Backyard swimming pools are among the best things a person can have at home! Cooling off after a hard day at work, splashing with the kids, pool parties, and of course, staying fit. To actually enjoy all these activities, the temperature must be right.
Having to wait for the pool water to heat up isn’t fun. Then again, overusing the heat pump doesn’t sound quite right. This dilemma is more common than you think, and we often hear the question “should I leave my pool heat pump ON all the time?”.
The answer to that is: it depends!
How Long Does It Take a Heat Pump to Warm Your Pool
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This depends on various factors:
- The size of the pool
- The capacity of the heat pump
- The current season and average temperature
- Daytime or nighttime heating
- Wind speed
- Whether or not you have a pool cover
- The target temperature of the pool water
Most people prefer pool temperatures between 78ºF to 82ºF. Professional athletes often go with the lower end of the range, while young children and elderly people are more comfortable with the higher end.
Ultimately, it’s a personal preference. But the warmer you want the pool water to be, the longer the heat pump would need to work. On average, a heat pump takes 10-72 hours to reach the desired temperature.
In the summertime, and assuming that you use a solar pool cover, the time needed to warm up a medium-sized pool to around 80ºF would be about 5 hours. In winter, it could take two and half days to bring the pool to a similar temperature.
The Mechanical Side of Things
Pool heat pumps are a lot like air conditioners, but they achieve the opposite goal. Some people think that they actively heat up the water in a manner similar to gas heaters, but that’s not accurate at all.
They contain freon gas inside a series of solenoids, compressors, and pumps. The hot ambient air is used to energize the freon into a gas state, then it’s compressed further into a hotter gas. The heat generated in the process is transmitted to the pool water by conduction. And the gas returns to its liquid state.
This process is repeated as many times as needed to elevate the temperature of the pool water. Clearly, it’s highly dependent on the ambient temperature, as well as the capacity of the pump.
Overusing the pump translates to extra running costs of replacing parts or fixing malfunctions. That’s why we try to operate it only as needed.
The Financial Side of Things
The initial cost of buying a heat pump is probably a bit more than getting a gas pool heater. However, according to the US Department of Energy, the running costs and long-term expenses are significantly less.
The energy needed to heat up a pool depends on various factors, like the size of the pool, the capacity of the pump, time of the year, current temperatures, and many other factors. To demonstrate, let’s check out the energy consumption bills of a medium-sized pool in a few states.
In Miami, heating up the pool to 78ºF costs around $1000 per year. Raising the target temperature to 82ºF raises the costs to $1845. It’s worth noting that if a pool cover is used, the figures become $215 and $410 respectively.
In the warm State of Phoenix, the 78ºF setting costs around $680 per year, while the warmer selection of 82ºF hikes the costs to $1090. A covered pool lowers the range nicely to $45 and $125.
These are only average figures, as each pool would have its own utilization parameters.
The Energy Efficiency Truths and Myths
For quite a while, we’ve heard a theory that it’s more energy efficient to keep a heat pump ON at all times.
The reasoning for that was that it’s easier for the pump to maintain the same water temperature than to bring up cold water to the desired temperature. This is a myth since the power used in both cases is the same.
There’s also another factor that should be taken into consideration, which is the longevity of the mechanical pieces and the need for periodic maintenance. Heat pumps contain plenty of moving parts, and all of them have specific lifespans that they shouldn’t exceed.
If a heat pump stays ON all the time, these parts will need replacement quite frequently. The cost of maintenance and repairs if the pump is kept on obviously increases.
Should I Leave the Pool Heat Pump on All the Time
The optimal usage of a pool heat pump is that which matches the actual utilization of the pool. For example, a family that only uses the pool on weekends would be wasting energy and cash by keeping the pump ON at all times. In the summertime, switching it on a few hours before usage would be sufficient.
A family that uses the pool in the afternoons only, would be advised to turn the heat pump by morning, then switch it OFF at night. As for another swimmer who takes daily dips at dawn, then he should leave it ON all night, to find the water toasty at the 5 am splash.
There’s one last scenario which is a combination of all of the above. Some families are serious merfolks, and it seems like someone is always having a swim day or night, summer or winter. These high-octane people should definitely leave the pool heat pump ON at all times!
We all like to use our resources efficiently. That’s why the question of consistent heating compared to on-demand heating always pops up. We’re actually glad to answer it, since the energy efficiency myth of preferring consistent heating has dominated for quite a while.
The operating time of the pool heat pump depends entirely on how often the pool is used. Matching the actual utilization is key to saving energy and cash.
The seasons are a crucial factor as well. In winter, the difference between the current and desired temperatures could mandate leaving the heat pump ON at all times. That is, if you want to have the pool constantly ready for use. Otherwise, the on-demand rules apply.