Heat pumps are the most energy efficient HVAC (heating, ventilating and air conditioning) system on today's market and are becoming an increasingly popular way to provide heating and domestic hot water for new properties and renovations throughout the UK.
Rayotec can design, supply and install heat pumps to help reduce energy bills and in turn make a positive contribution to the environment. Let us tell you how it works...
What is a heat pump?
Heat pumps work by using solar energy that is stored in the earth, air and water around us. Through the process of refrigeration a heat pump uses the low temperature energy received from the heat source to provide domestic hot water and heating to our homes. Common examples of heat pumps found in the home are refrigerators, freezers, water chillers and air conditioning units.
There are 3 different types of heat pumps on the market, these include:
1 - What is air to water heap pump?
The air/water heat pump is an ideal solution when it is difficult to install a bore hole system due to cost/ type of land or if land space for the use of a loop system is limited. The air/water heat pumps have been designed to convert the energy of the outside air into heat for underfloor heating and domestic hot water requirements.
Even though these systems can not cover all the heating requirements throughout the year, it still offers great economic benefits. The air/water heat pumps provide the majority of the domestic hot water and underfloor heating requirements, only needing a back up system for peak cold periods.
Heat pumps can produce up to 3.5kW of energy for every 1kW of energy put in, making them ideal for today's rocketing fuel prices.
2 - What is heat recovery based on exhaust air heat pump?
A home that does not take advantage of heat recovery, is a home without the use of a proper ventilation system - solely relying upon windows and other uncontrollable domestic forms to create the necessary ventilation. This means that the energy from the inside air is not used and being wasted. The ventilation heat requirement however does account for 40-50% of the total heat requirement of a home!
Controlled domestic ventilation with heat recovery reuses the energy from the exhaust air. In addition to this, heat is also utilised through heat recovery internally from lighting, people and domestic appliances.
The exhaust air heat pumps facilitate heat recovery and supply domestic hot water and heating from the energy recovered from exhaust air. The COP can be as high as 2.8 with a exhaust heat recovery system and creates a healthy comfortable environment within a home
Function
- A. Fresh outside air is supplied to the house through cleanable outside vent holes.
- B. The air overflow occurs under the door or through the overflow vent holes.
- C. The warm inside air (exhaust air) is drawn into the ventilation system.
- D. Warm exhaust air is supplied to the heat pump for heat recovery.
- E. The heat pump provides the house with domestic hot water and/or hot water for the radiators.
- F. When the exhaust air has passed through the heat pump the discharge air is released into the open air. Before this, the heat pump has extracted so much energy from the exhaust air that the temperature of the discharge air is only about 0°C (depending on the system).
- G. Extractor hood.
3 - What are geothermal heat pumps?
Geothermal heat pumps take energy from the earth (land or large water source) and use it to heat and supply domestic hot water to a building. It relies on the fact that the earth's temperature is fairly constant throughout the year (12°C) below the frost line.
Unlike a traditional boiler, a geothermal heat pump does not create heat, rather it uses a small amount of energy (electricity) to transport heat from the heat source (earth) to the heat sink (building). The environmentally friendly anti freeze/water mixture runs through the plastic pipes in the earth picking up low grade heat. The heat pump uses a condenser, expansion vessel, evaporator and compressor vessel to extract the low grade heat from the water/anti freeze mix and turns it into high grade heat for the house heating system and domestic hot water. The heat pump can produce enough heat so that a boiler is not required! The process can also be reversed to provide cooling in the summer.
The most common types of closed loop geothermal systems are the horizontal loop, bore hole and Pond loop, these are explained as the following:
Horizontal loop
A horizontal closed loop system is popular for projects where land availability is large enough to allow for trenching. A trench is dug to a depth of approximately 1m being just under the frost line. Horizontal closed loops are popular due to their ease of installation and lack of drilling required.
Pond loop
The closed loop pond system is an economic substitute when a source of water is near to the property as a result of eliminating excavation costs. The environmentally friendly antifreeze/water mix is pumped through coils of the heat collector pipe which is installed at the bottom of a large pond, lake or well.
Vertical bore hole
In a vertical bore hole, a loop is installed 60-150m vertically into the earth. The advantage of this system is that it does not require a great area of land, but unfortunately drilling can be expensive and the exact price is often unknown until the drillers are on site.
