Green Building Forum - All Discussions

In the long run high tech building solutions have no future

Ethics-Man — Sun, 03 Feb 2008 23:02:19 +0000

Lots of talk here about building airtight houses with mechanical ventilation.

What happens when MVHR, or any other critically necessary high tech solution breaks down and the occupants are either:

1. Too poor to repair or replace it

2. Too stupid to realise it's happened

3. Just don't realise it's significance in the first place

4. Live in a post industrial future that just doesn't offer the option to repair or replace these things.

All this stuff will go the way of the dodo after cheap oil is finished.

I don't think high tech is the future.

Old cottage in mid wales - advice please

storm — Tue, 05 Feb 2008 14:05:34 +0000

My step father and I have moved from a comfortable leafy suburban house in London, to an at least 200 year old cottage in a very isolated position in the hills, Mid Wales. Been here approx a year, conditions are fairly primitive, cramped, no heating , single glazed etc Freezing ! Most of our possessions are still boxed up, awaiting an extension in early March. We have a quote for Â£75.000 for the extension. However, we would like a green build ideally to passivhaus standard , Originally was considering , Solar /Wind power, but am told this is very high maintenance and we need the property to be as LOW maintenance as possible. 1 ) Can we get a specialist architect/ project manager at short notice to monitor this build, and how much input can be reasonably expected from him ? 2) The sorrounding area to the cottage dips, forming a wind tunnel, so the structure will need to be extra strong to cope with the harsh weather. 3) How much extra approximately would our ideal extension cost ? Any comments/advice much appreciated.

Linking multifuel stove with oil boiler.

Scotch — Thu, 14 Feb 2008 11:18:18 +0000

Hi all,
We currently have an oil fired central heating/hot water system which uses a normal hot water cylinder. We are planning to do house renovations and wish to install a multi fuel stove. As well as be a focal point and a source of heat for the room (open plan kitchen, dinning, living area, which will be roughly 15 feet x 33 feet x 8 feet ) I would like to use the stove to contribute heat for both hot water and central heating thus reducing our oil bill. I have looked at a few different systems for linking a stove and oil boiler:

Dunsley nuetralizer: http://www.dunsleyheat.co.uk/linkupsys.htm
Heating innovations H2 Panel: http://h2panel.co.uk/
Thermal store/ heat bank: http://www.heatweb.com/ http://www.accumulatortanks.co.uk/

What I like about the thermal store/ heat bank system is that hot water is stored to provide heat later, and can provide hot water via mains pressure. However the thermal store/ heat bank system is a greater expense on top of buying the stove.
Where as if I use a Dunsley nuetralizer or H2 Panel with my current system, once the hot water cylinder is hot then any further hot water produced by the stove is effectively lost via heat leak or pumped through central heating (I guess going through central heating isnâ€™t exactly lost heat especially in winter!!!).

I live near Glasgow and I'm having problems finding someone with experience of using or fitting any of these systems. Does anyone on the forum use/fit any of these systems; can you give me the pros and cons?

Has anyone with a Dunsley neutralizer had problems getting it to work properly?

The heat bank from DPS is considerable smaller than accumulator tanks?

Thanks in advance for your help

retro-fit of condensing boiler

funcrusher — Wed, 11 Jul 2007 11:29:58 +0100

I'm looking at replacing my oil boiler, but am dubious about claims for condensing boilers.

Existing ch systems are sized for the coldest weather. Heat emission is very senstive to water temperature, so control of heating is achieved by two variables: water temperature and length of heating period. For comfort in cold weather they require water temperature of about 90C (even over 100C in some pressurised systems).

Most boiler info web sites indicate that condensing boilers operate at much lower temperatures, and require a return water temperature of below 55C, with flow temperatures far lower than 90C - more like 75 C when in condensing mode.

These low temperatures imply poor comfort and/or different hardware: slower response times, larger rads, larger diameter pipework - or operating the boiler in non-condensing mode and way off its design optimimum.

Official UK government info sites simply dismiss these major technical drawbacks with the phrase ' existing radiators are usually oversized anyway' .

