Underfloor heating with economy 7 ?

[Pretty Mouth]

The only way I can see this working is if you have a floor layed above the heating that is made of very thick stone slabs to store the heat generated overnight and allow it into the room during the day.

I came across something like this in a 1960s flat. Surprised to find that it was on night tariff, it heated up the whole floor slab and slowly released throughout the day. Original installation, still working 50 years on

 

[Zerax]

Best solution would be to use a back boiler from the wood burning stove to heat a thermal store... then use the heat from the thermal store for a wet underfloor heating system and domestic hot water too ! That could be a very cheap system to run (TP permitting...)

Couple that with a PV array and battery storage system, sufficient to give about 8-10kWh in the winter... you could go off-grid !!

 

[Lightbug]

Thanks I will not use e7 now thanks for all your posts

 

[Scambling]

Why are you requiring economy 7 for underfloor heating?

 

[DPG]

Why are you requiring economy 7 for underfloor heating?

He isn't now.

 

[Simon47]

I came across something like this in a 1960s flat. Surprised to find that it was on night tariff, it heated up the whole floor slab and slowly released throughout the day. Original installation, still working 50 years on

Gran had that setup in her sheltered flat. It was terrible, really really terrible.
Floors were hard because she could only have thin carpets, and temperature regulation was really really rubbish. Part of the problem was the south facing window - so on sunny afternoons the place would be roasting but still getting heat from the uncontrolled storage heater (aka floor slab). But that was only part of the problem - as mentioned, heat output is highest in the early hours when fully heated, and lowest in the evening (when you most want it) as the slab cools.

 

[SparkyHarry]

Gran had that setup in her sheltered flat. It was terrible, really really terrible.
Floors were hard because she could only have thin carpets, and temperature regulation was really really rubbish. Part of the problem was the south facing window - so on sunny afternoons the place would be roasting but still getting heat from the uncontrolled storage heater (aka floor slab). But that was only part of the problem - as mentioned, heat output is highest in the early hours when fully heated, and lowest in the evening (when you most want it) as the slab cools.

I have experienced a similar thing in an old flat. It was always too hot in the daytime.

 

[Howardhouse]

@Lightbug what was the result of your findings? I'm trying to work out best how to use economy 7 with underfloor heating in a newly purchased new build house.thanks

 

[Taylortwocities]

I assume it is electric underfloor heating? ?

If so, there's little point having it on E7. The floor will heat up when you are asleep and then switch off just about when you wake up.

 

[gaz101]

Yes we have e7 underfloor
stone oversite/100mm celotex / 100mm concrete/cable elements /50mm concrete /carpets
works very well room stat and contactor to control takes 2 days to heat up then stays constat all winter
cheaper running than our other house

 

[Simon47]

If so, there's little point having it on E7. The floor will heat up when you are asleep and then switch off just about when you wake up.

Indeed, many years ago one of my grand mothers moved into a flat with electric off-peak underfloor heating. It was truly terrible.
The theory was that using off-peak it would heat up the big concrete slab, which would keep the flat warm all day.
In practice, it meant that the floor was hot first thing in the morning and the flat a bit over heated. After a while it would all start cooling down. If it was a sunny day, then the sun would stream in through the large front window and the place would overheat for the afternoon. If there was no sun then things would just keep cooling down. And then in the evening, it would be getting cool or cold.
And of course, this was back in the 70s (IIRC) so not insulated to modern standards, hence needing considerable heat input - and meaning that only thin carpets & no underlay could be used. Not very comfortable underfoot.

 

[Howardhouse]

Yes we have e7 underfloor
stone oversite/100mm celotex / 100mm concrete/cable elements /50mm concrete /carpets
works very well room stat and contactor to control takes 2 days to heat up then stays constat all winter
cheaper running than our other house

Thanks for your reply @gaz101 are you saying you keep the UFH on day and night on a room thermostat to keep the temp constant all winter rather than switch on and off daily? Thanks

 

[gaz101]

Thanks for your reply @gaz101 are you saying you keep the UFH on day and night on a room thermostat to keep the temp constant all winter rather than switch on and off daily? Thanks

It is wired from the e7 timer only heats at night

 

[Howardhouse]

It is wired from the e7 timer only heats at night

Sorry not sure I understand that question. I can set the time the water is heated on the economy 7 panel and the UFH has zones to which we can set the times and temps.we pay a cheaper rate for electric at night on economy 7 compared to daytime hours.

 

[Howardhouse]

OK but have you tried it? No
I think I will just get it wired in and test it with a simple on off switch and see
How long it stays warm.. Also have a high wattage matting... If its stays warm until late afternoon I will be happy and it will cost next to nothing as economy seven is so cheap?
If it doesn't work then I can get it wired with normal supply and metre etc?