Discuss Rate of heating in a living room? in the USA area at PlumbersForums.net
So if it's heating up the room at a rate of between 2.5C - 3.0C / hour, this is too slow? I think it's too slow, but wondering what opinions are.
This is with heating system at ~60C at the boiler, and the thermostatic valve radiator turned up full.
Having used several online calculators the highest BTU I get on any calculator is 3788 BTU using: Radiator Sizing Calculator - BTU and KW - http://www.radcalcer.co.uk/ for the room.rad sounds undersized
It's a WB Combi 30i boiler with the rad below:You say you have a flow temperature of 60°c? Is this a condensing boiler.
I have pointed a contact free thermometer pointed very close to the rad and it gives a temp of ~58 C.From -10 to 21dc 14 mins so something isn’t right
does the rad get hot hot eg 60dc ish
I have pointed a contact free thermometer pointed very close to the rad and it gives a temp of ~58 C.
Thanks.I would say the specs that the manufacturer has claimed are over zealous and would estimate it to emit around 1.5-1.8 kw (max)as it’s basically a single panel rad
Unfortunately I don't have a plumbing background, so I'm unsure what exactly this means.
I understand that k2 is a type of rad. Do you mean if using a double panel 1.2m x 600mm K2 rad this would give an average BTU output of 7401 BTU?
The current rad type which I have would probably need to be a lot bigger to heat up the room in 30 minutes since it's heating the room at ~ 2.5C - 3.0C / hour.
So essentially if I wanted to get this make/model of rad to heat the room up in a reasonable amount of time (and I only wanted one rad as it's a small room) the rad may need to be in the region of twice the output size of the one currently installed?correct
or another rad installed in the same room eg two rads
Also because you are running with a boiler temp of 60C then you will only be getting ~ 65% of a 50 deg rad output or ~ 4810 BTU (1.4kw).So essentially if I wanted to get this make/model of rad to heat the room up in a reasonable amount of time (and I only wanted one rad as it's a small room) the rad may need to be in the region of twice the output size of the one currently installed?
Should the boiler temp be run at a different temperature? I've set the WB combi to the recommended "e" setting and this is usually about 60C.Also because you are running with a boiler temp of 60C then you will only be getting ~ 65% of a 50 deg rad output or ~ 4810 BTU (1.4kw).
If you increased the boiler temp to 75C and with a radiator deltaT of 15C, you would then almost have a 50 deg (47.5) rad again or 94%% output but the boiler is then running with a return temp of 60C which is very uneconomic, if you run with a delta T of 20c you are down to 87% output, all rads should really IMO be oversized by a factor of at least 1.5 to allow for condensing boilers which run most efficiently with return temperatures of 50C or less.It looks like their only larger rad of this style is:
which has 9163 BTU as opposed to the 8218 BTU for the one which I have. I'd guess this won't make a huge difference in getting the room warmed in 30 minutes, so perhaps I might look at some other radiator design.1800 x 560mm White Vertical Traditional 3 Column Radiator
Create an old fashioned traditional look with these vertical column radiators, 1800 x 560mm and triple layered for extra warmth.www.radiatoroutlet.co.uk
Should the boiler temp be run at a different temperature? I've set the WB combi to the recommended "e" setting and this is usually about 60C.
It looks like their only larger rad of this style is:
which has 9163 BTU as opposed to the 8218 BTU for the one which I have. I'd guess this won't make a huge difference in getting the room warmed in 30 minutes, so perhaps I might look at some other radiator design.1800 x 560mm White Vertical Traditional 3 Column Radiator
Create an old fashioned traditional look with these vertical column radiators, 1800 x 560mm and triple layered for extra warmth.www.radiatoroutlet.co.uk
Should the boiler temp be run at a different temperature? I've set the WB combi to the recommended "e" setting and this is usually about 60C.
Apparently, with regards to the vertical rad which I have, there is no specific flow/return and it can be installed either way.This site has numerous posts re problems with vertical rads, some have to be installed in a certain way as they have a baffle to get the water circulating properly and apparently sometimes this isn't pointed out in the installation instructions. I would suggest taking numerous temperature readings on the columns and make a little sketch with the temps noted on it, as a very quick check you might just measure the temperatures at the flow and return connections, if these are only a few degrees apart then IMO you have a problem, just feeling the rad all over even should tell a lot.
I suppose there are two calculations that the heating engineer should do when sizing radiators, one is the calculation for the heat loss and the other for the correction factor to apply to a 50 deg rad. A required return temp of 40C with deltaT of 20C will result in a 30 deg rad based on a required room temp of 20C or a 27 deg rad based on a more realistic required temp of 23C, this will result respectively in 51.5% output and a correction factor of 1.94 or 44.9% output with a correction factor of 2.22, so as suggested with the above slow warm up problem, maybe install another rad of the same size?. It would be interesting if the flow and return temps were actually measured in the above case as the "58C" measurement implies a delta T of 4C (boiler temp 60C) which is unlikely IMO.
