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3rd March, 2011

A mad ramble from the blog master !!

Heat pumps – The best thing ever invented, or another passing fad that’s over hyped? Well, picture those young Wright brothers when they took to the air with their flying contraption. Most people who had never even seen a car let alone this machine that took you off the ground must have thought that this will never catch on. Now I’m not saying that heat pumps will change our life, as probably air travel did, but things take a while to catch on as they say, and so will heat pump technology. It also sometimes takes a combination of circumstances to drive technology in a certain direction, so let’s take the little island where I live Great Britain as an example. Even 10 years ago there was plentiful cheap gas from the North Sea, throw in some coal and nuclear power - so why bother with this heat pump technology? I can heat my house without breaking the bank anyway.

Now travel forward 10 years in Doctor Who’s tardis and things have become slightly different. Hardly any gas left in the North Sea with most gas supplies coming from some pipeline snaking its way across Russia. Now i'm not saying that our Russian cousins will be unreliable, but as Scotty probably once said “there’s too many things to go wrong here, Captain”. So hence heat pumps enter stage left as the next great thing to save money and give you an affordable way to heat your house.

Like most things when people are trying to sell them, and heat pumps are no exception, you tend to focus on the positives and conveniently forget about any downsides the product may have. Take that time when you’ve bought your new car and tried to replicate the fuel consumption figures. Maybe with a breeze behind you, and you going slightly down hill, and no heavy accelerator foot, you might achieve the figure. It's very much the same for energy efficiency figures for heat pumps.

You will often see that a certain heat pump has a COP of 4, so what does this mean to the man in the street? All he wants to know is – can I heat my house for less using heat pumps or shall I stick to what I already have and know. So what is this magical COP value figure? Energy out versus energy in basically, so this COP value of 4 means for every 1 unit of electrical energy you put in you get out 4 units of heat energy. Marvellous I hear you say, these heat pumps are the best invention ever after all.

Ok, so before we all get carried away about heat pumps and fall asleep this is the slight catch. The energy efficiency is determined by how cold it is outside for an air source heat pump, and the amount of energy that can be absorbed into the system decreases as the outside temperature decreases. As Mr Scott definitely said “you cannot defy the laws physics, Captain”. So to re-cap everyone, yes heat pumps are very good, but don’t expect them to change your life or make you more attractive to the opposite sex.