Solar Pool Heater Aerial View

Windy Weather Cools Swimming Pools

In Education Leave a Comment

Solar pool heaters on many homes in Cape Coral, FL

This is the time of year that we start getting lots of calls about cold pools. That’s no surprise since windy weather cools swimming pools!

Wind blowing across the surface of a pool is like blowing on a hot bowl of soup. Even though we are experiencing daytime high temperatures in the mid-80’s in Southwest Florida, wind sucks heat out of pools. Windy nights are even worse. Cool nighttime temperatures in the 60’s combined with breezy weather will quickly draw out heat stored during the daytime.

The average unheated swimming pool in Southwest Florida today, November 2, 2016, is 76ºF. That’s wonderful by national standards, but often cooler than Southwest Florida residents and guests prefer. That partially because perceived temperatures are relative, so 85ºF daytime temperatures make 75ºF pools feel relatively cold. Wind doesn’t help. Getting out of a pool dripping wet feels cold in wind due to fast evaporation of water on the skin.

Wind Affects All Pool Heaters

It’s important to note that this applies to heated pools, too! Remember, you are always fighting against the weather when attempting to heat your pool with any source. Many people are surprised to find that a pool they heated to 85ºF with a heat pump or gas heater during the day is in the upper 70’s the next morning! So all of that money spent to heat the pool evaporates overnight – a sad realization.

The same phenomenon applies to solar heated pools, of course. The sun doesn’t shine at night, and the pool itself is the only “battery” in a solar pool heating system. The pool is where the energy (heat) is stored. Throughout the day a solar pool heater will return the pool to comfortable swimming temperatures (for free), but windy weather during the day or night is the enemy of optimal heat retention.

Heating a Pool in Windy Weather

Wind is a normal feature of late fall and winter weather in Southwest Florida. So what strategies can you use to heat your pool more effectively during windy weather?

  • Use a pool cover. Covering your pool reduces evaporation and protects your pool’s surface from the wind. This is the single most effective way to retain heat in your pool generated from any pool heating source. You will start each day with a warmer pool. You will obtain higher ultimate temperatures with solar pool heaters and reduce heating costs with electric or gas heaters. We realize that this is not a desirable or realistic option for most, so read on for other options.
  • Protect your pool surface from wind with landscaping or other physical barriers to wind. Even a screened enclosure will somewhat reduce the cooling effect of wind compared to an unscreened pool. If you are building a new pool, consider its location relative to the home and how you can reduce wind effects.
  • Consider a heating hybrid system by combining solar panels with gas or electric auxiliary heat. While more expensive, you get the best features of each heat source, increasing heating reliability while reducing overall operating costs. Unfortunately, this does not eliminate the phenomenon of cooler morning temperatures unless you run your pool pump and traditional heater at night, which is terribly inefficient and costly.
  • Change your swimming habits. Plan to swim in the afternoon when your pool heater has had time to recoup heat lost overnight. You will enjoy your pool more and reduce heating costs. Note that electric heaters work far more efficiently during warm weather. Gas heaters are technically equally efficient in any weather at any time of day, but heating too far in advance of swimming may be counterproductive and unnecessary, wasting costly fuel. Solar heaters obviously only work during the day when the sun is out.
  • Oversize your pool heater. While adding more solar panels will have a marginal impact on the ultimate temperature achievable, oversizing a solar pool heater will help recover lost heat quicker, allowing enjoyable swimming earlier in the day. Oversizing a gas heater will also heat your pool faster, but will burn more fuel proportionally. Oversizing a heat pump will heat your pool faster, too, but larger heat pumps are less efficient and increase heating costs.

Realistic Expectations

We want it all, and we should have it. Southwest Florida is one of the best places to enjoy swimming pools, and the percentage of homes with pools is among the highest in the nation.

There is no silver bullet, but making some smart decisions and being realistic will greatly improve your swimming enjoyment. The fact is that even unheated pools in Southwest Florida can be used comfortably more days of the year than just about anywhere. While 72ºF might be considered acceptable swimming temperature in Ohio, New Jersey, or Minnesota*, we find that people often demand pools in the 85ºF – 90ºF range here.

Realistic? Sure, but you can’t expect it every day of the year without astronomical cost. If you temper your expectations to swim mostly when the weather is ideal you will drastically cut your pool heating costs and ultimately enjoy your pool more. If you expect to swim in an 90ºF pool day or night in any weather, expect to pay dearly for it. Better yet, consider an above-ground spa to use when the weather gets really rough.

This time of the year is tough for any pool heating professional. We are faced with people wanting it all, and not realizing that windy weather is one of the toughest pool heating challenges. Paying for electricity or gas is throwing money at the problem. Solar heating works great as long as expectations are set realistically.

*Okay, let’s be serious… A 60ºF pool in Minnesota is bath water! 🙂 Haha, I can say that having come from Winnipeg.

“Close The Door!”

Heating your pool with an electric heat pump is like running the air conditioner with the door open. Kids in Florida know the common scream coming from parents and grandparents – “close the door!” (sometimes with an expletive inserted). If it’s windy out we all know how quickly all of the cool air inside a home can be sucked out.

If you think about it, it’s really quite crazy to heat a swimming pool with electricity or gas. You’re effectively running the A/C with the doors wide open.

Heating a pool with solar panels doesn’t cost anything other than the initial price of the system. While wind works against any kind of pool heating, at least your hard earned money isn’t evaporating (quite literally) when running your solar pool heater. That’s why it’s so incredibly popular here in Southwest Florida. You get to enjoy temperatures warmer than an unheated pool every day of the year.

If you are ready to take the plunge into your pool this season, let’s shoot the breeze! Contact us today for your free consultation.

Leave a Comment