Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!
Column radiators for heat pump
I have seen a couple of fancy column radiator recommendations kicking about in this forum which work well with a heat pump. Currently our single panel classic convection radiator in the hallway is not large enough to match the heat loss of the hall with the door opening etc.
I really want to go traditional column rather than stelrad K2 or K3... is this a bad idea? Does anyone have a calculator for calculating the BTU at lower temperatures?
Posted by: @encI have seen a couple of fancy column radiator recommendations kicking about in this forum which work well with a heat pump. Currently our single panel classic convection radiator in the hallway is not large enough to match the heat loss of the hall with the door opening etc.
I really want to go traditional column rather than stelrad K2 or K3... is this a bad idea? Does anyone have a calculator for calculating the BTU at lower temperatures?
Radiator manufacturers generally provide either outputs at lower temperatures, an equation, or the 'exponent'. For radiators other than fan radiators (and possibly radiators with a very high 'aspect ratio') the equation is invariably "output is proportional to deltaT^n" where deltaT is the average temp difference radiator to room and ^n means raised to the power of n (n is 'the exponent'). Furthermore n is almost invariably 1.3 or very close, so output is proportional to deltaT^1.3.
Thus (for example) a radiator that outputs 1kW at 50C deltaT will output (25/50)^1.3x1kW at 25C deltaT = 406W.
I don't know of any reason why fancy column radiators should perform particularly badly or particularly well with a heat pump, however others might,
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
I have a couple of tall (1.8m) column radiators im my kitchen diner. I presently have a boiler and have assumed the usual downrating for ASHPs. One problem I have experienced with my boiler setup is that it takes an age for the radiator to heat up. Flow and return are both at the bottom of the radiator and the installer did not fit the baffle - available seperately - to divert the flow up the first column to the top of the radiator. Conequently, the flow much refers to go straight across the bottom of the radiator from inlet to outlet. I don't know what would happen with the lower flow temperatures and higher flow rate with an ASHP in this situation, but I would definitely recommend ensuring flow across diagonal corners one way or another.
We have an 1800x500x100 mm. radiator in our dining area (insufficient wall space for conventional shape. This one works with our heat pump and provides a very even radiant heat over the whole panel space and I assume the convection is equally good - but it is well above our heads! Regards, Toodles.
Toodles, heats his home with cold draughts and cooks food with magnets.
- 26 Forums
- 2,725 Topics
- 63.8 K Posts
- 1,307 Online
- 7,126 Members
Join Us!
Installer Finder
Degrees of Separation
Latest Posts
-
RE: Jokes and fun posts about heat pumps and renewables
@transparent I’ve heard that that is why American cars ...
By Toodles , 1 hour ago
-
RE: HeatGeek vs Octopus surveys: puzzling disparity - any ideas why?
Have either quote provided room by room heat loss calcu...
By Old_Scientist , 15 hours ago
-
RE: Heat Pump Servicing & Maintenance – Good Value or Rip-Off?
@old_scientist if you are going DIY then you may wan...
By Papahuhu , 2 days ago
-
RE: Indevolt Batteries UK Support & Info Thread
After a short while that was followed by the 'power war...
By JamesPa , 2 days ago
-
RE: Samsung heat pump - data cable issue
That's well done. Cable is the correct type (LIYCY = 2x...
By bobflux , 2 days ago
-
RE: Electricity price predictions
I agree, we will find out at the next budget whether th...
By Old_Scientist , 3 days ago
-
RE: Missing flow temperature in Heat Geek proposal
@editor I went through HG website, so should be ok for ...
By sttpd1917 , 3 days ago
-
Who did the Freedom Heat Pump cloud server and what did...
By Mars , 3 days ago
-
RE: Who's your electricity provider and what's your tariff?
Reading between the lines of what octopus are doing wit...
By JamesPa , 3 days ago
-
RE: Air to air bus grant installer anywhere
The through wall two hole ones have their place (listed...
By EtchedPixels , 3 days ago
-
I hope it goes ok, Hon can be hard to set up IF the sof...
By Graham Hendra , 3 days ago
-
@clockworks Hi, So there is a big difference between st...
By ASHP-BOBBA , 3 days ago
-
@editor wellvery comprehensive answer. I will get all i...
By Keithb , 3 days ago
-
RE: Advice on my Heat Pump Journey: Old Stone Built Detached Cottage
all good advice I will follow this up
By PaulC , 3 days ago
-
Heat of vaporization of water is 2.25 MJ/kg (0.625 kWh/...
By bobflux , 4 days ago






