could pay for, but the advice I've received here has saved me money in needing that! :) At $100/hr for her services I greatly appreciatte all of your advice!

Some of these upgrades I would have completed regardless of the rebates, and others may not have a big enough ROI to consider otherwise, but the additional rebates covering most of the cost it really changes our perspective.

Regarding using foam board insulation on the exterior of the house, as David_Carey said, that is simply not worth the cost in our climate. Believe me, I am originally from Northern Ontario and every house I've ever seen built there had foam board insulation on the exterior, so I thought it was a normal part of the building process and thus I have asked a lot of questions on this topic, and it simply isn't worth it here. In reality upping the insulation in our walls to R19 would be sufficient, but we need R21 to get us up to that 45% over code requirement to get the full rebate to help pay for some of the other upgrades. Also, while fiberglass is not a "green" product, it takes much less energy and chemicals to produce than foam board (or foam insulation). Ideally I'd like to use a truly green insulation option, but that isn't in the budget.

What I find surprising is that most new construction in my area has the furnace and water heater in an unconditioned attic, however it seems to be one of the major things to avoid that I see on this site. If this is so awful, why is it allowed under Title 24, and is continued to be allowed under the 2013 update to title 24? Regarding spray foam in the attic, the payoff isn't there for us. While I haven't received an official quote, given the size of our sprawling single story home with a truss roof and cost for square foot I've seen posted here and online I'm certain it would cost nearly as much as the combined cost of all our other upgrades. Another comparison, it would be more than our out of pocket costs (after tax credits and rebates) for putting in solar! We can't afford both - so which would you pick? :)

We do have a radiant barrier on the roof, and the roof tiles are considered a "cool roof" (mean it has a low solar reflectivity) and an attic fan to help with extreme attic temperatures. And again, the whole house fan to decrease our need of running the AC.

We will be making sure that the insulation is installed properly to reduce leakage, that the insulated can lights are used, and that windows are all well sealed. Anything else we can do/request to prevent leakage?


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RE: Energy efficiency upgrades � what is worth it?

Oh, and our lighting is a combination of CFLs and LEDs, there isn't a single incandesent or halogen light in the house! :)

Wait... there will be incandesents in the chandelier in the dining room - waiting for the LEDs to come down in price on that one, and I hate the dimmable CFLs!

We are already required to have a certain percentage of CFL/LED lights included in our home, but we have already switch in our current home so we didn't even worry about this one.

California is actually phasing out the sale of incandesent lights by 2018!


 o
RE: Energy efficiency upgrades � what is worth it?

Sounds like your hard work is paying off! I think other than the blower door testing, everything you've done is quite cost-effective in your climate zone with short paybacks.

Didnt mean to imply you werent meeting code. Mainly letting people know that there are International Building Codes IECC that local municipalities dont enforce. It doesnt mean you are building illegally but youre not meeting minimum energy codes according to the IECC 2012.

Blower door testing is required by this code (ACH50 of 5 in Zone 3) among other important things that will soon be required by law like mechanical ventilation with fresh air introduction. Pretty hard to put a cost-effective number on fresh outdoor air but Iam glad its finally going to be required by law soon.

Here is a link that might be useful: Southface PDF of IECC 2012 vs 2009


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RE: Energy efficiency upgrades � what is worth it?

Interesting overview - thanks! Though, I'm pretty certain that there are very few items in the IECC that aren't also covered by Title 24, but it would appear that blower door testing is one of them.

This post was edited by Laura12 on Mon, Feb 4, 13 at 19:29


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RE: Energy efficiency upgrades � what is worth it?

Laura,
You asked how much we use our AC in the summer with our Whole House Fan. Unfortunately I can't give you a good number because my DH runs the AC too much! He has to sleep with low temps, so I freeze while DH and our boys are happy. I wear a fleece jacket in the evenings and sleep with a comforter in the middle of summer!


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RE: Energy efficiency upgrades � what is worth it?

