Heat in the home

[Jdsk]

Yes, this is all making me think about putting a different blind over the big widow that causes trouble on our top floor.
...

Have you tried negotiating with her first?

; - )

Jonathan

[Nearholmer]

Crikey, if the MiL finds me writing things like that I’ll be dead on the spot.

(to be fair, she is actually a small widow)

[al_yrpal]

The folk with the mock Georgian house who suffer high temperatures have ultra thick loft insulation and the whole place is insulated way way beyond usual standards. In the winter they heat with bottled gas which costs them only £60 per annum (old prices) for a 2000 sq ft house, so I think their problem is solar and air temperature gain, gained very slowly.

There is a company called Magnaglaze that does acrylic window panels. But on sliding sashes you cant really use them because the magnets on the upper sash would foul the lower sash. In the summer we play with the sashes in hot weather to get optimum temperatures. I have thought about acrylic sheets temporarily fixed in place though.
The windows fit tightly there are no draughts.

We have to be so careful what we do here because of the listed building folk who have a terrible reputation for draconian rulings.

Al

[DaveReading]

Perhaps the key thing is that our curtains are lined, so the surface facing out is a light calico colour, not far off white, and reflects most of the light back through the glass without it being converted to heat as it would be if it hit a dark coloured surface.

Goes away to Google how to convert light into heat ...

[Biospace]

Now so many homes are made comfortable in winter by heating the air rather than having a source of radiation in a cool house - a fire range or central mass of brick fireplace and chimney, we've forgotten the importance of radiation in feeling comfortable warm, or cool. For me, most air conditioned cars in midsummer sun are not so comfortable as you're surrounded by surfaces radiating heat at you, why a house with cold walls and other surfaces still feels cool even if the air is heated to well over 20C.

I've never been able to picture (using my 6th form physics of 55 years ago) how closing the curtains can make any difference to heat loss or gain in a house from radiant heat (the sunshine) coming through the window glass. Once the radiant heat is caught in the house (by the furnishing, walls, etc. or just the closed curtains) it'll heat whatever it shines on...

To prevent inner house heat gain from sunshine on the windows, you'd have to have the curtains (or shutters) outside the window, wouldn't you?

Yes, external shutters are the most effective at keeping radiation out but interal shutters are still very effective, as are thick floor-length curtains and even roller blinds. They all prevent radiation warming a room's internal surfaces, reduce draughts and form a layer of insulating air between the glass and the room. Improvements in radiation, convection and conduction. Internal barriers will soak up some heat themselves, but less so than a flag floor or internal wall. But a sheet of steel wouldn't make a good internal blind, so clearly choice of material matters.

Windows often represent the single largest gains and losses of heat into/from the home, after a poorly-insulated roof. Which is why the Scandinavians have been fitting airtight, triple glazed ones for decades longer than we have and why French houses have external shutters. I remember sitting in a traditional North African house with one tiny window high up on the East wall, purely for light and ventilation. Outside was in the high 30s, inside it was a deliciously cool 28C.

If you have a cold day and have heated bricks outside your home that you want to bring inside to warm your home overnight, you will be opening and closing the door repeatedly, losing heat as you do that.

I think 853 is in the experimental stage, I don't believe he's intending carrying bricks around to keep warm. Although if you carried enough, you definitely would be

The folk with the mock Georgian house who suffer high temperatures have ultra thick loft insulation and the whole place is insulated way way beyond usual standards. In the winter they heat with bottled gas which costs them only £60 per annum (old prices) for a 2000 sq ft house, so I think their problem is solar and air temperature gain, gained very slowly.

There is a company called Magnaglaze that does acrylic window panels. But on sliding sashes you cant really use them because the magnets on the upper sash would foul the lower sash. In the summer we play with the sashes in hot weather to get optimum temperatures. I have thought about acrylic sheets temporarily fixed in place though.
The windows fit tightly there are no draughts.

We have to be so careful what we do here because of the listed building folk who have a terrible reputation for draconian rulings.

Yes, a highly insulated house will keep the heat in overnight far better than a tin shed, so in the sort of summer we had this year it'd be oppressively hot. A hot roofspace won't help, but the heat will have warmed up the whole internal structure (stone worktops, concrete floor, corckery in cupboards etc to a high temperature, the insulation will prevent this escaping so easily. Open windows and fans running through the night would be a partial solution, although with nighttime air temps approaching 20C that's not much of a differential to pull stored heat out.

