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Retrofit Efficiency - Chance of Improvement

Posted by cebury (My Page) on
Tue, Aug 30, 11 at 20:33

I live in Central CA (hot/dry) and looking to purchase Solar, a new gas-pack HVAC on roof, and possibly new washer/dryer, and dishwasher. The home is a 1990 small suburban track home, single story, 1350 sqft.

CHF has an Energy Retrofit program that is quite nice, covering an initial energy audit, some incentives, and final audit. But what I really want is the 3% loan offered for the renewables (like PV), only available IF you first improve your home >=10% in energy efficiency improvements.

The problem: I'm not sure I'll qualify since I've done all the DIYer changes to the home already. (see below)

I have the list of exactly what the energy auditor checks, but which are the "big ones" that would bring improvement the most -- specifically for determining that % improvement for the energy efficiency number, using software like EnergySoft's EnergyPro 5.

Question: Is it BY FAR the ducting and envelope sealing above all else show the largest % improvements?

What are the chances of showing a 10% improvement rate for my situation? There is quite a wait time for scheduling the audit and I need a new HVAC fast (no hurry on solar or the appliances).

I completely agree with the "efficiency before production" concept, but I may have improved my home right out of a great loan. But alas, I also see the logic in only offering the loan to homes that "really need it".

TIY

==================================
DIY Changes I've made:
1) sealed MOST spaces between the attic and living space (exhausts, recessed lights, etc),
2) sealed every joint of my ducting (gobs of mastic, twist ties to lock 'em down, and metallic tape), including the plenum
3) added LOTS more insulation (minimum 12" of blown cellulose everywhere and covered with R-8 or R20 batting on top of that for certain rooms needing it),
4) and added radiant barrier on top of attic insulation, including plenum,
5) put thick solar-block insect screens + UV block film on all sun faced windows,
6) and lots more of the little easy stuff (bulbs, fans, etc).


Follow-Up Postings:

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RE: Retrofit Efficiency - Chance of Improvement

A simple answer to your simple question: YES!

It sounds like you already knew this based on your other info and the actions youve taken. Congratulations for being much better educated in this area compared to most people.

The most Cost Effective approach to reducing Energy Costs is Air sealing the Building Envelope. The only way to measure this is with a before and after blower door test. Your Auditor should do this.

Chances are you made it a little tougher on yourself by adding all that cellulose, which is a great thing to do but should have been done after the Audit. Not because of the increased R and resulting % increase but because it will make it tougher to air seal the ceiling plane. Not sure what your "etc." included but chances are, you missed some opportunity by only getting recessed lights and "exhausts". The initial test however might prove me wrong and show what a good air sealer you are :)

I hope you didnt put any of the UV block on well shaded South windows because that can actually hurt overall.

I bet youre on a slab there but if not, you will have huge air sealing potential for a crawl or basement.

Iam not sure about the more important answer youre after. You might be right about 10% being tough. If that 10% can improve your new HVAC equipment or possibly Water Heating, then you should be gold. If there is a way to get the intial Audit costs covered, even if you dont get the loan,there doesnt sound like much to lose. Let us know how it goes!

Here is a link that might be useful: Blower Door Test Explanation


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RE: Retrofit Efficiency - Chance of Improvement

Thanks for replying!

I figured it was mostly the building envelope (interface between conditioned and non-conditioned space). The local certified auditor moved up my appt and it was done over a week ago, so I'll get to see results tomorrow.

>>> adding cellulose...it will make it tougher to air seal the ceiling plane.
Yeah, bummer. It gets messy trying to move that stuff around. I know as there was already 4-6" of it up there and I did a lot of wiring (network cable, couple new electrical outlets, surround speakers, coax cable) before I added more.

>>> Not sure what your "etc." included
Nothing major: I sealed a couple attic-side holes where existing wiring when into walls, sealed gaps & supply registers where the boot meets drywall, added weather stripping on a few obvious windows, foam sheets behind outlet & light plates).

I had a blower door test done a while back (for free by the city) and the inspector said it was the "tightest home he'd ever seen". Alas, they only left me with 4 thermal images for suggested improvements (two exhaust vents, one door weather stripping was old, and one supply vent). No other hard #'s that would tell me CFM leak rates or what not. Turns out the butterfly valves on exhaust vents were working fine, all the basic non-actuated valves show leakage as there is intentional air space around it, it is not air-tight, in order for air flow to open the valve up. The one vent was showing heat on one edge only, which I discovered was right up against attic wood framing, so I'm guessing it was conductive heat transfer. The last spot was clearly bad, as my garage & back doors have warped a bit and do not seal perfectly against the 10yr old weather stripping.

Hopefully, the above blower door test was shabby & I did a crappy job sealing it ... gotta make that 10%!

I hope you didnt put any of the UV block on well shaded South windows because that can actually hurt overall.
Don't have any shaded south windows (yet). I planted some deciduous fruit trees so I'm hoping will help out in the next few years.

What can it hurt, you mean during Winter time? That would make sense.

I bet youre on a slab there but if not
Yes, slab.

I'll post my results when I get them.
Thanks!


