Double or single glaze door?

[MikeG.]

.........Thermal mass stores surplus energy. Free surplus heat from the sun in MikeG's concrete house.......

..........Obviously the expensive concrete building would have lower bills..........

Both of these things can't be right. Less heat is put into the high thermal mass house than into the better-insulated but lightweight house, and the same amount of sunlight went into both. (Same with the concrete cube vs plywood cube). Therefore there is less "surplus" heat in the heavyweight house. Honest to god, Jacob, you spout this stuff as though you are some sort of expert, and virtually every claim you make is wrong.

 

[scooby]

Glad to see you've decided to continue posting Mike. Its been interesting reading your posts.

 

[Jacob]

.........Thermal mass stores surplus energy. Free surplus heat from the sun in MikeG's concrete house.......

..........Obviously the expensive concrete building would have lower bills..........

Both of these things can't be right. Less heat is put into the high thermal mass house than into the better-insulated but lightweight house. (Same with the concrete cube vs plywood cube). Therefore there is less "surplus" heat in the heavyweight house. Honest to god, Jacob, you spout this stuff as though you are some sort of expert, and virtually every claim you make is wrong.

You have to heat the thermal mass before it is thermal, that's where the surplus heat goes. That's the whole idea. It's a buffer. From cold it will take longer to heat up than a low thermal mass house, but then will take longer to cool down.
I'm surprised you don't understand it - I guess that is what the bad temper is all about.
PS

Less heat is put into the high thermal mass house than into the better-insulated but lightweight house, and the same amount of sunlight went into both. 

Can't be true - same amount of sunlight is same amount of heat.
The difference is that the thermal mass house will save more of it (act as a buffer) but then you have to pay for the building in of thermal mass, set off against the reduced heating bill.
But ultimately the economics depends on the pattern of use - if you are in and out erratically then quicker heating of a low thermal mass building may suit and the buffer effect be redundant and wasted.

 

[scooby]

I feel sorry for the OP.

Wow, never had so much interest in one of my posts.

Don't worry about me, just had an email from customer saying they are happy to go with single glazing so all good.

As always thank you everybody for all the help and advice :roll:

Doug

Good to hear everything is sorted.

 

[doctor Bob]

I think this pie chart will help to clarify a few points?

 

[OscarG]

These 4 pages are pretty much a microcosm of that BBC thread.

Perhaps this one will also get to 372 pages!

I feel sorry for the OP.

Agreed!

Hope his door turns out nice, whatever he decides.

 

[MikeG.]

.......Can't be true - same amount of sunlight is same amount of heat.........

Sunlight wasn't the only heat source. They got the same amount of sunlight, but required different amounts of heat from the central heating system. Your tosh about "spare heat" is just bizarre. The high thermal mass house required less heat than the low thermal mass house to maintain the same internal temperature. However much you twist and squirm, them's the facts.

 

[Lons]

Always reminds me of this. :lol:

 

[Jacob]

.......Can't be true - same amount of sunlight is same amount of heat.........

Sunlight wasn't the only heat source. They got the same amount of sunlight, but required different amounts of heat from the central heating system. Your tosh about "spare heat" is just bizarre. The high thermal mass house required less heat than the low thermal mass house to maintain the same internal temperature. However much you twist and squirm, them's the facts.

OK yes - I thought you were talking about the amount of solar heat.
But you have to pay for the material which makes up the thermal mass which brings up cost effectiveness as the decider. Or pay even more for a Trombe wall set up - which is why they are extremely rare and nobody does it.
That's all I was saying, however much you rant and rave.
Preferred compromise option to a Trombe wall is a normal conservatory in a masonry building. You have the glazing and the thermal mass but you use the space between them and can see out of the windows!
By "spare" or "surplus" heat I was talking about sunlight when in excess, as on sunny days with large areas of glass when you have to ventilate etc, unless you have some sort of thermal mass effect going on to absorb it. Or similarly, bio mass boiler burning away efficiently but with heat you can't use at the same rate except to heat thermal store i.e. insulated water tank. The water tank can also be heated by solar panels on the roof which is going to be more effective and much cheaper than a Trombe wall set up.

 

[MikeG.]

.........But you have to pay for the material which makes up the thermal mass which brings up cost effectiveness as the decider. Or pay even more for a Trombe wall set up - which is why they are extremely rare and nobody does it. That's all I was saying, however much you rant and rave............

No, that's a lie. That is not all you were saying. You said:

......Thermal store only makes sense if you have a substantial source of free surplus energy. ..........

.......Thermal mass doesn't help with heating except as a store of surplus energy - as a buffer. Otherwise it's easier to just turn it down or off rather than heating up a lump of concrete.........

.........Thermal mass stores surplus energy.

........But it has another inherent problem - it's a heat sink, until it you get it up to temp, by which time you may be out of the building or whatever.

All of which shows a complete lack of understanding of how thermal mass in a building works.

Why is it, Jacob, that every single zero-energy house built in our climate is high thermal mass? There are now hundreds of them, and every last one that I know of uses heavyweight construction externally insulated. They're all wrong, obviously, despite all the evidence to the contrary. Despite the many side-by-side real-world experiments of lightweight vs heavyweight, such as my own which I described earlier, or the Nottingham University estate of low energy trial homes, you still think that they require extra energy to raise the thermal mass to temperature.

