[Broncho]

I’ve got hive and have the water on constantly so it’s always hot, I have the heating on a schedule am I better off just setting the heating to say 20 degrees all year round and just let it do its thing?

Biggest question is which is more efficient?

[TimMcC]

Originally Posted by Broncho

I’ve got hive and have the water on constantly so it’s always hot, I have the heating on a schedule am I better off just setting the heating to say 20 degrees all year round and just let it do its thing?

Biggest question is which is more efficient?

The bigger the difference between temperatures between inside and out, the quicker the house will leak heat. You can decrease the rate of leakage in general with better insulation etc, but it will always leak quicker with a bigger temperature difference.

So if it's 20C inside and 0C outside, the house will lose 1C of heat in a shorter time than an identical house which is 16C inside.

Therefore it's better to let the house cool while you're out, and only heat it when you need it.

The real question is what does this equate to in £s for your house, and what's your comfort worth? In an ideal world a smart thermostat will ensure your house is always up to temp while you're in it, and cools down when you're away.

[Watsey]

Originally Posted by TimMcC

The bigger the difference between temperatures between inside and out, the quicker the house will leak heat. You can decrease the rate of leakage in general with better insulation etc, but it will always leak quicker with a bigger temperature difference.

So if it's 20C inside and 0C outside, the house will lose 1C of heat in a shorter time than an identical house which is 16C inside.

Therefore it's better to let the house cool while you're out, and only heat it when you need it.

The real question is what does this equate to in £s for your house, and what's your comfort worth? In an ideal world a smart thermostat will ensure your house is always up to temp while you're in it, and cools down when you're away.

This.

Apart from the subjective benefits of always returning to a warm home, any property (unless it's insulated to ridiculously high levels) will always lose heat when there's a temperature gradient.

It's pretty wasteful to heat an empty home.

[Daftasabrush]

Originally Posted by Watsey

This.

Apart from the subjective benefits of always returning to a warm home, any property (unless it's insulated to ridiculously high levels) will always lose heat when there's a temperature gradient.

It's pretty wasteful to heat an empty home.

Have you got any proof of that? I always thought it was pretty much a tie between the two options. If you leave it running, the fabric of the building retains more heat so doesn't require as much energy to keep it constant, whereas if you leave it off, you have to heat the fabric of the building before you really notice the benefits of having the heating on.

We have warm air heating and it's fantastic for instant heat so we can leave the house to get quite cold when not in and then within a few seconds of turning the heating on the air is warm. The problem with this is that everything else in the house is cold and if you turn the heating off, the air gets cold very quickly again (within a minute or two). If we leave the house warm-ish, the contents and building don't cool down too much meaning that it uses less energy to re-heat the air.

[TimMcC]

Originally Posted by Daftasabrush

Have you got any proof of that?

Newton's law of cooling:

http://www.ugrad.math.ubc.ca/coursed...feqs/cool.html

"the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature"

[SkyJawa]

https://www.moneysavingexpert.com/ut...y-saving-myths

[Watsey]

Originally Posted by TimMcC

Newton's law of cooling:

http://www.ugrad.math.ubc.ca/coursed...feqs/cool.html

"the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature"

This, again

An object which experiences a temperature gradient will always lose heat more quickly than one without. Total heat loss must therefore also be higher. Unless it is perfectly insulated.

[Daftasabrush]

Originally Posted by TimMcC

Newton's law of cooling:

http://www.ugrad.math.ubc.ca/coursed...feqs/cool.html

"the rate of change of the temperature of an object is proportional to the difference between its own temperature and the ambient temperature"

Originally Posted by Watsey

This, again

An object which experiences a temperature gradient will always lose heat more quickly than one without. Total heat loss must therefore also be higher. Unless it is perfectly insulated.

^That, I understand, but it doesn't taken into account that in a building, you're not just heating the air inside, you're heating everything (very slowly).

[Daftasabrush]

Originally Posted by Lobb

It's an interesting point and one with which I can help you with. I've had discussions with has engineers on the same subject. The school of thought that they subscribed to was in the cold weather, leave the heating on. So having worked from home for fifteen years before throwing the towel in, I thought I'd try it and see if there was any increase in cost.