In fact it seems that condensing boilers are only suitable for under-floor heating, which is a wasteful method of heat distribution unless the building is in continuous occupation.

Are condensing boilers really just another government spin? Efficient at converting fuel to low temperature (ie thermodynamically low-grade heat) which can only be utilised in a wasteful way, with no improvement in overall efficiency of home heating?

Comments and experiences please!

BR Doc A - Structure: Wall Thickness and height

Captain Tuba — Thu, 07 Feb 2008 18:34:18 +0000

Hi folks - my first post to the forum.
I've been reading a lot of good stuff here - keep up the good work :-)

I'm researching how to refurbishing and extend our 1930's bungalow to maximise it's energy efficiency.
The current plan is to remove the roof and build a highly insulated timber frame upper storey and roof.

However I'm not sure how to interpret the height I can go to based on the current wall thickness.
Can you folks help?
----
The original cavity walls are nominally 2 x 4" leaves with a 50mm cavity.

From Document A (http://www.planningportal.gov.uk/uploads/br/BR_PDF_AD_A_2004.pdf)
Para 2C6 suggest a wall thickness of 1/16th the height of the wall
Para 2C8 for cavity walls say to use a wall thickness of "the combined thickness of the two leaves plus 10mm"
Does this thickness include the cavity?

As I want to add another floor the gable end wall height will between 3.5m & 9m.
Although most walls are less than 9m in length - the L shaped building does have two walls over 9m long (but less than 12m).
Table 3 suggests I'm OK for short walls - but it means my longest 250mm thick walls are limited to a 3.5m high.

Is this right?
Do these regs apply to a timber frame upper floor?

Cheers
C.T.

Wood Burning stove (with back boiler) for sale

Katymac — Fri, 27 Jul 2007 16:15:43 +0100

Hi all

I replaced my Franco Belge Savoy with an Aarowe Stratford as I wanted a full Central heating system.

The Savoy heats a fair sized room and domestic hot water plus a radiator and a towel rail. It is 5 years old and is almost as good as new. The glass is clear and we love it and want it to go to a new home.

Offers around Â£350 (buyer collects or arranges courier.....remember it is quite heavy)

Energy Consumption for domestic buildings

agu — Wed, 13 Feb 2008 16:40:16 +0000

Hey,

I'm trying to find websites or information on the avareage energy consumption of a house. I would like all energy consumption if possible (i.e. heating, water, lighting, appliances etc)

Does anybody know where I can look or can anybody help with some figures??

Agu

New chimney

TheDoctor — Mon, 04 Feb 2008 11:11:19 +0000

I am building a new chimney in an old property.

There is an existing chimney, but it stands in a wall that will be removed.

I am building a new chimney to replace it, which will serve a wood burning stove, double sided, situated between two rooms.

I am more than comfortable designing / detailing a chimney from a technical point of view. However, a bit of green guidance wouldn't go amiss! I am building a chimney breast about 1800 to 2000 wide, in dense block and sandstone from the original chimney. I want this to be a large thermal store between the rooms. No problem there.

Most chimney systems work on insulating the flue gasses as much as possible from the surrounding construction, double metal liners, pummice systems, insulating fills etc. Should i rely on heat from the unit itself to heat the mass above it, or how can i harness the flue heat within the chimney to maximise this?

What is your preferred lining for this situation?1

cheers

Stone farmhouse SW France - insulation options

Noyers — Fri, 11 Jan 2008 22:17:15 +0000

Hi, I am a new member and have been following some fascinating discussions on this great site, I have almost got my head around all those acronyms you are so fond of! I see many references to superinsulation and to "designing out" the need for a heating system but can this be achieved for a 200 year old stone house? External insulation is impossible on many grounds.
The problems in SW France are: it's too hot in summer and far too cold in winter. The house is on three levels on the side of a hill so the basement has one wall underground; overall plan dimensions 16m x 5.5m.
Basement: solid reinforced concrete slab floor (new), no insulation under; headroom 1.90m; walls 800mm solid limestone. Floor cannot be lowered as there are no foundations to these houses.
Ground floor: headroom 2.6m suspended wood floor; ceiling could be lowered. Walls 700mm solid limestone.
Grenier , room in the roof (2nd floor): suspended wood floor; severe headroom problem (1.4m rising to 2.5m). Walls 550mm solid.
Roof: about 30 degree pitch, pan tiles, battens (no counter battens) plastic non breathing membrane, rafters 70mm x 75mm at 500 centres (don't ask!) but supported at 1.5m by oak purlins, 250mm x 250mm. Insulation in house currently nil.

