How to Cool Down Your Swimming Pool Water

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Getting into a nice cold pool on a hot summer day can be the greatest feeling. However, that same hot day can lead to the pool in your water getting uncomfortably warm, and it is not nearly so refreshing when your pool is the right temperature for bathwater. How do you avoid this problem, though?

Pool Water Cooling Techniques

Pool cooling options range from the practical to the extremely impractical and include a wide variety of choices:

  • Reverse heat pumps
  • Water fountains
  • Evaporative coolers
  • Ice
  • Shade
  • Drain and refill

The most common options are the reverse heat pump (also known as a chiller) and the water fountain. The former is much more expensive than the latter, but also more effective. Chillers will produce a 10-15 degree drop in water temperature, while fountains and coolers will be more likely to produce a 5 degree drop (or less). However, water fountains and evaporative coolers should not be underestimated as an option for those on a budget.

Methods that work due to evaporation are more effective if used at night, when the air is cooler. They are also more effective when the air is drier. During periods of high humidity, less evaporation occurs and therefore less cooling. One nice feature of fountains is that they can also double as entertainment, especially for kids.

If you haven’t had your pool installed yet, or if you need to replace the heat pump, consider getting one with a reverse function. This means that the same device provides heating or cooling, depending on the need. These are simple to use and can help keep temperatures in line no matter what the outside temperature. Standalone chillers can also be purchased and installed on pools that already have a heat pump without a chill function.

Ice is a rather impractical option, although it might work if you happened to have a source of literally tons of ice and a way to get it into your pool. Shade is a very practical option, but much more of a long-term solution because trees take time to grow. Some people choose to put a shadecloth over part or all of their pool, though, and this can be done quicker.

Draining and refilling your pool, at least partially, can be effective if the replacement water is cooler. However, it is very wasteful, and unless you use another method along with this one, chances are good that the replacement water will just heat right back up. It is not an option if your area relies on surface water that is already warm when it gets to you, though.

Factors to Consider

Of the common methods of cooling swimming pools, each can be described in terms of these essential characteristics:

  • Cost
  • Efficacy
  • Practicality

For example, adding ice to your pool is probably neither practical nor inexpensive. It may be effective, but that doesn’t matter much if you can’t afford it and can’t figure out how to get the 2,000 pounds of ice you had delivered actually in to the pool. (For reference, you would need about 2,187.5 pounds of ice to cool a 10,000 gallon swimming pool by five degrees)

How to Choose

Consider the long-term benefits/drawbacks as well as the short-term effects when choosing a method of cooling your pool. If you won’t be living in the same place next year, you might not want to invest in expensive equipment. Energy costs should also be taken into consideration, because anything that requires electricity to run is going to cost you money whenever you use it, not just upfront.

Personal preference also plays a role. A chiller might be more effective than a water fountain, but maybe your kids have been after you to add a water feature for years. A fun fountain might be able to cool the water just enough while providing hours of enjoyment. Shade has the added benefit of reducing human exposure to UV rays while simultaneously preventing the sun from heating up the pool.