On Sat, 07 May 2005 16:46:48 +0100, tom wrote:

Hi,
The price of the 13.4 kw propane gas heaters is about £90 - £100
nowadays but I have heard many people say that they are great but you
have to huddle round the heating pole.
I saw a tv program the other week "City Gardener" where he used some
small electric heaters that looked like floodlight's. I cant remember
how much he said they were or what make/model they were.

My patio is 26ft x 9ft so i suppose its long & thin.

Does anyone know whats the best way of heating such a space?

Should I use the 13.5 kw gas type you see in B&Q or is there something
better?

The gas ones seem a bit big & bulky.

I saw an old thread that mentioned infra red heaters, but i think it
was about a year old and semed to say the heat blows away easily in
the wind.

My pation is quite breezy.

Thanks

I've always thought the concept of patio heating to be bizarre and
profligate. Consequently I know little about them, but here are some
thoughts anyway.

Infra red (IR) radiation ('light', if you prefer) is like visible
radiation (light). It doesn't blow away. But I can see why air heated
by a bottled-gas heater will. I presume the bit at the top of such a
heater gets red hot and will emit IR radiation. But a large proportion
of the heat will just go straight up and blow away.

The ones you describe as being like floodlights sound like IR units.
IR heating works by warming the surfaces that the IR radiation shines
on. I would have thought they were the better bet for a patio, if you
must. They will be more efficient and may be cheaper to run than gas
heaters, hence the lower power rating of 1.3 kW. But they will be
directional, i.e. you point them at the people who need warming, so
you may need several. But you can only run a maximum of two off a 13A
extension cable. And the inverse square law will apply, i.e. if you
sit twelve feet from the heater, you only get a quarter of the amount
of heat compared to if you sit six feet from it (but that would also
apply to IR radiation from a gas heater, which is probably why people
have to huddle close to them to keep warm). Presumably bottled-gas
heaters have to be extra powerful for people to feel any benefit, as
most of the heat goes straight up and the whole world gets just a tiny
bit warmer, which is where I came in.

Screwfix do 1.3 kW electric IR patio heaters by Vent-Axia for approx
£135, plus postage: www.screwfix.com

Bottled gas will give you approximately 7 kW-hrs per litre of liquid.
For a 13.4 kW gas heater, that means it'll burn roughly 2 litres of
liquid gas per hour. I don't know how much small bottles of gas cost
and how many litres of liquid they contain, but you can find out and
work out the running costs. The 1.3 kW IR heaters will use 1.3 units
of electricity per hour, at whatever rate you pay per unit, but
probably about 10p per hour per heater. I imagine the bottled-gas
heater will be cheaper to buy and more expensive to run, while the
electric IR heaters will be more expensive to buy but cheaper to run.
You pays your money.....

I think I'd stick with jumpers and internal heating using fuel from
another type of bottle ;-)



--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net