With regards to the point above, the valve retailer states that they, "recommend installing the wheel head on the flow in and the lock-shield on the return."The TRV is installed on the return, ensure it is bi directional (arrows pointing both ways), I would open it fully, remove the head and using the shaft of a a reversed hammer press the actuating pin firmly in, it should spring out but the movement is only ~ 5MM,
It's a steel radiator, just in the style of a traditional column rad.Heat up time of 20 minutes seems very long but again if these are cast iron maybe normal, I'm sure some one on here can advise,
Practically speaking my only suggestion is to get hold of a oil filled rad or equivalent, turn off the rad, set the electric heater to whatever power settings are available and that should point you in the right direction. My oil filled rad has three settings, 0.8kw(2730BTU), 1.2kw(4094BTU) and 2kw(6824BTU)
Okay; thanks very much.Yes, any kind of electric heater of known power that you plug in to get a comparison, I can't think of any other way.
Yes, any kind of electric heater of known power that you plug in to get a comparison
Replace that with a decent double glazed unit and you'll probably reduce the heat loss and hence radiator size by a significant amount, typically, about a third.One window (Single glazed): 0.80 m x 1.53 m
So, I've used a 2 kW heater without the fan on so as to make it as similar to the radiator as possible. I placed it at the same room location as the rad.
I've had the heating off in that room so the unheated room had a temperature of 11 C. It took 2.5 hours to get the room temperature up to 20 C.
The heater cut out at 20 C, so presumably the thermostat cut in. I turned the heater off at this point so that I could determine how quickly the room temperature then dropped. It dropped from 20 C to 15 C in 1 hour.
I know there are several pipes connected to the underside of the gas boiler. I could easily take the temperature with the contactless thermometer, however I wouldn't know which is the return pipe, or how this could be determined.With a high flow through it and a high return temp, this radiator will increase return temperature at the boiler substantially. What is the return pipe temperature at the boiler?
I'll look into that then.If your whole system was balanced so each radiator had a 15deg drop you might surprisingly be able to increase boiler flow temp yet lower return temp so increasing overall efficiency.
There are people in the properties next door. I think one particular issue with this room, is that I have removed all the paint from the timber window frame in order to re-paint. It was previously painted closed over decades and this may have helped keep cold air out!I am a bit surprised that with one external wall that is insulated this room temp drops to 11 deg overnight. Is the whole house cold? Are the properties next door empty? Sort that window!
I have done this and set the boiler temperature to 75 C for the heating system. Starting with a room temperature of 12 C, it took 4.5 hours to get up to 21 C.Increase your boiler set point to 75C, this should give you a 2.4 kw rad based on the 50 deg rating, if its "only" producing" 2.0 kw it should still heat up your room in 2.5 hrs. Once you have a rough idea of what these column rads are actually producing then combined with the window mod as suggested, may mean that you can retain this rad with a boiler temp of 60/65C.
The hottest pipe is the flow probably 22mm copper. Next hottest is the return. Often at opposite ends of the boiler. Measure after boiler on for 30 min or so.I know there are several pipes connected to the underside of the gas boiler
Perhaps return temp too high so boiler modulating down?Well, if a 2 kw electric heater got the temp up in 2.5 hours and a "2.4" kw column rad takes 4.5 hours then its pretty obvious that its not producing 2.4 kw for whatever reason, maybe original spec very optimistic as someone stated so what options now?
I could look into the temperature drop issue referred to by gpbeck above. Though even if this is sorted, perhaps it won't make the major improvement which would be required.Well, if a 2 kw electric heater got the temp up in 2.5 hours and a "2.4" kw column rad takes 4.5 hours then its pretty obvious that its not producing 2.4 kw for whatever reason, maybe original spec very optimistic as someone stated so what options now?
The hottest pipe is the flow probably 22mm copper. Next hottest is the return. Often at opposite ends of the boiler. Measure after boiler on for 30 min or so.
As you suggested, the flow and return are at opposite ends of the boiler, and are 22 mm pipes.The hottest pipe is the flow probably 22mm copper. Next hottest is the return. Often at opposite ends of the boiler. Measure after boiler on for 30 min or so.
The blank is on the right side of the rad directly above the lockshield which is also on the right. From what I have read earlier, the flow ideally should be connected to the TRV (especially since the TRV used here is not bi-directional), however as the lockshield valve is consistently hotter than the TRV, my suspicion is that this lockshield is connected to the flow.check if his is this way, ie the blank vent is directly above the flow pipe, also in the picture of his rad they have two circled items in red.
This, from a different (Rad) brochure above...
"Also due to the unique flow diverter built within all Revive column radiators the flow MUST to be on the same side as the permanent blank which is the opposite side to the air vent bleed valve."
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