magic thermostat.

retired2011

I was reading a form about cavity wall insulation and one of the statements was that after having cavity wall insulation installed I would be able to turn my thermostat down and still maintain the same temperature.

Yeah right!

If the thermostat is set at 22 deg C the temperature in my house is 22 deg C, regardless of the outside temperature and how much heat is going through the walls.

If I turn it down to 21 deg C the temperature in my house is 21 deg C regardless of the outside temperature and how much heat is going through the walls.

Pandoras_Socks

Whilst you're right in what you're saying about the thermostat i think what the leaflet is trying to get across, albeit wrongly, is that less heat will be lost through the walls meaning you will to turn your heating on less frequently

Nada666

But if the controlling thermostat is in an inside hallway and your living room has windows and outside walls (hopefully!) then cavity wall insulation can have an effect.

Also the inside side of your walls could then act as storage panels and provide more comfort (though that would affect more, as you suggest, energy used rather than thermostat settings.)

And as many people mistakenly impatiently tend to ramp up the thermostat more insulation can lessen that impatience.

ollski

Maybe they mean that once your room is 21 degrees you can turn the thermostat down and the room will stay at 21 degrees for much longer.

lstar337

ollski wrote: »

Maybe they mean that once your room is 21 degrees you can turn the thermostat down and the room will stay at 21 degrees for much longer.

While I'm sure that is what they mean, if the thermostat is working correctly, it shouldn't need to be touched!

Smiley_Dan

Not really on topic but you often hear people say, when the heating system is warming up, there's no point in turning up a thermostat because it will not get to temp any quicker.

Well I was thinking about this the other day and I have a theory that there is one example of thermostats where this might not be true. That's with modulating thermostats, for example TRVs.

This depends on the assumption that the TRV opens its value proportional to the temperature delta between current and target temperature. The higher the delta the more open the valve is, thus the target temperature is achieved quicker. You could in theory open up the valve to the top setting then turn it down and achieve temperature quicker.

Am I correct?

yangptangkipperbang

Smiley_Dan wrote: »

Am I correct?

You may be - but I threatened my kids with death and destruction when they did that, because after half an hour the house was like sauna :rotfl::rotfl:

Smiley_Dan

Yeah, you have to turn it down again afterwards

Johnandabby

retired2011 wrote: »

I was reading a form about cavity wall insulation and one of the statements was that after having cavity wall insulation installed I would be able to turn my thermostat down and still maintain the same temperature.

Yeah right!

If the thermostat is set at 22 deg C the temperature in my house is 22 deg C, regardless of the outside temperature and how much heat is going through the walls.

If I turn it down to 21 deg C the temperature in my house is 21 deg C regardless of the outside temperature and how much heat is going through the walls.

It's actually correct in a way, in that the temperature you experience (called a number of things such as operative temperature or resultant temperature) is a combination of air temperature and radiant temperature. If you don't have external wall insulation then the radiant temperature of the inside surface of the wall will be cold - this lowers the operative temperature and people may turn up the thermostat to increase the air temperature to compensate.

When you have insulation installed then the radiant temperature of the inside surface of the wall increases, thereby needing a lower air temperature to deliver the same operative temperature.

When you set your thermostat at 22 deg C all it means is that the air temperature at the thermostat is at 22 deg C, not that the house is 22 deg C or that you are actually experiencing 22 deg C.

As others have said, generally you find that people just turn up the heating temperature after having insulation installed, as they find they get higher comfort levels for the same running cost.

sheffield_lad

what's magic about your room stat is the fact it won't click in as often as before the insulation saving you £££