OT: Any heater recommendations?

[R D S]

Does halogen warm a space? Or does it merely warm things in it's line of sight?

[Lino expert]

I *think* they've got a fan in to push the heat out...but am willing to don orthopaedic shoes and stand corrected should anyone know better.

[The Natural Philosopher]

both.

[T i m]

Picking up on that if I may ... so I have one of those split unit air con thingmys that has heat and cool options. Is it more efficient than say a fan heater at heating then you say?

Cheers, T i m

[T i m]

Hmmm, while we are on the subject .. ;-)

Our daughters (box) room is North facing and exposed on 3 sides. The house was built in 1897 and is solid 9" brick construction. There is no central heating but 'clever' storage rads in the main bedroom and bathroom that seem to work pretty well.

There is reasonable insulation in the loft over the whole house and a bit more over her room. The Nth and West (the flank) internal walls were lined with that 1/2" fiberboard (for insulation and to pin stuff to) and the one smallish window (facing East and the neighbours 'rear addition') is double glazed.

She has one of those mini wall mounted balanced flue gas heaters in there which seems to do the job very well [1] but is a bit slow to get started. As an experiment I've fixed up a little 500W convector heater and whilst that also seems to work well, again, takes a while to get going (as expected).

So, I was considering a wall mounted fan heater (so nothing could get left in front of it) as that would give fairly instant heat, be thermostatic and quiet (as in vibration heard through the floor). But, which is likely to be the most energy efficient these days (roughly) please?

We are on BG for the gas an Eon with Economy 7 lekky.

Cheers, T i m

[1] It always seems such a shame that so much heat has to go out through a hole in the wall. :-(

[Owain]

It might be, as long as it's a proper heat pump for heating, and not just a convector heater concealed in the indoor unit.

"Approximately 75% of the energy needed for heating comes from the environment. This means that for every 1kWh of electricity used to power the heat pump compressor, between 3 and 4kWh of heating energy are produced, giving the heat pump an efficiency of 300 ? 400% or higher." (dimplex.co.uk)

"Unfortunately [air-source system] may not be cheaper to run than a very well-controlled condensing natural-gas system at present. However, if your only fuel option is oil, then a well optimised air-source system could save you a significant amount of money and benefit the environment. Be mindful that these units can be a little noisy, will not last as long as a ground source system, and are not very efficient in mid-Winter."

source heat pumps do not work well below about 5degC outdoor temperature, depending on system, so additional heating is usually required. They also tend to work better with gentle, continuous heating with an output temp of 35-50degC which is cooler than conventional CH rtadiators. A house would therefore be slower to warm up than with radiators. Under floor heating and heat pumps are usually a good combination.

Owain

[Owain]

A Robinson Willey flued wall gas heater with 3kW output is listed as having a typical 80% efficiency, which is pretty good.

Some of the Baxi ones are flueless. I woudl not recommend those for bedrooms (or any room).

That's only an additional one-sixth extra power, which isn't a great improvement.

Best would probably be to upgrade the gas wall heater to a 5-8kW one. Despite being recommended by Dribble, Rinnai came up on a google as the sort of thing to look for

would involve comparatively little work if the gas pipe can stand it.

Otherwise a 3kW wall fan heater would be fairly oomphy eg Dimplex PHF, wall mounting, tilt/swivel and optional remote control.

Or a storage heater, although they'er not usually great for bedrooms. Seems a shame to use peak rate electricity when offpeak is available.

Owain

[Andrew Gabriel]

I use mine when I'm working at home during the day, and only need to heat the one room, and not the whole house, and sometimes at weekends too. Very rarely has it been cold enough outside during the day that the heat pump won't work. That's more likely at night, when I wouldn't be using it anyway.

I've had a power meter on it for 7 months now (covered some spring heating, summer cooling, and autumn/winter heating), and it's clocked up 103 units so far (around £15). It's difficult to know how much I've saved by not using the central heating, and thus questionable how long it would take to pay back what it cost.

[Andrew Gabriel]

That would be completely OTT for a box room IMO.

Before I installed central heating, I had a number of gas wall heaters. Most of the heating was done by the one in the dining room, a Drugasar 4.5kW output with modulating burner (which could keep the room temperature stable to 0.1C, the limit of my measuring accuracy). That had an enamelled pressed steel heat exchanger, which is very fast warmup (much less than a minute to full heat output), but those heat exchangers eventually crack or corrode through, so I ditched it when the central heating went in. However, in the large main bedroom, there was a Potterton Levante which was newer, and has a cast iron heat exchanger which last very much longer. Heat output is something like 2.5kW, and that's more than ample to heat the room, but the cast iron heat exchanger takes perhaps

10 minutes to heat up. I've kept it as backup for the central heating, and it still works fine.

