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

captainhindsight_2

There is no one answer that applies to all homes/buildings. It depends on so many variables.

wales786

I use a dehumidifier in the room im airing clothes in

Frankl

I am now retired and keep my heating on at 21C 24/7.
I live in a 3-bed semi and my annual bill is around £850 for BOTH gas and electricity. Exactly the same as when I was working and the heating was only switching on for 6 hours per day.
Keep switching on and off is false economy. Every time the heating is switched on it has to heat all the walls of the house before you feel any benefit in the room as the cold still radiates from the walls. There is also the problem with the damp in the cavity due to the heating being switched off which exacerbates the heat loss.

lstar337

Frankl wrote: »

I am now retired and keep my heating on at 21C 24/7.
I live in a 3-bed semi and my annual bill is around £850 for BOTH gas and electricity. Exactly the same as when I was working and the heating was only switching on for 6 hours per day.
Keep switching on and off is false economy. Every time the heating is switched on it has to heat all the walls of the house before you feel any benefit in the room as the cold still radiates from the walls. There is also the problem with the damp in the cavity due to the heating being switched off which exacerbates the heat loss.

Most of what you have written is total garbage. :T

lstar337

From another thread:

Cardew wrote: »

Worth reading: http://www.moneysavingexpert.com/utilities/energy-saving-myths?utm_source=MSE_Newsletter&utm_medium=bignote-three&utm_term=25-Nov-14-lt&utm_campaign=utilities&utm_content=2

Should I leave the heating on low all day even when I'm out, or turn it up only when I need it?

According to leading energy experts at the Energy Saving Trust, as well as British Gas, the idea that it's cheaper to leave the heating on low all day is a myth. They're clear that you'll save energy, and therefore money, by only having the heating on when it's required. (Using a timer's best, because your thermostat is designed to turn your heating on and off to keep your home at the temperature you set it.)
The key thing to understand here is that it's all about the total amount of energy required to heat your home.
It's a given that a certain amount of energy is constantly leaking out of your home (though exactly how much will depend on how good your insulation is). So if you're keeping the heating on all day you're losing energy all day - it's better to heat your home only when you need it, even if that means whacking the temperature up high.

Should I keep the hot water boiler on all the time, or turn it on and off as needed?

A. If you have a gas, oil or LPG (liquefied petroleum gas) central heating system, it will always be cheaper to time the system so the hot water comes on only when required.

squirrelz

Frankl wrote: »

....the cold still radiates from the walls.

Astonishing. Cold cannot radiate. Heat radiates.

Mind you the Energy Saving Mythbuster is also incorrect:

Turning your radiators up and down using thermostatic radiator valves on the side of them affects how quickly the room heats up.

This is just not true. The TRVs shut off the flow when the ambient temperature (around the valve) reaches a certain level. They should (in theory) allow full flow if the temperature is well below this. The 1-6 levels affect the cut-off temp, not the flow rate.

Cardew

squirrelz wrote: »

This is just not true. The TRVs shut off the flow when the ambient temperature (around the valve) reaches a certain level. They should (in theory) allow full flow if the temperature is well below this. The 1-6 levels affect the cut-off temp, not the flow rate.

Whilst I agree with the thrust of your post, TRVs do alter the flow rate of water into the radiator. If they didn't they would simply be like a solenoid valve, switching the flow fully on or fully off.


The flow of water through the TRV is regulated by a valve that is operated by a spindle. When this spindle is fully up the valve in the TRV is fully open allowing maximum water flow through the radiator. As the room temperature approaches that set on the TRV the 'bellows' expand pushing the spindle down and the valve gradually reduces the flow of hot water into the radiator.


http://www.draytoncontrols.co.uk/RadiatorValves.aspx

TRVs sense the air temperature around them and regulate the flow of water through the radiator which they are fitted to.

spiro123

How about the boiler thermostat? My engineer recommends max. Should it be set high or low at this time of year? I did read theres an optimum temperature that the returning water to the boiler should be at.

Cardew

spiro123 wrote: »

How about the boiler thermostat? My engineer recommends max. Should it be set high or low at this time of year? I did read theres an optimum temperature that the returning water to the boiler should be at.

Depends if the boiler is a condensing boiler or an old non-condensing boiler.


With condensing boilers the return water temperature should be low - below 55C - for the boiler to stay in condensing mode. So set as low as possible, whilst still keeping the CH warm enough for your requirements.


With a non-condensing boiler there is very little difference in efficiency at any of the set water temperatures.

orrery

squirrelz wrote: »

Astonishing. Cold cannot radiate. Heat radiates.

True, I'm sure. But the stability will depend on the surface we are talking about re-radiating its heat back into the room. If the surface is freezing cold then you'll feel the absence of the normal radiation you'd expect from a warm surface and this will be interpreted by an observer as being the cold radiating from the surface.