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The Science Behind Heat pumps.

To quote Arthur C. Clarke, “Any sufficiently advanced technology is indistinguishable from magic” And Heat Pumps are essentially just that! MAGIC! An electric heater gives you a 1 to 1 energy in - energy out ratio, but Heat Pumps can give you up to 5 times the energy out than went in! HOW? Let’s have some fun and learn together! Let’s understand how a Heat Pump works by following the journey of the refrigerant step by step. We’ll start at the compressor.

  1. The compressor will have compressed the refrigerant into a high temperature and high-pressure gas. This gas is then sent to the indoor heat exchanger, Moving the heat from the refrigerant to the water that flows through your radiators to heat your home.

  2. As the heat is removed from the gaseous refrigerant, it condenses into a high-pressure liquid, which is sent to the expansion valve,

  3. The expansion valve allows the refrigerant to expand in volume, providing further cooling and allowing the refrigerant to condense further into a liquid.

  4. The liquid refrigerant then heads to the outdoor heat exchanger, blowing the outside air through itself, warming the refrigerant into a low pressure, low temperature vapor.

  5. The refrigerant vapor then heads to the compressor, turning it into a high temperature and high-pressure gas to kickstart the cycle all over again!

A Diagram of the refrigerant cycle

This cycle explains the very basics of the refrigerant cycle but what does that actually mean and how is it “Eco-Friendly”? Well, we are extracting energy from the outside air, which is an ambient, renewable energy source of heat. We may be putting some electrical input into the system but most of the energy is coming from the cool air passing over an even cooler liquid. This works even down to -25C.

The fundamental principle behind Heat Pumps is the phase change of refrigerants. This process involves refrigerants changing between liquid and gas states, which allows them to absorb and release heat effectively.

Heat Pumps don’t just do heating! Heat Pumps can be used for cooling your home too, but this is mainly implemented in warmer countries and not functionality that’s really implemented in the UK, however your home might already have something inside using cooling refrigeration cycles like your fridge or freezer! These follow essentially the same process as described above but in reverse.

In conclusion, Heat Pumps are an efficient, and eco-friendly way to manage indoor heating. By understanding the basic physics behind them, we can get a better appreciation of their role in modern heating and cooling systems. So next time you’re in the depths of winter, just remember, your Heat Pump is working real magic to keep your home comfortable.

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