How to turn a lovley old house with solid walls into a warm efficient home



air pump Installation


Having committed to my heat pump and done a deal to save money by installing it myself, I now had to decide where to site the pump, and, in my case, the buffer tank too. The pump need to be outside, free of obstruction and with good airflow around it. Poor airflow might force the ejected cold air to be recirculated, causing inefficiency. It's also advantageous to keep the pump as close to the house as possible to minimise the length of external pipe run. Though the external water pipes will be well insulated, the shorter the better.

I chose my location against a boundary wall. As the air flows into the back of the pump and the fans eject air to the front, I placed it facing away from the prevailing south westerly winds. I figured that a heat pummp facing into a strong headwind might force recirculation in extreme conditions.

I chopped back a section of hedge to give good airflow at the front and set about creating a solid base for the pump. I dug out, laid hardore then created a level concrete base. I then co-opted some friends to help me through with the pump.

groundworks, concrete base, eco The buffer tank has a 650 footprint. It was tight, but I planned to create a cupboard within my utility room to house the tank. I prepared pipework for the heating that would be inaccesible with the tank in place then squeezed the tank in. It fitted nicely. The tank is actually two tanks, one above the other. The lower half of the tank is my DHW tank. It's 200 litres and has within it an indirect heat transfer coil. Ther is more coil than you would find in a traditional tank as it is important for efficiency of the system to maximise heat transfer. The top half of the tank is my central heating buffer tank. This is a direct feed 200 litre tank. Tanks intended for other purposes may have a heat transfer coil wihtin a buffer tank too, but to increase efficiency it is important in this scenario that the tank is direct feed. being a sealed syste, two expansion vessels were required, one for each tank.

air source heat pump, eco, green dealAll I had to do now is work out what pipes to connect to what - there did seem like an awful lot of ports and gubbins.





air source heat pump pipework, eco, green

buffer tank fitting, eco, green, renovationInstallation the pump itself was fairly straight forward. It was mostly drilling holes in walls and connecting up the two pipes - flow and return. I used 25mm flexipipe, which worked well and meant there were no joints to leak. The electrics were supplied from a dedicated MCB within my consumer unit with appropriate isolating switch nearby the pump. The electronics for the pump were also pretty straight forward. All the wires for sensors etc. were coiled up inside the pump casing. It was mostly a case of making holes in the wall and feeding them through to the buffer tank where I also sited the main control panel. All the connectores were already attached so it was pretty much plug and play.

[col class="span4"]This is not intended to be an article on plumbing, so I won't detail every step in the connection of the tank. However, though it looks a bit spaceage the connections, sensors, pump and valves are standard central heating connections. There is a three port valve that is activated to direct the pumps hot water output to the top buffer tank or the lower DHW tank as demanded and controlled by the controller dependant upon the user settings.

buffer tank connection, eco

I built myself a pump house / woodstore to make it look neat. The roof over the pump is open at the back so there is no restriction in airflow - it just looks neater. All in all the installation of the pump was simple. i am lucky that I had a friendly heating engineer to call in if I got confused about pipework and he could also sign off the completed system, which is needed as it is an unvented CH system. The biggest difficulty was, as is often the case with any CH system, purging the air.

The pump would be commissioned and started up by the suppliers to check all was ok.

air source heat pump house, location, green deal


© Christopher Thompson