Gas heater vs Heat Pump in the Austin, TX area

[Ozsplace]

I'm looking at adding a heater to our pool and wanted to know if any one on here has either a gas heater or heat pump in the Austin TX area. The reason I ask is our gas is really cheap compared to electric (12 cents kWh) - I've read about the cost savings of running a heat pump vs gas but it seems like it would be pretty expensive to use a heat pump.

Any one in Austin mind giving me ball parks on how much your bill went up gas or electric

Any help would be great!

I checked the AquaComfort website and it had a huge cost difference of about $700 for a heat pump.

Pool will be 35' x 15' and has sun about 10 hours a day.

 

[jblizzle]

What do you want the heater for exactly?

If gas is cheap, that is the way to go if you need to add a lot of heat quickly.

Solar is an option for "free" heat that can help on the shoulder seasons.

 

[Ozsplace]

Thanks for the fast reply!

Really to extend the season into March and November - I think during the summer months I'll have the opposite problem and have to setup a mist chiller (lots on this site!).

Yeah our gas cost is only 75 cents per Therm and I can't imagine that a heat pump could really be cheaper.

I'll have a solar cover too to help retain heat.

 

[jblizzle]

Solar with a cover might be able to extend you a bit on both ends.
You can also run the solar at night and cool the pool in the summer.

But, it does cost a bit more up front and will not add heat fast like a gas heater would.

With my solar the water can hit 80 in March (without a cover). Seems to not go as late into the fall ... although once the kids are in school the usage is much less.

 

[Spa Owner]

The principle of heat pump operation can be explained as 5 litres at 20 degrees Celsius (sorry for metric) contains the same amount of energy as 1 litre at 100 degrees. The heat pump is the device that can capture the heat from the 5 litres and convert it to get the temperature in the 1 litre. This is termed the coefficient of performance and typically 4:1 lots of other factors.


What has happened in this market is manufacturers realised the industry was comparing on coefficient of performance at 4:1 so started to fiddle about with the other factors to get coefficient of performance at 6:1, and other silly numbers. Unfortunately it is very mathematical to convert back to equal every one out. Can be done takes time and a forum is not the place for that. Consequently, for the consumer, life gets very confusing as many dealers are unaware of above and will promote what they believe and honestly think is best being the unit with the highest claimed coefficient of performance.
The cheaper to run comes from the amount of energy input.


A water body is simple to heat we have a saying it goes kilowatts in kilowatts out. By this we mean the amount of energy required to heat a pool is no more or less regardless of when it is required or how it is delivered.


To properly asess the difference first convert the heat load to a common factor in my case kW, you may work on BTU or mj or something.


Target temperature - starting temperature by volume by a factor applicable for your area will give energy required.
Energy required divided by units of energy cost for gas gives a notional run cost for gas
Energy required divided by 4 of energy cost for electricity gives a notional run cost for power


From this very rough estimate a fairer comparison can be made.


Having said all that...Heat pumps are better at holding a temperature for a long period of time. Say all year round. Gas heaters are better at getting a lot of energy into a pool fast. Therefore the gas heater is better if switching off and on with say a days notice a heat pump can take a week to heat a pool up from cold.


Another factor is temperature.


Gas heating if you dial in 28 degrees you get 28 degrees


Heat pump if you dial in 28 degrees you get anywhere from 24 to 30 depending on other ambient conditions.


Final hint: If you have a high humidity climate. Heat pumps work better. In a dry arid climate heat pumps still work but just not as well.

 

[slickrock22]

Been down this exact road and live in Austin! I replaced all of my pool equipment before I even knew what a heat pump was. As you, I recently started searching about how to extended my pool season on the front and back end. Not sure we needed it this year as the heat came early and is not going away.

If you have a hot tub, I think you have to have a gas heater regardless of what other/additional heat sources you add. Unless you are an amazing planner and turn on the heat pump hours before you want to use it (not sure of actual time).

If you want to extend your pool season and have the ground or roof area to support solar its probably about $6K-$8K initial and then pump electricity to pump the water up and down to heat it. Depending on the number of panels I think i recalled the guy saying 10-20 degrees increase. Which sounded perfect. My neighbors and wife would kill me if I put panels on the southern facing portion of our roof.

Next step was to explore heat pump. I think after the initial outlay of $3500-ish, The cost to raise 10-15 degrees on the either end of the season with Austin electricity prices was roughly $150-$200 bucks / month - Not bad at all - This would have been my choice and still may be.

There was this new toy to connect to your existing HVAC compressor and borrow the heat that kicked off from your AC Compressor was interesting. But will not work on Variable Speed compressors. Not compatible.
Heat Recovery Pool Heater | Compare To Solar Pool Heater | HotSpot Energy LLC

Then was the gas option (which I already had) and I think that ran about $400/month based on my calculations. I don't love my children that much!

 

[PoolguyinCT]

Go for both!!

 

[slickrock22]

[emoji15]