Brian_knight,

So I googled mechanical ventilation and now I have another question ;)

If I have mechanical ventilation set up without a heat exchanger can it help cool my house if I run it at night?

Here is a link that might be useful: mechanical ventilation


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RE: Energy efficiency upgrades � what is worth it?

Chispa - That is hilarious!


 o
RE: Energy efficiency upgrades � what is worth it?

That's a great link Laura, thanks! Humid climates definitely not and in yours probably not much Iam afraid.

I think your theory would work better without a heat exchanger (HRV/ERV)with your cool nights but it would be a penalty during extreme weather. The ole cost-effectiveness debate of an HRV/ERV is a tough one for your climate but personally I would go with an exhaust only system at least.

Your builder is going to hate you in the short term but tell them its for their own good in the long run. Better to be ahead of the game rather than catching up. Much like you and the people who have bothered to read this far!


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RE: Energy efficiency upgrades � what is worth it?

Brian - I won't ask you to explain why my energy audit has it so wrong, but why does the Manual J not even come close to those numbers?

And linking a 20 year old dissertation - ie no publication in peer reviewed journal - isn't helpful.

And - the best I can tell is that the articles talks about a 35% reduction in infiltration losses between a well built house and a leaky house. Not a 35% reduction in energy use, just the component that is infiltration. The article has very little to do with real houses.


 o
RE: Energy efficiency upgrades � what is worth it?

I didn't know about this previously, but mechanical ventilation is required for our home and already included in our bid.

Is there any reasons we shouldn't set up mechanical ventiation without the HRV/ERV and then just not run it during the day? Or have some sort of damper on it that allows air to either be run through the HRV/ERV or come direction in from outside?

Something along those lines would be great as we could get fresh warm air into the house during winter days, and fresh cool air during the summer evenings...

This post was edited by Laura12 on Tue, Feb 5, 13 at 12:37


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RE: Energy efficiency upgrades � what is worth it?

So you have mechanical ventilation but no requirement for ERV?

A strange requirement (particularly without a blower door test) so you will have to check with builder to see if you have control of it. Maybe has to run 24/7.

Usually the amount of air is not enough to "bring cool air" in to make a difference. It is likely nowhere near what an open window would do.


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RE: Energy efficiency upgrades � what is worth it?

Hmm... That's what I thought, but maybe I'm mixing something up. I have a meeting tomorrow with the energy consultant and I'll clarify then.


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RE: Energy efficiency upgrades � what is worth it?

Sorry for that UT A&M article, its a tough read but in the conclusion, does refer to energy loads. This one Iam linking to now is more appropriate, informative and easy to read. Author John Straube needs no introduction in the building science community. Its a good article for anyone building a home that explores air infiltration impacts on homes other than energy use. On infiltration's impacts to energy use related to HVAC, he agrees with wickipedia too: 1/3.

Verifying Airtightness with blower doors saves energy, prevents rot and helps ensure we have CONTROL over mechanical ventilation.

Manual J is an amazing tool. Its incredible how accurate it can be in the hands of a skilled user. I dont think Manual J or other energy software results are being used appropriately when extremely detailed outputs from limited samples involving many variables with built in fudge factors are being used to talk the community into building below energy code minimums.

Here is a link that might be useful: Building Science.com link; Air Leaks--How they rot homes and waste money

This post was edited by Brian_Knight on Tue, Feb 5, 13 at 22:19


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RE: Energy efficiency upgrades � what is worth it?

Just wanted to loop back and thank all of you for you feedback!

We ended up including the upgrades on the insulation, the AC and furnace, as well as adding additional testing which includes: Duct Leakage HERS, verified Fan Watt Draw HERS measure, verified Cooling Coil Airflow HERS measure & Blower door tests (after all!)

Also, we will have mechanical air ventilation as well - I didn't know in advance that this was a requirement.


 o
Follow up

Also - for all those familiar with California Title 24 - we will be 50% over the requirements!


 o Post a Follow-Up

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