Without a doubt, heat pumps are one of the most budget-friendly ways to warm your swimming pool efficiently. Extending your swim season to its full potential no longer has to come with painful energy bills.
Across the market, you'll find a wide mix of swimming pool heat pumps available. Before selecting one, it's important to confirm the correct size to get the most out of your investment.
In this guide, we'll walk through how pool heat pumps work and compare their varying sizes. With a clear table, we'll help you choose the right heat pump for your pool. We'll also explore the key factors that influence pool heat pump sizing.
Why Choose a Heat Pump for Your Pool?
Going with a heat pump to warm your swimming pool makes sense for several compelling reasons:
Reliable Heating
A pool heat pump delivers steady, dependable, and uniform heat. That means you can enjoy a comfortable water temperature throughout your entire swim season.
Eco-Conscious Choice
Pool heat pumps leave a much smaller carbon footprint than alternative heating systems. They don't burn fossil fuels — instead, they draw renewable energy from the surrounding air, making them an eco-friendlier pick.
Energy Efficient
Heat pumps are incredibly energy-efficient and cost-effective water heating solutions. They require very little electricity to operate, mostly just to move warmth from the outside air into your pool.
Built to Last
With proper maintenance, heat pumps typically last 15 to 20 years or more. That long service life ensures lasting comfort and value from your equipment.
How Pool Heat Pumps Work
A swimming pool heat pump is an energy-smart method for heating pool water. It helps you achieve the temperature you want while trimming up to 75% off heating costs. An air-source pool heat pump works in four main steps:
1. Pulling in Ambient Air
The heat pump captures warmth from the outside air, regardless of the temperature. Think of it as a fan drawing in the surrounding environment.
2. Compressing the Air
The captured air is compressed, raising its temperature. It then passes over an evaporator coil, where it meets the refrigerant in liquid form.
The refrigerant absorbs that heat and evaporates into a gas.
3. Transferring Heat to the Water
The hot refrigerant, now a gas, flows through a heat exchanger. Its job is to hand off the heat to the cooler pool water.
This gradually raises your pool temperature until it reaches the setting you selected.
4. The Cycle Continues
Once the heat is delivered, the refrigerant returns to liquid form via the expansion valve, and the cycle repeats continuously.
As a result, your pool warms up slowly and steadily, delivering a comfortable swimming experience.
On/Off Pool Heat Pumps vs. Inverter Pool Heat Pumps
There are two main types of pool heat pumps operating on different principles. These are on/off heat pumps and inverter heat pumps. Let's compare them briefly.
On/Off Heat Pumps
The fixed output or on/off heat pump runs in either an on or off state.
This means the compressor of this type of heat pump operates at a steady, constant speed. It's often a fixed-frequency model, typically running around 50Hz.
As a result, the compressor needs to cycle on and off several times during operation. It always runs at its maximum capacity. The goal is to reach the target pool temperature at the right moment.
This approach has been common for many years. It has long been regarded as the standard method for regulating pool water temperature.
Inverter Heat Pumps
Inverter heat pumps are a newer technology. They've steadily grown in popularity in recent years, thanks to their strong efficiency.
In this design, the fan and compressor can run at variable speeds. That gives the heat pump the ability to adjust. The unit precisely matches the desired set temperature.
When the pool approaches the ideal temperature, the device reduces its power usage by 25 to 50%.
Inverter pool heat pumps provide several advantages over their on/off counterparts. These include quieter operation, eco-friendlier performance, cost savings, and greater energy efficiency.
Factors That Affect Pool Heat Pump Sizing
Pool heat pump sizing doesn't refer to the unit's physical dimensions. It points to the system's heating output.
You need to weigh several factors when figuring out the size of a pool heat pump for your needs.
Pool Size
The pool's size is the clearest factor shaping the size of the heat pump. The larger the pool, the more power needed to heat it effectively. So, you need a more capable pool heat pump.
Swimming Habits and How Often You Use It
Your swimming routine and usage can also influence the size of heat pump you need. If you plan to run your pool year-round, you'll need a larger-sized unit capable of holding a steady temperature through the colder months.
Climate
You may already know that air-source heat pumps draw heat from the outside environment. If you're in a cooler area, your unit has to work harder to keep up with demand. That's needed to get your water up to the target temperature (around 28°C).
In that situation, a larger pool heat pump is the smarter choice.
Pool Type
Finally, heat pump sizing is also influenced by your pool type. Consider pools like outdoor or indoor ones, or those that are above-ground or in-ground. All these have different heating demands to reach and hold temperature.
How to Calculate Pool Heat Pump Size
The sizing or heating capacity of your pool heat pump is expressed in kilowatts (kW). The higher the heating capacity, the less time it will take to heat the pool. So, it's suited to higher-volume swimming pools.
The chart below serves as a rough reference for calculating pool heat pump sizing. For reference, pool volumes are compared with sizing in colder climates (15°C) and warmer ones (28°C).
| Swimming Pool Volume (m³) | Heat Pump Size in Cold Air | Heat Pump Size in Warm Air |
|---|---|---|
| 20 to 40 | 9kW | 6kW |
| 40 to 60 | 13kW | 9.5kW |
| 60 to 80 | 25kW | 15kW |
| 80 to 100 | 30kW | 18kW |
Source: 1st Direct Pools
Worth noting: larger-sized heat pumps heat pool water more quickly. Once the target temperature is reached, they only need minimal energy to maintain it.
Ready to Heat Your Pool Efficiently?
If you're looking for a powerful, reliable solution to warm a medium to large pool, the Blue Torrent 65,000 BTU heat pump can heat up to 13,000 gallons with ease — keeping your swim season going longer.
Shop Blue Torrent CFT 65Final Thoughts
Choosing to invest in a heat pump for your swimming pool is a smart move. You need to confirm the one you select gives you the expected returns and efficiency. That's why selecting the right pool heat pump size for your pool is so important.
To wrap up, the factors that shape pool heat pump sizing include:
- The size of your pool
- Your swimming routine and usage frequency
- Your local climate
- The type of swimming pool you have