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View Full Version : What is the difference?

chillyma
Dec 16, 2006, 12:49 AM
I am changing over from a gas heat system to electric. I have read how efficient the heat pumps are but it gets pretty confusing. I am looking at the goodman 2.5 ton ac unit and seporate airhandler (10kw heat strips) package 13 seer and I am looking at the goodman 2.5 ton heatpump with the same airhandler or furnace 13 seer. The heat pump package costs more.

My question, if both packages are 13 seer how can one be more efficient than the other? Why spend more money on the package with the heat pump? What is the benefit?

Thanks:o

Fr_Chuck
Dec 16, 2006, 08:09 AM
The heat pump does not use the heat strips until it gets real cold,

But my electric bill on my home with my heat pump is about 25 percent less than my neighbor with a standard air conditioner and heater.

I can't explain exactly how it works but the heat pumps pulls and warms the air to a percentage. So the actual heating coils don't come on till the air outside is colder than the heat pump can raise the temp.

NorthernHeat
Dec 17, 2006, 09:50 AM
A heat pump provides heat at aprox' the same cost as an air conditioner. When it gets to cold outside for the heat pump to keep up then the electric heat turns on.

When your A/C runs the outside unit blows hot and the indoor unit runs cold. A heat pump can change the direction of the refrigerant so that the outside unit blows cold and the inside unit blows heat.

labman
Dec 17, 2006, 11:14 AM
I think the seer may only be for the air conditioning, comparing the power used to the heat transferred. For both theoretical and real world reasons, it is never 100 % efficient. There is some other factor for heating that is important, the coefficient of something or other(COP?). It looks at the heat supplied compared to the power used. Heating strips are as close to 100% as anything in the real world, providing one watt of heat for each watt of electricity. However, heat pumps actually provide more watts of heat than the watts of electricity consumed. It does that by robbing the outside air of its heat.

You may want to look at average degree days for heating in your area. If it is fairly low, the power saved by a heat pump may not be worth while. Unless whoever is selling the units can give you figures showing you the heat pump saves enough to be worth while, I would go with the cheaper system.

I am not convinced that abandoning gas heat is a good idea now. The publicized horrible spike in gas rates last year never happened in much of the country, and gas is actually lower this year than last. Again, this is highly dependent on your degree days. Also if your house was built for electric heat, or retrofitted to the higher insulation specs. Do you live in Miami or Minneapolis?

NorthernHeat
Dec 17, 2006, 02:46 PM
SEER is seasonal enegy efficiency ratio. Same energy formula for cool and heat. If I remember correctly replacing a 10 seer with a 13 seer is 1-(10/13)=23% cheaper to operate the 13 seer.