efficient heating

[Doctor Drivel]

"Colin Wilson" wrote in message news: [e-mail]...

It is undersized then.

[Doctor Drivel]

The norm in Germany is 100mm min'.

[Ed Sirett]

The things you can do quickly and cheaply are the simple things.

1) Draught proofing. 2) Make sure the boiler controls have thermostats on both cylinder and for heating. 3) lag pipes and cylinder in airing cupboard especially.

Slightly more work: Loft insulation. TRVs on radiators. modern HW cylinder or thermal store.

Much more work: double glazing (probably not justifiable for oil saving alone) modern boiler. dry lining?

If the radiators heat the house there is only a marginal benefit in fitting ones with fins and the only with a modern condensing boiler.

[Ed Sirett]

This is a trend in some of the new flats being built now. Each rooms has a wall stat or prog stat. Each room has wet UFH and each room is a zone. The supply for the UFH is from a large thermal store heated by over-night electric.

The standard of insulation is very high and the number do add up (which is some what irksome for a gas installer to admit).

[Colin Wilson]

We actually purposely went oversize compared to what the installer was recommending - if nothing else to get better throughput of DHW !

[Doctor Drivel]

"Colin Wilson" wrote in message news: [e-mail]...

Unless the rads are undersized or the pipes are undersized.

[Andy Hall]

No you don't. You reduce it unless the boiler can modulate down to match the heat extracted from the store.

Obviously. A thermal store will not eliminate that if the heat drawn from it is in the low kW range.

The only thing that you can affect with a thermal store in terms of cycling is the period of on and off times.

Unless you can reduce the boiler output, it will cycle. The question is then what the times will actually be.

[Colin Wilson]

Fairly standard sizes afaik, and standard pipework too (not microbore)

The rad sizes are as follows (as near as dammit)

32" master bedroom 27" bedroom 2 27" bedroom 3 16" hallway 24" bathroom 40" living room

As I say, these are all doubles and internally finned (which I believe is supposed to increase their output efficiency) - not sure what would normally be recommended though :-}

[meow2222]

It all depends. In some houses with no insulayion between rooms here, if one room is turned off the room temp drops quite a lot, so theres still plenty of saving to be had. It wont go cold, but down 4 degrees maybe, it all reduces losses.

50% of houses dont get average use, if those quartiles see decent savings that may make it worth it.

NT

[meow2222]

Depends how you install it. The only thing that need be seen is the stat.

6x warts @3w each = 18w = 0.18p/day. In pracitce it'll be less as they wont be powering the valve all the time.

NT

[meow2222]

tablets

NT

[Doctor Drivel]

Matt, you can eliminate it. You don't know these sort of things.

[Dave Plowman (News)]

I already drop the overall house temperature by 5 degrees for daytime. I doubt the bedrooms would drop much further than that most days.

Maybe.

[Andy Hall]

Please explain to me how you prevent a boiler producing (say) 20kW of output, if fixed when on and a load requirement of 10kW from turning on and off. All that can be achieved with a store is to reduce the frequency of this. That may be worth doing in itself, but it is not correct to say that it eliminates cycling. It can't - only the rate of on/off cycles.

[Doctor Drivel]

Matt, have it heat the cylinder directly using two stats with a tall cylinder with baffles.

[Dave Plowman (News)]

As in much else dribble will have is *own* figures for what consists of cycling. Comes from not understanding the meaning of words.

[dennis]

Its not very good though is it. You power the valve when it doesn't need heat. At least with a spring return valve you power it when you need heat so the electricity adds to the heat.

With a properly designed system with valves and timer stats on each room the boiler runs at maximum efficiency at all times and any electricity used adds to the heat when it needed.

Its just these stupid TRVs that cause the problems in the first place. They are just a stop-gap to retrofit to old systems and are cr@p for new systems.

[Doctor Drivel]

Please eff off as you are a total plantpot. The dumbest Jock of them all.

[Doctor Drivel]

Have it heat the water in the cylinder in "one-pass". No cycling.

>

[Andy Hall]

You are missing the point. When the cylinder thermostat is satisfied, the boiler will turn off. It will turn back on again when the heat is depleted. This is cycling. It may be on a long period of time but it is still cycling. OTOH if you meant to say no *short* cycling, as in what happens if the boiler output is much higher than the heat load and can't be reduced and so the boiler cycles on and off very frequently, then I agree with you.

The only way to prevent cycling altogether is with a boiler whose output can be modulated to match the demand.