When are you putting the heating on this year and what temperature and general heating advice

markin

Coffeekup said:

Grotdog said:

This is a tricky topic - but something I've been very involved with over the years - we run a Chartered Survey company, and I've written the book on dampness in homes - and the effect that temperature has on the building fabric. I'm sure Martin won't mind me mentioning the name of the book - its out on the 17th Sept, and pre-orders are being taken - called The Warm Dry Home and available on our website - just look for the Heritage House website.. (I'm not sure about the admin rules for posting links) So, back to the topic.

A warm house is a dry one. For a house to be dry, it needs to be warm enough that condensation doesn't form within the building fabric. That means the walls and structure have to be kept above the Dew Point - the temperature at which condensation occurs. Its not something that just forms on surfaces - it forms within the walls, which is what that old fraud of rising damp is about - moisture condensing in brickwork or stone. Where does the moisture come from? Mostly we humans - living, breathing, cooking, showering. It has to go somewhere, and most houses are NOT well enough ventilated - so moisture is able to settle within the fabric - it passes through it as a gas, but if that gas is cooled down below Dew Point, it condenses, and is held in the walls and fabric as water.

 A damp wall transmits heat much quicker than a dry wall, so house gets colder and damper. How do we stop this happening?

We make sure the building stays above a critical temperature - we have a guideline of 15 degrees C., at an RH of 50% - and total moisture content of 7 grams water per cubic metre of air. That's about a teaspoon. Given those parameters, the Dew Point is about 4 degrees C. So you wont get damp, and the house stays dry.

So - how does this relate to the OP? When to turn heating on? You turn it on in such a way that you don't allow the FABRIC of the building to drop below 15 degrees C. You keep it on - constant low temperature heating is cheap to run, and ensures you keep a DRY house, so long as it is well ventilated. I can't emphasise enough that for all this to work you need to ventilate - humidity controlled extraction in kitchens and bathrooms is a must.

So when night time temps start to dip below 15 degrees, you need to get the heating just ticking over, to maintain temps at the right level.  Its not about when, so much as 'what are the temperatures'.. In ALL rooms as well ! Don't leave some rooms with heating off - they'll just get mouldy and manky.

Make sure you also check the building - guttering and downpipes work, drains are clear, there are no cracks allowing water into the ground and soaking the soil at low level - ground levels externally are 150mm below internal floor levels.

All of this promotes dry walls, and thus best chance of maintaining a warm home - which wont lose heat nearly as quickly, and cost less to heat. Remember - it costs a lot more to heat damp air than dry air. 

Very interesting.... Slightly off topic and strange question... How does this compare with condensation on the outside of window in winter times? Is outside conde


 

Very good glass will be cold on the outside, so it's a good sign but a bit annoying.

[Deleted User]

Grotdog said:

This is a tricky topic - but something I've been very involved with over the years - we run a Chartered Survey company, and I've written the book on dampness in homes - and the effect that temperature has on the building fabric. I'm sure Martin won't mind me mentioning the name of the book - its out on the 17th Sept, and pre-orders are being taken - called The Warm Dry Home and available on our website - just look for the Heritage House website.. (I'm not sure about the admin rules for posting links) So, back to the topic.

A warm house is a dry one. For a house to be dry, it needs to be warm enough that condensation doesn't form within the building fabric. That means the walls and structure have to be kept above the Dew Point - the temperature at which condensation occurs. Its not something that just forms on surfaces - it forms within the walls, which is what that old fraud of rising damp is about - moisture condensing in brickwork or stone. Where does the moisture come from? Mostly we humans - living, breathing, cooking, showering. It has to go somewhere, and most houses are NOT well enough ventilated - so moisture is able to settle within the fabric - it passes through it as a gas, but if that gas is cooled down below Dew Point, it condenses, and is held in the walls and fabric as water.

 A damp wall transmits heat much quicker than a dry wall, so house gets colder and damper. How do we stop this happening?

We make sure the building stays above a critical temperature - we have a guideline of 15 degrees C., at an RH of 50% - and total moisture content of 7 grams water per cubic metre of air. That's about a teaspoon. Given those parameters, the Dew Point is about 4 degrees C. So you wont get damp, and the house stays dry.

So - how does this relate to the OP? When to turn heating on? You turn it on in such a way that you don't allow the FABRIC of the building to drop below 15 degrees C. You keep it on - constant low temperature heating is cheap to run, and ensures you keep a DRY house, so long as it is well ventilated. I can't emphasise enough that for all this to work you need to ventilate - humidity controlled extraction in kitchens and bathrooms is a must.

So when night time temps start to dip below 15 degrees, you need to get the heating just ticking over, to maintain temps at the right level.  Its not about when, so much as 'what are the temperatures'.. In ALL rooms as well ! Don't leave some rooms with heating off - they'll just get mouldy and manky.

