Radiator placement

[robbiejustice]

Hello all, I have an odd shaped kitchen diner, which a single vertical radiator fails to warm up so I am going to add a new type 22 radiator. We have a concrete floor so ideally we will locate the new one close to the old one. I've drawn a picture below but concerned that I am putting the new radiator in cubby hole so may not do a good job of heating the room although the kitchen part of the room doesn't really need to be that warm. The blue boxes are windows or french doors. Any thoughts?

 

[BlueLoo]

That's a big room with lots of glass for a single rad.
Kitchens are high traffic areas so doors are always open and heat losses are difficult to control. That said, i find my kitchen always too warm with the rads on because we are usually in there when cooking.

My kitchen only has a small window though.

I'd put a big one on the 3.33m wall tbh. Away from the kitchen heat, but closer to the dining space.
A few heat calcs (simple enough) would give you the btu rating.

 

[robbiejustice]

I've just done the calcs and it appears I need about 8000 BTU. The existing column one I think is about 4000 BTU so I need about the same again, which I can fit in the proposed cuby hole area, just. I would prefer to go large on the radiator, as per your suggestion, and then just run the CH at a lower temperature but the plumber will need to run a lot of pipe over there from the existing radiator and not sure it's worth the extra hassle if the cuby hole one works... only i suspect it might just heat that area up.

 

[BlueLoo]

I've just done the calcs and it appears I need about 8000 BTU. The existing column one I think is about 4000 BTU so I need about the same again, which I can fit in the proposed cuby hole area, just. I would prefer to go large on the radiator, as per your suggestion, and then just run the CH at a lower temperature but the plumber will need to run a lot of pipe over there from the existing radiator and not sure it's worth the extra hassle if the cuby hole one works... only i suspect it might just heat that area up.

Sounds about rights.

Benefit of a rad on the back wall is it will be horizontal. Vertical rads are crap at heating efficiently. The horizontal rad will also be good for washing in the winter....

The existing location is rubbish. Your experience confirms this.

Sometimes doing a job correctly is the only way.

 

[robbiejustice]

Thanks

I need to investigate if can run through the floor. It's a 50s house and I think there are asbestos floor tiles underneath our current flooring.

 

[Madrab]

The existing column one I think is about 4000 BTU so I need about the same again,

Waste of time including that rad in the calcs, the column rad will be adding very little to the heat into the room due to the way it heats. Only about 20% of that heat will be transferred into useable heat for the space

Get rid of the column rad and add in convecting rads, there are lots of new contemporary designs that will heat the space properly and also look good.

 

[robbiejustice]

Where is the other 80% of the heat going?

 

[BlueLoo]

Where is the other 80% of the heat going?

The ceiling.

Or not.

Convection heaters like radiators work bythe principles of heat rising and cold falling. So 1stly a long radiator is going to do that convection job much better than a slim one.
Secondly, convection heater work by conducting heat to the air. The bigger the temp delta, the more efficient they are. In a tall slim heater, the cold air gets heated at the bottom and then not much more as it rises up over the rest of the rad.

In reality, the tall radiators work mostly on radiation than convection.

Look nice but are a bit rubbish

 

[BlueLoo]

A creative solution would be to use kick board heaters under the kitchen units.

 

[robbiejustice]

Our vertical one is great if you stand next to it!

I am looking at those boxed in skirting boards as a way of piping it round to that wall without have to disturb those floor tiles.

 

[Madrab]

Where is the other 80% of the heat going?

Into anything that is less than 3ft away.

Most heat loss calculations consider that the space will be heated up by traditional convection methods, convection being the most efficient way to heat a space - Air is drawn in through the bottom of the heat source, it is warmed and then rises out the top and into the room and the cycle repeats in a circle. You may remember convection currents from school?

Convecting rads, like the old school ribbed ones with internals fins transfer 80% of their heat into the air that is drawn up through the rad and over the fins and out into the room and the remaining 20% is lost through radiation, i.e. it heats up what ever is close to it . Most designer column rads work the opposite way around, 80% of their heat radiates out and heats up anything with ~ 3ft and only 20% of the heat convects. Try it, when the column rad is on, stand a couple of ft away, you will feel the heat from it, move away and you don't.

 

[Madrab]

Yes, the rebated skirting can be a convenient way to hide pipework, conduit can be another, Talon do a great pipe covering, others I'm sure are available.

Just saw the last post, you do feel warm standing next to them but move a few ft away and you won't. If nothing else is close then feel the wall, that and as they can't release their heat efficiently, that hot water ends up back at the boiler and starts the cycling process.

 

[robbiejustice]

Thanks to both.

I am going to go with putting a large convection Stelrad type 22 or K3 on the 3.33m wall. There are french doors next to it so that should help with getting the convection going.

The question is how large... 8000 BTU for the whole room estimated but the kitchen area doesn't really need to be that warm and we are generally cooking when in that area plus there is no where to put a radiator there. I was going to go with an 8000BTU.

The area where the existing vertical is so narrow I think I will just leave it be. I could replace it with a 400mm wide panel radiator but not sure it would make much difference given the BTU is only 2700. That said the column radiator probably wastes heat radiating to the ceiling and through the roof as there is no upstairs above.

Any other comments?

 

[Madrab]

I am going to go with putting a large convection Stelrad type 22 or K3 on the 3.33m wall. There are french doors next to it so that should help with getting the convection going.

Keep in mind the size and length of supply pipe heading to the rad before the largest possible rad is thrown on the wall. Too big a rad will need a fair amount of heat supplied to it for it to warm up. The 8000BTU could be taken up by a 600x1400 K2 which isn't overly huge.

Another point to note, large amounts of glass, even double glazing, can act as a heat soak and can become a hinderance to heating a room properly. I recommend lined curtains or blinds as another option, to act as a barrier, if heating becomes an issue.

 

[BlueLoo]

I'd also consider if the rad is going to be exposed or not. Exposed, I'd be getting something that looks decent. If it's going in a rad cover, something efficient will be best.

Rad covers get a lot of hate but if done well, can add the finishing touch.

Something to consider