Crappy night-time economy 7 electric heaters

[mich]

Last time I looked I was me and I dont think I am you!

Obviously not as uncommon a situation as either of us have thought.

[John Smith]

Mich, you're not me are you!? Virtually identical story except that I have had mine for much longer.

[Scott M]

Errr, you'd have them switched off at the wall in summer.

[Scott M]

One thing I've found again and again with E7 heaters is that only a very few sad people (like me) can be bothered to work out how they work and how best to work with them. The upshot is that "they" will crank both controls to maximum and wonder why it's cold by 10am.

[Scott M]

Just to add: this was a general observation and not a pop at the OP!

[Lurch]

On Mon, 05 Jul 2004 15:35:45 GMT, Scott M strung together this:

Yep, that's usually all the 'fault' is when I get called out to storage heaters that aren't working, when of course they are.

[Matt Beard]

Each heater has 2 thermostats. The heater won't get any hotter once the "input" stat has reached its set temperature, and the heater will try not to give out any more heat once the room has reached the "output" stat temperature. Whatever time the power is turned on and off to the heater the temperature of the room will only really depend on the setting of the two dials (unless you try and drain more heat than it contains!).

[John Smith]

No offence taken - no, we are fully aware of the 'boost' capabuility and have been from day one. Those manuals - they're amazing aren't they!? ;-)

[Michael Murray]

As someone who has just bought a flat, Electric Storage heating was enough to dismiss any potential flat. I didn't even go to see any. No way. I have lived with it for a few months at future mother in laws. Gas Combi boiler is (in my opinion!) the way forward.

M.

[Martin Angove]

It is possible, even in Britain, to have a house so well insulated that it needs (next to) no additional space heating at all. As one example of many, Bob and Brenda Vale in their book "The New Autonomous House" built a house which needed no space heating at all, save for a single wood-burning stove in the central hall which was lit for a total of (something like, I don't have the book to hand) 20 days in the first winter while the house was still drying out. All the rest of the heat in the house came from incidental gains from the sun and from people and appliances in the house - a 100W lightbulb acts like a 90W heater for example :-)

Unfortunately retro-fitting this level of insulation to an existing house is nigh-on impossible.

As you will find if you look at previous discussions on uk.d-i-y with the usual groups.google search, there seem to be two camps in this field. The first advocates extremely thermally "lightweight" houses where the insulation is as close as possible to the inside of the box - with these you only have to heat the air in the room and not the structure of the house. It has the advantage of very quick heat-up times, but the disadvantage of very little incidental storage of heat energy and so relies on short bursts of heat input and cannot take (much) advantage of "free" energy from diverse sources such as the sun and even occupants. It is probably best suited to people who only occupy the house for short periods - i.e. are out at work during the day and out playing at night. The house can be left unheated (or heated to a lower than normal level) when unoccupied, and will very quickly come up to temperature when required.

The second camp advocates thermally "heavy" houses. In these you use the construction of the house as part of your thermal control system. For example, earth-sheltered houses are built partly underground. If you build far enough underground you'll find that the ground temperature is relatively constant through the year. It may only be around 8 degrees or so, but in the summer this makes keeping cool easier, and in winter it is likely to be higher than the outside air temperature. Less of a thermal gradient across your structure means less energy flow.

With or without an earth shelter, if you build your house using large amounts of concrete and masonry (and preferably plaster rather than board) then it is also possible to take advantage of heat gains (perhaps from the sun) by "storing" them in the structure of the building. For example on a sunny day, a south-facing room might get quite warm just from the sun. If it is made with heavy walls and floors then some of this heat will be stored in the walls and floor, keeping the room slightly cooler, and will be released into the room during the night when the air is cooler.

The major disadvantage is that it takes a long time for the house to heat up from "cold". These days it is easier to get around this by using compensating heating controllers with external temperature sensors, and this sort of control is often fitted in conjunction with a high-latency heating system such as underfloor heating. What it really means though is that a thermally heavy house is best suited to a family which will be in the house more than they are out. The house is then kept at a relatively constant temperature.

Both types of construction require high amounts of insulation - way beyond current regulations - and also only really work when the structure is as airtight as possible to avoid chilling draughts. With airtight structures you then have to have some controlled means of changing the air in the house and this often falls to some kind of mechanical system. These are becoming quite popular now, especially the ones which recover the heat from the outgoing "stale" air and transfer it to the incoming "fresh".

Of course, there is a lot you can do retrospectively even in an old house, but don't expect to do away with the need for a properly-planned heating system!

As I said, there's been a lot of discussion on these topics on this list over the years, but we haven't had one for a while... as IMM and Andy seem to be at it again in other threads, perhaps now is the time :-)

Hwyl!

M.

[Dave Liquorice]

It's the constant fiddling with the two settings, one of which ideally needs to be done with knowledge of the future, that is the PITA. Now if they had a central control point so you didn't have to wander round each heater twice a day storage heaters might be far more user friendly.

[Lurch]

On Sun, 11 Jul 2004 09:16:04 +0100 (BST), "Dave Liquorice" strung together this:

Some do, but not many are fitted with the central controller as it adds to the cost. I suppose its much the same as the gravity\pumped heating arguments when pumped first became available.