If I was prepared to loose 100 - 150mm from internal walls and 200mm under rafters what would you experts recommend?

Its been suggested I use Triso-10 (or equivalent) under rafters, perhaps with solid foam sheets beneath the Triso and Triso-10 for all the walls. I can see two problems: do solid limestone wall, with mud interiors and lime mortars count as "breathing" walls, if so how compatible is Triso-10 with this wall construction; SECONDLY the wild life is very active hereabouts, Triso doesn't look very rodent proof.

Most local French houses do not have rooms in the roof, they leave the idiot English to convert these old ruins. Most "in roof bedroom conversions" are impossibly hot in summer so a priority is preventing heat entering the Greniier (think loft space). All ideas gratefully considered.

Startup v. running cost of ASHP

dnfh — Tue, 12 Feb 2008 15:12:30 +0000

I have been told that ASHP's do not work well when run for short bursts, as the startup uses more energy. Does anyone know (or can point me where to find out) roughly how many hours of steady running equals the extra cost of starting?

Hot Water usage/ solar

Leo — Tue, 09 Oct 2007 20:18:42 +0100

I've been getting quotes for a solar thermal system and have been a bit taken aback buy the size of cylinder installers have been proposing.

Our current system has a 180l vented cylinder which seems perfectly adequte for us (2 adults and 2 small children).
The advice seems to be to replace it with a 300l cylinder, which although my house is a fairly large (5-bed) place seems excessive for our needs (I've got no problem waiting 20 mins for a bath), won't fit in the existing space (in the cellar) as it's too tall - and would mean eating into living space or obscuring a window.

Is this sizing advice sound? If so what work-arounds has anybody got experience of (can I for example get a non-standard short, fat or horizontal cylinder, or even as one person suggested string two together)?

I've also asked installers about using thermal stores as I like the idea of losing the 100 gal cold water storage in the loft (am I right in finding this excessive too?) and have been met with blank looks or statements that a thermal store would need to be larger still or be inefficient. What do you all think about this?

All ideas welcome.

Realising a Vision - aka worrying story

GBP-Keith — Wed, 28 Nov 2007 18:40:23 +0000

Here is the final story from Mike Hillard as we will publish it on 10th December. it is about his new 5,000 sq ft home near Stroud.

The story creates as many questions as it answers so please feel free to discuss them here and I'm sure the author will be glad to answer them. I may well publish some of the comments especially if they help clarify or even rebutt the claims made.

Here at the office of GBmag, we have done our best to ensure that the author has evidence to back up his claims but as the story makes clear, he says that some evidence is confidential.

It is our policy to allow everyone to have a voice as it aids discussion and the dissemination of information. We try not restrict authors to 'our own line'. I for one disagree almost entirely with Mikes claims regarding PV power and Biomass heating.

http://www.greenbuildingmagazine.co.uk/winter07/realising_a_vision.pdf

New electric supply.. Â£10,000!

Lobbi — Mon, 11 Feb 2008 17:21:51 +0000

I have just recieved an estimate of Â£10,200 +vat for an electric supply for a new build.
The nearest existing supply is 200 metres away. The site is bordering a road.
Is it possible to be charged this amount? It seems outrageous.
Before i phone to see if there's a mistake could somone offer an opinion as to whether on not this could be a fair price?
Yours in shock
David:sad:

spray insulation

Trog — Fri, 08 Feb 2008 09:28:13 +0000

Does anyone out there know about or has had experience of spray foam insulation. I am thinking of having it done on my side walls and on the roof. I need to know if you can render straight on top of it.
Muchos Gracios
:shocked:

Radio 4 are talking cobblers again

GBP-Keith — Fri, 08 Feb 2008 15:22:01 +0000

I've just listened in to 'Costing the Earth' on radio 4 and their presenter introduced a chap from Southampton University that told the listener that they could buy and install 15 sq metres of solar PV for just Â£5,000!!

