Water Source Heat Pump

Find out how water source heat pumps work and if they are a cost effective solution for you. Water source heat pumps are an efficient technology that moves the heat from the water source to your household. Compared to any other heating systems, they are much more powerful. Water source heat pumps can use any kind of water, for example, a river or small stream.

If the temperature of the water is five to eight degrees Celsius above zero, the results can be outstanding. Water source heat pumps first appeared in the late 1940s after air source heat pumps. Their exchange medium is based on the constant water temperature instead of air temperature. Therefore their efficiency is twice as high as air source heat pumps. On the coldest days, water source heat pumps can reach an efficiency of 300 to 600% while air source heat pumps typically achieve only 175 to 250%.

The Advantages of Water Source Heat Pumps

  • The emission of carbon dioxide from a water source heat pump is lower than of the regular heating devices.
  • They are energy-efficient, therefore, if you replace your existing heating system with the water source heat pump system, you can save £2,325 to £3,690 annually, depending on your current heating system.
  • Water source heat pumps operate using electricity to heat the pumps that circulate the water through the loop. Two to four units of heat are generated from every unit of electricity which makes them an effective and long-lasting heating system.

Working Principle of Water Source Heat Pumps

Water source heat pumps are based on reverse cycle heat pump units which are connected by the water loop. Depending on the zones where they are installed, every unit has specific air comfort requirements. When the weather is cold, the heat is transferred from the water loop through a specifically designed refrigerant heat exchanger and then it is moved to the air.

If the weather conditions are extreme and more heat will be required then the units operate in heating mode. If the loop water doesn’t provide enough heat you will need to install an energy efficient fluid heater in the water loop to help the heating process. If the water source is close to the house, you will be able to reduce the amount of energy required for pumping water. This will help you reduce your energy expenses.

However, the water source can be situated relatively far if the diameter of the pipe is reasonably big. Keep in mind that installing water source heat pumps involves getting planning permission and completing the relevant paperwork before the installation begins. 

Water Source Heat Pumps Types

Closed-Loop System

A closed loop system is the most affordable and efficient option for you if you have an adequate water source near your home. A supply pipe starts in your house, then goes through the ground and ends in the water. Under the ground, a supply pipe is usually placed in circles at least eight feet below the ground to avoid freezing. The water source should meet some requirements when it comes to the volume, temperature, and quality.

Open-Loop System

For this system, you will need access to a well or the surface of a water source. After circulating through the system, the water returns to the ground through this well. This system is beneficial if there is a reasonable amount of clean water available. As with all the systems mentioned here, all the regulations should be followed and necessary paperwork completed.

Hybrid System

In a hybrid system, geothermal sources or a mix of geothermal and air is used. Hybrid systems are more useful in the situation if cooling is required more than heating. A standing column well is a good example of this type of system. It works as an alternative to the open-loop system with one or more vertical wells required.

Water comes from the bottom of the standing column and returns to the top. With the rejected heat, the bleed cycle system will cool the column while heating it during the heat extraction process.

Cost of The Water Source Heat Pumps

Originally, the initial price for water source heat pumps can be relatively high in comparison with other types of heat pumps. The average price for water source heat pumps can go up to £13,000. However, it is a reasonable investment that will pay off in the long run since it will significantly reduce the heating bills and make your house more energy-efficient. They also have low operating expenses which adds to the long term viability.

Last Updated on October 28, 2021


Author: Indra Gupta

Indra is an in-house writer with a love of Newcastle United and all things sustainable.

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