How much does not heating one room save?

[Alfred001]

If I have central heating on and I'm heating three rooms, two big ones and a small one, how much money would it save if I turned off one of the big rooms.

 

Obviously I'm not expecting an exact number, but I'm just curious whether it would be significant.

[dimreepr]

To many variables to come up with any meaningful number.

[DrKrettin]

Yes, too many variables. But if the rooms are adjacent and the the internal walls have no insulation value compared to the external walls, floors and ceilings of the apartment/house/castle/septic tank/cave, which is generally the case, I doubt whether it's going to make much difference.

[dimreepr]

I think the only real saving would be, if the smaller room wasn't heated and was surrounded by the bigger rooms.

[Delta1212]

You'd need to know the actual size of the room, the degree to which the room is insulated, the surface area that it shares with the other rooms and the outside, the temperature outside, the temperature to which you heat your rooms and the local rates for your area.

[dimreepr]

You'd need to know the actual size of the room, the degree to which the room is insulated, the surface area that it shares with the other rooms and the outside, the temperature outside, the temperature to which you heat your rooms and the local rates for your area.

 

Amongst others like mass/density of the walls or hours of sunlight/temperature...

[Phi for All]

The big room would need to be truly sealed off from the rest of the house. You need to block the air at the takeoff from the duct from blowing into the pipe leading to the big room, and you need to stop the other rooms from pulling heat from the big room. I don't think you'd get any benefit unless you could leave it like that the whole season.

[Acme]

... You need to block the air at the takeoff from the duct from blowing into the pipe leading to the big room, ...

Ideally, a central heating system is balanced in regards to the number & volume of rooms and the size and number of ducts and capacity of the blower. Completely blocking one room duct can cause backpressure on the blower which can make it work harder and use more juice. I'm not sure how this affects the efficiency of the heat source, whether it be gas or electric. ?

[Alfred001]

I see I should have clarified, I have the kind of central heating that uses a boiler fueled by gas to heat water and then runs the hot water through the radiators in the various rooms of the house.

 

Also, one person assumed I want to turn off the radiator in the small room, no, its one of the big rooms.

[jimmydasaint]

Oh about £120 per year, or £10 per month. There you go, done!

[Phi for All]

Ideally, a central heating system is balanced in regards to the number & volume of rooms and the size and number of ducts and capacity of the blower. Completely blocking one room duct can cause backpressure on the blower which can make it work harder and use more juice. I'm not sure how this affects the efficiency of the heat source, whether it be gas or electric. ?

 

True. I was thinking he'd heat fewer rooms up more quickly, running the blower less. But checking with an expert friend of mine, your blower lasts longer if it's properly rated (30 BTUs/sf for moderate climates). So it might help slightly, but over time might cause more wear than it's worth.

 

I see I should have clarified, I have the kind of central heating that uses a boiler fueled by gas to heat water and then runs the hot water through the radiators in the various rooms of the house.

 

Also, one person assumed I want to turn off the radiator in the small room, no, its one of the big rooms.

 

So it's not forced air, but you still have the problem of the cold room pulling heat from the warm rooms if it's not sealed against this. It doesn't really matter if the radiator is off in the cold room, if the warm rooms are radiating also.

[studiot]

Just get TRVs (thermostatic radiator valves) on each rad and turn them right down in the rooms you hardly want to heat.

 

Allowing too large a temperature differential will cause significant heat to flow from the warmer room to the colder - it will find a way.

 

In really cold weather you will also get condensation in the colder room which can lead to mould growth and corrosion of metal items.

[StringJunky]

Just get TRVs (thermostatic radiator valves) on each rad and turn them right down in the rooms you hardly want to heat.

 

Allowing too large a temperature differential will cause significant heat to flow from the warmer room to the colder - it will find a way.

 

In really cold weather you will also get condensation in the colder room which can lead to mould growth and corrosion of metal items.

Yeah, the room, with no air movement and heat will create ideal conditions for mould and then you've later got more cost fixing that problem with mould-damaged items that are in that room. Been there... If you want to leave room cold you need good ventilation to prevent fustiness and that defeats the object

Edited December 19, 2016 by StringJunky

[Alfred001]

 

True. I was thinking he'd heat fewer rooms up more quickly, running the blower less. But checking with an expert friend of mine, your blower lasts longer if it's properly rated (30 BTUs/sf for moderate climates). So it might help slightly, but over time might cause more wear than it's worth.

 

 

So it's not forced air, but you still have the problem of the cold room pulling heat from the warm rooms if it's not sealed against this. It doesn't really matter if the radiator is off in the cold room, if the warm rooms are radiating also.

 

The unheated room is very cold, so I don't think much heat is escaping from the big room that is being heated (which is directly below it, same size) or the small room which is next to it.