Vertical rads positioning vs efficiency

Housewifeofnowhere · 27 Nov 2023

Adding a vertical rad into our new extension. I noticed the pipes were centered in the wall which I didn’t like so I asked the plumber could we move the rad closer to the corner.

Does anyone know of this affects the efficiency of the rad?
We were told by moving it closer it would reduce the efficiency by 30%

88v8 · 1 Dec 2023

Rads should be under the window.
A vertical rad is usually a style/lack of space compromise.
Putting the rad anywhere but under the window risks creating a thermocline where the cold air moves down from the window and up from the rad, creating an uncomfortable circulation.
Don't know about the 30%.

BlueLoo · 1 Dec 2023

Women love this ****.

Vertical rads, rad covers, putting the sofa, chair, the dog, Infront of them, moving them to corners, behind doors etc etc....

"It's cold".......

omph · 1 Dec 2023

88v8 said:
Rads should be under the window.
A vertical rad is usually a style/lack of space compromise.
Putting the rad anywhere but under the window risks creating a thermocline where the cold air moves down from the window and up from the rad, creating an uncomfortable circulation.
Don't know about the 30%.

But isn't that also applicable to external facing uninsulated walls, pvc french doors etc ? I thought the positioning of the radiator under the window was done back in the days to warm up any draughts getting through.

88v8 · 1 Dec 2023

omph said:
But isn't that also applicable to external facing uninsulated walls, pvc french doors etc ? I thought the positioning of the radiator under the window was done back in the days to warm up any draughts getting through.

Yes it was, but there will always be cold air 'falling down' the window. Even with dg, the glass is going to be the coldest surface in the room. So that's where the heat needs to be.
Just be careful that when the curtains are drawn they don't cover the rad. That elementary error can be avoided with a wide window cill.

Housewifeofnowhere · 2 Dec 2023

BlueLoo said:
Women love this ****.

Vertical rads, rad covers, putting the sofa, chair, the dog, Infront of them, moving them to corners, behind doors etc etc....

"It's cold".......

Really helpful thanks

Madrab · 2 Dec 2023

88v8 said:
Rads should be under the window.

There is a long running discussion (years and years) over whether rads should be sited under the window or next to the door, either or seems to be the norm depending on how it's looked at.

@ the door so it warms any colder air entering the room through or under the door to minimise draughts, the other to create a thermal barrier and reduce heat soak that a large piece of glass can be.

Housewifeofnowhere said:
vertical rad

Is this a column rad? If so, I wouldn't worry too much about efficiency as they are now being found to be absolutely useless at heating anything but the smallest of spaces due to the way they heat the space around them

omph · 2 Dec 2023

Madrab said:
Is this a column rad? If so, I wouldn't worry too much about efficiency as they are now being found to be absolutely useless at heating anything but the smallest of spaces due to the way they heat the space around them

Do you have any more info on this ? Is this for single or double ? also because they dont have any convector fins ?

Madrab · 2 Dec 2023

omph said:
Do you have any more info on this ? Is this for single or double ? also because they dont have any convector fins ?

Yes, exactly, very little convection.

Only real evidence I can give you is real world experience - having warned clients not to fit them, them insisting that they are fitted, then fitted them and then back a year later to rip them out and replace them with convecting rads - that has proven that they look good but are absolute crap at space heating. That coupled with poor internal circulation, slow heat up times and unless they are well supplied with flow from the system never actually heat up properly.

The science behind it is, column rads are 80%/90% radiation, 20%/10% convection (double/single) so they are great at heating everything within 3 ft of them, expecting anything else is just a waste of time.
Normal convecting rads are 90% convection and 10% radiation, therefore heat the larger space much more efficiently using convection currents and will heat the space much quicker.

88v8 · 2 Dec 2023

Madrab said:
Yes, exactly, very little convection.

Only real evidence I can give you is real world experience - having warned clients not to fit them, them insisting that they are fitted, then fitted them and then back a year later to rip them out and replace them with convecting rads ...

Column rads can be excellent in terms of heat from a small wall space... if they're like this... one of a complete cast iron system I installed in 1982 in our previous house

Crane... four column, ten section, 30" high, 4500 btu. Weight 150lb... I had more muscle back then....

Madrab · 2 Dec 2023

88v8 said:
Column rads can be excellent in terms of heat from a small wall space... if they're like this... one of a complete cast iron system I installed in 1982 in our previous house

Crane... four column, ten section, 30" high, 4500 btu. Weight 150lb... I had more muscle back then....

Totally agree, in smaller speaces and bathrooms etc then they can work just as well as their radiated heat can reach most of the user space that and the one in your pic is very different to the modern designer ones that everyone is installing these days. Should maybe be clearer when discussing the subject. The one in your pic will have a better convection ratio given they have lots more air slots etc.

Don't get me wrong I'm not saying column rads cannot ever work but to do the job as efficiently as the convecting rads they usually replace then they normally have to be oversized and therefore require more heat. Most people match the new rads output to the standard rads they have at the time and that just doesn't usually work. That and they try to use them in large open spaces and again they don't tend to be anywhere near as effective. As suggested I have had to replace lots of them where clients have changed the old ones out for designer columns and they just didn't manage to heat the space properly, once they were back changed to the old albeit contemporary/designer types of convecting rads they were back to normal again.