New pool and solar questions
 

We are looking into getting a pool installed for the first time. Because of medical reasons, we need the pool to be used year-round. Which now begs the question what is the best way to heat the pool. We have natural gas on the property, and I've been told a heat pump would be cheaper than natural gas to run. I would like to heat the pool to about 84 degrees year -round.

My roof is 22 years old, and I'm about due for a new roof so will my pay be better with a hot water solar or pv electric panels to run the heat pump. I've been told neither would get me to 84 during the cold cloudy days. The pool has to be located on the north due to property shape and the panels would be on the south. I would like to hear from others who have had this situation. I understand with pv panels i can connect to the electric grid, and even using the pv to run my A/C on peak summer days the return is small. Looking for ideas. Thanks

Solar panels used to generate electricity have been discussed on many threads on this website. Do a search. But, they are not worth the investment because the payback period is too long.

Go with the gas heater and solar hot water for the pool.
As far as the heat pump goes, you'll be using it during the colder months, trying to pull heat out of already cold air, it works to a point then it struggles. Homes with heat pumps have emergency heat, with is electric heater strips because the heat pumps can't get enough heat in the colder months.

The solar hot water will cost you a little more in pump run time and speed. Yes, in the winter months it won't provide a lot of heat, but it will help maintain the temperature. Use the gas heat to supplement and it won't have to run long. The gas heater will put between 300-400,000 BTUs of heat into the water no matter what the temperature, a heat pump, not even close.

Since you have a south facing exposure for the solar, you win! Tell them to fill every inch they can with the pool water solar panels. They'll tell you you don't need that much, not in the summer of course, in the winter every square foot of solar is that much less gas to use.

For the PV there are 2 questions to ask, 1) what's the ROI (return on investment) - how long will it take to recover what you invest by the money you save, if it's more than 5 years, walk away. 2) What it the typical maintenance cycle - how long until you may need to start replacing panels (and how much are they). If the maintenance cycle is less than the ROI, walk away, every time you need to replace a panel or inverter or battery or anything else, it lengthens the ROI.

My experience so far in The Villages, I've had a pool 4 years, it is comfortable (80+) 10 months out of the year on just the solar. I have gas heat (300K btu), the last time I used it raised my 15,000 gal pool from about 70 to 86 in just under 3 hours when family come in in the winter and wanted to swim.

If you want a hot tub included with the pool and want to use it in the winter, gas will bring it up to temperature (103) in 15-30 min starting from about 50 degrees.

I don't believe salesman, I believe engineers, I was both and never trusted my coworkers while in sales.

No experience. I have wondered if solar electric would be a good option. They will produce electric every day and what you do not need it electric would be stored by Duke until you need it. (I think you might have an $11 a month charge). The reason for the panels is that on poor solar days you get the electric from Duke and replace it on good days. If electric pool heat makes sense then probably go with whole house AFTER your new roof. I would not expect a return on investment but then you did not expect a return on the pool.

OP, you might want to look into a larger spa (like a swim spa), much lower cost than a pool, very quick installation, and easily available year round. We have 6 person (8' by 8') hot tub that I use year round. From what I have seen your pool will be about 1 year from order date to use date. Do not use solar PV for your heat source, use solar HOT water, BUT these appear to be much less effective in the winter, so you will need an additional heat source for the pool.
The larger spa will cost much less to operate, will have lots of therapeutic jets, and if you were like me, I keep the temperature at 102 for relieving sore muscles.

We have a pump that pushes water through the panels on the roof and it only works in the warm weather months. We have a buried tank to heat it in cold weather and it costs an arm and a leg.

Gas heater plus solar water panels.
Heat pumps just can not do the job during the cold days of our winters.
Once the night time temps start going below 70 the differential to get to the 80+ degrees just gets too great for the solar panels to "catch up".
Gas heater can do it. The colder the outdoor temp the more expensive it gets.

We have a gas heater with solar water panels. Like HVAC for your house, it can't keep up with the BTU's of gas and cannot get the pool warm enough in the cooler months. My wife likes the water temperature close to 90. I joke that she is actually swimming- Su Vide. We use the solar water panels in the warmest months alone and both in the other months. Solar alone will not suffice in the winter or on cloudy days.
Remember that in the coldest of months, unless you are submerged up to your chin, the cold air temperature will make your upper body cold and become unpleasant.

