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High air source heat pump running costs – Vaillant AroTherm Plus
I expect the heatexchanger box will already be insulated inside. If it's easy to open, take a look and pics are always good! I'm suggesting insulation around the pipes and manual valve below it.
It's only a little bit of insulation - you can get small amounts of XPS from ebay. The pipe type insulation and bubble wrap can be found in diy stores.
Lots of small companies install PV - ours was done by Navitron about 10 years ago. They don't exist anymore sadly, probably as a result of the boom-bust of the PV industry as incentives change over time. Ours has been great, it's made more elec than we have used in the last 10 years, and paid for itself now too. Most PV elec is in the summer, (20kWh/day), while in winter it might b 2kW/day, so not a lot of use for directly offsetting a heatpump. I'd suggest googling for them in your area. Only choose "RECC" approved installers, which I think stops "double glazing" sales tactics etc.
I expect the heatexchanger box will already be insulated inside. If it's easy to open, take a look and pics are always good! I'm suggesting insulation around the pipes and manual valve below it.
It's only a little bit of insulation - you can get small amounts of XPS from ebay. The pipe type insulation and bubble wrap can be found in diy stores.
Lots of small companies install PV - ours was done by Navitron about 10 years ago. They don't exist anymore sadly, probably as a result of the boom-bust of the PV industry as incentives change over time. Ours has been great, it's made more elec than we have used in the last 10 years, and paid for itself now too. Most PV elec is in the summer, (20kWh/day), while in winter it might b 2kW/day, so not a lot of use for directly offsetting a heatpump. I'd suggest googling for them in your area. Only choose "RECC" approved installers, which I think stops "double glazing" sales tactics etc.
Thanks, I was thinking of IWI on the entire room. The water to 46 deg and averages about 4kwh over the last few days. What are you doing with the excess electricity?
Excess elec is a financial issue, rather than a green one; it will always find a good home, you just might not get paid for it!
At the moment we are on a special trial tariff because we have a V2G Nissan Leaf, and we get paid to export electricity (the car charges at night, and then discharges to grid in the evening). After the trial is over there's no incentive to export power, we will likely convert the car charger to V2H so excess solar would go to it and stop the car flattening(80%->20%) every evening into the grid! Maybe we'll get a house battery too - that would allow us to have more PV - we cannot at present, as we are not allowed to export >16A due to limitations of the local grid. Many people use an iboost or Solic 200 or similar solar diverter, to push spare elec to heating a water tank.
We use ~6MWh/year in total (3MWh for "stuff", 1.5MWh for heating & dhw, 1.5MWh for driving the car. Solar provides 3.5MWh/year. Due to the V2G trial there's also the energy cycling of the car of ~4MWh/year in, ~3MWh/year out. I'd love more PV, to break even over the year 🙂
@colin hi Colin, any chance you can share your anti legionnela settings? System used 8kwh on this cycle last night and temperature is only reading 48 deg C. Thanks.
@colin hi Colin, any chance you can share your anti legionnela settings? System used 8kwh on this cycle last night and temperature is only reading 48 deg C. Thanks.
Hi, no problem. I've attached the monthly DHW electricity consumption and yield as well to help you compare.
A couple of pictures, the first is the inside of the heat exchanger box. The polystyrene seems to insulate well and is a tight fit.
The second is a pipe "loop" for hot water that feeds back into the CW inlet. I understand that this is so hot water 'arrives' quickly at all outlets in the house. We have never plugged in or switched it on because hot water tends to be there very quickly anyway. However, I noticed the other day that this pipe was very warm to touch which surprised me and could therefore be inefficient if hot water circulates through it? I don't really understand what it does or how it works. Any thoughts on this welcome...
@webcmg Mine was set to 10, I think it's the threshold before it starts charging the cylinder again assuming it's within an enabled time period. I lowered it to 8 because some days we didn't lose more than 8ºC so it missed charging up the cylinder during the cheap nightly time window.
@colin Hi Colin, we've certainly reduced our Kwh usage for the hot water based on the settings. We now currently use between 3-4 Kwh per day to heat the water. 2kwh in the morning and 1-2kwh in the afternoon depending on usage (n.b. flat rate tariff). The anti legionnela cycle seemed to reach the required temperature when I checked this week which is also good. Thanks for your help.