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RE: Retrofit Efficiency - Chance of Improvement

Well I got my results. The guy was a bit disappointed and admitted having to really struggle to make it all add up correctly given I had already done so much DIY.

The house envelope seal leakage (door-blower) test revealed only 1000cfm (at 50pascals). Everything I find online says that is excellent, but they said it was above average. They till recommend they seal the "final little things" I didn't do. Which amounts to the ceiling interface for: 3 bedroom fans, 1 kitchen overhead light cabinet, and a couple structural beams in vaulted LR. They will box-up tight 3 can lights. Applying tyvek to a knee wall. Also replace, seal and insulate (to the roof) all exhaust vents (bathroom, plumbing, etc). That's all which is remaining to do, getting only a couple % improvement total.

All that runs over $2k. They admitted this isn't a lot of work compared to most homes. But I imagine it's still a big pain trying to move around 12-18" of insulation to get at the stuff.

The ducting (I sealed) is showing 14% leakage (good considering IMO leaks are in/between gas-pack adapter somewhere). Replacing all the ducts with their tightest silver-R6 estimates about 6% overall home efficiency improvement (target of 3-5% new duct leakage). Add another couple $k.

Since I haven't replaced the AC yet, there's another 6% improvement. So, just the ducts & AC meet the 10% but I'm almost positive "fully sealing" the envelope is expected (if not required) for the CHF program.

If I replace the water heater, it adds another percent or two, which gets me closer to 20% total which would qualify me for even more rebate incentives. It amazes me that large government rebate programs/incentives abound, even after the 2010 stuff expired.

I like this company and they have spent a whole lot of time on this workup and will be spending even more on red-tape to participate in the CHF program. I just have to work the numbers now on their solar and see if their "whole" is matches/better than the sum of competitors individual parts. Then the intangibles: whether Solar is better installed by a specialty company, whether I trust them to install & service my gas-pack, etc.


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RE: Retrofit Efficiency - Chance of Improvement

In addition to CHF loans, California utilities and local governments are offering up to $4,000 back in rebates for energy efficiency projects:

Energy Upgrade California


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RE: Retrofit Efficiency - Chance of Improvement

Thanks.

>>> which gets me closer to 20% total which would qualify me for even more rebate incentives.
This rebate was the same one EnergyUpgradesCA advertises. At 20% it's $2000, 15% was 1500. The company was well aware of all the rebates (good).

For solar: Federal tax credit is $7k, CEC rebate (via PG&E/CA) is ~$1300. For the home improvements, it's $1950 from CHF, and $2000 (energyupgradeCA) and the (now-reduced) tax credits for energystar: $300 for gas-pack and some small amount for water heater.

Entire project (4k SolarPV, 2.5t Carrier gas-pack and ducts, water heater, home sealing) is $35k. Rebates & incentives is $5300 returned in Cash and tax credit is $7500. On top of this: ZERO down loan at 3% Interest for 15years. No credit debt/income ratio checks and it's 100% financed. We're putting the $5300 back as down payment.

End Costs: Monthly loan payment is only $200, LESS than my utility payment WAS. So what I"m paying in electricity is directed toward all these improvements instead. I'm in the black from Year 1 and the Solar is completely paid for in less than 8 years.

Incredible.


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RE: Retrofit Efficiency - Chance of Improvement

I actually work for Energy Upgrade California (on behalf of the State), so it's nice to see that contractors are aware of the rebates and are promoting them.

Sounds like you're doing everything right -- congratulations and good luck!


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RE: Retrofit Efficiency - Chance of Improvement

4) and added radiant barrier on top of attic insulation

this will only save you money while it isn't dusty
as dust buildup will reduce reflectivity. even double sided foils installed on floor of attic due to the bottom side of rb has no air space between it and insulation.
see florida solar energy center's faq's about radiant barriers.

"The ducting (I sealed) is showing 14% leakage (good considering IMO leaks are in/between gas-pack adapter somewhere). Replacing all the ducts with their tightest silver-R6 estimates about 6% overall home efficiency improvement (target of 3-5% new duct leakage). Add another couple $k."

14% duct leakage isn't bad, I'd weigh the cost of replacing ducts with R-6, as old duct wrap is R4.2 it isn't much of an upgrade. and you've sealed most of the leakage. flex or hard pipe ducts??
Energy Star says 10% duct leakage..you are very close.
for me it doesn't add up to spend 2K for minimal insulation upgrade and 4% duct sealing.
unless they are talking about adding R-6 to the existing duct in the form of foil bubble foil wrap.
do understand that for this product to achieve any R-value
that the spacers beween the fbf and the existing duct insulation has to be near perfect. just wrapping it around existing ductwork doesn't achieve much.
in my area it causes condensation between the two vapor barriers, but you don't have our humidity.

hvac upgrades give you good savings..heat pump?
your house is pretty tight, you have to be careful not to cross into needing mechanical ventilation which would be at .35 air changes or less.
water heaters also use a lot of energy. look for energy factors..electric standard tanks high efficiency is .95
for standard gas water heaters .65 and you can always add a blanket for more insulation. if you have gas...tankless gas water heaters installed on exterior of house have high energy factors. or even heat pump water heaters which provide and extra half ton of ac.

best of luck.


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