CO2 Heat Pumps //
What Are CO2 Heat Pumps
Heat pumps move thermal energy in the opposite direction of spontaneous heat transfer, by absorbing heat from a cold space and releasing it to a warmer one. A heat pump uses external power to accomplish the work of transferring energy from the heat source to the heat sink. The most common design of a heat pump involves four main components – a condenser, an expansion valve, an evaporator and a compressor. The heat transfer medium circulated through these components is called refrigerant.
While air conditioners and freezers are familiar examples of heat pumps, the term “heat pump” is more general and applies to many heating, ventilating, and air conditioning (HVAC) devices used for space heating or space cooling. Heat pumps usually can be used either in heating mode or cooling mode, as required by the user. When a heat pump is used for heating, it employs the same basic refrigeration-type cycle used by an air conditioner or a refrigerator, but in the opposite direction – releasing heat into the conditioned space rather than the surrounding environment. In this use, heat pumps generally draw heat from the cooler external air or from the ground. Heat pumps can also be used in district heating and are a main element of cold district heating systems.
Why Invest in a CO2 Heat Pump
When discussing heat pump efficiencies, the following terms are commonly used: coefficient of performance (COP), seasonal coefficient of performance (SCOP) and seasonal performance factor (SPF). The higher the number, the more efficient a heat pump is, the less energy it consumes, and the more cost-effective it is to operate.
Heat pump technology is well established and works well at all scales. Unfortunately the traditional refrigerant fluids used have very high GWP (global warming potential; a multiple of the impact of CO2, with many being over 600). Regulators have already outlawed the use of the really bad refrigerants and are closing the door on the others, leaving a few low GWP and “natural” refrigerants.
Clade are the UK leaders in the natural refrigerant CO2 with the lowest GWP possible of 1. CO2 is also the easiest to maintain and is comparable in cost to R32 but without the flammability or toxic nature.
What’s the difference between CO2 heat pump and atmospheric CO2?
It is easy for confusion to arise, after all how can a CO2 heat pump help reduce CO2 emissions?
Combustion appliances like boilers and fossil fuel engines continuously produce CO2 as a by product of their operation, this CO2 is released into the atmosphere via the flue or exhaust.
By contrast CO2 heat pumps use Carbon Dioxide as the working fluid, the CO2 is contained permanently within the appliance. It is the thermodynamic properties of the expansion and compression of CO2 that enables a heat pump to work.
The CO2 that Clade use is captured as a by-product of other industrial processes. Unlike other natural refrigerants such as; propane which is component of natural gas, or ammonia which is made in a high carbon process.
Other types of heat pump use different working fluids, typically HFCs or HFOs which contribute more to global warming. This contribution is measured using GWP “global warming potential”, CO2 has the lowest possible score of 1.
Using CO2 heat pumps will result in an improvement in carbon reduction both directly in the heat output and indirectly through the production, service and disposal of the working fluid.
Other advantages of CO2 heat pumps include higher operating temperatures which more closely match existing heating systems and enable greater value in heat recovery. This can reduce the cost of the installation and operation of your facility.
CO2 is non toxic and inert which makes the burden of managing the risks lower than other working fluids.