Our heat pump has functionality to disinfect the boiler (hot water tank) on a weekly schedule. I wanted to understand how much energy this consumes and how long this takes.
Test setup
- Daikin heat pump
- By default our hot tap water in the tank is set to 45 degrees Celsius
- Energy meters:
- 1 main meter for the overall house consumption (red graph)
- 2 sub meters measuring for the heat pump installation (1) the outdoor heat exchanger and (2) the indoor boiler. (yellow and blue graphs)
- Heat pump user interface with Advanced user enabled
- The test was done mid-October with an average outside temperature of 7 degrees Celsius
Test background
The disinfection was scheduled to start at 19:00 and the disinfection temperature was set to 60 degrees for a duration of 40 minutes. All of these parameters can be edited through the installer settings.
Test results
The graph clearly shows that the outdoor unit consumes energy (between 2300 and 1700W) first to start heating the incoming water up to 60 degrees from 19:00 until 19:40. From 19:34 onwards, the boiler itself consumes energy (4100W down to 3000W) to further heat the water inside the boiler up to 60 degrees Celsius until 20:18.
Summary
The heat pump consumes on an average 5-7kWh per disinfection that lasts roughly 80-90 minutes. The total estimated consumption per year is in between 250-350kWh.
Hi,
ReplyDeleteI have an Altherma Heat Pump LT also and a non-daikin storage tank with an electrical heater element. If I set the disinfection interval, when the pump tries to start the disinfection cycle it throws a warning that the booster heater is not present. In your configuration the storage tank is Daikin and is it linked in some way to the heat pump?
I was expecting that the disinfection will be carried out by the heat pump using it's own electrical booster.
Not related to the above issue: I have monitored the consumed energy and I found that very often (5 min) the heat pump is sampling the temperature of the heating agent but in my case it only needs to heat once per day as the building is insulated at a passive house standard so sampling at 5 minutes is quite ineffective.Do you know how to change that sampling frequency? (no luck with daikin support with this)
Thanks