The 12kW Air to Water Heat Pump was chosen because we have no depth of earth before hitting rock here in Ratooragh, so the prospect of a major expense drilling a well influenced our decision.
It works like a big air conditioner in reverse, using a heat exchange system to take heat from the air and transfer it into our big Buffer Tank to be used in the under floor heating. We usually have the temperatur of the Heat Pump set at 30 to 35degs C which is usually sufficient. A normal boiler/radiator system has to heat the water to about 75degs C to work properly, so underfloor heating is much more efficient.
The only time there is a problem is when the air temperature stays below +5deg C, and the system becomes less efficient. This is because it gets iced up and spends some time each day de-icing automatically. Fortunately, living so close to the sea, we have a very temperate climate, so very rarely have this problem.
During late 2020 the Heat Pump started to cut out with a High Pressure Error.
Over the months leading up to Christmas this became more frequent. I had this looked at by two engineers, but they coudl find nothing. I even changed the pump, but no good! So having a spare I tried with a friend who knows a lot about this particular pump, but we faied to get it going without showing multiple errors.
In the end I gave up and bought a new pump. It is a Panasonic 9kW Air to Water Heat Pump. The installer also improved the underfloor pumping system in the house, and Bingo!!!! What an improvement! Also during the cold snap at the end of the first week in February when air temperatures were below +4C for a few days the pump kept producing the correct heat, and the house temperature was fine. Magic!
We now have the warmest house we have ever had, and the amount of electricity the new pump uses is about 2/3 less than the old one, saving about €60 a month!
The graph below shows the three months from December 2020 to February 2021. The difference in Energy Use is dramatic. The red is the Heat Pump use. The change is easy to see.