2) Has anyone direct experience of air to water heatpumps? Is the system working well for you, are the running costs excessive?
3) How has the system performed during the recent cold snap?
4) If you were installing a heating system again, what (if anything) would you change?
I want to built a well insulated, airtight structure that is efficient to heat. So far Energy Master have been good to deal with. Any help greatly appreciated.
Q. 1,2 & 3:
I have an air-to-water heating system in the house which I moved into last summer. Following numerous teething problems, the unit heats the house fine downstairs, where there is underfloor heating. There are oversized rads upstairs (to compensate for the fact that such a system operates at a lower water temperature), which don't work terribly well to be honest.
It has to be said that, so far, the ESB costs are very high (about €500 every 2 months in the coldest weather). I have been trying to bring this down by adjusting the settings in conjunction with the installers, but not much luck so far to be honest.
Again in conjunction with the installers, I have concluded that the system needs to be supplemented with an oil boiler for the rads upstairs. This will have the effect of freeing up capacity on the system, thus taking the strain off it and hopefully reducing running costs. Also, it will heat the upstairs rads to a higher temp.
4) If you were installing a heating system again, what (if anything) would you change?
I would put in a backup system (e.g. oil boiler, stove with back boiler).
Ensure house is insulated fully and properly (this was an issue for me).
Ensure no rads are on the system.
In summary, when the system works as it should, it is great - very comfortable heat and tons of hot water all the time. But is is definitely (so far anyway for me) more expensive to run than I thought it would be.