Radiator

metricspaces

Would anyone know what is the brand\manufacturer of the radiator in the photos below? It's a little over a year old.

Front:


Top:


Side:


Angle:

metricspaces

The only identification marks I could see are on the valve cover which has Myson on it. So I'm guessing it's a Myson rad
Looks identical to this one here https://www.myson.co.uk/products/premier_he_metric.htm

I'm looking at replacing it with a different sized rad. So I wanted to know the BTU of my current one. Based on the Myson site is 4793 BTU for my 1000m x 450m rad.

John.G

metricspaces wrote: »

The only identification marks I could see are on the valve cover which has Myson on it. So I'm guessing it's a Myson rad
Looks identical to this one here https://www.myson.co.uk/products/premier_he_metric.htm

I'm looking at replacing it with a different sized rad. So I wanted to know the BTU of my current one. Based on the Myson site is 4793 BTU for my 1000m x 450m rad.

Based on the "Product Selector" in that very interesting link above, the 4793 BTU (1.4 KW) is based on a "50 deg" standard ie Flow 75C, Return 65C, room temp 20C. That standard is fine for SE (non condensing) boilers but if you have a condensing boiler you should maybe consider running it with say Flow 65C and Return 45C, that means you will be running it with a very high rate of condensing (greater efficiency) but if you do that then to get the same 4793 BTU output you would have to install a 1600MM X 450MM rad. The 1000X450 above would only output 2866 BTU (0.84 KW) at 65/45C or only 60% of its output at 75/65C. Of course if all your other rads are based on the "50C" (or even 60C) standard then it might take a very long time to heat up the house from cold if you run the boiler at those lower, more efficient, temperatures.

metricspaces

Thanks! I will check to see what type of boiler I have.

On the topic of BTU. Is there any reliable calculator out there to calculate the BTU for a room? Every one of them I use online give a different number.

My house is A3 rated, timber frame, built in 2017.

Is there some calculator that BER assessors use to calculate and specify that BTU output should be available for a heat source for a particular room?

John.G

metricspaces wrote: »

Thanks! I will check to see what type of boiler I have.

On the topic of BTU. Is there any reliable calculator out there to calculate the BTU for a room? Every one of them I use online give a different number.

My house is A3 rated, timber frame, built in 2017.

Is there some calculator that BER assessors use to calculate and specify that BTU output should be available for a heat source for a particular room?

There are a lot of views out there on how to calculate the heat loss, some say that there should be a figure available (from your BER) for each room heat loss based on the various U factors etc when the BER is carried out, the DEAP then say something like.... the heat required in watts is that loss (fabric+vent)X max temp differential X1.1, the max differential temp loss might be taken as 22 (21 - -1)), I have seen other sort of rule of thumb? saying to use the room area in M2X35(or40) to give the power required in watts, maybe in a new build a heating engineer should carry out the calcs?.
If you have all your rads all ready installed it would be interesting to see their sizing vs each room area, what is the area of the room with that 1000X450MM (1.4 KW) Radiator?.
Most of (1972 house) my rads were vastly over sized but I have fitted TRV's in all except two which are controlled by the room thermostat and all the rooms heat up rapidly and then throttle in to give the required constant state heat.

Forgot to say that I have a SE (non condensing) oil boiler but if/when I do fit a HE boiler and run it at 65/45c then, in most cases I will still have sufficient radiator surface.

metricspaces

The room with this radiator is the living room. It is 4m x 4m and 2.4m height.

The room has double glazing uPVC window (Munster Joinery future proof range). I'd guess 2m x 2.5m roughly. It is directly south facing.

Room has solid concrete floor. The room above is a heated room.

I've TRVs on all my rads. I don't mind oversizing as TRV can deal with that. What I want to avoid is undersizing and end up paying twice.

My thinking is the builder would have had to size the radiator appropriately to get his BER ( I'm just guessing - but when I was getting the multi fuel stove for the same room the builder said it needed to have a certain output so he could get his A BER rating). So if I just match the BTU of this existing radiator I should be ok?

John.G

metricspaces wrote: »

The room with this radiator is the living room. It is 4m x 4m and 2.4m height.

The room has double glazing uPVC window (Munster Joinery future proof range). I'd guess 2m x 2.5m roughly. It is directly south facing.

Room has solid concrete floor. The room above is a heated room.

I've TRVs on all my rads. I don't mind oversizing as TRV can deal with that. What I want to avoid is undersizing and end up paying twice.

My thinking is the builder would have had to size the radiator appropriately to get his BER ( I'm just guessing - but when I was getting the multi fuel stove for the same room the builder said it needed to have a certain output so he could get his A BER rating). So if I just match the BTU of this existing radiator I should be ok?

Getting a bit confused now, are you saying that you want to replace the 4903 BTU Rad with one dimensionally different? But having the same output which seems fine.

metricspaces

John.G wrote: »

Getting a bit confused now, are you saying that you want to replace the 4903 BTU Rad with one dimensionally different? But having the same output which seems fine.

Yes that's correct. Replace existing radiator with one dimensionally different but with similar output.

