2nd page it is cut off at the bottom Total 38,752.2 1

page1 load calc for option 2 (American Standard- 5 ton) I am not sure where he got the information from other than from the house layout as he did not walk around my house where as contractor with option 1 went through every room in my house (also I see under option 2 he listed 6 people live in the house when it is actually 4 - don't know if that makes a difference?)

page 2 of load calc

Also to answer the question about what we currently have,- 5 ton air handler /condenser (mismatched) air handler is original 20+ years old (Janitrol) and condenser is around 13 years old. Do they work ...well yes. Electric bill is so high tough that we don't turn up air or heat just try to keep it bearable. But yes they do work "ok" I guess.

If the current system is operatig at capacity, that number trumps the model-building.

Can you clarify what you mean by "if it is operating at capacity" ? How would I be able to determine that? Do you mean do we get air and heat? Then, yes.

City is offering $1400 for conversion to gas furnace.

do you have any gas appliances? or will gas be
new to you?

why not bid for heat pump, if you chose not
to use gas?

take some time...this is a big decision.

best of luck.

What I mean is if the system is producing its full capacity even though it is old. When it is/was operating normally at it full capacity, did it keep the house cool enough for you?

do you have any gas appliances? or will gas be
new to you?

We are converting to gas water heater so the gas piping will already be at the same spot as the furnace is going.

why not bid for heat pump, if you chose not
to use gas?
Yes, we also did get bids on heat pumps - the prices were comparable but the rebate is half the amount ($700) and with high electric rates we were leaning toward converting to the gas furnace

When it is/was operating normally at it full capacity, did it keep the house cool enough for you?

Yes, we can get the house cool enough if we set thermostat at around 68 - but in reality we normally set it around 70 and turn on the fans because running it at 68 is costly.

If you have to set the thermostat to 68-70 to stay comfortable, that is very indicative of an oversized system, which at that age was doubtfully running at its full nominal capacity, especially if on undersized ductwork. It likely did not run long enough cycles to dehumidify well, and you had to set the space temp lower (costly) to compensate. Load calculations are only good if the information put into them is accurate. Make sure the ductwork is adequate to support whichever system you install. 2-stage units are certainly no excuse to oversize, as even on low stage you would be close to 4 tons and likely not run long enough to ever be efficient and provide you with even comfort.

This post was edited by ryanhughes on Sun, Apr 21, 13 at 13:59

Just a thought.

If you are intent on going with a gas furnace and I see no reason not to, I would go with the 80 KBTU XV80 or AS equivalent with a 4 ton rated blower. Low stage for that model would be sized very close to your heating load and rarely if ever you would need the high stage. Of course, you would need a true two stage thermostat to control heating stages and this assumes 4 ton is correct size condenser on cooling.

To be clear, what is size of current outside condenser, not size of air handler. Post mdl number if you have it.

IMO

Ryan - you make some very good (and appreciated) points. And I understand what you're saying about the 2 stage system. We are adding gas for the new hot water heater so I figured with the piping cost and the gas furnace rebate of $1400 we should strongly consider gas. But, I am now second guessing myself (once again) on if I would be better off replacing with a higher efficiency heat pump. Worth $700 rebate (actually putting the cost lower than the Trane system noted above)
Trane heat pump 4 ton xb14 15 seer 12.5 eer 9.0 hspf
Condenser: 4twb4049e1000b
Air handler; TAM7A0C48H41SB
Heat strip:bayevac10lg1aa

Your thoughts on this option?

The model # of my current outside condenser is a Carrier 38YCC060300

I reviewed the load calculations you posted. Option 1 indicates a heat gain of 46,000 BTU. The total seems reasonable for your house and location, but unfortunately there is no details as to how the amount was derived.

The option 2 has a lot of details, but I question the results. The calculation shows a gain of 35,200 BTU, but there is another 20,500 BTU associated with duct losses to bring the total up to 55,700 BTU. That is a huge loss. I doubt the loss is that large, but if it is then you are better off spending the money on fixing the duct work and getting a 4 ton condenser.

