Not sure rad is big enough

[ChrisJ78]

As the title really, not long had a new radiator installed in our small bedroom, but it doesn't seem to heat the room much. It takes the edge off but that's about it.

The rad is 600 high by 800 wide K1 or single panel with fins. The radiator itself gets damn hot.

The room is 2.3 long x 1.84 wide x 2.4 high (roughly). The room does have 2 external walls, one if which is insulated and the other is not as it has tiles on the front and I guess wood behind it.

Looking at the calculators online, the rad should have a high enough BTU output. Any ideas or am I just being paranoid? The room will be a nursery after our baby is born, so I don't want to cook him/her but I don't want to freeze baby either.

 

[muggles]

What are the dimensions of the windows and are they single or double glazed? Is your loft insulated and if so to what approx depth? What are the walls made of (bricks, blocks, cob...)?

Let me know these things, I'll run a proper calculation for you and let you know how much heat I think you need, and what size rad that equates to

 

[Agile]

Your rad is about 750W.

I would have specified about 1.4-1.5 kW based on what you have told us and a typical senario, d/g window, 100 mm loft insluation etc.

Tony

 

[Goldspoon]

Out of interest I ran the scenario through two online calculator thingymajigs and got approx. 0.7 KW from both...

 

[Agile]

I find those calcaculators seem to under estimate the heat required for small rooms on the corner of a house with two external walls.

I presume that the calculators took into account the two external walls.

When I look at rooms with a view to considering the size of rads I take into account other factors like exposure to wind etc, when heating is in adjacient rooms etc. that the calculators dont look at.

Tony

 

[TicklyT]

The calculators may give a reasonable indication of the heat loss through the building fabric from a sealed empty room in still air. In the real world people open and close doors, walk around, and some even dare to breathe in an effort to upset the calculations.

In the real world you need more output to warm the room up in the first place, overcoming the thermal inertia of the building fabric and all the fixtures and furnishings, and then maintain the temperature despite the best efforts of both the people living in the room and the weather outside.

You can throttle down a large radiator, but a small one can't work any harder than flat out.

 

[kirkgas]

off the top of my head i would fit a 600x600 k2 (about 1.2kw?) in a room that size

 

[usslessatdiy]

If I can jump in on this thread, I have kitchen/diner part of which is an extension. It's approx 6 x 4mtrs, the extension part (4x3) has three outside walls, double glazed French doors and a DG window, the old part has just one outside wall. The builder assured me the room would hardly need any heating as the insulation was so good and just relocated the existing rad which is a single 160 x60cm. The room is so cold so I've resorted to topping up the heat with an electric heater. What size rad would I need to heat this room to a comfortable level? I did use an online calculator but bearing in mind what others have said about them not being very accurate, I thought I'd ask you experts.

 

[ChrisJ78]

Ok, window is 120cm wide by 105 deep and double glazed. Loft insulation is 300mm, inner wall I think is breeze but I don't know. The cavity wall was insulated in January, but the wall where the window is on the front of the house couldn't be done because of tiles there.

I see what you're saying about the K2, Kirk. My bathroom has a 500w X 600h double and double fin and that gets loads warmer.

My living room is considerably larger incorporating the dining room, and that has 2 600x1200 K2 radiators and it seems to warm up quite nicely.

 

[Agile]

Ok, window is 120cm wide by 105 deep and double glazed. Loft insulation is 300mm, inner wall I think is breeze but I don't know. The cavity wall was insulated in January, but the wall where the window is on the front of the house couldn't be done because of tiles there.

Are you totally sure the wall there is a cavity?

If it is then I dont see why it could not be insulated. Indeed as the cavity "goes round the corner" I dont see how it would NOT become insulated when the other one was being done.

Sometimes those tiles hide the fact that its only a single leaf !

Tony

 

[ChrisJ78]

Well they wouldn't have been able to drill into them anyway. I think it's wood behind those tiles and then a layer of breeze block, but you're right to assume I'm not 100% sure. Assessor said it couldn't be done. Under the downstairs window is insulated, it's just that upper part. The side and back are fully insulated, apart from the loft walls obviously.

 

[heatingman]

hanging tile fascias are either batten & felt or brick/block with insufficient gap for cavity wall injection. There is a minimum. The tiles themselves have very good insulating properties.

 

[muggles]

If I can jump in on this thread, I have kitchen/diner part of which is an extension. It's approx 6 x 4mtrs, the extension part (4x3) has three outside walls, double glazed French doors and a DG window, the old part has just one outside wall. The builder assured me the room would hardly need any heating as the insulation was so good and just relocated the existing rad which is a single 160 x60cm. The room is so cold so I've resorted to topping up the heat with an electric heater. What size rad would I need to heat this room to a comfortable level? I did use an online calculator but bearing in mind what others have said about them not being very accurate, I thought I'd ask you experts.

What size are the windows/doors and how high is the ceiling please?

 

[muggles]

I'd go for 1.0-1.2kw minimum, more if you like your bedrooms hot

 

[ChrisJ78]

Would the system need to be drained to change a radiator upstairs?