28 Dec 2010

Heat pumps: yes or no?

The District Council has been investing in heat pumps as part of the solution to tackle climate change, fuel poverty - and managing to sort out energy needs of homes that are not on gas. They have installed a number as part of a pilot scheme and indeed this was a small part of why they were awarded best Council in SW for tackling climate change (see here). However I recently read an Ecologist article suggesting heat pumps release HFC gases and could be increasing climate change gases rather than decreasing - See here.

Photo: home with heat pump taking part in the eco-renovation open homes weekends

Heat pumps use, and emit, hydrofluorocarbon (HFC) gases that are as much as 2,000 times more potent in heating the atmosphere than garden variety carbon dioxide. It is reported that studies have shown these leak and consequently are not all they are cracked up to be.

Well concerned, I emailed the Council officers and have had some initial answers from the company who are providing the pumps. They are somewhat reassuring. They note that the notion that heat pumps "emit hydrofluorocarbon gases" is completely untrue and miss leading. A fully functioning and correctly installed split heat pump system will never emit HFCs . The only time a unit will release these HFC gases into the atmosphere is when there is a leak within the refrigeration circuit. It is mandatory that all systems installed in the UK are done so by engineers qualified in the safe handling of refrigeration (city and guilds 2078). This in general means that they follow strict law as set out by the FGas regulation.

They do note that HFC gasses such as R410a and R407c are harmful to the atmosphere when released into it and they have a large global warming potential. However they note that the law in the UK ensures that these gases will never be released in to the atmosphere when installed to there strict regulations. This company pressure tests a unit for a minimum of 12hrs at twice the working pressure before introducing refrigerant into the system. They also check installed systems.

So what is going on? Well talking to folk it is suspected that there is some element of truth to the claims when you look at installations of equipment on the continent where regulations are a lot more relaxed, but it is not thought this is the case in the UK.

More interesting for me was the news that there is a heat pump available to the UK market that does not use HFCs - it uses CO2 as refrigerant or R744 as it is known in the trade. CO2 is still a natural refrigerant gas and does not fall under FGas law and the same goes for the natural refrigerant ammonia. CO2 is commonly used in air to water heat pumps in Japan where there climate is slightly different they call them "Eco-cutes"! On the downside using CO2 as a refrigerant means very much higher pressures when compared to HFCs. I understand Officers are looking into these alternatives but they appear at first glance to be more expensive.

It goes back to an issue I have raised before on this blog - no-one is geared up to explain any of the heating or renewable heating options in terms of their total lifecycle impact, to individuals who just want to know what to do when their oil boiler dies.

From what I understand I think it is more than reasonable that the Council continues to trial them. For some people they will finally be able to afford to install a heating system that they can control and that indisputably does make use of renewable solar energy.

With all new technologies there is much to learn - this blog for example has criticised the small urban wind turbines and their adoption by some too quickly - see my most recent post on that here.

Anyway I would welcome comments - do others have views on this issue?

1 comment:

Kevin said...

I like this.