Heat distribution around home Featured

First question: why is there a difference? Is it one end is south facing (ie solar gain)? More electricial appliances? Better insulated?

Or just that your radiators aren't properly balanced?

Yes, a few people have tried that:

I think you need to understand what the problem actually is before throwing things at fixing it.

Theo

So is ours.

Only 3°C? Ours is 4 - 5, but then we have a log-burning stove in the lounge, and that keeps us as warm as toast and the wireless stat in the lounge doesn't turn the heating on, so all the rads remain cold. I let the stove burn out around 9pm, and then put the stat in our bedroom so the rad there comes on. It's warm enough in time for bed. Sure, it's a bit cold in the kitchen, but we aren't in there for long and any cooking can soon warm it up.

Is there any reason you need to heat the bungalow all through? If so, then there would appear to be an imbalance in the rads, and/or the insulation in the loft is a lot thinner at the cold end of the bungalow.

No doubt, but it might also create a draft - air moving one way means it has to enter the fan by moving from somewhere else.

Or you could temporarily use a fan heater for the times you actually need to be in the "cold" part of the house.

It is probably better to rebalance the radiators so that you even out the temperatures. Moving air tends to be perceived as a draft!

It has to be quite a bit above ambient before it feels warm.

Bleeding any radiators that are cold at the top is the other obvious one.

Figuring out why different bits are at different temperatures would be my first suggestion. Adding insulated heat reflectors down the back of any radiators on outside walls can only help warm the room.

My wood burning stove has a TEC powered fan on top which runs because of the huge temperature difference between the stove and the warm air above it. The net effect is to move very warm air out of the inglenook around the stove where it would otherwise stagnate getting hotter and hotter.

I was surprised quite how much of a difference it made.

Do you want the whole house at the same temperature? As a general ‘rule’ ( note quotes) bedrooms should be slightly cooler for example than sitting rooms. Before the days of radiator thermostatic valves, this was ( in theory) entirely achieved by having larger radiators in some rooms than others and balancing the system.

Thermostatic rad valves refined this idea, allowing for personal taste.

Smart / Wi-Fi rad valves further refine the idea, including for example, not heating bedrooms during the day and perhaps the sitting room first thing in the morning.

There are also zone valves, you could split the house into areas to be heated at different times.

We have a Hive system and dumb rad thermostatic valves. Plus we turn of the rads in the rooms we don’t use, except when we have visitors etc.

By careful tweaking*, I’ve reduced the gas use by about 25 to 30% and we are still comfortable. I recently tweaked the flow temp. I’ve not noticed a drop in comfort but it is too early to judge consumption.

• on/off times, main temp, and rad settings etc.

Thanks for all the replies. Here's a mass reply back :)

House shape is an "L" - not sure what that does to heat distribution.

Radiators are all bled.

We had the whole place insulated under a grant in 2005 - cavity wall and extra loft. Can that degrade ?

Radiators have backing.

Being the 2 of us (just SWMBO during the day) there are whole rooms that don't need the same level of heating. Hence the vague idea of smart valves.

Surely if you use a fan to move warm air from the hot end to the cold end, you'll just cause the hot end to cool down and need extra heating?

if you want to even the temp, the solution is normally to fix the heating. If for some reason that's unworkable, moving air around is done with fans, but a fan makes the air feel colder, increasing the cost of feeling comfortable.

I've done it a few times. It increases rad output a bit, no way is it going to move air from one room to another. It doesn't improve efficiency significantly, though I expect if all rads got a fan it would slightly by dropping the return temp. It also reduces temp behind the rad, causing a slight heat loss reduction, but these effects are small.

it would help you feel colder.

why would you need those?

absolutely.

Should be provided that you don't have any fancy mirror or metallic finish ones. Any colour of paint pigment is black in the thermal band.

The other option if you are prepared to get a plumber in is to split the heating system into 2 zones. Typically daytime and night time configurations that allow you to control where actually gets heated.

