That depends on the perceived need.
For example, in the past, tulip bulbs were imported at outrageous black market and legitimate prices, more recently ladies hosiery and nowadays it's tobacco and alcohol.
One doesn't *need* any of these but if the perception is there that these are luxury items then people will buy.
Do you have those pneumatic plunger time delay light switches? ;-)
.andy
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I never really understood those. You can get a DIN rail unit to do accurate hall light timing that can be connected up to any number of 99p non-latching switches. Instead, people install those pneumatic monstrosities (average service life: 2 months) at about 15-20 quid a piece.
Christian.
No, they re installed throughout. They all have stats, but not on teh water. On the fans :-)
They are on a seprate zone, altho it has some TRV rads as well.
Flow switch won't work. They don't cut the flow, just the fans :-)
Thats what happens now. HWC or that zone comngh in starts boiler - but its purely on timoimg for convector/TRV zone...
Pump is run continously. But that is what you said was a nono?
Right now, the water curculates all teh time, and teh boiler jts cuts in when its temp drops.
Well ... they don't have internal valves..
Well thats easy then. We wil eiher install 5 of them in paralllel, or simply buy some foreign ones in.
Er, five in parallel would make them flash more. That would draw 500W, so the fitting would flash on for 1 second and off for 19.
It is easily bypassed, as in you could remove the fitting, or use side lamps. OTOH, if you had a particularly nasty BCO, such a fitting could prove useful. One trick, I suppose, if you are a builder, is to have your horrible fluorescent fittings and just remove them after the inspection until you get to the next house. Not that the BCO will care.
Christian.
P.S. I'm still not serious about this.
You can't make the assumption in relation to the approved document. And yes, I do expect people to have the heating on during the summer, if they get too hot they open the window(s)...
My opinion of the great unwashed isn't that high.
Obviously, flow switch will only work directly on the convectors if they have internal valves.
You could increase efficiency by having boiler connected to a TRV zone flow switch or'ed with the convectors when any heater is active (either from the thermostats via a relay, or any output contacts provided by the heater).
I can't find anything that says the pump needs an interlock, only the boiler. It is sensible to stop the pump, if possible, though. I'm not sure I'd want mine on all the time. Electricity is four times the cost of gas, as well. However, stopping the pump would require some electronics, or it won't be able to start again. The electronics just consist of a device to pulse for two seconds every ten minutes. Then the pump will run for 2 seconds every 10 minutes OR whenever the boiler pump output is active.
Christian.
I should, perhaps, reiterate that the pulsing will only affect the radiator circuit, in that it will look to see if TRVs have opened during the pulse. In the event of the fan convector (or HWC) demanding heat, the boiler and pump will start immediately. The TRVs (and hence boiler) will modulate down in normal action, so only when the demand for heat has dropped very considerably, will the flow switch close and revert to the pulsing pump action. In this event, large amounts of heat are unlikely to be rapidly required, and the 10 minute period is unlikely to be problematic.
Christian.
In most short hold rental flats the replacement of light bulbs would normally be the responsibility of the tenant. If the tenant left with the bulbs their cost would coem from the deposit.
It's tradition. Also I suspect that it would take quite a bit of rearraging the wiring to convert the existing switching arrangements to using a timer.
1) There'll be 3+E between the switches but not between the MCB and the light fittings and on to the first switch. 2) Many older installations will probably not have a din rail unit but rather still use semi enclosed rewireables. 3) Commercially: The maintenance electrician will be called in to fix/replace a single duff air delay switch. He doesn't have the authority to spend the money to fix things better for the longer tmer.
Thank god the people who installed my boiler didn't expect it to be on all the time, as this thread seems to be saying is a Good Thing.
My bathroom would be roasting from the heat given off by the boiler being 'up to temp' constantly, from what I am gathering here. And that'd be with the rad off completely.
As it is, the bathroom rad is on only a fraction (not even half a turn!) solely to provide very low level heat to dry off my towel. The heating of the room is provided by the boiler itself, and if that ran constantly in winter, it'd be too hot, let alone if it was doing that in spring/summer!!
I *could* turn the heating off in summer, but I don't. The reason why? I have a programmable room stat. No TRV's, just the stat. In the summer the stat never calls for heat. Because it's set on the low side, I tend to notch it up a few degrees in winter per heating period, if I'm in, then I know it'll reset to a lower temp once I'm not there. This means it never fires in summer unless it's very unseasonable weather.