Result? Fuck all difference in cost. Large increase in comfort

I too noticed no discernible difference in cost between running it all the time and having it on as and when needed. As a result, it gets left on lower than we'd normally have it and we just turn it up when we're sat downstairs.

[TimMcC]

Originally Posted by Daftasabrush

^That, I understand, but it doesn't taken into account that in a building, you're not just heating the air inside, you're heating everything (very slowly).

They're all objects which lose heat to their surroundings. Heating the building fabric is of course a big deal, and it's why a house which has been cold for a long time takes a long time to feel truly warm. But that's more to do with the thermal properties of the objects we're talking about and how well they're insulated.

None of it changes the fundamental science that you'll use less fuel keeping the heating off when you're not in, which is what I interpreted the original question as asking.

What difference this actually makes in £s depends in reality for how long the house is empty. In Lobb's case you're probably only out for 10 hours of the day so it may make little difference is the house is insulated to a good standard.

But if you went away on holiday for 2 weeks and left the heating on, you'd use significantly more fuel than if you'd left it off.

So really it's a balance between comfort and fuel cost, and part of the equation is how long the heating will be off.

[Techno 9000]

Originally Posted by Broncho

..., I have the heating on a schedule am I better off just setting the heating to say 20 degrees all year round and just let it do its thing...

I used to have Central Heating on 'twice a day', morning and evening. During the mid winter in the Off periods in between, the temperature would plummet, rather uncomfortable.

Now I have a digital thermostat that is programmable with four time periods and temperatures each day.
So overnight it's set to 17 deg C, morning 21 deg C, daytime 19 deg C and evenings 20 deg C. Result is a comfortable temperature at all times.

I'm fairly sure it uses some more Gas, but not a huge amount. The way I see it is akin to having the house on a 'simmer', rather than putting it on a 'boil' from cold twice a day.

[225]

We have Nest which senses when you walk past. It's clever stuff as it learns your patterns of being in the house and turns off the heating appropriately if it doesn't sense anyone for a while. Often going away for the weekend it hasn't heated the house since Friday with out me doing anything.

On the way home just launch the app from the phone and get the house heating again. A lot more efficient than old school on or off

[....,,,,..,,..]

If you have Nest then you can use BMW app IFTTT and have it heat house when you start off for home or enter a geofence area.

I believe this will be a working app for the next gen 3 series rather than having to keep it open on idrive.

[allachie9]

5 years ago we moved into a new, very well insulated, triple-glazed, single story house. All rooms have underfloor heating powered by a Worcester Bosch gas boiler.
Despite having had good advice from our builder and the installing plumber, we thought we knew best ( ! ) and treated the heating like our previous gas-fired, radiator heating system in our previous single story house. We turned the 'stats down at night, then back up again early afternoon. Once the concrete floors get warm, they stay warm for quite some time, both in the carpeted rooms and the rooms with Amtico flooring.

A couple of years ago, after talking to neighbours with the same heating systems, we decided to follow their advice and simply leave the heating to 'do it's own thing'. September to April the stats are left at 20 in the main rooms and 18 in the bedrooms. Even in the coldest weather the heating circuits rarely operate after late morning.
Since doing that, our gas consumption has gone down by more than 10%.

I've no idea how that squares with the theories described above, but allowing the heating to do what it wants is saving me money.

[ajfoggy]

Do you think I should leave the heating on in my new house

[Broncho]

Interesting replies with no definitive answer

To add a bit of perspective the front of the house is less efficient than the back so we kind of have 2 halves so it’s quite hard to settle in the best compromise.

[Broncho]

Originally Posted by ajfoggy

Do you think I should leave the heating on in my new house

Genuinely honest, mine looked like that 18 months ago, like a carbon copy!

[Watsey]

Originally Posted by ajfoggy

Do you think I should leave the heating on in my new house

Let me guess. The builder told you he'll be finished next week

[ajfoggy]

Originally Posted by Watsey

Let me guess. The builder told you he'll be finished next week

I wish!! End of May. Hopefully!!

[kzg1969]

IMO - both hot water & heating on timer. Even when on timer our heating turns off when we leave the house (GPS thingy).

I would however say that there should be a minimum temperature when off (ours 15deg) as if the fabric of our house drops below that it takes forever to warm up again.