Somewhere I have a link for a Scottish company specialising in invisible secondary glazing which is designed for sash windows, I'll dig it out if you're interested.

Perhaps we pay too little attention to windows normally. We get double glazing and think the job is done, but playing around with blinds and curtains, of the right sort, can help regulate room temperature.

YES!

[853]

Following advice from my consultant ( ), I am very happy to report success in experiment 2

I managed to find an old plastic cool-box, from about 30 years ago, so I used this with the acrylic sheet on top. Although it has been sunny here in the North Midlands, it has also been very windy with gusts of 30mph. I couldn't angle the cool box to the sun because of the wind, and I had to use two bricks on top of the acrylic sheet to keep it down. My thinking was that only the top brick would get any real heat, and this would only be if it was raised within the box. To my surprise, when I came back about 6 hours later I had four hot bricks which I carried inside the house within the cool box. I don't have measuring equipment to find out how hot they were, but they were definitely hot to touch and probably around 50 degrees C.

A good result. Time to work quickly if you want any free heat this year, there are only a few weeks left where the sun will significantly warm things up!

You are, of course, correct. Again.

I think that by the time I have designed and built something that will be worth doing, it might be ready for March to catch the equivalent spring heat. I take on the advice of all of my consultants, and so it all hinges on whether I can obtain a radiator free of charge. One of my neighbours is going to replace their elderly ones soon, so I may develop the idea further.

In the mean time, I have a better idea. Or at least I think it's a better idea, so I'd be grateful if those of you who know more will scrutinize it fully. Here goes:

Imagine filling 100 litres of tap water, (currently around 15 degrees C), into plastic containers and putting these into an empty freezer and freezing them to -15 degrees C. Then, once frozen, taking out the ice and discarding it in the garden and repeating this with 100 litres of 15 degrees C water again.

If I did this, the freezer could be used like a ground source heat pump - but with a very different initial cost outlay. Is this viable?

Any constructive advice/criticism/calculations gladly accepted

[Jdsk]

What's the objective?

Where would the freezer be?

Thanks

Jonathan

[rjb]

There was a Victorian terraced house in Bristol which became an eco project. They had a glass panel on the outside brick wall with a black bin liner on the wall. A brick removed top and bottom gave an airflow into the interior room controlled by vents. Free heating on sunny days.

[Biospace]

I think that by the time I have designed and built something that will be worth doing, it might be ready for March to catch the equivalent spring heat. I take on the advice of all of my consultants, and so it all hinges on whether I can obtain a radiator free of charge. One of my neighbours is going to replace their elderly ones soon, so I may develop the idea further.

In the mean time, I have a better idea. Or at least I think it's a better idea, so I'd be grateful if those of you who know more will scrutinize it fully. Here goes:

Imagine filling 100 litres of tap water, (currently around 15 degrees C), into plastic containers and putting these into an empty freezer and freezing them to -15 degrees C. Then, once frozen, taking out the ice and discarding it in the garden and repeating this with 100 litres of 15 degrees C water again.

If I did this, the freezer could be used like a ground source heat pump - but with a very different initial cost outlay. Is this viable?

Any constructive advice/criticism/calculations gladly accepted

Very intriguing!

My initial thought is that it will work from a point of view of heat generated (although not so much heat), but economically not.

Unless you've a diesel generator running on free, waste plant oil to power the freezer. In which case you'd hook it up to a small electric heater.

[Nearholmer]

It will certainly extract heat energy from the water and deposit it outside the freezer. I’ve forgotten the “coefficient of performance” of ‘fridges, but you’d need to use that and the specific heat capacity of water, which I’ve also forgotten, plus the energy consumption of the freezer, to calculate whether it would make monetary sense. My instinct is that it will.
[Revised: I just looked up the CoP of deep freezers, and my instinct is now that it won’t make monetary sense]

And the latent heat of freezing.

[Biospace]

Somewhere I have a link for a Scottish company specialising in invisible secondary glazing which is designed for sash windows, I'll dig it out if you're interested.

Seemed to make sense to post it publically, here it is - found it faster than I thought.

https://geckoglazing.co.uk/

If you live in Edinburgh it's fitted for free.

[853]

What's the objective?

Er, this is the 'Heat in the home' thread

Where would the freezer be?

