Radiator Sizes

[baby chicken]

Hello everyone

I'm hoping one of you will be kind enough to help me out, I'm wanting to change all the radiators on my heating system for new, but I'm unsure of the sizes I will need.

I downloaded the stelrad stars programme and tried to find the sizes, but it just confused me in the end.

At the moment I have what I presume to be a single pipe system (one pipe runs underneath radiators and tee'd off to both valves) with an old Baxi 501FS (I think) free standing boiler, gravity fed system.

So here are the dimensions of the rooms if someone would like to spare the time and help me out.All ceiling heights are 2.4m.

Hallway

4.3m length (1 Internal, 1 External wall) x 1.8m width (1 front door, 1 Internal wall) x 2.4m height.
No window.

Downstairs WC

2.1m length (1 Internal, 1 External wall) x 0.9m width (1 Internal, 1 External wall).
Window 0.8m length x 0.6m height.

Kitchen

3.8m length (1 Internal, 1 External wall) x 2.6m width (Both Internal walls).
Window 2.3m length x 1.0m height.

Utility

2.1m length (Both External walls) x 2.5m width (1 Internal, 1 External wall).
2 x Windows both 1.1m length x 1.0m height.Also a glazed back door.

Dining

3.7m length (1 Internal, 1 External wall) x 2.6m width (1 Internal, 1 External wall).
French doors 2.3m length x 2.0m height.

Lounge

4.3m length (1 Internal, 1 External wall) x 3.4m width (1 Internal, 1 External wall).
Window 2.9m length x 1.3m height.

Landing

3.9m length (Both Internal walls) x 1.8m width (1 Internal, 1 External wall).
Window 1.2m length x 1.2m height.

Bathroom

2.9m length (1 Internal, 1 External wall) x 2.2m width (1 Internal, 1 External wall).
Window 1.2m length x 1.0m height.

Main Bedroom

3.8m length (1 Internal, 1 x External wall) x 3.5m width (1 Internal, 1 External wall).
Window 2.9m length x 1.3m height.

Bedroom 2

3.6m length (1 Internal, 1 External wall) x 2.9m width (1 Internal, 1 External wall).
Window 1.8m length x 1.2m height.

Bedroom 3

3.8m length (1 Internal, 1 External wall) x 2.3m width (1 Internal, 1 External wall).
Window 1.8m length x 1.2m height.

Bedroom 4

2.7m length (Both Internal walls) x 2.3m width (1 Internal, 1 External wall).
Window 1.8m length x 1.2m height.

All bedrooms are above a living space except bedroom 3 which is above an Internal garage, and the loft is insulated to about 270mm.

If you are still here, thanks for taking the time to read and thanks in advance for any help given.

 

[SimonJohns]

One pipe systems used to use special radiatiors to work correctly. You will need to speak to manufacturers of the radiators to check that they are comparable with a one pipe system

 

[diamondgas]

You just replacing the radiators, why? Do your rooms heat up okay with the radiators you have installed already? All the rads get hot top to bottom? If not then bigger ones aren't going to help IMO! If they are okay and you just want new ones then why not replace them with their new equivalent size? much less hastle. Repiping different size radiators onto the original one pipe system could be asking for trouble It all seems a bit of a strange request ...... Hohummmmmm!

Good luck !

 

[dontknowitall]

As a rough guide:

l x w x h x 0.045 = Kw required
I also think it's 1Kw per 5 m3

These are really rough and ready figures though and will work for a calculation for a one off room.

When doing the whole house (in your case) it's much better to conduct a whole of house heating requirement (can't remember the exact phrase), ensure the boiler is the correct size, correct sized pipes, then radiators, etc, etc.

The reason for doing this is that although the radiators might be sized correctly for each room, the boiler might not and the end result might well not work as expected and could well be worse than the present system.

In my most humble opinion, errors and ommissions excepted, caveat .... etc, etc, etc!!

 

[PlumbBobBob]

measure the radiators you have at the moment if they are recent enough they should in metric if not there will need to be adjustments made to the pipework to the radiators

 

[AWheating]

you first need to work out the U values of the walls..... for example solid brick of 340mm with plaster is 1.64, solid brick of 100mm is 2.97, cavity (brick,gap,brick) is 1.37, solid concreate 200mm is 2.8.

then the U values of the floors and ceilings. Once you have these values then you can calculate the heat lossess from each room.

Or you could use this

City Plumbing Supplies - Find your nearest CPS branches

once you have done this you will need to phone a radiator manufacture and request information of there radiator heat outputs for a single pipe heating system. The tables they normally base there heat outputs on are designed for a 2 pipe system with a flow and return difference of 20*c.

 

[PlumbBobBob]

did you fall asleep there?

 

[AWheating]

LOL

i was trying to eat my dinner while typing and somehow managed to click the reply button.

 

[baby chicken]

Thanks to all who have replied.

To answer diamondgas's post, all radiators now get hot top and bottom after removing radiators and flushing out, I have also had some sentinel cleaner run through the system.

The problem is that the rads get hot but they don't seem to throw any heat out or very little, I dont know if this is due to them being corroded or rusted up inside or to do with the layers of paint on them.When we moved into the property the kitchen and bathroom rads had already been changed to newer double convectors and you can feel the heat being thrown out of these.

I do realise that fitting larger rads may cause problems but I thought it might be worth giving it a try or at least fit new rads the same size.I intend on getting a combi fitted in the future and I would guess that this will then need changing to a 2 pipe system, but that is beyond my budget at the moment.

The rooms do get to temperature eventually but it does take quite a while.

 

[diamondgas]

Thanks to all who have replied.

To answer diamondgas's post, all radiators now get hot top and bottom after removing radiators and flushing out ...The rooms do get to temperature eventually but it does take quite a while.

Replacing old single panel radiators with the newer ones with the fins on the back (convector radiators) can make a significant difference without any major pipe alterations or decorating needed. Measure your old radiators width and height and post them here. You'll quickly get a response as to whether they're easily swapped or not

If the rooms are getting hot enough now then in my opinion replacing them with their equivalent new convector radiators will most likely give you the improvements you're looking for. No guarantees on a one pipe system alas You need special TRV's for one pipe systems by-the-way.