Smart valves might do what you want provided that there is a bypass - otherwise for radiators that are in series it could have unintended consequences.

A better, long term solution is identify why there is a temperature difference and fix it with effective insulation (which at some point becomes cost negative)

Bungalows tend to have a poor perimeter to area calculation which means increased heat loss from that 1 metre wide strip of floor that follows the perimeter external walls. Even worse if assorted ad-hoc extensions have been added over the years.

If your bungalow is also on sloping land such that ~half of it has many courses of exposed brickwork *below* the dpc + facing north or east then you have a significant flooring heat loss too. If it was built with solid/screeded floors then triple whammy heatloss.

A conservative councillor came in for a lot of stick when she made that claim on ??GB news recently. She seemed to think that it would solve all the energy problems.

If you have solid and uninsulated external walls and the radiator is on an external wall then that reflective stuff reduces the heat *loss* through the wall, but only if it was behind the radiator and extended up the wall too. This is not the same as 'warming up' the room.

If the walls have cavities which are insulated then the benefits of this stuff are minimal (which probably explains why the sheds don't seem to sell this stuff as much as they used to).

BBC "Inside Health" podcast 1-Nov-2022

"How can a cold home affect your health?"

"Women prefer the thermostat set to 23C, so they should have control of it".

Interviewer - "That's Hot !, That should bring comfort to at least half the population"

More external walls means more losses. Does the cool part have more wall area or face north?

Should be, although I'd put some black tape on the pipes to avoid reflectivity affecting the readings.

Note that the point of balancing is to adjust the kW going into the room, so if you have too little kW coming out of the radiator it won't be able to keep up with the losses from the room. While a starting point is to balance for a particular temp difference from flow to return, the point of which is to avoid one room hogging all the heat, really what you want is to control the kW so all rooms are at the same baseline temp even though they have different losses. If the room is cold even with the TRV full on, maybe you want to open the lockshield a bit so you get more flow through the rad.

Not unless it's got damp, which I would only expect if you had roof problems.

Do you have TRVs? A TRV will allow you to adjust the temperatures of rooms individually.

A smart TRV will allow you to do that electronically. I could see two use cases for that - one is if you want to change temperatures across the day (eg warm in the daytime, cool at night) at a more fine-grained level than just tweaking the main thermostat. The other is if adjusting mechanical TRVs is awkward, eg if you can't lean down to twist them.

For a lot of people they just want rooms at an unchanging temperature (living room warm, bedroom cooler, spare room barely heated) and the smart TRV is overkill, because it can be done by properly balancing the rad, a regular TRV and the main thermostat. No need to throw extra tech at it unless those won't do what you want.

Theo

But then they don't have that internal chimney, better known as a staircase, where all the ground floor heat disappears up the stairs into the bedrooms!

Although we are on a slope, the slope is down to the west (where there is a garage), and the front is to the south.

You are the smart. All you need is a (thermostatic?) valve to shut down areas not needing heat.

Agreed - although the gross benefits (comfort, environmental, stress, etc.) may benefit things out a little more.

Not much, but colour can make a difference:

It won't solve them but it will stop the radiators thermal footprint being visible on the outside wall. Every little helps.

It is good enough to have it behind the radiator. A lot of radiators are on external walls traditionally in front of the windows so that warm air ends up going up behind the curtains unless you are careful.

It makes not one jot of difference to a radiator on an internal wall.

I'd say less. But my walls are all solid stone or three courses of handmade Victorian engineering brick so it does work for me. A fair proportion of houses from the Victorian era are solid wall.

I’ve not had much joy using an IR thermometer on pipes. I suspect the ‘sensor area’ averages and includes the pipe and the area behind, giving a lower reading.

You could, perhaps, use the corner of the rad near the valve / exit but it is probably less accurate.

A couple of thermocouples and clamps with a cheap meter?