We need to find his supplier.

Though the presenter then went on to say this would provide the average householder with all their energy for the year. In defense of the Southampton boffin he did say this would be 'in theory'

Who does their research?

Nice to hear Dave Elliot of the Open University on the programme who, by the way, did talk a lot of sense.

Insulation: 1930s Terraced House

rrr — Mon, 04 Feb 2008 16:00:26 +0000

Hello,

I have recently purchased a 1930s terraced house in London. It is without central heating or insulation and as such is very cold. My loft space is quite basic. A pitched roof (no felt, just tiles directly over joists).

I am waiting to install central heating, but am ready to install the insulation straight away. I have applied for the grants at energysavingtrust.org.uk and will see what occurs and I have already searched the forums here. But I am not an expert and any help is much appreciated.

I have the following questions:

1) Is there such a thing as "green" (eco-friendly) cavity wall insulation?
2) Is there any type of cavity wall insulation I can install myself?
3)In the loft, should I just insulate the tiles? the floor space? or both? (I am assuming both, but how for each?)
4) which product should I use? I have found Warmcell, Thermafleece and Glasswool. Are there other products I should consider? - someone mentioned a foil product for insulating the tiles.
5) can someone explain how insulation products are rated and what the differences mean in the real world (i.e. energy costs)? Thermafleece is much more expensive, is it worth it? (i.e. either for longevity or for insulative properties - I found it would cost about Â£200 for Warmcell about the same (or a bit less) for Glasswool and Â£550 for thermafleece) (For my 50m2 loft space and 100mm of insulation on the floor only).
6) How do I draft proof around windows and at the bottom of the skirting boards?
7)Is there some kind of eco-expanding foam? (That seems unlikely but worth asking).

All comments are appreciated,

Cheers

rrr

Solar powered air conditioning

Albert — Fri, 08 Feb 2008 12:51:14 +0000

http://www.rotartica.com/pub/ingl/index.html

I saw a discussion of this on another forum and it does seem to be the ultimate green, possibly off-grid, solution to keeping cool. As the poster said, "It struck me over 30 years ago, in Southern Spain, when I was involved in modular system building projects to the Third World that the dichotomy of wanting coldness when the sun was at its highest meant that by combining solar energy with absorbtion refrigeration, one was using free energy to overcome its negative effects on buildings!"

As I understand it, the primary cooling energy comes from solar thermal panels and the small (<300W) electrical demand could be supplied by a PV array.

Has anybody here had dealings with anything similar? I'd be looking to install something like it in a house in one of the warmer bits of France in a couple of years time.

Tenant Participation in sustainable refurbishment

Neil Adam Hall — Mon, 11 Feb 2008 16:49:53 +0000

Hi guys

I am a student at the University of Brighton reading MSc Sustainability of the Built Environment.

I am currently undertaking research for my dissertation, in collaboration with Notting Hill Housing Group, Bioregional, Camden and SEA, the title of which is 'The significance of tenant participation in the sustainable refurbishment of dwellings.'

I am looking for anyone who has had experience of large scale sustainable refurbishment of existing social dwellings, either at present or in the past, working on behalf of a housing association, tenant association, or as an architect, designer, consultant or contractor. I would be interested to find out your experiences in tenant participation, such as the extent, cost, impact and feasibility of participation, tenant reaction and contentment (especially in their eagerness for a 'sustainable' dwelling), as well as any problems, obvious or unforeseen.

Also anyone who can point me in the direction of other, similar studies or schemes to examine, or relevant literature, would be welcome!

I would be keen to discuss any aspect of the study if you drop me an email at ajp24@brighton.ac.uk.

I hope someone can be of help, I seem to have a daunting but exciting task ahead of me.
Thanks guys.

New boiler query

Rustychain — Thu, 08 Nov 2007 22:04:43 +0000

Following on from my thread about downlighters, I'm now after advice on choosing a boiler!

I live in a three bedroom semi (50's, which may get an extra bedroom in time). As part of the current building work to provide a larger kitchen, I'm going to renew the 10+ year old boiler for a more effficient model.