Thanks

Jonathan

In the lounge, this is the only room I heat; the bathroom and main bedroom sit above the lounge, and as the house was built in 1986 there is no insulation above the lounge ceiling. I accept there would be 30-40db of noise from the freezer, which may influence positioning

[jois]

Following advice from my consultant ( ), I am very happy to report success in experiment 2

I managed to find an old plastic cool-box, from about 30 years ago, so I used this with the acrylic sheet on top. Although it has been sunny here in the North Midlands, it has also been very windy with gusts of 30mph. I couldn't angle the cool box to the sun because of the wind, and I had to use two bricks on top of the acrylic sheet to keep it down. My thinking was that only the top brick would get any real heat, and this would only be if it was raised within the box. To my surprise, when I came back about 6 hours later I had four hot bricks which I carried inside the house within the cool box. I don't have measuring equipment to find out how hot they were, but they were definitely hot to touch and probably around 50 degrees C.

A good result. Time to work quickly if you want any free heat this year, there are only a few weeks left where the sun will significantly warm things up!

You are, of course, correct. Again.

I think that by the time I have designed and built something that will be worth doing, it might be ready for March to catch the equivalent spring heat. I take on the advice of all of my consultants, and so it all hinges on whether I can obtain a radiator free of charge. One of my neighbours is going to replace their elderly ones soon, so I may develop the idea further.

In the mean time, I have a better idea. Or at least I think it's a better idea, so I'd be grateful if those of you who know more will scrutinize it fully. Here goes:

Imagine filling 100 litres of tap water, (currently around 15 degrees C), into plastic containers and putting these into an empty freezer and freezing them to -15 degrees C. Then, once frozen, taking out the ice and discarding it in the garden and repeating this with 100 litres of 15 degrees C water again.

If I did this, the freezer could be used like a ground source heat pump - but with a very different initial cost outlay. Is this viable?

Any constructive advice/criticism/calculations gladly accepted

Possibly, we had a gas powered fridge at one point and that kept the kitchen nice and warm. though I think it would make better economic sense to do away with the freezer all together and buy a halogen heater

[853]

I think that by the time I have designed and built something that will be worth doing, it might be ready for March to catch the equivalent spring heat. I take on the advice of all of my consultants, and so it all hinges on whether I can obtain a radiator free of charge. One of my neighbours is going to replace their elderly ones soon, so I may develop the idea further.

In the mean time, I have a better idea. Or at least I think it's a better idea, so I'd be grateful if those of you who know more will scrutinize it fully. Here goes:

Imagine filling 100 litres of tap water, (currently around 15 degrees C), into plastic containers and putting these into an empty freezer and freezing them to -15 degrees C. Then, once frozen, taking out the ice and discarding it in the garden and repeating this with 100 litres of 15 degrees C water again.

If I did this, the freezer could be used like a ground source heat pump - but with a very different initial cost outlay. Is this viable?

Any constructive advice/criticism/calculations gladly accepted

Very intriguing!

My initial thought is that it will work from a point of view of heat generated (although not so much heat), but economically not.

Unless you've a diesel generator running on free, waste plant oil to power the freezer. In which case you'd hook it up to a small electric heater.

100 litres of water weighs 100kg. The specific heat capacity of water is 4184J/kg/1 degree C this equates to 418400J/degree C. In other words, a large number of heat would be produced - which might be significant for a small and well insulated house

I have been told that a ground-source heat pump produces 4W of heat for every 1W of electric used to power the pump. If that is true, and I can get any 'issues' sorted out, that's what I'm looking at. Of the 1W used for pumping, any inefficiency would result in further heat in the house.

[Biospace]

I have been told that a ground-source heat pump produces 4W of heat for every 1W of electric used to power the pump. If that is true, and I can get any 'issues' sorted out, that's what I'm looking at. Of the 1W used for pumping, any inefficiency would result in further heat in the house.

Somehow I doubt it, I believe the workings of a domestic heating HP aren't the same as those on a freezer. There will be a little free heat, but it's perhaps best thought of as a small background source rather than something to keep you warm - unless your home is to passivehouse standards or nearly so.

Here are a couple of links,

https://www.quora.com/Why-is-the-COP-of ... frigerator
https://www.scielo.br/j/jbsmse/a/5zVF4y ... J/?lang=en