Heat Pump or Solar in Arizona

[newpoolinphoenix]

I am researching two options for increasing the pool season on a pool I am in the process of building. The pool will about 12,000 gallon in ground gunite/shotcrete with infloor cleaning. I understand the solar will increase the swim season to about 9-10 months out of the year but probably won't for the remainder 2-3 winter months. Does anyone know if a heat pump would allow me the additional 2-3 months of pool usage in phoenix? Can anyone recommend a heat pump to install? What size of heat pump would I need?

Thanks for any advice offered.

 

[Poolsean]

A heat pump will probably be a better choice than solar, depending on operating conditions. What temperature are you looking to maintain and will you use a solar blanket?

Solar panels should have a southern exposure and should be at least 50% of the surface area of your pool. So, you need to make sure first of all that you have the space and exposure for a proper installation.
You'll want to heat the pool during the day with a solar panel system. Operating at night, when it gets cooler out, will not provide any heat to your pool. It will instead cool off your water. Running during the day instead should provide a decent amount of heat, depending on the amount of solar panels you have and if you have a long enough period of sunlight to generate enough heat.

A Heat Pump will be more consistent heat and should work all year long. It is not as dependent on sunlight exposure and will provide heat on rainy days, or at nighttime.

In either case, you will want to use a solar (bubble) cover to retain the heat overnight.

AquaCal has sold thousands of heat pumps in and around Phoenix. You should also consider a heat and cool (we call ours the Ice Breaker) model, which will allow you to cool off your water during the hot summer months, where the "too hot" water can make it less enjoyable to use your pool.

Regarding the size, you can't get too large a heat pump. The larger, the more BTU's, the less it will run to maintain your water temp. Infloor return heads will increase the efficiency of heating your pool. But for a 12,000 gallon pool, 100,000 to 120,000 BTUs minimum should be sufficient.

Should you choose a heat pump, look for the BTU output, and COP (coefficiency of performance) which is a matter of the efficiency of the system. There is a national code, ARI Standard 1160, which requires that a heat pump be able to meet a minimum of 4.0 COP at 80 degrees water temperature, 50 degrees ambient air temperature, 63 % relative humidity. There are few heat pumps that meet this standard.

Listen to how quiet our Super Quiet models are. http://aquacal.com/

 

[dschlic1]

I am in the Tampabay area of Florida. I have solar heating, no heat pump. I can honestly say that the solar panels keep the water warm enough to swim year around. The only time we don't swim is when the air temp is too cold!

 

[jerrypar72]

Hello Schlick,
Are you also using a solar cover on your pool? I don't like the idea of having to remove and reinstall the cover each night.

 

[dschlic1]

I do use a cover, but only during the "winter". My wife and I like our water warm, so we usually set the water temp at 90F. This means that if the air temp falls, evoporation is a real killer on the pool. For example right now we are in the middle of a cold front: Friday had high in the 90's, last night the low was in the 50's. So I placed the cover on the pool Friday evening. It took me onl,y about 15 minutes to get the covers out of storage, and place them on the pool. Normally during the summer, we do not use the covers.

 

[polyvue]

I think Phoenix and Tampa weather patterns are different enough to make comparisons difficult. Florida has lots of summer humidity and higher relative overnight temperatures, thereby reducing evaporative cooling and the need for a solar cover to preserve the pool's heat. Phoenix, I believe, is more like where I live: soaring day time temps, low humidity, followed by significant nighttime temperature drop --- both day and night environments favor use of a solar cover.

Arizonans and Floridians, feel free to let me know if I'm "all wet" on this!

 

[Brentr]

I really think that a heat pump is very necessary. My goal is to have both however we went with a Heat Pump first. We bought a Heat Siphon from Poolheatpumps.com Our thought process is that we wanted the ability to use the pool all year round and Marcus recommended this one for us. It has COP is 7.2 or 7.3 and so far it have been great for us. Both Marcus and Kevin are very knowledgable and will answer all your questions.

dschlic1, we live in Jacksonville and this past weekend we got a cold front. I noticed that I lost a lot of water due to evaporation even though I used my solar cover. I am loosing about 3/16" per day. Is this normal? How much are you losing with your solar cover on?

Thanks in advance

 

[op999]

Say, how many panels (and what size) would it take to warm a 20-22K pool in Orlando during the winter? Water temps can drop to 55F during the coldest 30F spells. (Water temp during an average winter is 65F). If I can get the water to 78-82 I'll be happy, but I know nothing about if that's even possible, since everywhere I read, panels will heat pools an average of 10F.) I am thinking of installing some in the front side of the roof, since that's the one area that always faces the sun at this time. (And, during the summer months, I don't even plan on using the heated water.)

 

[polyvue]

Say, how many panels (and what size) would it take to warm a 20-22K pool in Orlando during the winter? Water temps can drop to 55F during the coldest 30F spells. (Water temp during an average winter is 65F). If I can get the water to 78-82 I'll be happy, but I know nothing about if that's even possible, since everywhere I read, panels will heat pools an average of 10F.) I am thinking of installing some in the front side of the roof, since that's the one area that always faces the sun at this time. (And, during the summer months, I don't even plan on using the heated water.)

As wonderful as are Orlando winters, you have noted that water temperatures can drop to as low as 55 degrees F. Solar panels will not do you much good at that time of year... you best answer is a heat pump, possibly supplemented with solar panels. A heat pump should be able to extract enough heat from air that stays 50 degrees more or less to heat your pool.

 

[dschlic1]

Brentr: I would say that losing 3/16" of water per day with solar covers on is a little high. With the solar covers on I don't lose that much in a week.

op999: I doubt that with solar panels alone you will be able to maintain 78 degress in winter. However temps in the loww to mid 70's are possible. Solar panels in the northern hemisphere should always be mounted on a south facing roof or structure. Ideally the angle of the panels will be your latitude in degrees. This maximizes the solar radition recieved by the panels.

 

[op999]

Well it appears that my idea of year-round swimming won't be becoming a reality, at least with solar panels alone. So, I'll settle for 9 months out of the year.

I saw someone selling 4x10 panels Fafco (type, not sure if they are real Fafco) for $55 each. Good deal it sounds like.

Speaking to my neighbor, he pointed out that, since panels would have to face south, that installing them in the front area of the roof, which faces that direction, will likely raise an issue with the homeowner association. So I devised a plan to install them in the south side of the roof, but installed on a large rectangular piece of plywood, leaning against the adjacent enclosed patio screen, and facing south. That was it won't be visible from the front, but it will still face south.

I'm wondering how much water these panels can hold at a time, and how heavy they can be when filled with water. I don't want to see my project laying on the floor when I'm done. (Not that I'm near there by any means!)

Op