The fastest way to heat your pool is to use a gas pool heater and a solar cover. It's like heating up your coffee in the microwave and putting a lid on it. No matter how you plan to heat your pool, you should at least have a solar cover (or liquid solar cover) to help you retain the heat.
Using the heater only when the water dips below a certain point keeps the energy consumption down. For the average person, a pool that is 78 degrees or higher is comfortable. If you are trying to save money or energy, run your heater only when the pool water temperature dips below 78.
The efficiency of the heater? Physicist: The correct answer is always to leave the heater off for as long as possible, as often as possible. The one and only gain from leaving a pool heater on is that it will be warm when you get in. The same is true of all heaters (pool, car, space, whatever).
The typical way in which to heat a residential outdoor swimming pool would be an air source heat pump. Heat pumps work by moving the water into the heat pump via the filtration system.
If you want to get as much time as possible out of your pool, however, a heater is a good investment. With a pool heater, you can easily be swimming May through mid-October, giving you a good five months of use out of your pool. That's literally double the amount of time you'd get without one.
Conclusion. Solar rings not only keep your pool water warm but also reduce the amount of dirt and debris that might end up in your pool. With solar rings, you won't have to worry about any chemicals or electricity to maintain the temperature of your pool.
Set your pool heater's thermostat to a temperature between 78°F and 82°F (26°C and 28°C) to keep the majority of swimmers comfortable. Maybe a little cooler if you're in an area with very hot summers, or a little warmer if you live in a milder climate.
A pool that is uncovered can lose up to 5 degrees F overnight; a good cover can cut that loss by half. Used at night or whenever your pool is not in use, the pool cover can help save fuel costs by cutting heat loss regardless of the type of heating you utilize.
You should never leave your pool heater on overnight. Doing so is not efficient and will cost you more than it would if you just turned the pool heater off. While many of us know that heating a pool can take up to several hours, running it overnight defeats the purpose of heating it at all.
As long as you are willing to wait for the pool to heat, it is cheaper to turn off the heater when you aren't using the pool. BTUs are BTUs. The pool needs a certain amount to heat to a certain temp and will lose a certain amount.
A 100,000 BTU heater uses 1 therm of natural gas per hour, so a 400,000 heater consumes 4 therms an hour. 4 therms an hour x $1.67 = $6.68 per hour. So the magic number based on the most common 400,000 BTU pool/ spa heater is $6.68 per hour in gas cost to run your heater.
You know those black trash bags? They can hold heat too. Fix one up to a hula hoop and if you want, cut one side of a pool noodle to add buoyancy and you've got yourself a super cheap pool heater.
Use a gas heater
Gas pool heaters offer the fastest heating of all the options in this post. And that makes sense because just like a grill or oven, a gas heater creates heat by burning gas. But at the same time, they also have the highest monthly operating cost of all pool heating options.
On average, natural gas burns about 1 therm per 100,000 BTUs per hour (British Thermal Units). Meaning, an average pool heater between 300,000 and 400,000 BTUs will cost anywhere from $3.30 to $4.40 per hour to heat your pool.
Heat transfer efficiency is higher with higher flow rates. However, you have to look at total efficiency and cost. It may be worth the extra heat loss to run the pump at lower speeds.
When pool water evaporates, it carries with it heat and therefore cools the pool water down. So if evaporation is prevented, then there will be much least heat loss. So simply put, covering your pool you will help warm the water up.
While the solar cover does help mainly by preventing loss to evaporation. The blue bubbles do not in fact help heat the water. The top few inches will feel warmer due to the cover getting hot and conducting heat, but you will in fact better heat the bulk of the water without the "solar" cover on.
Water temperatures are slow to heat up, and just as slow to cool down. Water is very "stubborn" to change temperature. It takes 4 times the energy to heat up water than to heat air. Water also "feels" colder because water is a more efficent medium than air to cool our body down.
Day Heat Warms the Water
Sunshine warms the water starting in the later morning until the late afternoon so that by nightfall, the water is at its highest temperature.
Swimming in water that is too warm -- over 90 degrees Fahrenheit -- can lead to overheating and exhaustion -- particularly when you are exerting yourself by swimming several laps or a marathon. Warm water increases your body temperature, which also raises your sweat rate and quickens dehydration.
This result was validated by repeatedly heating 10' x 19' test pools to a maximum of 8 degrees farenheit in 4 days and reached plateau after that. Approximately 67% of the pool was covered with Solar Sun Rings®.
Top positive review
The 10 rings covered about 80% - 90% of the pool and did exactly as they said. They reduced the evaporation substantially and warmed up the pool nicely. Because the temperature here is not super hot they did not make the pool too warm but just comfortable, and certainly better than no cover.
Yes, liquid solar covers actually work and quite well. While they don't attract the sun's heat to your pool water, they help reduce water evaporation at night to keep the heat in your water.