3 contrators reccomending 2.5 seems convincing enough reason to go with 2.5. It would be foolish to suggest otherwise by way of the net.

The problem is that neither Carrier nor Trane variable speed heat pumps come in half-ton configurations for some reason.

If you want variable speed, go with 3 ton. They are correct in saying it will act like less than 3 ton if tempiture requires less. As far as it being commonly said that an over sized unit is wastful,that is correct if it is single speed and grossly over sized. 3 ton single speed would not be grossly over size in an older 1k sq ft home such as yours if the only other choice was 2 ton.

We're talking about a 2-stage compressor with a variable speed blower? Be sure to specify a 2-stage thermostat to operate the system.

The 2-stage compressor will run at about 2 tons in its lower stage, and move up to 3 tons on the hotter days.

Did the contractor who did the Manual J calculate the size to be 2 tons? Did he show you the calculation? If the answer is yes, then 2 tons is the correct size. It makes sense for 1000 square foot house row house. I assume you only have exterior walls on the front and back and those areas are smaller than the two sides.

Just because a large group of people guess at the answer does not make it correct.

I would much rather have a correctly sized sgl stage XL15i or XR15 than an oversized two stage 3 ton model,,,any day!...

IMO

I like to read details on HP systems. U say replace HP? What exactly is replaced? I live in mn. Air source HP systems are somewhat rare. I think ground source are more common here? Is your system an air source? Fan cooled outside condenser/compressor? And a separate a-coil inside plenum box in house? Or attic?

Thank you for the feedback. Currently, there is a 3T unit now, so we know the ductwork etc can support a 3T unit. I'm concerned that a 2T unit will not be enough to cool and heat the floor (to be clear, there is a separate unit that heats/cools the downstairs). The higher-end models do not appear to come in the 2.5T size.

The XL15i and XR15 are excellent single stage Trane heat pumps.

5198250 Active Systems XR15 WEATHERTRON TRANE 4TWR5030G1 *AM7A0C36H31 1050 32200 13.00 16.00 30000 9.00 18700 1 HRCU-A-CB 244 646 Yes

New Heat Pump System

Here is my general spec sheet for new 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
10 yr warranty on parts and compressor

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.

My personal recommendation is Trane/AmStd, Rudd/Rheem, and Carrier/Bryant.

Depending on your location, I would not purchase a new system that did not have electronic demand defrost.

IMO

This post was edited by tigerdunes on Thu, Oct 31, 13 at 12:33

"Currently, there is a 3T unit now, so we know the ductwork etc can support a 3T unit."

May I ask how you know this? Has a static pressure test been done on the existing duct system? The older system used a PSC blower, so if the ductwork was undersized/deficient, it would just move less air, resulting in less capacity and generally more stress on the equipment itself. The new variable speed air handler will actually ramp-up to move more air, which could result in a rather loud, less reliable system. Many homes are lacking in sufficient return/supply capacity for the equipment installed in them. A competent dealer can measure the supply and return external static pressure to actually determine if your ductwork is sufficient.

3 tons for 1000 sqft of average construction is crazy -- could likely cool the entire home, but of course living area (sqft) alone does not explicitly dictate the heat load (though sadly some contractors seem to think so -- generally 500 sqft/ton is the incorrect rule of thumb used). Many like to add a fudge factor to the load calcs to get the results they want, which provides no benefit to the consumer in terms of comfort or efficiency (the opposite). I would just caution you to avoid oversizing and review calcs with the dealers. It makes no sense to oversize a high-end, dual-stage system that will spend all of its time in low stage.

The 2-ton installer is probably correct, and if they are reputable and will guarantee the system will perform to your design conditions, I see no reason not to go that route from upfront cost, comfort, and efficiency perspectives. You should tell them what you plan to keep the temperature setting at during the winter and summer.

TD has recommended a good system above. Without reviewing the calcs myself, 2.5 tons is the absolute most I could sanely recommend for your upstairs.

Please keep us posted; I look forward to seeing how this plays out. I would personally give great consideration to the contractor who performed the load calc and said that 2 tons was appropriate. But to be very clear I am not saying that this size system is appropriate; as stated, a load calc needs to be done correctly to determine that. But it is true that many companies have the tendency to oversize and everyone is afraid of undersizing (understandably!), so if a reputable company is suggesting a 2 ton system and will design it correctly and stand behind it, then that says something. 2 tons does "sound" appropriate and common for the average 1000 square foot living space, if not more than enough capacity. But it does depend on many factors, including your ductwork -- if it is poorly designed, leaks, and has little to no insulation -- which in itself would be something to look into. Ductwork is often overlooked but equally as important as equipment selection/sizing.

Best of luck.

This post was edited by ryanhughes on Fri, Nov 1, 13 at 23:19

We had the contractor come out again to do a more definitive measurement of the upstairs.

Ultimately, he recommended that we go with the 2-ton XR-17, and based on a recommendation from another installer, a 2.5 ton Hyperion XL Series 7 air handler.

Should I have any concerns about having an air handler with a different capacity than the heat pump?

Thanks so much for all of your helpful comments.

No, the size difference is not uncommon (larger indoor coil capacity), and in fact the 2.5 ton TAM7 is the only correct match for the 2-ton XR17 heat pump. Kudos for avoiding an oversized system. Installed and set up properly, I think you will be very happy with this setup. As I said above, many are quick to oversize but afraid to undersize, so I think you're going in the right direction assuming the load calc was performed properly.

FYI and for what it's worth: In the AHRI directory, the actual rated capacity of this combination at test conditions is actually a little over the nominal 2 ton capacity (24,000 btuh): 25,800 btuh cooling and 25,000 btuh heating.

With efficiency ratings of 13 EER, 17 SEER, and 8.5 HSPF, this will surely be more efficient and provide you with better comfort than the oversized 3 ton system would. Longer run times are what you want and what the equipment was designed to do.

Lastly: I would recommend the Trane XL803 thermostat (model #TCONT803) and consider adding a 4-5" media filter cabinet.

This post was edited by ryanhughes on Tue, Nov 5, 13 at 22:57

I will be a contrarian. I think two stage condensers for small living areas is overkill, waste of money, and can not be cost justified.

To make matters worse for this premium HP condenser, the HSPF efficiency of 8.5 can only be described as mediocre. See below.

5773514 Active Systems XR17 TRANE 4TWR7024A1 *AM7A0B30H21 940 735 25800 13.00 17.00 25000 8.50 15200 1 HRCU-A-CB Yes 184 570 Yes

Now take a look at the XL15i

That would be my choice.
5020850 Active Systems XL15I WEATHERTRON TRANE 4TWX5024B1 *AM7A0B30H21 835 24000 13.00 16.00 22600 9.00 13400 1 HRCU-A-CB Yes 182 538 Yes

Anything said about the thermostat? Should be Trane 803 or identical HW Mdl 8321.

What size heat strip was quoted? Of course new refrigerant lineset is indicated.

IMO