Energy myth-busting: Is it cheaper to have heating on all day?

Toxteth_OGrady

wantanswers wrote: »

BTW does the insurance cover pipe repairs or just flood damage?

BTW also do you know what an 'extended period' might be time wise?

In both cases it varies depending on the policy.

eastberks44

I beg to differ with WestonDave about vented v. condensor tumble dryers. Condensors do not recover heat to the house, but to a tank of cold mains water that then gets tipped down the drain once it has warmed up. This costs a lot in water consumption as well as electricity. The moisture from the clothes is trapped inside the drum while the water is warming up and being changed, so drying takes 2 hours or more.

A vented dryer *appears* to be wasteful as it blasts hot air through a hole in the wall, but as the clothes are continually bathed in hot dry air, they dry much more quickly.

Having tried both types and measured with a plug-in kWh meter, I can confirm that a vented dryer uses less energy, simply because it gets the job done in half the time.

Cardew

eastberks44 wrote: »

I beg to differ with WestonDave about vented v. condensor tumble dryers. Condensors do not recover heat to the house, but to a tank of cold mains water that then gets tipped down the drain once it has warmed up. This costs a lot in water consumption as well as electricity. The moisture from the clothes is trapped inside the drum while the water is warming up and being changed, so drying takes 2 hours or more.

A vented dryer *appears* to be wasteful as it blasts hot air through a hole in the wall, but as the clothes are continually bathed in hot dry air, they dry much more quickly.

Having tried both types and measured with a plug-in kWh meter, I can confirm that a vented dryer uses less energy, simply because it gets the job done in half the time.

Firstly a condensor dryer has no water input - or at least all the many models I have used - so how it can use a tank of mains water beats me!

You put the damp clothes in the drum and the only output(apart from dry clothes) is a pint or so of cold water extracted from those clothes - which you can re-use. If you connect the output to the drain you lose that pint or so - but they all have container to hold the extracted water.

So all of the heat produced by the condensor dryer remains in the house as there is nothing vented outside; as there is with a vented dryer.

Secondly a condensor dryer doesn't necessarily use more electricity than a vented dryer.

This link rates the operating cost of all dryers in UK:

http://www.sust-it.net/energy-saving.php?id=41

You might notice that the cheapest to run is a condensor dryer, and of the top 15 models marketed in UK, 11 are condensor dryers and 4 vented dryers.

That, together with the fact that all heat produced by the condensor dryer stays in the property(and isn't vented outside) seems to me to make the condensor the winner in the economy stakes!

Boxman

If it's of interest, as per my post last month over 6 days I tried leaving the heating for a 14 hour period per day instead of the customary two timed periods we usually use and found that the daily gas consumption went up by about 40% although the comfort level obviously increased as well (not that it was too bad before). The weather before, during and after the trial was consistent at just above freezing during the day and just below at night.

So for us it would seem that the benefit received from the significantly higher cost would not be enough to continue in this mode.

grahamc2003

eastberks44 wrote: »

I beg to differ with WestonDave about vented v. condensor tumble dryers. Condensors do not recover heat to the house, but to a tank of cold mains water that then gets tipped down the drain once it has warmed up. This costs a lot in water consumption as well as electricity. The moisture from the clothes is trapped inside the drum while the water is warming up and being changed, so drying takes 2 hours or more.

A vented dryer *appears* to be wasteful as it blasts hot air through a hole in the wall, but as the clothes are continually bathed in hot dry air, they dry much more quickly.

Having tried both types and measured with a plug-in kWh meter, I can confirm that a vented dryer uses less energy, simply because it gets the job done in half the time.

A few facts about my condensing tumble dryer

It doesn't have a cold water tank

It returns more heat to the house than the electricity it consumes

It has zero water consumption

No water is trapped in the drum

Drying time is variable depending on many factors, but no more than my previous non-condensing model, and probably less.

A vented dryer IS wasteful by expelling hot moist air, a condensing dryer doesn't and therefore isn't

My condensing dryer uses typically 1.2kWh per cycle, all of which (and more) is used to heat the house, my vented one, iirc, used around 3 or 4kWh per cycle.