Fan heaters are normally quite noisey.

[T i m]

Hmm, ok, I'll have a closer look, thanks.

T i m

[T i m]

Ok ..

Well as I've already got mine for cooling on the few unbearable days we get some years (not had such this year that I remember?) it luckily doesn't have to justify it's existence if used as a heater (if that's what you meant)?

I'll have to have another look on the info panel and see if I can provide more info.

Cheers, T i m

[T i m]

Oh, ok, that sounds pretty good. Any idea how that compares to a fan heater? I was thinking that because there is no flue there would be less directly wasted heat but then there is the motor etc?

This little beast is more than powerful enough and she generally keeps it on 1 (of 3) *once* the room has come up to temp.

Sorry, I meant instead of. ;-)

The experiment was to see if 500W would be enough to get the room warm (it seems to be) and do so quicker than the gas fire (don't think so).

Well that was my other thought. It would also mix the air better and I'm thinking the thermostat might read the temp better if not on the floor?

She had a small one in there (I fitted years ago) but because it's a particularly cold room it often couldn't cope. To be fair it generally could cope but we 'upgraded' it for the gas fire as that was more controllable and possibly cheaper to run at the time?

We still have the same size heater in the bathroom (in the 'airing cupboard') and because that's a new build room (block / cavity etc) it works much better.

Cheers, T i m

p.s. We had one of those fires behind a glass door at home when I was a kid and it heated the lounge very well. For other rooms we had on-demand fan heaters and they were good in that they gave instant heat. After playing in the snow with some mates one year we went back to their house (and we were frozen solid) and frustratingly for me they only had central heating (which was off in the day) and once on had to wait ages to get any noticeable heat in any of the rads!

[T i m]

That sounds like the one we still have here (in the lounge). It has 3 burners, the middle one being thermostatic and is rarely on 3 burners for more than a few mins and the middle burner turned down pretty low.

The little wall mounted b/f fire in daughter room also has a cast iron h/e and that suffers the same problem.

It wouldn't matter in daughters room as she wouldn't have it on at night and I thought if it was on the wall might not transmit as much noise through the floor (to the ceiling below) as a floor / plinth mounted one might? And, less chance of her leaving something in front of it.

Cheers, T i m

p.s. Do we have any rough figures re the running costs though for a gas b/f v on-peak fan heater / kw=kw etc please?

[Owain]

EDF for East Mids,

Electricity, lower of the two-part tariff, peak 10.36p/kWh. off-peak E7

4.71p/kWh

Gas, again the lower of the two-part tariff, 3.12p/kWh. However note the gas appliance is maybe 80% efficient compared to the electric.

It's easier to fit a timeswitch or runback timer to the electric appliance though, which might help with running costs.

Owain

[T i m]

Hmm (thanks) so could we say (roughly) that off peak lekky is probably about the same cost as gas (when it comes to simple space heating) now?

Yeah, that's true, and certainly easier to install and maintain. ;-)

So, to get the best of both worlds, daughter goes in her room at midday and turns her fan and gas heaters on. Let's say the gas heater will eventually hold the room at 21 deg, if we set the thermostat on the fan heater to say 19 degrees (assuming we could etc) she'd get the fast warm up of the fan plus the economy (and silence) of on-peak gas? ;-)

Cheers, T i m

[Owain]

Yes, but off peak lekky heaters aren't as convenient so may be left on at a higher-than-optimum level to avoid cold spells

Even better would be an lower heat level stat on the fan so if it was warmer than say 15degC the fan wouldn't come on at all and would leave the gas to do the job.

Owain

[T i m]

Understood.

We don't generally have any heating on if we aren't here so it would only be a matter of her turning both heaters on when she's going to be in the room for a while, lekky for fast warm up then the gas to take over (fan stat set accordingly etc).

If she was just going to be in her room for say less than an hour then she'd probably just use the fan heater.

Cheers, T i m

[geoff]

In message , T i m writes

Have you thought about one of these for short periods of usage?

offer for less than £9 ARM in their flier

[T i m]

Hi Geoff, ;-)

Hmm, yes, I sorta had considered such (and that's a good price for sure) but I think it's going to have to be something wall mounted (and I'm not sure I should modify a floor standing unit to be wall mounted)?

I had thought of one of those bathroom radiant wall heaters as it's only a small room and the radiated heat may be enough to make her feel 'warm' quickly. Nice and quiet but do they do one with a thermostat though?

Cheers, T i m

[Owain]

"direct debit" out of her pocket money should cure those habits!

Owain