Cheap heating

[Fred]

I've often thought that a tumble dryer using a heat pump would be an ideal unit but have never seen one. Who makes this type?

[meow2222]

At 700w per sqm, thats around 5.6m2.

Yes and no. CH isnt run at night, night warmth comes from storage in the house bricks. You capture the heat in the day, it warms the bricks up, and this heat stores for a while, warming the interior air.

Closer to twice that. But you can harvest more heat, and theres no run cost.

If you need to do it cheap, a set of polythene faced panels should come in at under 100. By the time the poly goes you should have saved enough for rigid plastic of glass.

No, this is a complete misunderstanding. Solar flat plate space heating has nothing to do with water, thermal stores, UFH, or pumps. The collectors are glazed frames with black cloth absorber, and nothing else. The hot air rises out by convection, no pumping is needed. The fabric of the house does the storage. Since heat capture is so cheap you can go a bit above your target temp in the day, giving good storage.

Full set of panels youre looking around =A3300. For automated control you need a thermostat and a motorised damper. Thats it.

NT

[Andrew Gabriel]

I made one. It's an airing cupboard with no hot water cylinder in it, but a dehumidifier. Dries a load of washing in about an hour, or longer if it was all towels and/or heavy cotten jeans. It has a humidistat so it cuts out when the cloths are dry.

The dehumidifier is 400W, so you get 400W of heating, plus the extra effect of the dehudification drying. I had to fit a thermostat too, so it cuts out if the temperature gets to 30C (max working temp of the dehumidifier). Usually get about 1.5 litres of water from it for a typical wash (which includes a 1400RPM spin), most of which is used for watering the plants, and a little in the steam iron.

[John Rumm]

Yup that is it... the refrigerant can absorb heat from the (apparently cool) outside buy virtue of having that side of its heat exchanger cooled well below the ambient outside temp.

There will come a point where the outside temp falls so low that there is no nett heat flow to the heat exchanger. This will be governed by the refrigerant used and the pressure differential used in the refrigeration system.

yup...

Well if you are installing one for cooling it makes sense to pay a little extra for one that can be a heat pump also.

As a source of heat it is a good deal cheaper to run than a straight electric heater, even if the efficiency does tail off in the coldest weather.

Very true... there have been plenty of occasions I have been explaining something to someone that I thought I understood quite well, only to have a sudden flash of realisation that now I really do understand it!

[Andy Wade]

Hi Russell, OOI how much do you pay for Electricity over there? And are energy prices rising rapidly like they are over here?

[John Rumm]

Twas dribble who was recommending stores, pumps, and UFH etc... I was just highlighting the cost of his suggestion was a tad more than running a pump!

[Doctor Drivel]

There is not problem there at all. This is how it is.

[Doctor Drivel]

AEG, someone else, and now Whirlpool in the USA. They use 30% less energy. Over a year a substantial amount of electricity saved. Fridges are quite cheap throw away items. I see no reason why heat pump tumble dryers can't be the same, as they use similar components.

I see no reason why a heat exchanger cam be fitted in a tumble dryer and have it run off the CH system, which would make running them very cheap too.

[Matt]

The "standing charge" not always higher but they still screw you!

National Power

E7 Day First 61 units 13.1p (=£2.94 standing charge) E7 Day after 61 units 8.27p E7 Night 3p

Normal Tariff first 121 units at 10.46p (=£3.34 standing charge) then 7.7p per unit

[Matt]

No its not. "-272C above absolute zero" is impossible, even in your wishy washy world of kW/h water meters.

[Matt]

There is no reason for them to, the rest of their economy might be on the verge of collapse but at least the lights won't go out as just about the only thing France has got right is the huge amount of nuclear generation. But, having seen the quality of the plumbing and wiring on a Renault 5, it might ultimately prove to be a bad idea :-)

[Doctor Drivel]

[Matt]

"Doctor Drivel" in a drunken soggy footed haze:

Read what you wrote Dribble "-272C above absolute zero"

Back to the counter you utter fool and sell some more copper.

[Doctor Drivel]

More drivel to have to snip.

[Richard Conway]

I generally find that explaining things is a great way of sorting it out in your head. That's why it doesn't really bother me when SWMBO is clearly not listening to me when I'm telling her about my latest idea/project - its only for my benefit that I'm telling her anyway!

[Hugh]

Try

and the Toshiba Daisekai brand with COP o

4.5, it is not advertised on the site but I bought one over the phone Cheers

Hug

-- Hugh

[meow2222]

ah right:) He didnt notice that the real world run cost is the capital cost amortised, which for his wet system would be high.

NT

[meow2222]

Ever had those times where finally you do understand it, until some new point comes along, at which point all is not understood. Then when that ones workwed thru you do again, properly this time. Then another comes along... :)

Who said life was simple?

NT

[Doctor Drivel]

A solar air system is cheap and efficient enough, but storing heat is problematic. You need water or lots of stones to do so.

[manatbandq]

At work we decided every engineer really needs a cardboard cutout of another engineer to talk to. It was never actually implemented but anytime someone has a problem they just drop by a colleague's desk and ask for some cardboard cutout time. A mirror on the desk so you can talk to yourself may also work.

MBQ