Planning on getting one 55cm W x 65cm H x 23cm D.

I'm trying to gain back wall space to allow me push a sofa right up against the wall. The wall is about 2.9m wide so roughly:
* 20cm gap to edge of sofa
* 190cm sofa
* 80cm for space for radiator & gap either side

The only place for the sofa is against same wall as radiator. And only place for radiator is in this same wall. So it's not ideal on two fronts - blocks heat getting into room and pushes sofa further into room.

See mockup below:

3D view



Plan view (missing window on wall at bottom of image!)



Real life mockup of new radiator size

John.G

No, you cant get that output from a rad within those dimensions, you can get 3684 BTU (1.08 KW) from a 540X690MM rad (only 40MM higher than your spec) but IMOP that output should be adequate for your requirements, with a room of 16 M2 (4X4), facing South, especially with a A3 BER

metricspaces

Definitely you can get a radiator with those dimensions and output. See https://www.dqheating.com/column-radiator-collection/peta.html

metricspaces

John.G wrote: »

you can get 3684 BTU (1.08 KW) from a 540X690MM rad

Do you have a link to more details on this rad?

Whilst the link I provided above does have a rad with my spec to give the same heat output as existing rad, they are very pricey. If I can get a much cheaper one that's close to my spec and gives sufficient heat output I would consider.

John.G

metricspaces wrote: »

Do you have a link to more details on this rad?

Whilst the link I provided above does have a rad with my spec to give the same heat output as existing rad, they are very pricey. If I can get a much cheaper one that's close to my spec and gives sufficient heat output I would consider.

Didn't get a chance to view that link yet but probably aluminium.

Re the 1.08 Kw one that I suggested above, I got that from your original Myson link above.
Premier HE27 DC 21 Double Convector 690mm 540mm 1079 watts
If this does put out the claimed output then it should be OK for your A3 rated room, You won't get any steel rad double of those dimensions (maybe a treble?) to output 1.4 KW IMO at 75/65/20C.

Theoretically, if you use the "finger in the air" rule of thumb of 35watts/M2 then 0.56 KW(1910 BTU) should be sufficient for a 16M2 room!!.

Wearb

It is unlikely that an A3 rated house is running at Delta t 50.
What is your heat source?

John.G

Wearb wrote: »

It is unlikely that an A3 rated house is running at Delta t 50.
What is your heat source?

Don,t know what his heating source is but per correction calcs that 50C Rad (1.08 KW) should output 0.68 KW at a delta T of 35C (65/45/20), do you think that is sufficient to heat up and maintain 20C in a South Facing 4M X 4M A3 rated room?.

metricspaces

Wearb wrote: »

It is unlikely that an A3 rated house is running at Delta t 50.
What is your heat source?

The heat source is gas. I'll look tonight to see what kind of boiler it is.

How do builder size radiators when fitting out a house? Surely there must be some recognized standard way of calculating the heat requirements for a room? Like I mentioned above, every BTU calculator I use online has a different result.

I would be uncomfortable ordering a radiator with lower BTU than my current one unless I had a good confidence in how to calculate the BTU for the room. Otherwise I risk pay twice for a rad and twice for a plumber.

John.G

metricspaces wrote: »

The heat source is gas. I'll look tonight to see what kind of boiler it is.

How do builder size radiators when fitting out a house? Surely there must be some recognized standard way of calculating the heat requirements for a room? Like I mentioned above, every BTU calculator I use online has a different result.

I would be uncomfortable ordering a radiator with lower BTU than my current one unless I had a good confidence in how to calculate the BTU for the room. Otherwise I risk pay twice for a rad and twice for a plumber.

It's probably prudent to try and get a Rad of the same output.... have you considered a vertical rad or do you consider them too ugly or what?, I think you have plenty of height?.

metricspaces

John.G wrote: »

Didn't get a chance to view that link yet but probably aluminium.

There are "mild steel" according to website https://www.dqheating.com/column-radiator-collection/peta.html

John.G wrote: »

Re the 1.08 Kw one that I suggested above, I got that from your original Myson link above.
Premier HE27 DC 21 Double Convector 690mm 540mm 1079 watts
If this does put out the claimed output then it should be OK for your A3 rated room, You won't get any steel rad double of those dimensions (maybe a treble?) to output 1.4 KW IMO at 75/65/20C.

Ah, I see it now. I was looking at the wrong catalog. They have a few.

I see they have a compact range with a Triple Convector Type 33 https://www.myson.co.uk/static_files/my/media/downloads/04.%20SelectCompact.pdf

metricspaces

John.G wrote: »

have you considered a vertical rad or do you consider them too ugly or what?, I think you have plenty of height?.

Yes I've ruled out a vertical rad. The room is small so it will not look good. Also I will have paneling up to 900mm height from ground and wallpaper above the paneling. The panelling will be painted white, so a white rad will blend in with it and "disappear" somewhat.

You'll see purple tape on the photo where I mocked up the cardboard rad. This tape is where the paneling will stop and wallpaper will start, so I want to keep the rad below this tape level.