Did you post your gas and electric rates? You need to look at the rates to see whether it makes sense to heat with gas or not.

One thing to consider on the heat pump vs. gas furnace is the life expectancy of the equipment. Heat pumps live a rough life in that they have to operate in summer and winter. An AC condenser has to work only in summer, so its life expectancy is longer than a heat pump. A gas furnace has the longest life expectancy since it heats during the winter and is not exposed to the outside elements.

Mike-great point on the load calc. I will ask about that. I did feel that the contractor for option 1 trane 4 ton 1 stage was more through in his evaluation and was the only contractor out of 4 who looked at my system to recommend 4 ton and fixes to the duct work. All others said 45 ton and no mention of duct work.

The city says the utility rates are .10773 kw and 1.09207 per 100 cubic feet for gas. My electric bill avg is $166.75/month. I am switching to gas water heater

Any other thoughts on this?

I know you are still deciding between gas/straight ac and a heat pump, but I will make comments on the heat pump system, as I believe they are a great way to comfortably and efficiently heat a home in many situations. You provided your utility costs; would you mind sharing your location?

The heat pump system you've been quoted is a great system. The XB14 is equivalent to the XR15 mechanically, but lacks some sound deadening features and features a different cabinet. It would be worth asking for a price on the XR15 -- if the upgrade cost is not much additional I would substitute the XB14 with it; however the XB14 is also a fine piece of equipment with a few less features.

Many contractors are afraid to undersize or put in a smaller system even though that's what you need. Some will fudge the numbers to obtain the results they want (in no way do I mean to suggest contractor 2 did this intentionally, but if the 4 ton contractor was more thorough, I'd trust his calculations more). Going down in size when necessary will really bring some noticeable improvements. Lower sound level (~400 less cfm) indoors, more efficient operation, and greater indoor comfort from longer runtimes and better dehumidification. I would use the TCONT803 thermostat and enable Comfort-R (ramp-up profile for enhanced dehumidifcation -- many brands have a similar feature). Or better yet, ask about a VisionPRO IAQ thermostat that can be wired and set up to reduce blower speed to 80% on a call for dehumidifcation (this drops the coil temperature and more moisture is removed from the air). You'll want to make sure that the airflow is properly set upon installation according to your home's load requirement (a detailed load calculation would help determine what is optimal) and ductwork capability. Many would leave on the default factory setting. The smaller system will just work much better with your current ductwork assuming it is marginal in size as many are. Definitely important to address the ductwork issues -- the fact that a contractor pointed them out shows that they are concerned with the overall system operation and not just selling equipment.

This post was edited by ryanhughes on Mon, Apr 22, 13 at 11:42

North Florida is location...

See OP...

I thought you might be interested in what Option 1 (TRANE) said about his load calculation: ...." the load came back at 3.8 tons. Keep in mind that when I do a load calculation I do not enter my parameters exactly perfect, I always enter them worse case which means if I were to do a by the book very tight parameter load calculation it would probably come back at a 3 ton load. I will give you some examples of where I calculated a higher heat gain than what you actually have. If you look at your roof over conditioned space you will see that it is not a nice even rectangular number (see attached building sketch, A �" 2296 sq ft, B �" 322 sq ft for a total conditioned 2618 sq ft). The largest heat gain in the house is your attic, in my load calculation software I have a space where I enter the roof length by the width, my calculation for yours was 54ft x 65ft. All that roof over your garage should not be calculated, nor the roof over your open front porch. So I told the software your ceiling heat gain was larger than it really is, I also entered your attic insulation at R-25 when it is really a R-30. I figured every exterior wall to be in full sun all day when you have plenty of shade. All of those little changes add up and I do that just to be on the safe side especially when you have had a unit almost 2 tons larger than you need for so many years. I am extremely confident that a 4 ton unit will more than handle the load on your home, I guarantee it"

I am in North Florida where many people use heat pumps.
I also had same contractor quote the heat pump:
QTY: (1) Trane 4 Ton XB14 Series R410a split heat pump system, 15.0 SEER, 12.5 EER, and 9.0 HSPF including the following:
Condensing Unit Model # 4TWB4049E1000B
Air Handler Model # TAM7A0C48H41SB
Heat Strip Model# BAYEVAC10LG1AA

after rebates the heat pump is $200 more...but not an issue if the heat pump is the better way to go???

