New HVAC for Townhome

13 years ago

Hello, I'm located in central North Carolina and am getting ready to replace the original AC unit in my townhome built in 1980. It's a GE unit and is still running fine, but we know we could save a lot on our power bill and want to take advantage of the tax incentive as well as an incentive from Progress Energy.

We have a 1673 sq ft townhome and depending on the numbers entered on the Manual J calculation (particularly the winter and summer design conditions), the load sizing is between 2.6 and 3.0 ton. Because it's a townhome, we have a the fairly typical problem of having a poor cooling upstairs and poor heat downstairs. There isn't enough room to split the ducting into 2 zones, so it's been suggested that a 2-stage heat pump with a variable speed air handler is the best way to try to even out the heating and cooling.

Here are the systems I'm considering (listed in order of price (not shown)):

CARRIER 3 Ton, single stage PERFORMANCE 15

25HPA536H30 FV4BNB006 36000 13.00 16.00 36000 9.30 21800

TRANE 3 Ton, single stage XL15i

4TWX5036A1 4TEE3F40B1 37400 12.70 15.00 36200 9.00 23400

TRANE 3 Ton, 2-stage XL16i

4TWX6036E1 4TEE3F40B1 36400 13.00 17.55 35000 8.80 22200

CARRIER 3 Ton, 2-stage PERFORMANCE 16

25HPA636A30 FE4AN(B,F)003+UI 34600 12.50 16.00 37200 9.10 22600

YORK 3 Ton, 2-stage AFFINITY 8T

YZH03611 AV*36+TXV 35400 13.40 17.45 36000 9.60 26600

CARRIER 3 Ton, 2-stage INFINITY 19

25HNA936A32 FE4AN(B,F)005+UI 36400 13.20 17.80 36000 9.20 2100

I'd like anyone's thoughts on what system seems to make sense and I also have a few questions:

1. Does a 2-stage heat pump really make sense? At first I thought it sounded like a good idea, but I've read that the unit isn't all that efficient running at 80% most of the time. I've got quotes on 2-stage units from Trane, Carrier and York. Any comments on this?

2. I haven't really found many good comments about the XL16i... is this something I should avoid. If so, why?

3. I've read that the tin-plated copper coils in the Carrier unit tend to leak and that many prefer the aluminum coils (like in the Trane and York). Any comments about this?

4. If I go with the XL15i, will the variable speed air handler be able to deal with the humidity?

5. Does the thermostat make a difference in terms of humidity or dealing with the upstairs/downstairs temperature differential? I've read that the Honeywell VisionPro IAQ was a lot better than the Trane 803... Or I should ask for the 900 series TStat. Thoughts on this?

Thanks so much!

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Comments (5)

neohioheatpump
13 years ago
I've heard 2stage stuff is better for zoning and humidity control. It might work better at keeping an even heat/cool since it runs longer at a lower speed to maintain energy level.

I"m a fan of York. They make good stuff. So does trane ofcourse too.
ziggyhere
13 years ago
About the thermostat - the 900 series can only be used with a full communicating Trane system. You didn't list any above. Trane thermostats are manufactured by Honeywell. Both the IAQ and the 803 offer humidty control.

I'm curious as to what size indoor unit you have now. Any of the systems you list can be great but I don't think any of them will solve your air distribution problems. I would start off at looking at a zoning system to see if you can reduce the stratification. If you can't get the temps even in your home now - just replacing the system will not fix it and you won't be happy.

Once you get the temps at a level you are comfortable with, then I would start shopping for the new system. I would take into concideration of how much longer do you plan on living there (will it ever pay for itself); which is more important - saving money or being comfortable (Lord knows I like to save money but if the wife isn't comfortable - no one wins).

Look at how much you 'may' save over the years you plan on staying there and compare with the initial install cost.
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snoopywg
Original Author
13 years ago
Ziggyhere: The Trane quotes currently list an 803 tstat, but I had read that the HW was better at humidity control. I just mentioned the 900 because I had read that it was more like the HW, but if it doesn't talk to the systems I have listed, I think I will ask for the HW if I go with the XL15i.

The current unit is about 2.5 tons and works okay, but it was installed in 1980 and I think we're living on borrowed time. The ducting is literally crammed into the construction--running between the walls and floors as opposed to underneath in the crawl or up in the attic. As such, everyone has told me that unless I was willing to have the place torn apart to completely re-run the ducts, a zoned system just wasn't possible. That's where the 2-stage suggestion came from--a slower heating/cooling cycle in the lower stage would reduce (but not eliminate) the temperature differential.

Yes, our 'return on investment' is also something I'm considering which is why I'm leaning towards the XL15i as opposed to the Carrier Infinity.

I think we have a realistic expectation on what will improve (our power bill, for one).

Thanks for the input!
snoopywg
Original Author
13 years ago
Okay, I've narrowed the field. Since most comments regarding the XL16i have not been positive (and it looks like you don't benefit as much from 2 stages with the XL16i), I've reduced down to one single-stage option, and one 2-stage option:

TRANE 3 Ton, single stage XL15i
4TWX5036A1 4TEE3F40B1 37400 12.70 15.00 36200 9.00 23400

CARRIER 3 Ton, 2-stage PERFORMANCE 16
25HPA636A30 FE4AN(B,F)003+UI 34600 12.50 16.00 37200 9.10 22600

There's about a $800 difference between these two systems, but the Carrier is only about $200 more expensive than the XL16i (which is out of the running).

So I'm back to the single-stage vs 2-stage debate. Again, the argument being that is I can't change my ducting, will a 2-stage unit with the variable-speed air handler help to even out the upstairs/downstairs differential? I know it won't be perfect, but will it be worth the extra $800 for the second stage?

Thanks.
tigerdunes
13 years ago
snoop

these are my minimum specs for a new HP system. both outside and inside units should be replaced to have a properly matched system.

15 SEER, 12.5+ EER, 9 HSPF
best matching VS air handler
full BTUs in both cooling and heating for your rated size
R-410a refrigerant(same as Puron)
scroll compressor preferred
electronic demand defrost preferred
thermostat with "dehumidify on demand" feature
staged backup heat strips
new and correctly sized refrigerant lineset

you want a thorough inspection of your ductwork system. size, overall condition, supply and return lines, insulation qualities, leak test, etc.

any hot/cold spot issues in your home should be addressed.

I would only use authorized dealers for the various brands that provide quotes. see mfg websites.

I would look at Trane/AmStd,Rheem,Carrier/Bryant.

......

I don't like the idea of going up in size unless a properly performed load cal has been completed in writing to support that decision and your ductwork system has been inspected both supply and returns to determine that it can handle the extra CFMs of conditioned air.

I like the Trane system better because of electronic demand defrost that eliminates nuisance and unnecessary defrost calls.

and I recommend Trane's two stg 7/12 KW heat strip.

IMO

New HVAC for Townhome

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neohioheatpump

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