Condensation is only a problem if the water is cooled to below the dew point. As dew point varies it is important to monitor it and adjust the heat pump leaving temperature accordingly.
The down side of using warmer (less cool) water is that its cooling potential is reduced.
I have come to the conclusion that I am paranoid about global warming. My latest concern is that vegetation providing shading to the house is recommended as a way of reducing overheating. At the same time we are gaining a wildfire season and recommended precautions if there is chance of wildfires in your area is to ensure that there is a firebreak around your home. These two sets of advice are mutually exclusive.
I don’t suppose anyone else shares my worry?
Where have you got with this @Paul_Hadfield?
Further investigation reveals that all my contacts that have both A/C and A2W had the air con first. Then they had varying success in persuading installers that the A/C area did not need any/as much heating. One of them has a radiator on a frost stat and tops up the heat with the A/C when the room is needed.
We have a lot of vegetation, but my concern is subsidence.
I live in an area known as Clay Hill, so subsidence and slippage are both options in a changing climate. Fortunately there are no big trees close to the house but there are a few smaller ones.
The original house has about 18” foundations. The planning department insisted on 1m foundations for our extension. Any movement would rip the house apart at the join. Maybe we should have underpinned the older parts to the same depth, but that would leave the other half of the semi. Very tricky.
I’ve asked Daikin whether their air-to-water heat pumps with cooling rule them out for the BUS grant and will report back when I hear from them. Meanwhile, Trystan Lea of Open Energy Monitor posts on LinkedIn that “There are 31 air to water heat pump systems contributing data to HeatpumpMonitor that have been used for cooling over the last month”: LinkedIn
Your question about wildfire risk from vegetation around buildings would probably be worth addressing to the people at the Journal of Biophilic Design. Here’s an email just landed from FutureBuild, with input from said journal’s editor, heavily promoting such vegetation. I seem to think that the PassiveHouse and/or AECB standards frown upon architects relying on designing-in vegetation to achieve a comfortable building, on the basis that an occupier can remove it willy-nilly. (Then again, an occupier, or her/is builder, can knock large holes in the walls of a PassiveHouse, but I suppose that is not the architect’s problem.) But for individual householders, if the wildfire risk is low, as is probably the case in most built-up areas where they are away from forests, vegetation would seem to be a useful, low-cost comfort enhancer if subsidence risk can also be minimised.
I hope there are no insurers reading this. They object to trees within 7m of the house (presumably because of subsidence/heave worries), which is already quite a constraint on shade trees. I wouldn’t want to add tree fires to their worries.
Anyway, to address your point: the typical approach is to plant deciduous trees so as to get summer shade without excessively reducing winter solar gain. Here’s some Canadian advice:
“As a general rule, trees with leaves (deciduous) don’t burn nearly as fast or as intense as trees with needles (coniferous)… Deciduous stands often act as natural fuel breaks.”
Their “small exception” to this advice is that: “Deciduous trees can be extremely flammable in the early spring just before their new leaves emerge.”
My conclusion is that planting deciduous shade trees in UK urban environments presents a low fire risk. Easy enough to chop them down if the facts change.