I am not opposed to heat pumps. In fact I like them for the correct application including DF systems as long as fuel costs can be leveraged one against the other which BTW is getting mighty difficult these days.

It just seems contradictory somewhat to get nat gas service and just take advantage for hot water only.

And finally, I prefer the XR series condenser HP or AC any day over the XB series. Yes it does cost more.

IMO

With a low heat loss that is likely overstated as this dealer admits he was being on the safe side, you would seldom use gas heat. When you did, I imagine you would rarely if ever leave low stage. I looked at the ratings for the 4TWR5049 heat pump with an 80%, 80k btu input XV80 furnace. Most of the ratings were quite poor considering the unit's capabilities (most around 12 EER, 14.5 SEER and 7.7 HSPF). I did find one match-up using an oversized 063 coil to get reasonable ratings -- 12.5 EER, 15 SEER and 8.5 HSPF. Not sure I'd want the oversized coil for best dehumidification in North Florida. The ratings were great with the 048 TAM7 air handler, and I am a big believer in the EEV metering device used in them for oustanding performance in dehumidification. Also consider your average low temperature in the winter. Not very cold at all based on the weather data I looked at; correct me if I'm wrong. Prime application for a heat pump in my opinion.

There is the utility cost aspect to the decision as TD mentioned. However, I think a heat pump is the best choice here. It will of course be up to you, the homeowner, ultimately. If you did choose the dual fuel system, you want to go no higher than an 80k XV80.

Do you cook with gas?

This post was edited by ryanhughes on Mon, Apr 22, 13 at 17:29

The utility cost is a consideration. I do not cook with gas but as mentioned putting in gas water heater.
Our winter temp is overall mild but we can hit stretches of 30degree weather. We are just 20 miles from the georgia border in tallahassee.

I called the city mechanical inspector and actually had lenthy conversation. He felt the 4 ton would be more than adequate. He was familiar with this contractor and positive toward the accuracy of his load calc. So now i know who i will use and the remaining question is gas vs heat pump....

I suspect that I have missed something. Are you having gas brought into the house for the sole purpose of making hot water? Is your existing hot water heater electric?

Yes for water and furnace. Rebate of $1350 for water and $1400 for furnace plus $200 for ac

What is the cost of bringing in gas from the street?

Do you mean from street to meter? That is free from the city

It seems strange to me that there would be natural gas in the house, but the house is heated with a heat pump. Then again I live in an area where the gas price has now dropped to 93 cents per therm and the price of electricity is holding steady at 17.5 cent per kWh.

With the combination I referenced above (80k XV80 with 4TWR5049 and 4TXCD063 coil), at 32 deg outdoor temperature the heat pump produces around 37,000 btuh at a COP of 2.83. So it seems there will be several days of the year where gas backup heat may be needed (when you get those cold stretches). Depends on your actual heat loss. With a heat pump of course the electric heat would serve as backup heat and should be staged (5 kW + 5 kW).

This post was edited by ryanhughes on Mon, Apr 22, 13 at 17:28

mike,

Late comer here. If I get the thrust, it's an all electric house that the OP is bringing gas into for hot water heater and is considering also adding a gas furnace.

The OP just said bring gas in to his meter is free. (Wow!)

He also listed some rebates for furnace, hot water heater, and A/C.

I guess I'd be interested in the cost of the gas installation to have a gas hot water heater installed, less rebate, of course, compared to replacing old electric hot water heater with a heat pump hot water heater, less any rebates there also, of course.

