Is my radiator the correct size?

moneyistooshorttomention

There is a radiator in my house that I am having to set at higher temperature than average on the radiator thermostat and am still not sure its proving adequate to the task involved (ie heating my kitchen).

I found an online calculator from B & Q to help work out how many BTU's a radiator should be in accordance with the size of the room. Its a bit of an awkwardly-shaped set-up I have, but evening everything out as if it were all set-up into one room the space equates to approximately 5 metres x 4 metres and the ceiling height is approx. 2 metres high.

The radiator concerned is a double width one 710 mmx 610 mm.

The B & Q calculator said that the BTU output needed for that size of room is 2916 btu for "normal" heat levels and 3208 for "warm" heat levels.

Does this size radiator:
- match what is required for "normal" heat levels?
- match what is required for "warm" heat levels?

I would say I personally need it to be suitable for "warm" heat levels.

I have the feeling that this radiator is too small for this size room. Am I correct or is it down to my perception of things?

EDIT; The room has two windows and a back door in it (all doubleglazed).

Doozergirl

The B&Q calculator is a bit simplistic, I prefer this one as it takes a lot more into account.

http://www.bestheating.com/btu-calculator

We've just installed a system and I picked the radiators using this BTU calculator and it's been really successful.

There are two types of double panel radiators, one has a single convector (21) (the wavy bit between the two panels) and others have two (22). The 22s give off about a third more heat.

BTU calcs help, obviously, but it's down to whether you actually feel warm. You should check for draughts as this can affect temperature massively, especially in a big room like that!

moneyistooshorttomention

Just had a quick check and my radiator has:

front panel

"hillocky" bit (the best way I can think of to describe it...)(ie hill/valley/hill/valley and so on)

back panel

(guess the "hillocky" bit is what you mean by a convector? - which would mean it has a single convector then....)

EDIT: just checked another radiator here and two rows of "hillocky bits". Ah ha...two convectors then....I understand what you mean now..

moneyistooshorttomention

I've just filled in that calculator you gave and can see it rates things rather more fully than the B & Q one and then I looked for a "button" to push to say "calculate" or something similar and I couldn't find one.

I tried putting in a btu rating in the bottom 2 boxes to see if such a "button" would come up then, but still not...

Am I missing something please as to how to make the website calculate it for me with the figures I gave it?

ValHaller

Why the heck does B&Q's calculator work in BTU? BTU went out with the Ark, being the energy to heat 1lb of water by 1degF. It is all done in Watts now and radiator output is specified in Watts by all of the manufacturers. And if you do it in Watts, you can see it immediately in terms of equivalent electric heating

ValHaller

moneyistooshorttomention wrote: »

I've just filled in that calculator you gave and can see it rates things rather more fully than the B & Q one and then I looked for a "button" to push to say "calculate" or something similar and I couldn't find one.

I tried putting in a btu rating in the bottom 2 boxes to see if such a "button" would come up then, but still not...

Am I missing something please as to how to make the website calculate it for me with the figures I gave it?

You are right, that 'calculator' is just plain useless. Obviously they have 'improved' it since DG last used it.

moneyistooshorttomention

I see the point made Valhaller re watts.

As you will have gathered, I don't have any idea of the technicalities of this. I just assumed btu is what is used to measure output because the B & Q calculator says so and, on checking radiators for sale on Amazon, many of them say an output in btu's.

I'm beginning to wonder if, when I specified I wanted "double radiators" in some rooms that I shouldn't have assumed that double radiators is exactly what I will get (ie ones turning out double the output of a same size single radiator).

It looks like maybe I needed to use the words "double convector radiator", rather than the words "double radiator" and that perhaps my single convector radiator doesn't give out as much as double the heat of a single radiator that size. I would expect a heating firm to realise that the average person in the street (hmmm...being a bit sexist here....and that includes some middle-aged women like myelf....might need a bit of "interpreting" into technical terms and they would have interpreted what I said correctly into their language OR explained how things are a bit to me and asked me exactly what I wanted).

I'm hazarding a guess that maybe it turns out about 175% of the heat of a same size single radiator?? But a double convector radiator would turn out double the heat?

moneyistooshorttomention

Now I know its a single convector radiator, I've been able to check out Amazon website better.

I've found a radiator that is same size/identical in appearance to mine but is a double convector radiator (rather than the single convector radiator mine is).

Its far too complicated a link to give, but on Amazon it comes up when inputting "radiators compact double panel" and is the third one in line and priced at £54.99.

I can see its output is down as 4,109 btus or 1204 watts.

So, I'm guessing, from previous comments that the radiator I have would be about 3,000 btus then??. That is, a single panel radiator would, presumably, be 2,054 btus. Thus making a double panel single convector radiator somewhere between 2,054 btus and 4,109 btus and I am guessing at around 3,000 btus.

Does that sound about right?

ValHaller

Amazon selling in BTU is astounding ignorance.

The way to select a radiator from a Watts or BTU figure is to go to the manufacturer's website and look at their catalogue pages. Start with the width you have available and the height you would like and see what panel combination will do the job. Then look for that radiator by manufacturer and size.

Double radiators relates merely to the fact that the radiator has 2 panels. You cannot assume it is double the output, it will always be less. And for Stelrad, the radiator configurations are

• P1 = panel
• K1 = panel + fins
• P+ = panel + fins + panel
• K2 = (panel + fins) * 2

which gives a lot more options

ajd3

I have the same problem in my sittingroom and would welcome any advice about the radiator size as I don't think it is big enough for the room. The room is (L)4.7m x (W)3.7m x (H)2.3m one large window that is double glazed with a roller blind & lined curtains. The radiator is under the window (the curtains don't hang over it, I fold them up on the window ledge). The radiator is a panel one - 1m x 56cm and I have radiator foil on the wall behind it. My flat is 4-in-a-block, I'm upstairs and the loft is fully insulated (by govt scheme). The floor is carpeted and I have draught excluders at the doors. The radiator is on full (doesn't need bled, it's hot all over) but the room heats up at approx 1 deg per hour. Today my heating came on at 3pm and when I got home from work (at 5) the room temp was 12.1 deg, outside temp +3. At 8pm the room temp was 15.6 deg, outside temp is 0. I don't know what else I can do to get the room warm, how do I find out the output of the radiator? I'd like to compare it with the calculator someone posted a link to. Thanks in advance for any advice.

Davesnave

moneyistooshorttomention wrote: »

I've just filled in that calculator you gave and can see it rates things rather more fully than the B & Q one and then I looked for a "button" to push to say "calculate" or something similar and I couldn't find one.

I tried putting in a btu rating in the bottom 2 boxes to see if such a "button" would come up then, but still not...

Am I missing something please as to how to make the website calculate it for me with the figures I gave it?

I filled in the calculator and it worked fine.


It calculates if you give it all the info, and without pressing buttons.