John.G

metricspaces wrote: »

Yes I've ruled out a vertical rad. The room is small so it will not look good. Also I will have paneling up to 900mm height from ground and wallpaper above the paneling. The panelling will be painted white, so a white rad will blend in with it and "disappear" somewhat.

You'll see purple tape on the photo where I mocked up the cardboard rad. This tape is where the paneling will stop and wallpaper will start, so I want to keep the rad below this tape level.

There is a triple 600X600 (myson) which outputs 1.4 Kw, will this fit?/suit?. there is no 600X500 only 600X400 which only gives 0.95KW.

Wearb

Also there are fan assisted rads which would give greater output for a smaller size. I have no experience of them, they might be noisy.

If your boiler is high efficiency, it will have a condensate drain going to a gully or soil stack.

metricspaces

John.G wrote: »

There is a triple 600X600 (myson) which outputs 1.4 Kw, will this fit?/suit?. there is no 600X500 only 600X400 which only gives 0.95KW.

When they say "It uses a 33mm pitch", does that mean it is 33mm from the wall when hung? Or the rad itself is 33mm depth?

I would need 100mm either side for pipes\valves. Which brings overall width to 800mm. Slightly wider than I wanted.

John.G

metricspaces wrote: »

When they say "It uses a 33mm pitch", does that mean it is 33mm from the wall when hung? Or the rad itself is 33mm depth?

I would need 100mm either side for pipes\valves. Which brings overall width to 800mm. Slightly wider than I wanted.

I am seeing rad (type33) debth of 152mm, rad front face to wall 170mm which gives 18mm rear face from wall.

metricspaces

Wearb wrote: »

It is unlikely that an A3 rated house is running at Delta t 50.
What is your heat source?

I've a condensing boiler. Model 30 from spec below.

Wearb

metricspaces wrote: »

I've a condensing boiler. Model 30 from spec below.

Then it's really unlikely that your system is set to run at Delta 50. You might need to factor in another 40 or 50% increase in radiator size if you are reading from a Delta 50 chart.

metricspaces

Wearb wrote: »

Then it's really unlikely that your system is set to run at Delta 50. You might need to factor in another 40 or 50% increase in radiator size if you are reading from a Delta 50 chart.

How do I tell what Delta my system is running at?

Wearb

metricspaces wrote: »

How do I tell what Delta my system is running at?

Plummer or your rgi might be able to help. You could measure steady state flow and return at boiler. Also you could work out heat loss for each room and compare that to existing rad size.

metricspaces

Wearb wrote: »

You could measure steady state flow and return at boiler.

How do you measure this?

Wearb wrote: »

Also you could work out heat loss for each room and compare that to existing rad size.

Do you mean the BTU value? How would you calculate this?

John.G

metricspaces wrote: »

How do you measure this?

You could try a thermal gun and take the flow and return temp on your existing Rad and also take it as close as you can to the boiler flow&return lines as close to the boiler as you can, I have never found these (thermal gun) readings to be very accurate (usually anything up to -10C lower) but it will give a fairly good idea of the delta T between the two.
What is the boiler stat set at just now? that will give you a very accurate idea of the flow temperature at least.

If the 1.4 KW rad is heating the room OK now then the new rad at 1.4 KW should be fine except that you turn down the boiler stat settings to minimum, then, as I stated before the rad output might fall to 0.84 KW or so.

Wearb

metricspaces wrote: »

How do you measure this?



Do you mean the BTU value? How would you calculate this?

Some equipment such as multimeters and Flue gas Analysers have the functionality to measure temperature. Also thermal ir guns.

There are lots of online calculators to measure btu or Kw/h. You could use a few and average it out.

But as suggested above, the best option is knowing if the existing rad is already good enough and matching its output to new one.

metricspaces

Wearb wrote: »

But as suggested above, the best option is knowing if the existing rad is already good enough and matching its output to new one.

Thanks guys! Yes, I think I will go with this. I will get a new rad that has BTU close to my current rad.

My rad is rated BTU 4793 @ Delta T50 and BTU 2455 @ Delta T30. If I buy another rad rated BTU 4793 @ Delta T50 will it be more or less the same figure at Delta T30?

If anyone knows any other brands that fit my requirement that would be helpful too. What I want is:
* Width 550mm or less
* Height 800mm or less
* Depth up to 300mm would be acceptable
* BTU around 4793 at Delta T50

John.G

metricspaces wrote: »

Thanks guys! Yes, I think I will go with this. I will get a new rad that has BTU close to my current rad.

My rad is rated BTU 4793 @ Delta T50 and BTU 2455 @ Delta T30. If I buy another rad rated BTU 4793 @ Delta T50 will it be more or less the same figure at Delta T30?

If anyone knows any other brands that fit my requirement that would be helpful too. What I want is:
* Width 550mm or less
* Height 800mm or less
* Depth up to 300mm would be acceptable
* BTU around 4793 at Delta T50

Yes, Your new Rad if rated 4793 BTU @ 50C Delta T should output 2455 BTU @ 30C Delta T.

For interest, here are the correction factors...
https://www.aelheating.com/how-to-calculate-delta-t/