We just got gas in our neighborhood about a year ago. Up till now we had no options. We are bringing in gas for hot water heater (tankless)and the cost after rebates will be around $1,200. The gas piping runs adjacent to where the furnace will go so there is no added piping involved. (There is also a rebate for a heat pump style water heater but truthfully I did not look into these.)

It does seem sort of ridiculous to bring in the gas for the water heater alone but I do imagine at some point I will switch to a gas dryer.

What would be the best way to compare present vs future utility cost. Electric is ,10773 kw vs gas at 1.09207 ccf. Is there a formula for converting KWs used to ccf?

Ryan - you mention the TCONT803 thermostat or VisionPRO IAQ thermostat -- I thought those only work with 2 stage systems? Will they work with t he XR15? I understand it would drop the fan speed to low getting the coil colder for more moisture removal but it wonâÂÂt run in low stage, right? (I did ask the contractor and the 803 is $115 more.) Does the VisionPro work the same way?

Yes the 803 and IAQ will control single and two-stage systems (including the XR15). The IAQ has the ability to stage the back-up heat and would the one to get should you opt for dual fuel. The IAQ can reduce blower speed as you described, but the 803 will not; it will only overcool by 1-3 deg (set by installer) to dehumidify. Both are good thermostats. If you go with the heat pump option, the 803 and IAQ would both work well, with the IAQ being preferable for its dehumidify on demand feature (hopefully, the installers have experience with them in configuring dehumidify on demand. Not difficult with the installation instructions provided, however). If you do get the IAQ and they set up dehumidify on demand, I do want to say again that I recommend they raise the blower speed above the factory 350 cfm/ton as you will already be reducing blower speed by 80% on a call to dehumidify. 400 cfm/ton is the typical standard (more in dry climates and less in humid climates) and is what I like to aim for especially with the benefit of dehumidify on demand where you can drop the CFM to ~1280 or 320 cfm/ton for enhanced dehumidifcation. With the EEVs this feature works very well. There are many possible cooling/heating airflow options on the TAM7s that should be selected according to your home's needs and what your duct system is capable of delivering.

The Trane TCONT802 is the equivalent to the Honeywell TH8320, as the TCONT803 is to the HW TH8321.

I now have the comparison on trane xr15 to the 2 stage xr16 . The cost difference after rebates is $1069. When i calc annual cost to run. I come up with $264 ( i calculated the xr16 at a 60 percent 36,000 btu and 40 percent at 48,000 btu and the xr15 at straight 48,000 100 percent). At this rate 4-5year payoff . All things considered do you all think it is worth the upgrade? Are there negatives to the xr16?

BTW - i find it interesting when i contacted the "other" contractor about the btu duct loss on his load calc he never responded.....

There is virtually no energy saving by running a 2-stage compressor on the low stage. It may seem like you are using less energy to run the low stage at 3 tons versus the high stage at 4 tons, but the run time in the low stage will be longer. You should have less cycling and you are moving less air which means less duct losses, but these savings are small.

There may be some savings if the humidity is low enough to allow you to raise the thermostat setting 2 - 3 degrees. For example suppose you typically set your thermostat at 75 with the humidity level at 50%. If the 2-stage unit can lower the humidity level to 40% then you may be able to raise the temperature setting to 77 or 78 and still feel comfortable. The increase in temperature setting would be a measurable savings.

Pindot

Not my intent to muddy the water.

I don't want to leave a mistaken impression from my last post from Monday.

I like both heat pump systems and DF systems for the right application. I personally think though a DF system is overkill taking into consideration your N Florida location/climate. I would think AC is more important than heating.

If not a gas furnace paired with high eff straight AC then a straight HP system with var speed air handler. For either system, I would want HW VP IAQ stat that has dehumidify on demand feature for AC cooling. With the XV80 furnace, the HW VP IAQ stat also gives you true staging on the furnace which for your situation would be low stage except for any bad cold snaps.

