There really should be no reason for any commercial building with any dx air conditioning to have boilers providing hot water during summer time.
Retro fit desuperheater to comp discharge to supply free hot water.
At least Mitsubishi electric are doing heat pump boilers which can be fitted like any other indoor unit to the R2 City Multi heat recovery system. If the system is in cooling only mode then you get free hot water. If the system is heating then you still get hot water from outside air heat pump cycle.
There are 1000's of City Multi systems installed in the uk over the last 16 years.
So why not retro fit to all of them & scrap the boilers ???

Think of all the buildings you work in & all the computer room cooling dx systems throwing vast quanties of heat away 24/7 !!!

I was on a site the other day,,, massive office block about 100 City Multi indoor units, about 20 cooling only outdoor units. Boilers & perimiter radiator heating system. January & out side ambient less than 5 deg C.Been installed obout 8 years.

You know what is going to follow dont you.

Heating system on, radiators red hot, City Multi systems running like the clappers to cool offices which were being heated by the radiators.

Customer admitted this was a waist of energy & have submitted proposals to upgrade to energy efficent system but no funds available for this financial year.

On the domestic front we should see the CO2 heat pump water heaters coming to europe soon which should be interesting, but it would be good to get some feed back form the japanese service engineers who have been doing maintenance on these things for the last 6 or 7 years.