Heat Pump SEER Ratings

[ss7b8zs]

What is your opinion on using a unit with a SEER rating of 17 vs a SEER 13 or 14 in an area such as Phoenix with a mild winter and blasting hot summer? I'm a homeowner looking at a system with dual compressors and two-stage cooling / 3-stage heating rated at SEER 17.9... is that overdoing it? My neighbors all seem to have a single compressor SEER 12 - 14.

[BaldLoonie]

Much of the benefit of 2 stage cooling is humidity control, which isn't of interest to you in the desert. There MAY be a payback in energy savings of the super SEER 2 stage units in your hot climate but those suckers are so pricey, even in your climate there may not be. What's your cost per kwh? I might be able to crunch some possible cost differences.

[ss7b8zs]

Thanks for the offer to help, BaldLoonie. Here are my rates:
On-peak $.0723
Off-peak $.0674

[BaldLoonie]

First, I have NO idea the accuracy of these figures. I've used this formula before in our area and they seem fairly close. They come from the Air Conditioning & Refrigeration Institute.

Using Trane as an example,

the XL14i rated at 14.00 SEER and 8.55 HSPF calculates to $280 cooling & $286 heating annually.

the XL16i 2 stage rated at 17.00 SEER and a whopping 10.55 HSPF calculates to $237 cooling & $232 heating annually.

This is for a house with a 36,000 BTU heat gain & loss and a 36,000 BTU heat pump with electric backup. I used 1800 cooling load hours, 1500 heating load hours & 7 cents per kwh.

Looks like $100 a year in savings for the XL16i over XL14i if this is accurate. You're probably one of the few areas with some payback for a super SEER unit.

[ss7b8zs]

Wow - that's good news. The unit I'm considering is actually a Trane XLi9i rated up to a 17.90 SEER and up to 8.90 HSPF. It's got sound insulators to make it the quietest running in the residential line - important to me as we have a small lot and it's going to sit right next to the picnic area. It's got a 10 yr MFG warranty on the compressors, coil, air handler, thermostat and all functional parts. It costs about $2500 more than the XL14 model, but I was hoping to make up the diff in two really hot summers (last year we had a couple of 122 degree days and many many 116 degree days).

Thanks for calc-ing it out for me!

[ss7b8zs]

Correcting type-o - it's a XL19i

[BaldLoonie]

Well, what size XL19i? Don't let the model # fool you, efficiencies aren't that great. Might as well get the newer technology of the 2 stage scroll of the XL16i. There have been compressor problems on the 19i pumps, the little one doesn't hold up. One member on here recently reported that his replaced new & improved 19i just lost another comp.

On the 3 ton example I gave, the XL16i SEER was 17.00 while the 19i is 17.6 hardly a big deal

Heating wise, the XL16i was an incredible HSPF of 10.55, while the 19i is a much lower 8.4, lower than some 12 SEER units can do. Those old recips don't heat like a scroll.

$2500 more? It will long be in the grave before you see any hint of savings. Plus a good scroll will be much quieter than a blanket over the old Climatuff recip.

[Edited by BaldLoonie on 03-07-2005 at 06:08 PM]

[ss7b8zs]

It's the 5-ton uint with a 60,000BTUH cooling capacity and a 51,000 BTUH cooling capacity. My house is 2100 sq ft.

What does "those old recips don't heat like a scroll" mean (I don't know the lingo).

[BaldLoonie]

The 19i uses a reciprocating compressor, the 16i uses a scroll compressor. The scrolls are much better compressors for heat pumps, HSPF rating is higher, temp is warmer in cold weather.

Being 5 ton, obviously your costs will be higher annually but so will your savings. I highly doubt you'll see any payback at all on the 19i. As I pointed out, cooling performance is similar, on the 5 ton the 16i might have an advantage. The 16i certainly has an efficiency advantage on heating. I'd ask for a quote on it, skip the 19i.

Or if you want quiet, look into the Lennox Signature series. Their 19 will be quieter than anything Trane.

[duct dr]

Bald, would he really need a 5 Ton system on a 2100 SQFT house? I know it gets HOT in AZ as it does here in AL too. I would think that a 4 Ton XL16i would be more than enough to do the job. As well as saving money on power bills.
I just converted my parents from a 3 1/2 Ton straight cool to a 3 Ton XR12 410a system, and they love it.

[ss7b8zs]

Hi Duct DR - The unit I'm replacing is a 5 ton - does it make any diff that the house is a ranch with vaulted ceilings? The other houses in the neighborhood either have a 5 ton or, if two story, they have two 3 ton units. The house across the street has two 3 tons and one smaller one to cool their AZ room. The heating efficiency isn't real important as we don't see many cool nights here. Once every five years or so it gets down to 28 degrees. Mostly it's in the 40's winter nights. Of course we are all wearing parkas whenever it drops below 60 degrees (chuckle).

Anyway I went back and priced the 16i and it was $400 more (the 5 ton). Does that sound right? Again, Maybe I don't understand Trane's product numbering system, I thought the lower the number, the lower the price. I'm not a guy either, and all this equipment is a mystery to me. Thanks for helping me out.

[arizonaheat]

I am curious as to what you decided. I also live in the Phoenix area and am trying to decide on what system to install. I want a system that is comfortable, quiet and efficient. One dealer pushed the Trane 19XLI but another said that it wasn't worth it in terms of energy savings.

[ss7b8zs]

I went with the Trane XL19i. It's too soon to speak to the energy savings as I've not got my first elect bill yet and the weather has been mild. The unit runs quiet and I really like it when the system comes on that it first blows gently before kicking in. I also like the company I bought it from and the installation team who did a very professional job putting it in. Best of luck with your decision.