Make sure you also check the building - guttering and downpipes work, drains are clear, there are no cracks allowing water into the ground and soaking the soil at low level - ground levels externally are 150mm below internal floor levels.

All of this promotes dry walls, and thus best chance of maintaining a warm home - which wont lose heat nearly as quickly, and cost less to heat. Remember - it costs a lot more to heat damp air than dry air. 

What you are saying runs counter to much-promoted advice ‘save money - just heat the room that you are in’ via the use of smart eTRVs. My experience of Evohome in a previous home was that shutting off rooms and leaving them unheated was a ‘fools errand’. We ended up with a default of setting of 13C (slightly below your 15C). The savings were well below those suggested by Honeywell but we were happy with the result.

Freebird53

Novice_investor101 said:

I always used to feel cold even though the thermometer said it was 21c in my lounge & kitchen. Although never upstairs even though that was the same temp. 

That was solved when I bought a dehumidifier & ran it downstairs for a week. The amount of moisture that it sucked up was incredible! & it was coming out of the walls because I could smell it, & 2 small damp patches on internal walls dried up. Prior to that I’d never have thought of my house as damp because there’s no mould or signs of damp. I have the dehumidifier running all the time now, keeping the downstairs at a max 60% in the summer & 50% in the winter. I’ve never been cold with the heating on since. 

Upstairs I always have the bedroom & bathroom windows cracked open, that was probably the difference in humidity. 

Perhaps off-topic?  My second post, be kind...

De-Humidifier's are great. I use mine to dry the clothes on very cold or rainy days.

I put the clothes horse inside one of those mini plasic fabric greenhouse's with the De-Humidifer, so that it's not processing the air in the whole of the large room where i do this.

Also to increase efficiency (this is a compressor-type), i cut a square into the back of the greenhouse, so that it fits snugly over a radiator.

Thereby getting 'cheaper' gas powered heat from the CH, rather than using the expensive electric tumble dryer (which also ruins my bamboo clothing!).

Because the moisture is contained in the 'tent' and trapped by the De-Humidifier, i get no condensation on the windows.

Incidentally, i just measured a normal Washing cycle at 0.3kwh.

Freebird53

I can't seem to edit my post, as i forgot to add, that i'll be turning the heating on when it drops below 18C during the day in the house.

Mstty

In answer to my own question the heating went on yesterday.

I chose yesterday as there was a high of 20-21oC and the next week suggests a gentle fall down to 12oC. 

As we have an Air Source Heat Pump I wanted to get the underfloor concrete base nice and warm rather than getting it to heat up on a cooler day.

The effect was 8kWh use yesterday. Not bad for first fire up.but then it was a mild day.

Interestingly last year we didn't turn the heating on until 15th October.

Ally_E.

Temperature in the house had been coming down to 16.5C in the morning (we live in the South East) and no heating on just yet. Sun still manages to heat up the house to 18 degrees in most rooms and I have dehumidifier running at times contributing to the warmth. We lit the first fire in the woodburner last weekend on a cloudy day though.

Main reason I haven't had the heating on are all the plants that took residents around window sills and next to radiators and I couldn't be bothered to move them just yet. 

maisie_cat

When I got up at 5:30 to feed the cat it was 20 degrees in the kitchen, I tend to put the heating on when it's 15, hubby prefers 17. We spent most of last winter, the first with central heating, playing thermostat tennis, the maximum it went was 18 before I noticed.

DeeQS

This is our first winter in an EPC A house (having moved from an Listed Building with an EPC F). House is still 20-21c every day from the south facing sun alone.  We still have windows open all day/night.

Once internal temp drops to 16 I’ll use the Gas Stove in the Lounge first, then turn on heating in other rooms later. Wonder if we’ll make it to November without needing the central heating.

GwinHarper

Can't imagine how anyone can afford to what their home to above 28 degrees!!
We gave a rented house with very poor insulation etc.
Both me a Kiddo struggle with cold due to health conditions but I will wouldn't dream of putting heating above 20. Never have, even when I'm not paying the bill.
At the moment I have it set to come on at 16, occasionally if we're very cold I put it to 17.

Basically it has to be jumper, fleecey joggers, dressing gown, and thick socks first. Plenty of blankets for sofa, hot water bottles in our laps etc. 

Yorkie006

I haven't put the heating on yet. It's now 7 C outside and there's condensation on the outside of the windows. Kitchen and bathroom windows still ajar (to let steam from cooking, doing dishes and shower out - no extractor fans in either).
Will not be putting heating on at all this winter if I can help it. House is badly insulated with no room thermostat (EPC rating E, privately rented and landlord not interesting in improving it) and costs a fortune (and takes several hours) to heat to even just 16 C. I live on my own and don't have any guests coming over so make do with extra layers of clothes/blankets. If the temp gets really low, I have a 1500 W oil filled radiator that will take the chill off of one room.