I currently have a 'traditional' system with a hot water tank. I am looking to move over to a combi, as I figured they are more efficient due to only heating the water you need, when you need. Is this a good idea or are there issues I need to be aware of?

I would be willing to just upgrade the boiler as it would be a cheaper option (and possibly less problematic?). Another option is to go for a sealed system at the same time. What are peoples thoughts on these?

If I do go for a combi, I am keen on the Valliant Eco Tech range (ideally with a stainless steel HE). Any other goof makes out there?

Thanks

Underfloor heating - menace to the old?

chuckey — Wed, 30 May 2007 19:28:19 +0100

Just heard about an aged Aunt who stayed with her Sister. Her feet swelled up so did her ankles and her legs were sore. When She left her Sister, who had under floor heating, the symptoms disapeared.
She visited one of her mates at an old peoples home, who complained about the same symptoms. she then got the management to turn the temperature down in the dayroom (also underfloor heating) and her mates symptoms also disapeared.
Ok , so its just a couple of old ladies but I think it raises some issues that should be properly researched. With modern buildings tending to use UH more and more, is it actually suitable for old folk, should it be used at a maximum temperature with ordinary radiators to back it up?
Frank

black "metal" roof's in eifel germany

howdytom — Fri, 08 Feb 2008 19:26:20 +0000

just been in the Eifel region of germany an noted that most of the new/replacment roof's were made of what looked like black gloss painted, formed metal sheets that resembled pan tiles !.
I asked a "local builder" and he said that they helped melt the snow in winter ? ( I thought that snow kind of insulated buildings in really cold times ) and that in the summer they were open vented at the ridge and therefore cooled the house.
Had I drank too much snachps, was I dreaming or whats the real truth :confused: they were re-roofing a loverly old building in the center of town and it just seamed totally out of place..... do they have building regs and PP like us ?.
Tom

loft conversion & dormer - different question

pdurkan — Tue, 05 Feb 2008 21:05:35 +0000

it's timber frame with plasterboard, 100mm celotex, exterior-grade ply which is rendered, built 2005. like a caravan reallly - too hot in summer, too cold in the winter winds - dormer rather than slopey bit seems to be the problem.

Q1: is this compliant with regs? seems a bit rubbish
Q2: How long might it last (assuming well-built)? 5 years?

Heat Pump to heat pool??

sturharv — Fri, 06 Jul 2007 11:06:25 +0100

Hi,

Can anyone help me? We have a small outdoor pool in the rear garden and are considering heating the water with some sort of heat pump. The pool is near our consrvatory, which obviously captures alot of solar gain. Is there any way of utilising this heat within the conservatory to put through a unit to heat the pool water. By the way the pool is very small approx. 1.2D x 3.5W x 4L and we are not looking for sauna type temperatures.

I would appreciate your valuable comments.

Kind regards,

Stuart

:bigsmile:

Insulating my floor, enthusiasm required please

TomW — Mon, 21 Jan 2008 13:37:33 +0000

Having just started pulling up my floorboards to insulate underneath, I'm beginning to realise how big a job its going to be.
Although the house is Victorian (end terrace), a lot of renovation was done about 10 years ago, before my time, the floor is standard T/G boards and the walls have been replastered right down onto the boards, locking them in place.

Naturally I want to re-use as much as possible, but so far all the skirtings and architraves that have come off have been damaged beyond use despite my best efforts to be careful. I have had to cut the floorboards along the tongue and along the centre of a joist, using a nail puller to get the nails out with as little damage as possible to the boards. This is slow and laborious, and a lot of the boards are coming up damaged anyway.
On top of this I am going to have to remove a radiator, resite the gas meter, rewire the mains and telephone line, I'm begining to wish I'd never started, and I've still got another room and the hallway to do!

I think I may be better off not worrying about reusing the existing floor, and lay new boards. At least I can use the old floor as fire wood, when I get my wood burner fitted.
Its not easy being green! Any helpful or supportive comments appreciated
TomW

Slamming a door.

tony — Fri, 08 Feb 2008 22:36:53 +0000

If you are buying a new house a quick test of how good is is to have a go at slamming a bedroom door.

