Heat in the home

[Biospace]

The passive heating elements of the hoose are not the full set, consisting of: large windows that gain some radiant heat from the sun; plus between-the-skins wall & roof insulation that tends to keep heat in the house for a long time and also prevent too much solar gain via the roof and sun-facing walls in summer.

In all events, it's very noticeable that even in cold (currently 5 degree C) outside temperatures, the ground source heat pump doesn't come on if the sun is shining brightly.

Cugel

A way of storing all that free solar radiation is one of the best ways of improving our carbon footprint - often nothing more than good design. As we move to high levels of in-wall insulation, this inhibits solar energy stored in the structure from steadily warming internal spaces long into the evening, something I've noticed on sunny Spring days having come from thick stone walls to a modern build.

We need to somehow maximise the energy coming in through glass (I mentioned friends' solar wall inside a greenhouse on the sunny side of their house), and/or use the energy to heat water which can be used to warm a large mass such as a floor slab, even at this time of year. I'm considering solar water heating mounted vertically on a South-facing wall, designed to make the most of the sun when it's lower in the sky, it could easily be plumbed in to the heated floor slab, or for houses with radiators, into a heat storage tank to be pumped through radiators in the evening.

Thinking is evolving all the time, I see this page https://www.westcoastgreen.com/passive-solar-design/ suggests that wall insulation isn't always recommended for those which face the equator - I would like to see some data for a house with 3 insulated and 1 solid wall.

[al_yrpal]

Research by UK housebuilder Redrow found Britons spend an average of 37 minutes a week speaking about reducing their energy bills. A quarter of those admitted to discussing energy for an hour or more on average, so perhaps it is no surprise that energy-saving has become a central characteristic for men of the 2020s.

For some, the energy crisis has been something to buy your way out of. With enough solar panels, overnight EV tariffs and, naturally, a heat pump, you can drive down your energy bill simply by using less gas. The investments can stretch into the tens of thousands; for many who went all in it has paid off.

Source...the Torygraph.

Al

[francovendee]

Minus 5° outside and 13° inside. Lovely and sunny and warming up the house nicely.
As I worked all my life in the UK I receive a UK pension. I don't get a winter fuel payment as years back the government decided it was too warm here to qualify.
My daughter and grandchildren are visiting next week and she's already worrying about us not having central heating.

I was interrupted writing this by the delivery of my ebike.
A bit too cold to try it out today.

[Jdsk]

NAO report: "Energy bills support schemes":
https://www.nao.org.uk/reports/energy-b ... t-schemes/

Conclusions

BEIS deserves credit for working quickly to introduce the schemes so that most households and businesses have received support in time for winter, and flexing its approach to approving new programmes and staffing enabling it to do so.

BEIS recognised that by moving at speed it had to make compromises. For example, the schemes provided almost universal support which could lead to financial support going to households and businesses which did not need it. Rapid implementation meant BEIS could not complete as detailed an assessment of the potential for fraud and error as would normally be the case.

Moving to make the schemes more targeted will require BEIS to operate a more sophisticated approach to financial control and to consider the potential increased risk of fraud and error.

Jonathan

[Jdsk]

"MoneySavingExpert founder Martin Lewis has today written to Chancellor Jeremy Hunt urging him to keep the energy price guarantee (EPG) at a typical £2,500/year, rather than hiking it to £3,000/year from 1 April as planned."

https://www.moneysavingexpert.com/news/ ... nergy-sup/

Jonathan

[UpWrong]

Just had my bill for Jan. Yikes. I've come to the conclusion the patio doors are the biggest heat sink, even though they are double-glazed with full length lined curtains drawn all day. Next winter I shall find some insultation sheets to stick on all the glass for Dec/Jan/Feb. Does anybody have any recommendations?

[853]

Just had my bill for Jan. Yikes. I've come to the conclusion the patio doors are the biggest heat sink, even though they are double-glazed with full length lined curtains drawn all day. Next winter I shall find some insultation sheets to stick on all the glass for Dec/Jan/Feb. Does anybody have any recommendations?

I have double-glazed patio doors from 1997, which I would describe as thermally poor. See below my post from the 14th December 2022 for what I use successfully to reduce the heat loss.

viewtopic.php?p=1743409#p1743409

[UpWrong]

Just had my bill for Jan. Yikes. I've come to the conclusion the patio doors are the biggest heat sink, even though they are double-glazed with full length lined curtains drawn all day. Next winter I shall find some insultation sheets to stick on all the glass for Dec/Jan/Feb. Does anybody have any recommendations?

I have double-glazed patio doors from 1997, which I would describe as thermally poor. See below my post from the 14th December 2022 for what I use successfully to reduce the heat loss.

viewtopic.php?p=1743409#p1743409

I'll look into that thermawrap. Should be able to tape it to the glass or metal frame I guess.

