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SEER Savings

Posted by djn602 (My Page) on
Mon, May 23, 11 at 11:04


Need to replace an old and undersized system. I feel confident in the new sizing calcs and such what I am concerned with is payback on upgrading the efficiency. Will I really realize a 30% saving between a 13 seer and a 20 seer? I am very torn on what to do. I know I will get base savings moving from an undersized electric to a properly sized dual fuel system. My rates are .10 per kwh and .84 per Ccf. I am located in central Missouri. Also I must confess this is not going into a home but a Day Spa so it will run longer and the temps will probably be higher or lower to keep the customers happy. It is over 2000 sq ft in size.

Base system recommendation is 80% eff gas with 13 seer heat pump. Incremental costs: 95% $887, 95% 2 stage variable speed and modulating gas $1,573, 15 SEER $1,558, 16 seer two stage $2,997, 20 seer 2 stage dual compressor modulating $3,494. I am sure to use the higher seer you need a variable speed and therefore upgrade blower/furnace�

Thanks for getting me past my mental block and getting the contract signed so I can move on :)

Follow-Up Postings:

RE: SEER Savings

You state that your current system is undersized. An undersized system would run constantly at your design temperature and probably never reach temperature. Yet, you state that your proposed (larger) system will 'run longer' and produce higher (in heating) and lower (in cooling) temperatures. Can you elaborate as to what the heat calc stated as your heat loss/gain, and rating of your present equipment? Many original (older) installations were oversized, with undersized ductwork.

Has the company evaluated your duct system which could be largely responsible for your 'discomfort'.

FYI: a variable speed blower is very nice. It probably contributes about 1 SEER point.

RE: SEER Savings

The duct system is completely inadequate and will be replaced as well. The current system is an 8 SEER, 3.5 tons, and the strip is a whole 20kw. I do not have the calcs with me. Right now the system runs all day in winter and pretty much in summer to maintain 70 degrees. I do not know what it will be set at I am sure the ladies would like it warmer than 70 in winter and cooler in the summer but they are not paying the bill. The space is 2000+ sq ft.

RE: RE: SEER Savings

I should have said the current system runs all day and hardly ever reaches temp in the summer and I would almost say never reaches temp in winter.

RE: SEER Savings

Here are several calculators to try out:

The second one can be enhanced if you lookup cooling and heating degree days for your location. Try this website to do this:

RE: SEER Savings

Well it turns out none of these guys that quoted me actualy did a Manual J. So far I cannot find anyone local that does.

RE: SEER Savings

Did any of them comment on the duct system?


They all felt the ductwork needed gutted, new main trunk, new high velocity vents (for the 10 foot ceiling) and so on

RE: SEER Savings

Thanks for that degree day link. Last weekend, it seemed to me that it was way too difficult to find a convenient source.

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