The Green Agenda

[Stere]

Quote

Anyway, I've just accepted a quote for air to air heat pump installation on our Sweden home. Mitsubishi units, with up to 7kw of heating or cooling, split across two units. Total installation quote - £3195. Installation cost would at least double here.

 

Will this be with normal rads not underfloor as you said insulation in the house is already good?

 

What sort of COP do you  expect?

[Big J]

37 minutes ago, Stere said:

 

Will this be with normal rads not underfloor as you said insulation in the house is already good?

 

What sort of COP do you  expect?

 

The main heating system is geothermal (or ground source heat pump), running through normal radiators. It's a 2 year old system, so COP is supposed to be 4.4.

 

The idea with adding the air source pumps is to allow us to drop the geothermal system down from 20c to 18c, with the air source outlets boosting the living areas. They will also function as a/c in summer (which is a touch hotter than the hottest parts of the UK) and tie in nicely with the solar panel array we're planning to install.

 

COP on the air source is lower, at 3 or so, but hoping to be a net producer of electricity with the panels, so it won't really matter.

 

The house seems to be extremely well insulated. As I mentioned before, 10 times less energy is required to heat a square metre of our Swedish home than our Devon home.

[Big J]

Some interesting programmes on R4 yesterday relating to this. Call You and Yours was asking "what are you doing to live in a more environmentally friendly way?" and Costing the Earth was exploring whether it was more environmentally friendly to renovate older buildings or tear them down and build again.

 

Despite it somewhat disagreeing with the conclusions of Costing the Earth, I think in many cases tearing down and starting again is best. Some buildings are simply impossible to bring to a modern standard. If old, inefficient buildings are replaced with modern, timber constructed (ie, sequestering carbon) structures, a vast amount of fuel can be saved heating them.

 

Over the past 14 years of living in old farm cottages/houses in Scotland and Devon, we've burned around about 450 cubic metres of firewood. That's over 200t green weight. You could build a lot of houses out of that.

[trigger_andy]

Some interesting programmes on R4 yesterday relating to this. Call You and Yours was asking "what are you doing to live in a more environmentally friendly way?" and Costing the Earth was exploring whether it was more environmentally friendly to renovate older buildings or tear them down and build again.
 
Despite it somewhat disagreeing with the conclusions of Costing the Earth, I think in many cases tearing down and starting again is best. Some buildings are simply impossible to bring to a modern standard. If old, inefficient buildings are replaced with modern, timber constructed (ie, sequestering carbon) structures, a vast amount of fuel can be saved heating them.
 
Over the past 14 years of living in old farm cottages/houses in Scotland and Devon, we've burned around about 450 cubic metres of firewood. That's over 200t green weight. You could build a lot of houses out of that.

I don’t agree with is thinking at all.

1, Lose beautiful (eye of the beholder) old buildings that have been build with craftsmanship that simply can’t or won’t be replaced to build some boring rabbit hutch? No thanks.

2, Id put money on 50% of that 200t could not be used in construction. I’d say it could be as much as 90%. You are/where a miller. You know the recoverable amount of timber per log is fairly low. That’s out of sawlogs. I doubt you burned 200t of sawlogs either. What I envision you burned was a far lower grade and only suitable for firewood. With wood being close to as carbon neutral as you can get regardless how much you burned it was still “good for the environment”.

[Big J]

51 minutes ago, trigger_andy said:

 

I don’t agree with is thinking at all.

1, Lose beautiful (eye of the beholder) old buildings that have been build with craftsmanship that simply can’t or won’t be replaced to build some boring rabbit hutch? No thanks.

2, Id put money on 50% of that 200t could not be used in construction. I’d say it could be as much as 90%. You are/where a miller. You know the recoverable amount of timber per log is fairly low. That’s out of sawlogs. I doubt you burned 200t of sawlogs either. What I envision you burned was a far lower grade and only suitable for firewood. With wood being close to as carbon neutral as you can get regardless how much you burned it was still “good for the environment”.
 

 

 

1. A great many of the older buildings I'm referring to have no architectural merit. Most of what's been built since the 50's is shite, by whichever metric you measure.

 

2. It depends on the building method. Massive timber systems such as brettstapel utilise low grade timber in structural walls and are fairly straightforward to get to passive standard. But yes, some of what was burnt was too low a grade, even for that. There are however better uses for it, or indeed that timber could have heated more efficient structures.

 

A good friend up in Kincraig (by Aviemore) built himself a lovely (and quite spacious) 2 bed cottage several years back. He was mandated by planning to have to put a heating system in, but it's so well insulated that even in mid winter, one small fire (3 logs) in the stove is enough to heat the house for 3 days. It would take him about 20 years to burn what we burn in one winter here in our smaller (94 square metres versus 108) Devon farm house. Keep in mind that an Aviemore winter is at least 5c colder too.

 

I'm not saying rip everything down, but we need to be realistic that many buildings don't meet any kind of modern standard and never will.

 

You don't see old vehicles on the road much any more, and that's for very good reason. They aren't safe or efficient enough to meet modern standards. We ought to adopt some of that same pragmatism with our homes.

[Woodworks]

1 hour ago, Big J said:

Some interesting programmes on R4 yesterday relating to this. Call You and Yours was asking "what are you doing to live in a more environmentally friendly way?" and Costing the Earth was exploring whether it was more environmentally friendly to renovate older buildings or tear them down and build again.

 

Despite it somewhat disagreeing with the conclusions of Costing the Earth, I think in many cases tearing down and starting again is best. Some buildings are simply impossible to bring to a modern standard. If old, inefficient buildings are replaced with modern, timber constructed (ie, sequestering carbon) structures, a vast amount of fuel can be saved heating them.

 

Over the past 14 years of living in old farm cottages/houses in Scotland and Devon, we've burned around about 450 cubic metres of firewood. That's over 200t green weight. You could build a lot of houses out of that.

Not sure I am with on this one. Most buildings can be insulated either inside or out. We did our 200 year old barn inside and dads 300 year old farmhouse outside. External insulation completely changes the character of a building but it does make it easy to heat and far cheaper than knocking it down and starting again. 

[Big J]

1 minute ago, Woodworks said:

Not sure I am with on this one. Most buildings can be insulated either inside or out. We did our 200 year old barn inside and dads 300 year old farmhouse outside. External insulation completely changes the character of a building but it does make it easy to heat and far cheaper than knocking it down and starting again. 

 

The difficulty in internally insulating houses is that you lose interior space. Given that we live in the smallest houses in Europe, that's not really an option for most.

 

External insulation is in a way better (especially if you have a massive stone/brick structure, due to thermal storage and regulation) but very few British houses have decent overhangs on roofs, so a new roof would be required too. 

[Woodworks]

1 hour ago, Big J said:

 

The difficulty in internally insulating houses is that you lose interior space. Given that we live in the smallest houses in Europe, that's not really an option for most.

 

External insulation is in a way better (especially if you have a massive stone/brick structure, due to thermal storage and regulation) but very few British houses have decent overhangs on roofs, so a new roof would be required too. 

You dont need overhangs though. Sure its looks better with the eaves covering it but there are trims to work around the problem.

 

This is dads old farmhouse. I slate hung the south wall with insulation behind and its covered by the eaves and he had the other wall professionally insulted with capping trims at the top. It's not pretty but works. The roof will need doing in due course and we can then extend the roof to cover the insulation