I *could* turn the boiler off in summer, but it supplies my HW. And it uses the heating circuit to cool down after doing so, which gives the system a gently waft through to stop the "I've just turned my heating on and it's not working" problem.
I see no point in keeping a boiler 'up to temp' all year round, it's lunacy. Unless it's exceptionally well insulated, it'll always leak heat into the surroundings - and there will always be some degree of heat travel away from the boiler in the metal pipework to the near surroundings too.
Just doesn't make sense on either a personal comfort level, or on an economical level either.
Velvet
I don't think you understood the point being made or the technology involved
. Only older technology boilers heat up to the 80 or so degree temperatures during periods of low heat demand.
If your boiler is generating that much heat from the case, then it is presumably not a modulating or a condensing type.
If it were, then it would be modulating down to 40 degrees or so as the heat requirement becomes less. Under those conditions, very little energy is used warming the primary circuit water and typically the boiler, sensing the low rate of heat requirement won't fire anyway.
This has nothing to do with the case being insulated or even the pipework. The amount of heat generated is extremely low in any case.
Were you to have used a condensing boiler with even the fairly basic level of built in control, you would be enjoying gas bills approximately 25% lower and would not be experiencing the inappropriate heat from the appliance itself.
.andy
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manufacturers
Good points Owain.
A year or so back, California had a power shortage. They blamed all sorts for it. Very few hit the real point. They were telling people not to use their washing machines, dishwashers and dryers, as these would create brownouts and then blackout. US appliances are hopelessly inefficient. If the US government committed to an EU like AAA rating, then none of this would have happened. CRT usage is dropping, collective heavy power usage, due to the introduction of LCDs, but the US government still is not legislating to reduce power.
Legislating is the only way. Do you think the building industry would have voluntarily built to the insulation levels we are to see in 2005? Not in a million years!!!! In 1990 when insulation levels rose by a miniscule amount, the British Building Industry said insulation was "cosmetic". Apart from the windows, nothing else of insulation you see.
In the UK all appliances sold should be at least AAA and insulation levels to Scandinavian levels - BY LAW.
Quite possible I've not picked up on the types of boiler being talked about here. Mine's a non-modulating (though the one before it was indeed a modulating one). Don't have the foggiest if it's a condensing one - I doubt it (since they seem to be more expensive?).
FWIW, the old boiler (the modulating one) managed to heat the bathroom just as well. It's hard to say if this is actually from the case, or the fact that I have pipework running from the boiler down to the floor that 'you could hang fairy lights on, love' - it's not boxed in so there's a fair bit of heat radiating off those if the heating's on.
This thing about the boiler constantly staying warm/up to temp - are we talking about something that would apply to a system with a HW tank? I don't have one of those, and thinking about it I can see that perhaps it might make sense if there's a HW tank in the equation - though when thinking about that in the context of my other half's house, when the HW tank is warm (presumably it would be kept warm permanently by the boiler?) the airing cupboard *and* the rooms surrounding it are warm too, courtesy of unlagged pipes running under the floor from teh boiler to the airing cupboard.
I've been paying attention to this thread but it's rambled a lot and I really don't seem to have managed to gather the exact details of it all. I'd be grateful for anyone that could post a quick summary of the boiler and system layout this idea would and wouldn't be suitable for cos at some point I *will* own my own place, and chances are I *will* replace the boiler/CH/HW system in it :-)
Velvet
Not in a correctly specced design. Part L1 suggests a suitable arrangement to heat a HWC is to have a separate pumped zone (the pump can be shared with other zones, if convenient) and a reasonably rapid recovery coil with cylinder thermostat. This means it can heat the entire tank in around twenty minutes. Provided suitable hysteresis and good insulation, the boiler can be kept from firing for quite some time before the temperature drops. Keeping the primary circuit from being hot most of the time reduces primary circuit losses, and promotes having a short high burn from the boiler, which is efficient.
Christian.
Most don't pay the last month or twos rent and leave no deposit to be paid back, and generally owing rent.
This is simply not the case in my experience. Bad tenants do exist just like other kinds of bad people, they are a small minority especially where accomodation of any kind is at a premium.
Most tenancy agreements explicitly state that using the deposit to pay the last month's rent is forbidden and people abide by that agreement.
I know many people who rent out flats in London, and 50% of the time they have problems in payment. Most of the problems are with foreign tenants rather than with British, but most of the punters are foreign so they have little choice but to take them.
