Heat pump - domestic hot water

Cilar

Hello, looking for some tips on minimizing running cost with a heat pump during summer when heat pump only heats hot water cylinder.

My initial thinking was to put it on timer so that it only heats the hot water cylinder once a day in the warmest period of the day (afternoon from 3 to 6).

Is it a worth it or just a waste of time? Any other tips.

Thanks.

Cilar

Cilar wrote: »

Hello, looking for some tips on minimizing running cost with a heat pump during summer when heat pump only heats hot water cylinder.

My initial thinking was to put it on timer so that it only heats the hot water cylinder once a day in the warmest period of the day (afternoon from 3 to 6).

Is it a worth it or just a waste of time? Any other tips.

Thanks.

You can buy heat pumps already incorporated in a cylinder which is designed to work as a stand alone appliance.

John.G

Cilar wrote: »

Hello, looking for some tips on minimizing running cost with a heat pump during summer when heat pump only heats hot water cylinder.

My initial thinking was to put it on timer so that it only heats the hot water cylinder once a day in the warmest period of the day (afternoon from 3 to 6).

Is it a worth it or just a waste of time? Any other tips.

Thanks.

It should, for every degree C that the evaporation temperature rises, the HP efficiency should rise by around 2% so if there is a difference in the air temperature day/night of say 7C then the HP efficiency may rise by approx 14%. The temperature of the hot water produced has the biggest effect on the heat pump efficiency (COP), some systems, as far as I know, just boost the hot water temperature to 60C once per day (or week??) and maintain it around 40c most of the time. I dont know if your system carries this out automatically or not. The difference in efficiency, at 40C vs 60C, could be somewhere in the region of 40%.

Cilar

It's a Samsung Gen 5 heat pump, from Joule.

In my case, the system is configured to boost to 60C once per week (anti legionellosis), it keeps hot water to 48C otherwise, although I noticed that there is no heating at all until there is at least 5C difference between the target (48C) and current temperature (so DHW heating only started when temperature reach 43C).

I tried to set up the timer to get DHW heating only between 3 and 5.30 every day in afternoon, but noticed that the booster (immersion) got started instead. I suspect there are other parameters on why the system was picking booster vs heat pump in that case, but I am missing some of the details still as the system is quite complicated and the documentation very sparse. I suspect that the temperature difference between target and current was likely too large, and system decided to use booster instead of heat pump instead?

John.G

Cilar wrote: »

It's a Samsung Gen 5 heat pump, from Joule.

In my case, the system is configured to boost to 60C once per week (anti legionellosis), it keeps hot water to 48C otherwise, although I noticed that there is no heating at all until there is at least 5C difference between the target (48C) and current temperature (so DHW heating only started when temperature reach 43C).

I tried to set up the timer to get DHW heating only between 3 and 5.30 every day in afternoon, but noticed that the booster (immersion) got started instead. I suspect there are other parameters on why the system was picking booster vs heat pump in that case, but I am missing some of the details still as the system is quite complicated and the documentation very sparse. I suspect that the temperature difference between target and current was likely too large, and system decided to use booster instead of heat pump instead?

Just have a look through these as there is plenty of info on them, you might also post the exact model(s) you have.
https://www.joule.ie/wp-content/uploads/2015/10/Samsung-Heat-Pump-Gen-5-Manual.pdf