Honest EER efficiency ratings


Old 07-20-16, 06:47 AM
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Honest EER efficiency ratings

I am considering what AC system to buy and I am wondering what efficiency ratings one can trust. Because of the symbiotic relationship between our government and companies it regulates, one can't just go by simple SEER ratings, they are at least partly designed to help companies market new systems.

From what I read, SEER is specified for particular outside/inside conditions, not necessarily realistic ones. Also, newer scroll compressors have maximum efficiency in a narrow range of operating conditions compared with older reciprocating. So I am sure the systems are optimized to give high efficiency on paper.

I don't necessarily care about perfect comfort and keeping the temperature within 1 degree. I plan to somewhat undersize the AC and run almost in steady state. What would be the most efficient system? Does anyone know a website that lists EER instead of SEER? In particular, for single stage compressors, SEER ranges from 13 to 16. What are actual COP differences and hardware differences? It is a more efficient electric motor? A bigger heat exchange area?
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Old 07-20-16, 11:32 AM
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What type air conditioner are you shopping for? Window unit, split ductless, package unit?
Old 07-20-16, 04:44 PM
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Energy Efficiency Ratios are laboratory tests run under standardized conditions. Their sole purpose is to compare different units to each other. Contrary to popular opinion they are NOT to be used in calculating the efficiency or operating costs of any particular installation.
Old 07-20-16, 07:24 PM
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Usually a higher efficiency condensor will have a larger condensor coil and possibly a larger fan but slower spinning.

The ultra high efficiency systems have electronically controlled variable speed fans and two stage compressors. What energy savings these units save you they'll cost in repairs.

Are you adding this A/C system to a pre-existing gas furnace? That right there will kill your high efficiency savings.
Old 07-21-16, 10:24 AM
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There are a lot of factors that affect the cost of cooling your home irrespective of its EER Rating.

The home's efficiency, the duct system, you're on target slightly undersizing the condenser, add to that a SWING or cycles per hour adjustable temp-spread RM.TH for milder weather & you'll lower cooling costs.
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