I absolutely have to argue against those that condemn the heat pump.
As a installer just look at the facts. BTUs are BTUs. The ops are telling you to use gas, ok let's do the math. Your average home furnace is between 60-100 BTUs.
Imagine running 4/6 of them at a time.Second check with your roof contractors because most will void your warranty with non approved penetrations. A new heat pump of today's standard will more than adequately heat your pool in Florida weather! New heat pumps heat down to the 20 degree zone and are deadly efficient if sized correctly!!! Ask the ops how many times there emergency heat comes on in there house through out the winter, I can tell you,only to defrost,and how many times do we have frost. Remember just because everyone else has make ill fated technology related decisions, you don't have to. If heat pumps don't work why are they in stalled in so many homes up north!! Just the facts. They do work!!!

I have been looking at putting in a pool, but all contractors are telling me they are booked into 2022. Just plan ahead.

Solar
 

We have solar. The panels are on the south and west, the pool is on the west side. The most I’ve seen it raise by solar alone, 10 degrees so it works in the spring and fall but not in the winter. I don’t know but having solar and electric would seem to be best if they can do it. I have no knowledge of the possible ways to incorporate that. We don’t use the pool much anymore so I’ve never actually looked in to it. Good luck

The first thing you’ll need to stock up on is PATIENCE! It has now been mOre than a year since we first called to get an appointment with the pool company, and more than 9 months since they started the dig. We’re still probably 4 months from completion.

Extremely frustrating, but not much that can be done.

For those who have propane, is there anything to worry about with an underground storage tank in the yard? Many years ago, we couldn’t get homeowners on a house we were going to buy because of the UST.

Thanks for the info. I'm getting ready to ditch solar and heat mine with a heat pump.
Can you tell me who you install for?

Consider carefully having a pool installed. Are you really willing to spend the money for upkeep and heat when there is likely a Villages pool near your home? Give yourself 60 days swimming daily then re-evaluate your decision to build your own pool. I know a number of people who had the same idea you had. Enthusiastic at first and now regret having that big bathtub in the backyard that requires nothing but time and money to keep up. Good luck with your decision.

What is the average monthly heating cost of a pool?
 

In addition to the request for heating ideas, what have you experienced the different methods cost on a monthly basis? Thank you.

Heat pumps do work
 

We also wanted to be able to swim year round and I do like the water above 80 degrees. In looking into it, new model heat pumps are good down to 35 degrees and are much cheaper to run than gas. At very low temps they still work, but not as efficiently. We were able to buy a 96,000 BTU heat pump on line for $3300 and T and D installed it for $150. The company did the calculations for our pool and a heat pump was significantly cheaper to run. I have attached the costs they calculated. It is true it can't heat the pool as quickly as gas would, but it easily kept it at 85 degrees this last winter with a blanket The calculated cost difference was $1086 for heat pump versus $6255 per year for gas, which more than repays the cost of the heat pump. If you really want to save money you should use a pool cover in colder weather. It depends how much you want to spend. Using a floating pool cover in cold weather with the heat pump lowers my yearly heating costs to just $434 which works me. You would definitely need a pool cover for just solar in cool weather. You can also get a liquid blanket to save heating but I don't want to swim in chemicals. It is great to swim year round.

You need a multi-pronged approach. First, solar hot water heating on the roof. That will cover probably all of your heating for six months of the year, or even eight. Second, an electric heat pump, ideally on the south side. These two share most of the pipes and all. In the winter, your solar hot water heating will still cover most of the heating, but the heat pump is an important supplement. MUCH cheaper to use than natural gas. Third, a bubble-wrap sort of pool cover that rolls up. I think that will pay for itself in electricity savings in one winter. Without the cover, heat (and water, too) dissipate all night long. The cover holds in much of that heat.

I keep my pool at 92°, as I enjoy sitting in it and chatting with friends. I don’t actually swim in it. In the summer, the heat pump is turned off. The solar heater and the pool cover does the trick. If we have a long sunny stretch and the pool is overheating, I leave the pool cover rolled up. If it’s still too hot, I turn off the solar water heater flow, too. In the winter, I use the solar water heater and the pool cover. If I’m going to use the pool, I turn on the heat pump. I can leave it on all the time if I want to, but in my case I don’t use the pool all that often, so I turn it on when needed. As the water is already in the 70s in the winter with the other two things, the heat pump raises the temperature to 92° in two or three hours.

We have had our pool 7 years and definitely have one installed if we move. The pool service is only $115 per month including chemicals. We do not spend any time maintaining the pool. We use solar to heat the pool. Privacy and being able to swim at night is wonderful.

