Radiators and open windows in winter... How does it affect heating costs?

Question

I live in a shared house, with a gas powered central heating system, timed to come on at certain times every day. There are radiators in every room. An interesting debate arose recently:

If one person chooses to leave their window open (and their door closed] during the winter months, with their radiator on full, does this make the central heating system work 'harder', to heat the outside air, or does it not affect the amount of energy used? Does it make the rest of the house colder, because that radiator is on full while others may only be on half? Or does it just affect the temperature in that one room?

This is assuming that the overall boiler settings are not adjusted at all.

Many thanks for any help.

Mike

Answer 1

It should only affect the temperature in the one room with the open window. Unless you have a thermostatically controlled system, in which case, the thermostat in that room will make the system work harder to bring the temp in line with the setting.

Answer 2

The rate of heat loss through the open window will be higher than in the rest of the house, so the boiler will need to run to replace that heat. Even if the thermostat is in another room, the temperature of the water in the heating system will be reduced because of excessive loss from 1 radiator, so the effectiveness of the radiators in the remaining rooms will be reduced. Rate of heat transfer depends on the difference in temperature between the radiator and the room. So the cooler the radiator, the less heat is transferred. Also since interior walls are less well insulated than exterior walls, there will be greater heat loss from other roms to the one where the window is left open. So Yes, it makes the boiler work harder, and Yes, it reduces the temperature in the rest of the house. Overall, its a bad idea.

Answer 3

If the heating system is controlled by a thermostat and its not in his room I doubt you'd notice a difference.

A lot of energy is stored in the wall so if he were to open his door briefly you might notice a slight difference in temperature until the walls and radiators warn up the ambient air.

The boiler will work a little harder as the temperature drop across his radiator will be higher therefore the heating water will drop in temperature more than the other rooms requiring more energy (gas) to raise the temperature back.

Are there gaps under his door?? this might make the hall way cooler.

The room above might find it cooler as well requiring more heating for their room

The conservation of energy suggest it does, by how much a lot more info is required and probably not worth the time or effort, I charge £50/hour if you want me to do the maths lol. your essentiall increasing the temperature difference hence from a convection coefficient W/m²K more power is used in his room.

Your taking energy out of his window / the house which is being paid for.

If he finds it too hot why doesn't he try turning of the radiator or reducing it using the valve on the radiator???

When I don't use rooms in my house I turn the radiators in those rooms to low. Alternatively he could put lagging round his radiator?

Jon

Answer 4

Unless you have a really complicated heating system with thermostats in every room, I don't think radiators are smart enough to work out which rooms to 'send' more heat to. I think only the room with the open window will be colder, although doors are not totally heat proof and the person inside is bound to open the door at some point, and as soon as they do, whoooosh out goes the heat. And if they do it enough I suspect you will be turning the heating up. If that person for some reason enjoys being cold then I don't think you need worry about the rest of the heating being messed up.

Answer 5

Well the radiator in the room with open window will constantly try to reach its or boiler temperature setting but obviously will have difficulty ,if it does ,it will rapidly loose heat . This should not effect rest of house ,temperature wise ,although boiler will have to work harder to maintain said temperature & use a lot more fuel in so doing (very wasteful,speak about global warming)

Answer 6

The heat will dissipate through the open window, a waste of energy. Dependant on the system the boiler may well try to compensate.

In the same way, there is the futile practise of having an air conditioner on in the same room as an open window. No matter how many times you try to explain their folly, people seem not to understand that the aircon is then having to try to cool off the world. (No wonder water pours out of them).

Answer 7

I think it depends on whether or not there is a thermostat and where in the house it is located. If there is one fitted, the boiler will keep coming on to heat the air to the required temp set on the thermostat, and if the open window cools the air surrounding the thermostat, more fuel will be used as the boiler works to meet the required temp. If there is no thermostat, I don't think it would affect the fuel costs as the radiators are either on or off depending on the timer.

Answer 8

that person's room will be colder than any other. I suspect(though not certain) that the radiator would heat his room more but not lessen the energy in any others.

Answer 9

i do not understand if this is uncomplicated for elderly human beings yet when I had free warmth, i might want to open the homestead windows interior the approach iciness and blast warmth. What more effective powerful thanks to velocity up international warming?