We hear from many pool owners that while they really enjoy the experience of a warm pool, the cost of heating a pool can be significant even with a highly efficient system like a Heat Pump Pool Heater (HPPH). So they ask us, “How can I lower the cost of heating my swimming pool?”
There are six methods I can think of that will help. Some may not work for you but each of them on their own will save you heating costs.
I review them in no particular order of savings as each pool environment is different and while the value of each is universal they are not all universally applicable to a particular pool.
1) Solar as the primary heat source. Solar heating is essentially free (there are some small increases in water pumping cost to move the water through the large solar panels, but it is minimal)
The downside of solar is that it rarely meets the needs for a full season of heating demand or it fails, due to the nature of its design, to provide heat fast enough or when the sun isn’t shining due to time of day or cloud cover. But when solar is available and you have the budget to purchase a solar system with a Heat Pump Pool Heater backup, you can have the best, most economical system available.
2) If you have a Heat Pump Pool Heater (HPPH) system only, the time of day that you run your HPPH is a system operation parameter you should address. HPPH’s get their heat from the air. So, logically, the best time to run a HPPH is when the air temperature is at its warmest.
This is most easily accommodated by setting the controls for your filtration system to operate during the warmest time of the day. The Heat Pump Pool Heater (HPPH) will only operate when it has water flow, most commonly supplied by the filtration system. So, the HPPH will run when your filtration system runs. As long as your filtration is running at the warmest time of the day, your HPPH will operate at its optimum Coefficiency of Performance (COP). COP is the measure of energy output divided by energy input.
3) And speaking of COP…the COP is the efficiency rating of the HPPH. As mentioned in item 2, this measure of efficiency changes as the air temperature changes. The unit is more efficient the warmer the air temperature. Another aspect of COP to consider the overall COP rating as applied to the individual model of HPPH you purchase. Not all HPPHs are created equal. If we do a comparison of HPPHs and assume all have the same heating capacity, or BTUh, you will find a variety of COP ratings available on the market. The higher the COP rating, the more efficient the HPPH will be. The percentage difference between one COP rating and another will equate to the percentage savings available between the lower and higher rated COP heater. So what does this mean for you? It means you should buy the highest COP-rated unit your budget allows while making sure the model you select has the capacity, or BTUh, to meet your heating demand. Your Pool Professional or the Factory Customer Service department can help you with this decision process.
4) Controlling evaporation. Heat loss on any pool, heated by any means, is primarily driven by evaporation from the surface of the pool. Upwards of 75% of heat loss is through this method. So controlling that evaporative loss is key to reducing heating cost. There are several methods of achieving these savings.
One method is to use a solid pool blanket. There are two types commonly available. The first is also considered a “safety” blanket as well as a heat retention device. It is typified by its automated deployment through a series of tracks and a motor to roll the heavy duty vinyl blanket out over the surface of the pool. These are somewhat expensive yet highly valuable devices. They completely cover the surface of the pool and by their design and construction will bear the weight of a child who inadvertently enters the pool area thus supplying a very safe environment for children. The added value of the safety feature is that they also contain evaporation to a near zero rate. Excellent for both safety and efficiency.
Another type of blanket, far less expensive, but with no safety value, is what is called a floating blanket. This blanket is simply a thin vinyl sheet manufactured with tiny air bubbles…think bubble wrap on a large scale. This blanket does an excellent job of heat retention through the prevention of evaporation. However, they are not safety blankets and actually carry a safety risk should a child enter the pool area with a floating blanket in place. The blanket can become an entrapment hazard due to its free floating nature and the tendency to wrap around an individual who ventures onto it.
Many who have considered or used both of the above described blankets consider them to be unsightly and more difficult or expensive to utilize
The last type of blanket available on the market is the Liquid blanket. While this blanket poses no safety risks, is easy to use, and is inexpensive, it also carries the lowest level of effectiveness. The Liquid blanket is applied by simply pouring the Liquid blanket into the pool at a specified rate per square feet surface area of the pool. Simple, easy, and inexpensive. It is non-toxic and will not have a negative effect on the pool filtration system. It works by creating a molecule thick layer on the surface of the water thus slowing down the rate of evaporation. The Liquid blanket’s performance is affected by wind speed at the surface of the pool as well as water features that break the surface of the pool creating pool surface agitation. While it is the least effective of the three types of blankets, it is far better than doing nothing.
5) Speaking of wind…wind at the surface of the pool creates ripples or small waves on the surface of the pool. Heat loss through evaporation is a function of water temperature, air temperature, humidity, and surface area of the pool. A flat, tranquil pool will have a water surface area equal to the physical dimensions of the pool. Ripples and waves on the pool actually increase the surface area of the water and accelerate the losses from evaporation. So, creating a pool environment that is shielded from wind will be a great help in reducing heating cost.
6) The last item to address is the pool temperature set point. The warmer you heat your pool water, the more it will cost to keep it warm. Each degree rise in temperature can equate to an approximate 15-18% increase in operation cost. So, while an 88°F pool is nice and toasty warm, it will cost a lot more to maintain than a pool that is held at 85°F. Everybody has their own “thermostat” and comfort level when it comes to temperature. Husbands and wives can surely attest to that when it comes to the room temperature in the house. It’s no different with water temperature in a pool. Warmer is nice but costs more. Simple thermodynamics and economic math.
There is nothing better than a warm pool. These are some tried and true ways to help keep that cost to a minimum. I hope these ideas have been helpful to you.
If you have any questions or inquiries about a swimming pool heat pump unit, please call our Customer Service at 800.878.0998. We are here to help!