Following the fitting of the Air Source Heat Pump an new EPC assessment was carried out for the Fernery and the highest category of efficiency - A - has now been awarded. This means that the carbon footprint of the property is very low - we just need a few million other houses in the UK to follow suit so that we can achieve the target of  the UK being carbon neutral by 2050!

Just as we were about to reopen the Fernery after an extensive refurbishment our plumber told us that he could not give us a new gas safety certificate for a year as there was a lot of corrosion in the only 10 year old gas boiler. It was time to do our bit towards making the UK carbon neutral - we opted to fit an Air Source Heat Pump. Basically they are like a fridge in reverse but instead of using electricity to make the water inside them cooler they make the water warmer. They are green in that they can use electricity sourced from renewable sources as opposed to burning 'fossil fuel' gas which is non renewable and releases CO2. There are however a few downsides to an ASHP - they do not heat up water as quickly or to such high temperatures as a gas boiler, they are more expensive (initially - more on this in a second) and they weigh a lot - the one we fitted is 124Kg  - hence the crane in the picture! The ASHP needs to be located externally to the house and the gas boiler was on the 1st floor - this means we have 124Kg of ASHP hanging off a very strong metal frame about 12ft above the ground.

However there are answers to all of these potential issues:

• The concrete and polystyrene walls of the Fernery are very good at retaining heat - and the underfloor heating is very efficient at distributing heat - so we are already a good match for ASHP. See the picture below which shows a cross section of the wall where the old gas flue used to be?
• Our water heating is solar assisted and we already have a very big and well insulated hot water tank with an integrated heat exchanger. On a sunny day we have just as hot water as the gas boiler would have produced and on a cloudy day we can just adjust the shower mixers to use more hot and less cold water.
• Until March 2022 people installing renewable energy heating can take advantage of the governments RHI scheme (Renewable Heating Incentive). Basically we will be paid to use renewable energy and in 6-7 years time we will have covered the complete cost of the ASHP and its installation - including the crane!