Apart from those, I fully agree with your post.

maxmiler

grahamc2003 wrote: »

A few facts about my condensing tumble dryer

It returns more heat to the house than the electricity it consumes

.

Whilst I tend to agree that condenser driers give out heat inside the house and can be more economical than a vented one, I really can't see how it can give out more energy than it takes in.

grahamc2003

maxmiler wrote: »

Whilst I tend to agree that condenser driers give out heat inside the house and can be more economical than a vented one, I really can't see how it can give out more energy than it takes in.

Yes, I think you are correct. I was thinking about the latent heat of evaporation. While this will cause more heat than electricity from say dehumidifiers (which release the latent heat of evaporation), a condensing dryer does the opposite. So the heat the dryer gives out is the electricity consumed minus the latent heat of evaporation.

Thanks for pointing my error out.

elfoster

I have Air source heating (fitted by the council). I only have electric (no gas) and want to know if I am running the system the most cost effective way. My electric bill seems very high but I have never lived with just elec before.
The heating is set as constant but the thermostat in the hall is set at 17degrees. So the Air source thingy outside doesn't run constantly but goes on and off as per the thermostat. As the system doesn't heat water to 'hot' merely warm I have the hot water immersion come on for half an hour every morning.
Anybody able to tell if this is sensible or if not how I would be better working it.
Not that it is totally relevant, I have two young children, one of which is 2 and home nearly all day every day with one of us - basically can't just switch it off and wear more clothes!!! Lol x
Any help appreciated?
Also how much would someone expect to be paying on a small 3 bed semi-detached for electric these days?

harrypotter1981

So after many years of making my wife suffer from cold houses lack of hot water all because i was set on the idea setting a timer for heating and water was the right way forward. NOT! 11years being obsessed with what the hell the boiler is doing whether its on or offgoing to work having a wife phone me up at 7pm saying shes gone to bed because its cold in the house, went over my head, i thought i was saving us hundreds???? NOT!! well we have moved into a 5 bed house 7yrs old high spec with a very large potterton oil boiler with a 2000l tank outside, that put the wind up me so straight away set the timers for 2hrs hot water and 3hrs heat in morning and evening oh and maybe a 1hr boost at lunch if snowing! we have 2 foster kids so started thinking about my habbits are they cost effective? so the 1st month into winter november average temp over month was 1-2oc we used 13% oil thats with the hrs set above, just 3 weeks ago i said enough is enough un set timers to 24 7 and roomstat to 18 which keeps house 20 always all day all night and hot water 48oc always. average temp for jan here was 0oc and yet still waiting for oil gauge to go from 4 to 3 and thats the shallower end of tank as its not rectangle so when i used that 13% in 1 month thatwas the middle most vast area! so it works for me a warm house all day every day and a very hgappy wife!!

147718

harrypotter1981 wrote: »

So after many years of making my wife suffer from cold houses lack of hot water all because i was set on the idea setting a timer for heating and water was the right way forward. NOT! 11years being obsessed with what the hell the boiler is doing whether its on or offgoing to work having a wife phone me up at 7pm saying shes gone to bed because its cold in the house, went over my head, i thought i was saving us hundreds???? NOT!! well we have moved into a 5 bed house 7yrs old high spec with a very large potterton oil boiler with a 2000l tank outside, that put the wind up me so straight away set the timers for 2hrs hot water and 3hrs heat in morning and evening oh and maybe a 1hr boost at lunch if snowing! we have 2 foster kids so started thinking about my habbits are they cost effective? so the 1st month into winter november average temp over month was 1-2oc we used 13% oil thats with the hrs set above, just 3 weeks ago i said enough is enough un set timers to 24 7 and roomstat to 18 which keeps house 20 always all day all night and hot water 48oc always. average temp for jan here was 0oc and yet still waiting for oil gauge to go from 4 to 3 and thats the shallower end of tank as its not rectangle so when i used that 13% in 1 month thatwas the middle most vast area! so it works for me a warm house all day every day and a very hgappy wife!!

Thank you
That is fascinating and very useful and that you have pleased your wife. You should treasure the gold star which I no doubt she has given you:T