Radiator size

[goose]

can any body tell me where I can find the reccomended size of radiator( in lay terms!) for a room using a condensing boiler I believe they should be bigger as a condensing boiler runs cooler to be efficient ( please correct me if I am wrong) had C/H fitted and for example rad in bedroom (app 4mX4m 2.5 m ceiling) is about 600X600 single rad and seems very small I have searched for a site but newish to net and had no luck finding one that says Room x by x needs rad x size
please help got meeting with council in two days and need to know what regs are that they say it meets
thanks in advance

 

[oilman]

You'll have to do some more work, sorry. Radiator manufacturers give heat output in kW and your room will have heat losses dependant on the construction, window size, outside walls etc. You can't have a look-up table of rad size vs room size. Work out the losses at the required temp difference outside to inside, and then look up the kW required to give rad size.

 

[goose]

thanks for that but does a 600 by 600 rad sound about right for a bedroom?
ps glad I found this site looks excellent, first time user of any forum and am impressed

 

[oilman]

Yes, if its a small bedroom in a well insulated house and/or you don't want high temperatures anytime. What type of house is it? Modern? Victorian? Pre-fab? Mobile home?

 

[goose]

its a three bed council semi probably 50s style and all rads seem small but bedroom rads especially seem tiny compared to my parents similar house. Back bedroom rads same size as toilet rad in mums. Not got dimensions available as we have been moved out while work carried out but just told "regulations say it is right" just trying to find out for myself before we move back. it is cavity wall insulated and has old single glazed woodframe windows. living room is 5m by 4m with 2m by 1.5m window with two doors to hall and kitchen but any other dimensions would be guessing
thanks for your reply oilman

 

[oilman]

Hmmmm, need some help here. Is anybody aware of regulations which dictate the size of radiators? 600 x 600 seems small, so what regulations does it comply with?

 

[goose]

Have I got it right about condensing boilers needing bigger radiators or is it they need smaller? I think i heard/read it is because they run cooler in condensing mode which is most efficient and therefore a drawback was that larger radiators are required, to run at peak efficiency which is what I would prefer for economic as well as enviromental reasons but tried a couple of energy efficiency sites and couldnt get much of use on the subject apart from condensing boilers are more efficient but nothing about why. Anyone got a site that is more illuminating?
Thanks again.

 

[oilman]

You are right about needing bigger radiators.

The condensing boiler works by extracting the heat from the water vapour in the exaust by condensing the steam.

In 2005 every new boiler will have to be a condensing boiler.

The water that is condensed is not harmful and does not contain harmful chemicals. This is why it must drain into a foul sewer. (Smell any rats yet?)

There are about 1,000,000 new boilers fitted each year, if we say 20kW each and on for say 5 hrs a day someone can work out what the quantity of condensate that will be going down the sewers. Given that the sewers are run by microbes, I wonder how they will suffer when all 20,000,000 boilers in the country are condensing.

The reason for condensing boilers is to reduce the amount of fuel burnt by making more efficient use of what is burnt. All very laudable. WHY THEN, DO WE HAVE PROPOSALS TO BUILD LOTS OF NEW RUNWAYS FROM THE SAME PEOPLE WHO DEMAND CONDENSING BOILERS, ER, THE GOVERNMENT?

Bear in mind that unless the heating system is changed, most of these condensing boilers will not work in condensing mode for much of the time, so what real benefit are they? while we are gaily chucking these chemicals down the sewer, and the secondary heat exchanger needs more stainless steel.

Still think they're good for the environment?

 

[goose]

points taken oilman but you may notice I put economy before ecology! I think it is basically acid rain it kicks out from what i recall and I know that because something is painted green it doesn't mean it is underneath ie it takes so much extra energy to make double glazed alu windows it could take a lot lot longer than you think to make up the resources used in manufacture in what they save in use (not sure of numbers so wont quote them i am sure someone will have them) and this isnt always made clear by manufacturers but i think that is going off subject a little! With that said I would like to run an efficient heating system and if it is the wrong system that is fitted to boiler in the start it defeats the object a little and I cant seem to find much info on CORRECT use of condensing boilers lots on what is available and how much they can save and found a diagram, of how they work but not much that will back me up when I tell council that they have wasted money (yet again) on doing half a job.

 

[oilman]

Phew! That was a struggle, I'm fair out of breath. Think I understand what you mean, but here are a few full-stops for use in your next post...................

There's not much good info on these boilers, but have a look here , and search on the site for "condensing". There seems to be a bit of a hicough but have a couple of tries and you should get some salutary information.

Where does the acid rain come from? If it comes from the fuel (it only applies if there is sulphur in the fuel, forget the CO2, it's going to come out of the combustion whatever you do) and if it doesn't get into the atmosphere, it will go down the drain, and we will all pay for the extra maintenance of the sewage system, so don't be conned into thinking it will always cost you less.

If you want an economic heating system, turn the temperature down and put another jumper on, or give your house more insulation. (Don't block up the draughts, you will have to spent more on dealing with the extra moisture degrading the decorations.)

 

[goose]

Had a quick look at the site you reccomended thanks. Will have proper look tomorrow hopefully (past my bedtime!) Talking to a mate tonight who is a chemist and he was saying that the "acid rain" would come out as a gas anyway just spread over a wider area (Scandinavia mostly!) but as it would come out dissolved in water it would dissapear from gas emmissions figures! Which could be why they appear greener and government has targets to meet on emissions. But actual waste would remain the same and as you say may have effect on bacteria and stuff will have to wait and see. My thought was about big city sewer systems bricks and mortar they are past use by date what effect could acid have on lime based mortar? But obviously this will have been looked at too.................................................. wont it?
ps found full stop button just forget to use it

 

[oilman]

As I understand it, acid rain was a problem caused by coal fired power stations, for the most part. Two factors have changed this, the first was Mrs. Thatcher, who stopped most of the coal supply, and the other is the addition of flue gas de-sulphurisation plants. Chalk quarries now make their living from selling chalk in pieces sized for passing flue gases through to remove the sulphur. This makes gypsum, which may be why there is such a push to build new houses, to use as a dump for all the plasterboard made from the gypsum produced.

Central heating boilers will always be a less satisfactory way to burn fuel, as the combustion is small and so difficult to control, and with more CO produced (maybe 10 times more than a large burner)

The degrading of lime based mortar is probably much less nowadays, from atmosphere pollutants, than in the days of steam engines burning coal.

 

[ollski]

generally add 10% to the normal rad size to get the size for a condensing boiler rad

 

[Registered Gas Man]

Try this Radiator size calculator

www.radcalcs.com

You need your tape measure!!!!!!!!!!

 

[oilman]

Tried the calc, thought it would be useful, but I got:

ADODB.Field error '800a0bcd'
Either BOF or EOF is True, or the current record has been deleted. Requested operation requires a current record.
/calculate.asp, line 183

so its back to the wet finger.