IMO

Ok i see. Is there # of kw per degree calculation? or something like that i could compare the xr15 at 75 degrees to the xr16 at 78 degrees per kw hour. Or am i over analyzing this????

There are cooling dollar figure estimates given on AHRI directory both AC condensers and HP condensers. I can't say how reliable they are. I suspect not very and more of an average.

There are cooling degree days and heating degree days somewhere on Internet. Let Google be your friend. Maybe a weather site, can't recall. Sorry.

And yes I do believe you are over analyzing and have TMI.

IMO

Tigerdunes - i agree with your comment . The cost of df vs hp is actually less with city rebate etc thus our choice to go that route. You are correct the ac is more critical to us. When you say " straight high efficiency ac" do you consider the single stage xr15 to qualify or are you saying you prefer the 2 stage condenser? Also the hw vp iaq- will that work with trane system or do i need to get the trane equivilent?

Well I think if DF is less than straight HP with air handler and less than gas furnace with straight AC, then that seems to settle the decision for you. And you can always disable the HP on DF by setting the DF stat to emergency and just heat with gas. Understand you should have an outdoor sensor with the correct DF stat.

Whether a two stage condenser or single stage condenser AC or HP, I think that's more an issue of cost versus benefit. I would strongly advise though for the HW VP IAQ stat either way you decide for reasons given in my earlier post today.

IMO

This post was edited by tigerdunes on Wed, Apr 24, 13 at 12:10

And yes HW VP IAQ stat while a bit pricey is compatible for the systems you are looking at and will be less expensive than Trane 900 series- those are proprietary models made exclusively for Trane by Honeywell. Other Less expensive Trane stats are just rebadged HW models.

IMO

For the dual fuel option, your home will require the 80k XV80 furnace. That would be model TUD2C080B9V4. Do not accept an oversized 100k furnace (5 ton blower) despite marginal efficiency gains. The consequences of oversized equipment far outweigh any gains. Here is the configuration I'd suggest going with in a dual fuel application:

AHRI #3939597
TUD2C080B9V4 80k XV80, 4 ton blower
4TWR5049E1 XR15 heat pump, 4 ton
4TXCC060BC3 matching coil (same width as furnace)
12 EER, 15 SEER, 7.7 HSPF
46,000 btuh cooling capacity
46,000 btuh heating capacity

AHRI #5457684
same as above with 4TWR6048A1 2-stage XR16 heat pump (4-ton)
12 EER, 16 SEER, 8.5 HSPF
46,000 btuh cooling capacity
43,500 btuh heating capacity

Yes, the HSPF is low (minimum allowed) with the first dual fuel setup. That is one of the factors you will have to consider in making your decision. For comparison I will also provide the ratings with the XR15 and XR16 heat pump matched to the TAM7 variable speed air handler.

AHRI #4385456
4TWR5049E1 XR15
TAM7A0C48H41
12.5 EER, 15.5 SEER, 9 HSPF
49,000 btuh cooling capacity
47,500 btuh heating capacity

AHRI #5457482
4TWR6048A1 XR16
TAM7A0C48H41
12.5 EER, 17 SEER, 9 HSPF
47,000 btuh cooling capacity
46,000 btuh heating capacity

Better numbers and keep in mind a heat pump and air handler is overall a simpler system for what it's worth. I'll admit this is not an easy decision especially given the costs and the fact that you are bringing gas service to your home. I would weigh heavily both options as well. But, having lived in an all-electric home for ~20 years in MD, I can say I've never been displeased with the performance of a heat pump and we can get cold winters. I upgraded to a high-efficiency, 2-stage heat pump (the Trane XL20i) about 8 months ago, and I have been extremely impressed with the comfort and energy savings it provides compared to previous heat pumps I have had. Low stage is 50% capacity whereas on the XR16 it is 75-80% capacity, so there is more of a difference, but still from my experience all 2-stage heat pumps and air conditioners improve comfort throughout the home, mostly due to the longer runtimes in low achieving more even temperatures, more dehumidification, and also less noise as you are moving less air. This should certainly be noticeable for you, going from an oversized 5 ton system to a 4-ton 2-stage system. I do highly recommend the XR16 whichever way you go (heat pump/air handler or dual fuel). Sometimes the cost difference is unreasonable, but in this case I do not feel it is. I would include the Honeywell VisionPRO IAQ (model YTH9421) with whichever system you get.