........Takes a day or so to cool down to ambient temperatures as it's fairly draught proof.

Great. Our oil ran out unexpectedly in January. We had no heating for over ten days. The house lost half a degree a day. At that rate it would have taken some 3 weeks or more to get to ambient temperature.

 

[MikeG.]

...... Or pay even more for a Trombe wall set up - which is why they are extremely rare and nobody does it........

I'm not getting sucked into your financial red herring.

Trombe walls are actually quite common. Not here, because we have low levels of direct insolation. Basically, we're too cloudy, and so our sunlight is generally too diffuse for them to be effective. However, they are particularly common in areas of cool climate but high insolation, such as in mountainous regions, and in northern USA and Canada. It's nothing to do with cost, and everything to do with effectiveness in our climate.

 

[Jacob]

No you are still missing the point; COST EFFECTIVENESS.
Which is why zero energy houses, trombe walls, are rare and why the preferred and more common method of solar heat capture is by roof panels and hot water storage, or photo voltaic.
I forgot to add; basically, we're too cloudy, and so our sunlight is generally too diffuse for them to be effective. So we agree at last!

 

[MikeG.]

No you are still missing the point; COST EFFECTIVENESS.......

No, you are moving the goalposts, again. You made erroneous claims. Flat out wrong claims. Deal with those first, then I'll show you you're wrong on cost effectiveness. Before I discuss anything else with you on this subject, you need to acknowledge that you have mis-characterised the role of thermal mass in low energy design. It doesn't work the way you think it works.

I don't understand your attitude here, Jacob. You clearly have an interest in this subject, and you are interacting with someone who led the way in the UK. There were a only a couple of other guys working on low energy buildings here in the 90s. I've forgotten more about this subject than you've ever known. Why on earth don't you ask questions, try and have a conversation, explore some of the issues, rather than just continually telling me I'm wrong?

 

[Jacob]

Why on earth don't you ask questions, try and have a conversation, explore some of the issues, rather than just continually telling me I'm wrong?

You kicked off the argumentative tone with your first post.

I didn't know they were called "Trombe" walls.
We had an end of terrace with a massive three story featureless gable end, of 18" stone. Very cold when the sun went off. I wondered about glazing all over it but thought it was problematic - maintenance of the internal surfaces mainly. But then thought why not position it away so you could get behind it. And, ta-da, you have a three story conservatory! Much more useful then the Trombe wall!
Didn't get around to that either.

 

[RogerS]

.....Why on earth don't you ask questions, try and have a conversation, explore some of the issues, rather than just continually telling me I'm wrong?

He won't, Mike, because he is indulging in his favourite pastime - being a troll.

 

[MikeG.]

Why on earth don't you ask questions, try and have a conversation, explore some of the issues, rather than just continually telling me I'm wrong?

You kicked off the argumentative tone with your first post.

Because you made a claim that was completely and demonstrably wrong.

We had an end of terrace with a massive three story featureless gable end, of 18" stone. Very cold when sun as the sun went off. I wondered about glazing all over it but thought it was problematic - maintenance of the internal surfaces mainly. But then thought why not position it away so you could get behind it. And, ta-da, you have a three story conservatory! Much more useful then the Trombe wall!
Didn't get around to that either.

You don't mention the orientation, but of course this is standard stuff. Bedzed, in Sutton, London (another heavyweight-construction zero-energy place) uses three storey external sunspaces, for example. However, with your beloved cost-effectiveness in mind, it would be a lot cheaper to externally insulate that terrace gable wall than to create a 30 foot high glazed structure.

 

[MikeG.]

.....Why on earth don't you ask questions, try and have a conversation, explore some of the issues, rather than just continually telling me I'm wrong?

He won't, Mike, because he is indulging in his favourite pastime - being a troll.

I'm not getting involved any more. I'm going out to lay some bricks........

(Heavyweight thermal mass for a greenhouse).

 

[OscarG]

I hate to see energy wasted.

Wonder if there's an efficient way to recycle Jacob's hot air? :wink:

 

[thomashenry]

Not sure what the controversy is here. Unless my understanding of thermodynmics is totally wrong, the only thermal energy in a thermal mass store is energy that has been put into it. So it's useful for storing excess energy that is not needed at a given time, but would otherwise be lost. Plus of course, a thermal store has cost.

What's Jacob so wrong about?

 

[Lons]

Here's a little scenario.

Fella goes to the pub and one of the lads says "what's up mate, you look really down?"

"Just found out my missus has cancer, they're going to operate but it doesn't look good the consultant says no hope", poor bloke is in tears.

"Don't listen to them there consultants" says his mate, " they talk utter boslocks, have no idea, I'm sure they just say things to put the wind up you" " I had the same thing with my missus a few years ago but I googled everything and found the answer. Turns out she had athletes foot so I ignored the so called experts and treated that".
"Brilliant this Google lark - love it I'm always on the old ipad!"

"That's fantastic" said the first bloke, you can have my copy of The Guardian and I'll buy you a pint before I rush home to give the news to my missus".

As he's leaving he says " how long do you need to apply the athletes foot cream btw?"

"Dunno" says his mate "she died 'cos it had spread to her brain, the barstewards didn't tell me in time".