UFH controlled by Home Assistant/Virtual Machine

[Yonny24]

Hi all,

It's our second winter in our new house and have been getting used to the electric underfloor heating. Still fixing some wiring issues (conductors/layouts) thanks to Marconi's help.

Last winter we just used our log stove and A/C units in the bedrooms and it was not warm enough. Hard work lighting the wood every day also and A/C for heating at bedtime is not nice. (split units). fast to heta up but once off loses heat so fast. Noisy also.
We never touched the UFH as everyone said it was so expensive to run.
Well after some time adding some kWh meters to the system and running some tests with calculating the watts used per zone and cost per kWh turns out to be not so pricey as everyone said.
Comparing to inefficient wood (open stove) that costs about 120 USD a ton (our friends/neighbours do not hesitate spending this a month) I am sure I can run the UFH at the same cost. 1 - 1.5 tons a month consumed easily.

It feels so nice and keeps its warmth for hours after being turned off.

I've set up HomeAssistant on a VM running Ubuntu as I have many wifi switches (lights/pool control etc) installed including a main thermostat on the ground floor to override the old and inefficient UFH thermostats on the walls.

Anyway I am currently testing different cycles to see which is most efficient.

1) Turn on the UFH for 2-3 hours twice a day. Once the floor gets cold it takes so long to heat up again!
2) Have the UFH on 11pm-5pm (5pm-11pm is an expensive time to run so we will switch most items off in this period)

Running option 2 I have placed the thermostats on the floors to maintain a steady temp during the day and a lower temp during the night.
I am getting the impression it works out cheaper to maintain the heat steadily on and off rather than blasting them twice a day after they have lost all heat.

All coded in HomeAssistant with a UI and app also.
I'm monitoring the tolerances and graphs of temps/times. Also updates a google sheet to calculate the on/off times.

Do people here with UFH tend to keep it on and maintain it warm throughout the day rather than an on/off approach?

Thanks

 

[Wilko]

Hi - my 20p worth, perhaps a few times .
Utility and comfort first.
As a general rule there’s no point heating when you are out, except of course for damp or frost damage prevention.
However if the heating takes several hours to warm the house to a comfortable level then I would...
How long your system takes to reach a comfortable temp will depend on its power and the insulation etc, so it’s a matter of experimentation as you’re already doing.
UFH systems are often slow cookers and take a while to have effect.
Looking for cheap times (and suppliers) to use power is always good.