This post was edited by ryanhughes on Wed, Apr 24, 13 at 13:22

Dang, my husband just corrected my it is not DF it is gas furnance with straight AC (So sorry). The two we are comparing are the
xr 15v- single stage
Furnace; TUD2C100A9V5VB
Condenser: 4TTR5048E1000A
Coil: 4TXCC0049BC3HCB

x4 16 - 2 stage
Condensing Unit Model # 4TTR6048A1000A
Furnace Model # TUD2C100ACV52A
Evap Coil Model# 4TXCD063BC3HCB
AHRI # 5456117

Sounds like with either of these you all think the Vision Pro IAQ would make a difference for us as far as humidity control?

Well those are terrible HSPF heating efficiencies in the DF systems.

I believe I saw a good system with great numbers for same furnace with XR15 AC Condenser.

3937756 Active Systems XR15 TRANE 4TTR5049E1 4TXCD063BC3 *UD2C080B9V4 46000 13.00 16.00 1 RCU-A-CB 348 Yes

Have to admit the straight HP systems have very good numbers.

IMO

This post was edited by tigerdunes on Wed, Apr 24, 13 at 14:05

Pind54,

I still strongly advise against oversizing the furnace. Trane does make an 80k furnace with 4 ton blower capable of supporting any 4 ton system.

The second option with the XR16 is actually an XC80 furnace. Ask them if they are including the XL900 (TCONT900) thermostat. They may very well be, and this would be a good option for that system.

On both the proposal description is "XV80 series 80% variable speed" maybe the model is listed incorrectly on the xr15 proposal? I'll check on that.

I do like the idea of the xr16 running at low stage 70% of time....and yes the xl803 thermostat is included in that proposal.

He did not include it in the xr15 proposal but said we could upgrade if we wanted to. Additional cost of $115

The furnace model number with the XR16 is an XC80. Very similar to the XV80 but communicating. Must be a mistake.

TCONT803 is a fine thermostat to use with the XR16 air conditioner and furnace.

Overall, I do not agree with the equipment matchups proposed with the furnaces and air conditioners. Oversized furnace on both systems, and oversized coil to achieve marginal efficiency gains on the XR16 system.

I realize you may not understand all the implications of oversized equipment, but it is a big deal for comfort, efficiency and reliability. All things considered I still recommend the heat pump system.

This post was edited by ryanhughes on Wed, Apr 24, 13 at 13:54

I will discuss the above with contractor tomorrow. Thank you , SO MUCH for all the input, suggestions and time you took to help me out. I have learned a lot and feel much better prepared to discuss. It is amazing all the options that are out there and trying to sort through it from a laypersons perspective is overwhelming. You all have been fabulous and more than helpful. Many thanks.

Talked to contractor and downsizing furnace going with combo you suggested tigerdune the ...049 was not appearing inthe FL TRane book for some reason but he contacted rep and got pricing info, which is actually better than what i had and eligible for a larger rebate from city. Thank you!

Great...

Understand that is the XV80 80 KBTU furnace with the 4 ton XR15 AC condenser.

IMO

Got it, thanks again. Getting better system AND saving $.!!

And please, if you do select this system, I would strongly recommend both a pleated filter media cabinet and the HW Vision Pro IAQ stat that gives you true staging of the furnace based on demand and dehumidify on demand feature for AC cooling.

IMO

Sounds good to me. Enjoy the new system -- it sounds like you're dealing with a competent dealer, which is great given the importance of a proper installation. You've certainly covered all of your bases. Good luck.

This post was edited by ryanhughes on Thu, Apr 25, 13 at 11:41