Heat pump heating season runs long into a bad Irish Summer
When out at a heat pump today, a Nibe fighter 1245, I took a look at an interesting menu. This menu allows you to look at a graph of the average indoor temperature for the 52 weeks of the years. This heat pump had its summer mode set at 17 degrees, i.e. when the outdoor temperature was 17 degrees or more on average during a 24 hour period then the heat pump would switch into Summer mode, turns off the circulation pumps and put the 3 port diverting valve into the hot water position and will only do hot water production. You'll see from these photos that the heat pump has been available to do heating for the majority of the year. When the line of the graph turns to grey, then the heat pump will not be doing any heating. Normally you'd like to see the heat pump in Summer mode for 3 months of the year. On average 80% of the heat pump running time will be on heating the building, 20% on hot water. The longer the heat pump is on Summer mode, the greater the savings.