Heat Pump vs. A/C

[Woodboy]

I have a new home with a high efficiency forced air natural gas fueled furnace. I am evaluating adding central A/C and one contractor has suggested a heat pump vs. the traditional freestanding outside A/C unit. Living in Denver, we have many more “heating days” than “cooling days” with the real need for air conditioning rarely going over 2 – 3 months. For that reason the super efficient (high SEER) units don’t reach payback quickly enough to justify them. I assume a heat pump would add supplemental heating in the winter and act as a cooling device in the summer.

Any suggestions out there to help me evaluate this?

[Hellrazor]

Might be a good alternative with gas/oil costs going up.

[Popeye]

I'm not a HVAC type but.... If you already have a new home heated by gas, why is this guy trying to sell you a complete heating and cooling unit? When it gets very cold and I know Denver does a heat pump is not very good at heating. I hate the heat I get from mine. It blows a nice even 70 whatever. I grew up where we fought over the "real" heat coming from the floor registers. If you want A/C get them to install the A/C unit and an evaporator in your main plenum. BTW, one takes up just as much room in your yard as another. Just my two cents. Probably a HVAC guy can explain it better. Pat

[bhanna1]

another thought

Somewhere there is a utility burning gas to produce the electricity to run that heat pump at an efficiency of about 27%, so, no matter how high the efficiency of the heat pump, it's going to cost a LOT more to produce heat that way than by directly burning gas. Unless you can get the heat pump for a great deal less than an AC and you are going to sell the house really soon it isn't economically feasible. Below 40 degrees, the heat pump is running straight resistance heating anyway, with no greater efficiency than an electric space heater.

[9johnny5]

My brother lives in Aurora, and he has found that the best compromise is a "swamp cooler". He's installed them for himself and many of his freinds, so I know it's within the reach of most DIYers. Sort of an improvised a/c-fan-chilled water setup, but at a fraction of the price, since you use it a fraction of the days. I don't know all of the specifics, but I'm sure I can ask if you're interested. I'm sure googling it will turn up something.

johnny

[Crash2510]

we live in ohio and have electric heat with a heat pump works great and is much much much much much cheaper than propane. Heat pumps are unly efficient down to 20 degrees that is when emergeny heat kicks on and takes up a little more power, but as long as they are sized right they will have no problem heating or cooling your house although the heat they put out is not as warm as say wood or nat gas.

Another alternative if you have any farming buddies is a corn stove which is a warm efficient heat and you would probably only need 200 bushel or so a year or $200 to 400 dollars cost Ohio money of course.

[Crash2510]

Somewhere there is a utility burning gas to produce the electricity to run that heat pump at an efficiency of about 27%, so, no matter how high the efficiency of the heat pump, it's going to cost a LOT more to produce heat that way than by directly burning gas. Unless you can get the heat pump for a great deal less than an AC and you are going to sell the house really soon it isn't economically feasible. Below 40 degrees, the heat pump is running straight resistance heating anyway, with no greater efficiency than an electric space heater.

You might want to check your numbers on this the newer versions are 13 seer or so don't change over to resistance/emergency heat until 20 degrees or so and usually are cheaper if you are not looking at statistics from a natural gas/propane/govt website.

[jAngiel]

We have been using a heat pump for years here and it does a great job of heating and cooling our house. We have that gas backup on our unit though, I wanted no part of and all electric unit. When the heat pump can not keep up with the demand it automatically kicks on the gas backup heat to catch up. The one odd ball thing that a heat pump does is periodically it needs to run in reverse, taking heat from the house and using it to defrost the coils outside. At least that is how it was explained to me, when it does this the air that is blown inside does not feel that warm. If it doesn't do this the unit outside turns into a huge block of ice, our first unit did this when we built the house. It was a cheapo contractor grade unit (Janitrol, pos) that wouldn't work correctly, after the tornado it was replaced with a newer Janitrol, not as good as the Trane on the new addition but way better than the old pos.

Compared to my friends that have either an all electric house and those with a straight gas furnace and an electric ac, our bills are quite a bit lower taking into account the relative sizes of our houses. Naturally our house as well as those of our friends could benefit from some additional insulation. That said, I am quite happy with the heat pump/gas backup configuration that we have.

Whatever you decide to go with, stay with the name brands and not the generic contractor grade units, you will be much happier.

[jlake1998]

Heat pump is about the most efficient for electric heat. Used in areas that dont have natual gas readily available.
But your heating with natural gas which cost less yet.
Buy the air conditioner is my 2 cents.

[DUD]

Here in Jonesboro the heat pump is the best buy, even with electric auxilary heat. But when You combine the gas hear with a heat pump, it's a win win situation. Our electric rates are the cheapest around here. Bill

[vaking]

I have the house that has natural gas forced air heat and electric AC over the same ductwork throughout the house. I think that is also what you are considering. I also have an additional small heatpump in one room only. The heatpump has one advantage - if all your family spends a lot of time in that one room only - you can keep that room at best climate and the rest of the house colder in the winter or warmer in the summer saving the cost. In other words - heatpump can save by providing more granular control than central heat over entire house. If you are thinking of comparing heatpump vs central gas heat on the same distribution ductwork - I would stay with central gas.