Verical radiators - hopefully new questions

[Clive]

Hi,

I did a search on this group but didn't quite find my questions answered.

I need a couple of hot water radiators (driven by a conventional boiler and cylinder system) moved from horizontal in utterly stupid obtrusive positions to nice, lovely, shiny vertical radiators. This work is way beyond my capability so I have asked for quotes from plumbers recommended by friends.

First guy has been in and he calculated living room 1 needs 8600 BTUs and bedroom 2 requires 6200 BTUs.

Now, the only vertical radiator that approaches this output in wall space I have available in room 1 (500mm wide by 2000mm high) is the "Volcano"

and =A3500 !!! Ouch !!!

Consider the rad in living room 1. The existing horizontal radiator, two panel, no fins, 600mm high, 1800mm long, chucks out plenty of heat and achieves a temperature above my comfort level.

Three questions:

1) 600mm x 1800mm radiators are specified to only output about 5500BTUs. The heating performance delivered by the current rad is fine for me. So what I can't understand is why the calculation is coming up with 8600BTUs which can only be met by the expensive Volcano rad. Why can't I just get a 2 panel vertical rad with fins, 500mm x 2000mm, on the basis the existing horizontal rad is fine for me and ignore the quoted rating? Do vertical rads perform in a completely different manner to horizontal?

2) Is there a decent "online" calculator I can use to check (to within

500 BTUs) the figure the engineer has calculated? I know that seems (is) insulting of his knowledge and experience - but based on my difficulties understanding the heat output requirement I would like to check it (approximately) myself.

3) Would insulating the walls using 40mm Kingspan or Celotex cut down the heating requirement significantly and hence lead to smaller rads being required?

Thanks for any help or advice

Clive

[newshound]

Calculating requirements isn't all that exact a science. Did you tell the guy that your existing rad gives plenty of heat? He may have thought it safer to calculate from scratch and perhaps be a bit conservative to avoid possible future complaints of not enough heat. That said, I'd be inclined, as you suggest, to replace with nominal like for like output perhaps tweaked either way depending on the current comfort level.

Area for area, you'll get a little bit more effective output from a horizontal than a vertical (slightly warmer air will be passing the top of the radiator, so it will pick up less heat).

You could ask the guy to show you his calcs, and post them here. I expect if you say "why do I need 8600 when 5500 is fine now" he'll suggest a smaller rad. Won't save you much though, such is the price of being fashionable!

[mike]

There was a long discussion here about mounting a standard horizontal rad vertically:

you, I found it hard to find vertical rads that had high output, didn't look awful and weren't ridiculously overpriced. In the end, I found one at Wickes - higher output, lower price and not offensive to look at - so might be worth checking out their range and seeing if there's anything that's suitable. You can download the brochure and prices from the website.

[Clive]

Hi,

I discounted the idea of mounting a horizontal rad for two reasons

1) I assumed the "flow" in a horizontal rad is probably designed to require the inlet and outlet both to be a "low points" relative to the radiator

2) As in the thread (which I now remember skim reading when I first "researched" this topic) the mounting brackets will be positioned for horizontal fixing and would require an almighty bodge to convert to vertical fixing

I have found (surprisingly) B&Q have a fair range of vertical rads, mostly with the "Designer" label attached to the name. The best value for "high" output seems to be

Now, the quoted heat power output of 1800mm x 600mm 2 panel rads deliver about half of what my chappy calculated as needed by my room - implying I need to find a 4 panel rad ! The existing horizontal rad is (surprise) 1800mm x 600mm 2 panel with no convector fins - and performs quite nicely thank-you. Also, various online BTU calculators come up with a value of 4,000 BTU about half the original calculation. I'm going to have to talk to the chap and see where he is coming from with his 8,600 BTU value - it may be quite sensible.

I'm pretty committed to the vertical rad. As the lounge has an open fire - I can use that to supplement the heating on a really cold day - or put on a jumper - given I won't be able to afford the gas to heat the house.

Thanks for the replies.

Clive

[dennis]

Don't forget it possible to mount a couple of 12v pc fans on most rads and get far more heat out of them.

[Clive]

My local plumbers' merchant in Whetstone, North London, beat the price B&Q online were quoting for two vertical, 1800mm by 500mm rads. I have bought the rads, polyplumb pipe, connectors, valves etc. etc. Delivery is 2 days rather than 5 days from B&Q.

I sized the replacement rads on the basis the existing two panels without convector fins chuck out plenty enough heat for the lounge and the bedroom - so I have bought two replacement two-panel rads with the same surface area.

thanks for your comments.

Clive

[Martin Pentreath]

OK, I'm curious about this, because our living room can be a bit on the chilly side in the depths of winter. I was thinking about putting in another rad , but perhaps this would save me the cost of a new rad and a bit of upheaval. Any links/further info?

[dennis]

Its basic physics, more air flow, greater heat exchange. The airflow is normally limited by being convection generated, if you fan blow it it will be faster.

This all assumes that the pipe work and boiler have some spare capacity which they usually have.