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

orrery

matelodave said:

It sort of relies on the return water being hot enough to shut the boiler down and then leaving it cycling away all day...

So, a really inefficient system where the boiler is never in condensing mode.

We need to kick into touch the idea that there is really any sort of problem with having TRVs and a central stat - there isn't. It works well, and it works efficiently.

Biggus_Dickus

orrery said:

matelodave said:

It sort of relies on the return water being hot enough to shut the boiler down and then leaving it cycling away all day...

So, a really inefficient system where the boiler is never in condensing mode.

We need to kick into touch the idea that there is really any sort of problem with having TRVs and a central stat - there isn't. It works well, and it works efficiently.

A single strategically placed wall/room thermostat may work fine for some households but it’s always been a flawed policy for far too long, imho. It’s just too restrictive when it comes to effective/practical heating control throughout the home.  

However, the pendulum swung in 2018 and the recommendation now is that if an existing boiler is replaced (and on all new-builds) then each installation should have a room-thermostat plus individual heating control for every other room/area; e.g. TRV’s or individual networked control.  

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/697525/DBSCG_secure.pdf

 

 

orrery

Biggus_Dickus said:

A single strategically placed wall/room thermostat may work fine for some households but it’s always been a flawed policy for far too long, imho. It’s just too restrictive when it comes to effective/practical heating control throughout the home.

Would you like to explain that? I'd always assume that someone who knows what they are doing has set it all up - you can't say that systems that are badly installed, set up or used are sub-optimal, because that would apply to anything.

I suspect that the 'restrictive' bits you allude to are most likely to be bad installation, set up and usage. Main stats fitted near radiators or in the sun, radiators not balanced properly or ... probably the biggest limitation ... people who mess with the settings without understanding what they are doing. For example, the offices I worked in a few years ago has a conference room that was on a different floor and not linked to the main heating system. It was heated and cooled by a big aircon unit. It was common to go in and find the room freezing, then go to the next meeting and find it like a sauna - people couldn't get the idea of leaving the main stat at the right temperature and would push it to min or max. In the end I took a set of magic markers to it with a blue band, a red band and a central line with an arrow. That seemed to sort it.

The one message we have to get across here is that: not having the right controls for your system will cost you money.

Talldave

richardc1983 said:

Talldave said:

There's a significant difference between a system with "wall" thermostat and manual TRVs and a system with smart TRVs. In the latter case, any TRV can call for heat against its own temperature schedule and any form of overall thermostat is unnecessary. 

The cost of the two alternatives reflects the level of cleverness and customisation possible.  With the fully smart system you can keep bedrooms warm at night whilst letting other areas cool and then reverse the focus of heat to the living areas during the day.

How does that work if all the rooms are up to temp what will tell the boiler to turn off and the pump to stop if there is no main thermostat?

The wireless receiver that gets calls for heat from all the smart TRVs controls the boiler. As soon as one or more ask for heat it calls for heat from the boiler in exactly same was as a wall thermostat does by closing a relay. 

It's a step up from a wireless programmable thermostat which has one receiver and one temperature sensor; such a system will have one receiver and multiple temperature sensors (the TRVs).

ukbrown1

Thermostatic Radiator valves, Do you need them.  Working on the basis that heat rises our bedrooms were always the warmest rooms in the house.  On all radiators you can restrict the incoming flow so upstairs takes longer to warm up and thus you are directing the most heat to the downstairs, but the upstairs is still warm enough as quite a bit of heat rises.  If you feel a room is too cold let more water into the radiator.  Search for how to balance radiators

Lynne_sears

hansonaj said:

"Should I leave the heating on low all day, or turn the thermostat up and down?"

A heating engineer told me this once and I also thought it must be rubbish and a myth.

Yet I disagree with this myth being busted....and agree with those who say it is true.

Why ?

Because I installed a thermostat in my house and over the year I used less gas than previous years , as calculated by the meeting reading i take monthly

......AND we actually had a warm house.

Living in a large old house and having tje heating on a timer morning and night just meant years off cold. By the time the house had heated back up in the evening it was time to go to bed.

So for me the boiler running full on twice a day for 3-4 hours (yes it can take that long to heat up the house in winter), versus once for 3-4 hours in the morning andthen as needed seems to make sense to me. And my figures agree.

Maybenit is down to the age of the house, the insulation (I can mot have cavity wall insulation) etc. Rather than a blank myth or no myth!:)

Lynne_sears

Proof is in the energy Bill . I am upset that Martins logic says turn it off. If not turned off soft furnishings and walls act as radiators, and no energy gets sucked into these if the rooms do not cool down, no black mould either, even if drying washing on radiators. I have tried and tested both after reading a ‘Which’ report many years ago.  Leaving on low with a thermostat wins all hands down. Low being the word here, I leave it at 19 degrees centigrade, only boost to 21 at times, I open the window in the morning for just a few minutes, the damp air rushes out and after just minutes the room is as warm despite this. 

victor2

Proof is not just in the energy bill, it's also in how comfortable your house is.

My energy bill is much cheaper if I don't turn the heating on at all, and just wear warm clothes and put up with the cold.

Mickey666

Biggus_Dickus said:

orrery said:

matelodave said:

It sort of relies on the return water being hot enough to shut the boiler down and then leaving it cycling away all day...

So, a really inefficient system where the boiler is never in condensing mode.

We need to kick into touch the idea that there is really any sort of problem with having TRVs and a central stat - there isn't. It works well, and it works efficiently.

A single strategically placed wall/room thermostat may work fine for some households but it’s always been a flawed policy for far too long, imho. It’s just too restrictive when it comes to effective/practical heating control throughout the home.  

However, the pendulum swung in 2018 and the recommendation now is that if an existing boiler is replaced (and on all new-builds) then each installation should have a room-thermostat plus individual heating control for every other room/area; e.g. TRV’s or individual networked control.  

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/697525/DBSCG_secure.pdf

 

 

IMHO also.  I don't even WANT one temperature throughout my house so what't the point in just ONE thermostat somewhere?  I've installed a zoned system with TRVs and don't have a wall thermostat anywhere.

rickbon

In response to the recommendation to turn off your lights every time you leave a room, I would suggest the old wisdom was to selectively keep them on if you are returning any time soon e.g. in the next couple of hours or so. It's partly a case of balancing the cost of new lightbulbs due to shortening their life by turning them off and on again, vs the cost of electricity used whilst they are on in an empty room. With incandescent (filament) bulbs turning a bulb straight back on whilst it was still hot from just having been on was a way to dramatically shorten their life, even sometimes causing them to blow on the spot. It is also true, at least I think, that it is more welcoming to enter a room which is not entirely dark, for example the hall or the bedside lights.

However, following this advice I did find that my electric bills were higher than I wanted, even if I rarely had to buy new bulbs. And, of course, finding decent quality incandescent bulbs at a reasonable price was becoming difficult. A well-known brand on a major online merchant was particualrly unreliable, despite being labelled special service or similar with most of a pack of 20 bulbs poppin on first use. So, I embarked over a few months in a replacement of all my various lightbulb types with LED ones, not confusing these with halogen ones and being sure that the LED bulbs had not had their lifetime detrimented by mean manufacturing - I was looking for a lifetime of 15 to 25 years in each case. This bulb change cost quite a pretty penny, it was an expensive outlay. However, it paid for itself with the very first subsequent electric bill.

That has continued over the past 3 years since I swapped over, saving a lot of money by knocking our bills down by about 60%, even though I do still leave many lights on. Of course, old habits die hard, so I often find that my wife has turned off lights that I left on and the explanation of the economics of this hasn't changed that. Oh, well!