I know two who were so pissed off with the hassles involved they just sold up.
Yes. Unlike IMM, I don't know many who rent out properties, but have a good friend who does - and it's now his only source of income. He selects his tenants with care, and very rarely has money problems with them.
Of course, if you're renting out some rat hole, there's a good chance you'll get rats as tenants.
Probably not. They are a bit more expensive (£150 or so in a given model bracket) but the return on investment realises quite rapidly. An older type of boiler typically manages 65% seasonal efficiency, a newer conventional one around 78% (that's the minimum allowed now) and a condensing one around 91%. I replaced an oloder model with a condensing model and achieve 25-30% fuel savings.
During the heating season it reasonably should. Outside that, if the burner is modulating down properly the temperature should drop as low as 40 degrees except when recovering the hot water cylinder.
If you have a modulating boiler connected in this way, the way that it should work is that when the hot water cylinder requires heat, the motorised valve should move appropriately and the boiler to full power. The notion is that you want this job to happen quickly because a) you might want more hot water and b) in the winter you want the boiler to return to heating the house.
With a decent fast recovery cylinder, the recovery time should be a few minutes so in the summer the period that the boiler pipes are hot to 80 degrees quite short. One can always lag them as well In any case the hot water carrying pipes should be for some distance from the cylinder.. The cylinder in any case should be well insulated.
Let me try to summarise.
- The Building Regulations (the statutory instrument) require that reasonable provision is made to conserve energy when a heating system is fitted in a new house or a replacement in an existing one.
- The Approve Documents give guidance on how this *can* be achieved. They are not of themselves legally binding, but only recommendations - that is clear in the text.
- In other words you *can* do what is mentioned such as fitting a room thermostat to lock out the boiler, but it is not an absolute requirement. However, if you have a simple on/off 80 degree conventional boiler, this may well be an effective way to save some additional energy where TRVs are used. It is very unclear how much that would actually be because the room thermostat has to be set high enough to make sure that rooms with TRVs all get a heat supply for as long as is needed.
- If you fit a modulating, condensing boiler, apart from the inherent savings, it will tend to operate continuously at the required heat output rather than turning on and off. In the winter you want this and during the spring and autumn the power level simply drops as does the water temperature. In warmer weather, the heat required gets less and less and the boiler will respond to this by coming on at its lowest power level for ever shorter periods. In even warmer conditions this becomes very small indeed.
My point was therefore that the value of having a room thermostat just to lock out the boiler, becomes something that covers what is a corner case with this type of setup and the energy saved is down at or below the level that the pump is using.
Therefore to say that one needs to slavishly follow what it says in the Approved Documents is not true (because they don't require that) and some of the measures, like the room stat, become a lot less important with newer boiler technology because the equivalent effect, together with greater energy saving anyway can be achieved by using that newer technology. People seem to get confused by that and view the Approved Documents as being Gospel.
The Approved Document does allow for alternatives but proposes solutions assuming a minimum standard of boiler. My feeling is that this has been done because of the conservative nature of the heating and plumbing fitting industry, it was probably the maximum that the advisors to the legislators thought that they could get away with. Of course the other interested parties such as the controls industry would not have any objection either.
I think that it must also be realised that there is a political game here. The government has been pushing part L1, not for altruistic reasons but because it needs to be seen to doing something to meet the requirements of the Kyoto Protocol.
Having an engineering background, I tend to look at issues such as energy saving with a big picture view first and then to see which aspects are the most important in terms of return on investment, comfort, convenience etc. and to deal with those first, leaving other issues until later.
The government could have easily raised the barrier on boiler efficiency before now. Good quality condensing boilers have been in use elsewhere in Europe for 15 years at least, whereas the UK manufacturers did a very poor design, manufacture and marketing job with their first generation products, leading to a bad reputation in the trade.
This has paved the way for major German manufacturers such as Vaillant to enter the market themselves and by acquisition. The UK products have started to improve and there are smaller manufacturers such as Keston making excellent products at competitive prices.
The game is likely to change again in 2005. Current government thinking is to raise the seasonal efficiency barrier to 86%. This would essentially take conventional technology boilers off the market and mandate condensing products plus one or two other emerging technologies.
It would have been a much better move to have done this before and knock respectable sums from people's energy bills as well as reducing pollutant emissions rather than titting around with controls that make a lot less difference.
.andy
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