Heat Pump Vs Natural Gas Heater

[RochesterMark]

Our new pool instillation starts next week and we need to make a decision on the type of pool heater to use. Some background info, 23000 gallon in ground pool , solar cover, location Rochester NY, and we are on a municipal electric grid which is about 1/3 the price for electric in the area. I am pushing for a heat pump for the pool but my wife isn’t convinced that we would save that much money. The heat pump is about $1500.00 more than a gas heater for our pool size. My questions are:

1. Is there a formula to calculate the price per BTU output for both the heat pump and gas heaters?
2. What is or how can I find the average time to recover the extra cost of the heat pump?
3. Are there any other pros or cons that we need to know about?

Thanks

RochesterMark

[RavenNS]

Estimating Heat Pump Swimming Pool Heater Costs and Savings
For an outdoor swimming pool, use the following tables ( see link) to help estimate your annual heat pump pool heater costs and savings compared to using an electric resistance or a gas pool heater.

http://www.eere.energy.gov/consumer/.../mytopic=13220

There are lots of thread on this topic ( do a search)
here is the most recent:
http://www.poolforum.com/pf2/showthr...4862#post34862

[cleancloths]

Check some of the online vendors that sell heatpumps, most have a comparison chart of energy usage versus gas heaters. I've had my heatpump for 8 years and would never consider a gas heater.

[myLABSpool]

RocMark,
I also live in Fairport and just had a 24k gal. IG pool installed. I faced the same question because I'd like to take advantage of fpt electric, but I ultimately decided to go with gas. The main reason being is that my backyard faces south and is in the sun all day, so my heating needs are limited to early and late season and an occasional mid season boost if we have some cool weather.

Also with gas, I can allow the water to cool down (not run the heater at all) and then, for example, on the weekend I can run the gas heater and boost the temp by 1+ degrees per hour. I don’t think you can do that with a heat pump, so you must leave it on (I think).

Two of my next door neighbors also have pools and they don't run their gas heaters much at all. If our pool wasn’t in the sun all day, I think the decision might have leaned much more to a heat pump.

By far the biggest benefit for reducing heating costs (and chemical use) is to use a pool cover. Make sure it’s on the pool at least every night! If you don’t use a pool cover, the payback on the heatpump is a lot quicker.

I used the charts at the links below, in addition my neighbor’s experiences, to help me arrive at my conclusion. Based on this, I figured it might take 7+ years to break even on the heatpump, and that wasn't worth it for me.

Hope this helps and good luck!

Heat pump
http://www.eere.energy.gov/consumer/.../mytopic=13220

Gas
http://www.eere.energy.gov/consumer/.../mytopic=13180

about solar covers
http://www.eere.energy.gov/consumer/.../mytopic=13140

[cleancloths]

Excellent links!!!! Thanks for posting.

Please note that the methodology is good, but the energy numbers are out of date. They base the data on electricity at 8.5 cents per kwh and gas at $0.50 per therm. Thus, the actual economics will vary by a function of what you actually pay for energy.

In my neck of the woods gas is going for about 85 cents a therm in the summer (it goes to around $1.80 in the winter, but pool heating is in the summer.)

While electricity for those that pay for it is on average about 15 cents/kwh during the summer. When I installed my pool I went to time-of-day electric pricing which is now about 18 cents/kwh during the day and 8 cents per kwh at night. But since then I installed a 10kw solar pv array on my home which generates over 12,000 kwh per year. So, my electricity to heat the pool with the heat pump is very cheap.