I have to agree with the posts about heat pumps being the way to go. We had gas but it was terribly expensive, especially in the winter. So we added a heat pump but kept the gas in case we needed it in the winter. We went from a $500 avg monthly gas bill to a $100 avg added to the electric bill. Quite the savings. Then, if we decide to add solar for electric, we just add 1 or 2 extra panels and the heat pump is covered as well. We also upsized the heat pump to the next size up from what was recommended to make sure it would be more efficient.

Solar/gas heated pool
 

I agree. We've had a solar heated pool for 15 years and tried a heat pump for the first 6-8 years with little success in the winter. Switched to a gas heater and that works in the winter months, although it is so expensive in January (I have a very large pool), I just swim laps in our neighborhood pool instead.

Are the heat pumps for a pool fundamentally different than those used to heat a house? We have had homes in Pennsylvania and Virginia that were solely heated with a heat pump and were fine throughout the most bitter winter. When other wrote they struggle with the cold winters in Florida, I'm just scratching my head.

The key words are "sized correctly". As a retired commercial contractor, those 2 words are lacking by most contractors.

Oh my. Such difficult "first world" problems one has to deal with. Wish I had to make them. Good luck.

Heat pumps are inadequate
 

My HVAC friend told me most people are unhappy w heat pumps because they take longer to cool and longer to heat, and people expect faster results. Also, heat pumps have a shorter life span and don’t bring the expected payback toward the initial investment. He would never own a heat pump.

I had solar in Greyville Portland, Oregon to help heat my 36x16 pool and solar usually gave me a free 10 degrees, natural gas heated the remainder. I always believed it was a good investment, especially so in sunny Florida.

Fundamentally they are the same, the difference is in the specific heat capacity of water vs that of air and the density differences between water and air.

Water has a heat capacity about 4.25 that of air, this is measured commonly measured in BTUs/lbm/deg F.

Water density is nearly 800 times denser than air.

Together this means that a cubic foot of water hold/requires about 3300 times more energy per degree of change than air.

Comparing a house to a pool - a 2000 sq ft house with 8 ft ceiling is about 16000 cubic ft of air to heat. A 12000 gallon pool is about 1600 cubic ft of water. The pool has about 1/10 the volume of the house but will require 330 times the heat to raise the temperature of the pool water 1 degree as it will take to raise the air temperature in the house 1 degree.

Also, because the humidity is lower in the winter, evaporation increases in a pool, as it evaporates it gives off its latent heat of vaporization of about 970 BTUs per pound mass or about 7500 BTUs per gallon that evaporates. This is more heat that will have to be replaced to keep the pool water warm. When you see the steam rising off the pool in the morning, that is heat that is escaping.

So, if you want to heat the water a lot of energy has to be added, a typical heat pump will add between 50 and 150 thousand BTUs per hour, this is the peak output, and it drops off as temperature outside drops off. A gas heater typically provides between 250 and 500 thousand BTUs per hour, regardless of the outside temperature.

Comparing the operation and outcome of a house heat pump to a pool heat pump, while fundamentally the same machine, is a huge difference in work output required and the resultant heating affect.

Pool and solar panels
 

I'm going to "second guess" about your situation and offer my 2cents worth.

It reads to me that you are about to spend a large pile of money - and may not be happy with the results. Why do you need a pool? Is it for swimming laps? I cannot see it for any other reason. BUT - if it is just for therapy, why not invest in a much cheaper spa? I owned a spa for 14 years before moving here and am now looking for another. Keeping my water at a certain temperature was cheap. Because your purchase is connected to something medical, if a doctor writes you a prescription for a spa, that will eliminate the taxes associated with the purchase. By the way, they build swimming lap type spas, too. Hope I helped you!

I have difficultly with walking and most exercises. My doctors have suggested pool walking.When I have tried it with the local pools, it does helps me to move around better when I'm in water up to my shoulders since the water provide bouncy for me to walk. The main problem is someone has to drive me to the pool and pick me up, I need help with my walker and it is difficult to get in and out of the car. The pools have various schedules and I can't always get there when times are available. Sometime I get there and they are crowded. Walking the pool is basically the only exercise I can do with the lest amount of pain. I like the idea of a spa, but I don't think it would work for walking. I thank you for your suggestion.

I would call around to the spa dealers (we used Spa Kingdom) to see what is available. I have seen some swim spas that have a harness to keep you in place, others are free flowing, there may be similar options for walking exercises. I have also seen treadmills designed for under water use (this was a newscast), so a deeper spa and a treadmill might solve all of your problems.

OOPs other possible option might be a fiberglass pool, should be shorter install.

We use our soft tub during the winter months!! The salt water pool about 10 months a year with solar panels. WE have never regretted this combination!!