[Biospace]

It'd be worth estimating what the heat losses/costs through the patio doors are and working out pay-back times for what you plan. If the frames are alloy and not thermally broken - that's to say they're metal from inside to out - it might be worth considering entirely closing them off or even replacing them.

Heavy or thermally lined curtains are as good as anything if they don't leave a gap, adding bubble wrap to the glass is cost effective if unsightly, be aware that trapped condensation is thermally conductive. Adding external shutters would be belt and braces, plus they could help keep the room cool in hot summer sun.

[Jon in Sweden]

We used our heat pumps pretty liberally in January due to electricity being cheaper (conserve the firewood for when it's not). 917kwh used for the month (607kwh on heating, approximately, so 81w per square metre, per day). Average outside temperature for the month was 1.5c above freezing, so not especially cold.

Total cost about £220 for the month.

We've now shifted our tariff to an hour by hour price. That works well for us as we use electricity on the cheap days and stoke the fire when it's not.

February is the last properly cold month, then it starts to warm up a bit. The electricity bill last March (when we had the house, but weren't yet living here) was small compared to the previous month.

[UpWrong]

It'd be worth estimating what the heat losses/costs through the patio doors are and working out pay-back times for what you plan. If the frames are alloy and not thermally broken - that's to say they're metal from inside to out - it might be worth considering entirely closing them off or even replacing them.

Heavy or thermally lined curtains are as good as anything if they don't leave a gap, adding bubble wrap to the glass is cost effective if unsightly, be aware that trapped condensation is thermally conductive. Adding external shutters would be belt and braces, plus they could help keep the room cool in hot summer sun.

You've given me something to think about. It looks like the door frames are metal throughout and they feel damned cold this morning. So, replacing the doors and runners might be worth it. uPVC would be a thermal improvement. Maybe consider triple glazing if changing anyway. Otherwise double glazed plus bubble wrap stuck on the glass during winter months perhaps.

[squeaker]

I was speaking to someone today, and they mentioned Lot 20

I'd never heard of Lot 20, so I'm guessing many of you won't have either. It's all about legislation that aims to help manufacturers create EcoDesign products that use significantly less energy to provide heat to our homes. So the web site says ...

https://www.bestelectricradiators.co.uk ... ompliance/

I think I'm missing the point here (or rather how Lot 20 defines efficiency) as the linked article says

Under Lot 20, any heater classed as a ‘fixed electrical local space heater’ must have a minimum 38% efficiency rating if they produce heat of an output of 250W or higher.

Given that all the electricity put into a space heater ends up as heat (eventually, in one way or another), how is an efficiency of less than 100% result? Or to put it another way, does anyone know how is efficiency calculated under Lot 20?

[Jdsk]

Given that all the electricity put into a space heater ends up as heat (eventually, in one way or another), how is an efficiency of less than 100% result? Or to put it another way, does anyone know how is efficiency calculated under Lot 20?

It's a rating system based on points for features:
https://www.lot20ecodesign.co.uk/lot-20-faq

Jonathan

[axel_knutt]

I was speaking to someone today, and they mentioned Lot 20

I'd never heard of Lot 20, so I'm guessing many of you won't have either. It's all about legislation that aims to help manufacturers create EcoDesign products that use significantly less energy to provide heat to our homes. So the web site says ...

https://www.bestelectricradiators.co.uk ... ompliance/

I think I'm missing the point here (or rather how Lot 20 defines efficiency) as the linked article says

Under Lot 20, any heater classed as a ‘fixed electrical local space heater’ must have a minimum 38% efficiency rating if they produce heat of an output of 250W or higher.

Given that all the electricity put into a space heater ends up as heat (eventually, in one way or another), how is an efficiency of less than 100% result? Or to put it another way, does anyone know how is efficiency calculated under Lot 20?

Following their link to the EU specifications I just went down a rabbit hole into Wonderland, and got nowhere. Scrolling down the page to the tables, and also from this site, it looks as if that 38% has little to do with efficiency in any meaningful sense, it seems more like an exam mark, where brownie points are awarded for things deemed to be of merit.

[Biospace]

You've given me something to think about. It looks like the door frames are metal throughout and they feel damned cold this morning. So, replacing the doors and runners might be worth it. uPVC would be a thermal improvement. Maybe consider triple glazing if changing anyway. Otherwise double glazed plus bubble wrap stuck on the glass during winter months perhaps.

Metal which is only slightly cooler than ambient will feel colder to the touch than most other materials because of its ability to conduct heat so efficiently, but if the doors are older then there's a good chance the frames aren't thermally broken.

It would be interesting to know the U-values of older patio doors + thick curtain vs new ones without a curtain - I suspect the difference would be small or non-existant. Add bubble wrap as well as the curtains and it's very likely there'd be less heat loss with what you have now compared with new, without the extra - who'd wish to use bubble wrap with new patio doors?

It's well worth remembering our climate is a temperate oceanic one - mild, damp and breezy, with extremes relatively rare. Draughts are the single largest cause of heat loss.