If it slams shut forget it! It shouldn't be able to do that easily if it is in any way air sealed it should bounce on a cushion of air at or near the closing point.

Free wood - how best to use?

pdurkan — Tue, 05 Feb 2008 21:14:59 +0000

I have access to plentiful (more than I need) supplies of native hardwood suitable for burning. Time to stop using gas, methinks; wife's not opposed to an AGA or similar ....

what should I do?? stove + thermal store? if so, can we avoid cooking ourselves in summer??

Cheers

Paul

Non M HVR?

dickster — Fri, 08 Feb 2008 14:00:39 +0000

Is there anyone out there who has knowledge of non-Mechanical HVR, perhaps using gravity flow water system, air pressure differentials etc to achieve what MHVR does without electric motors?

How shall I heat a house I'm (eventually) gonna sell?

chocolatepixie — Fri, 08 Feb 2008 14:15:38 +0000

I'm renovating the luverly old cottage I'm currently living in but unfortunately, luverly tho it is, it's not where I want to be living eventually so while I'm renovating it I have to bear in mind that I will be trying to sell it in a couple of years.

Insulating it well is a top priority, and I will be doing that in natural materials because that's important to me, but because of the layout I think it's unlikely insulation alone will be enough (it's a tall thin house - think Rapunzel's tower! - and in an exposed location â€“the bedroom on the top floor is particularly chilly, with 4 outside walls - current solution is 3 duvets, 2 blankets, a hot water bottle, a woolly hat, 3 jumpers, thermal underwear and 2 catsâ€¦ :shocked: :bigsmile: )

So the big question is how to heat it and have hot water.

It's also a bit urgent as we're currently without either!

Thereâ€™s an old Aga in the kitchen that doesn't work (mostly cos there's no chimney or flue!) and is solid fuel anyway
In the living room there's an open fire with a leaking back boiler - can't use it at mo but at least the pipework is there
There is a hot water tank but the thermostat has gone on it and because of someoneâ€™s bodge job the thermostat canâ€™t be replaced without a major upheaval â€“ so itâ€™s a good time to replace the tank with a heat store/accumulator tank.
No radiators anywhere at present
There's a plentiful supply of driftwood (donâ€™t worry Tony â€“ anything I can use structurally/sculpturally I do!)

I recently heard about kachelovens and love the sound of them, and think it would be brilliant if it were possible to build one with a boiler in it and then combine this with a heat store/accumulator tank. In my next house, where I shall try to curb my nomadic tendancies, I would like to try this, but here would the unknown put potential buyers off?

Would a kacheloven (without boiler) in the kitchen and a woodburner with integral boiler in living room be less off-putting and maybe slightly intriguing?

Or does it make more sense to go for rayburn-type stove that does hot water and rads in kitchen and woodburner (with backboiler as the pipes are there?) in living room? And if this is the best way, is a reconditioned stove ok or is it best to stre-e-etch the budget here for a new one? Known brand or, eg, cheaper version from eastern europe?

Or do people look at a woodburning rayburn and think â€˜too much workâ€™? Would they prefer a woodburner (with integral boiler) in the living room and an electric cooker in the kitchen?

Total encapsulation problem?

tony — Wed, 30 Jan 2008 11:11:40 +0000

There is a problem with the idea of totally encapsulating a building with an external water and vapour and wind proof barrier. That is that the dew point is then within this barrier, in fact just inside it and so condensation would tend to form there and not be able to get away at all easily. The only way out would be to run down to the bottom and hope to find a way out, or to migrate back into the house. Neither of these options is very good and the latter could be extremely slow.

Flat roofs constructed on a warm roof basis have to have a vapour control layer at ceiling level and so there is no good source of condensate available to cause this problem under the roof membrane (the main source of condensate is from the warmer air within the house that inherently contains more moisture) though I think that it still does get damp regularly from condensation there but this is burned away again by the sun on the next sunny day. The void between the ceiling and the insulation is generally far from air tight having major access to outside air which reduces the problem if not largely eliminates it.

Wall structure

Tracy Oldfield — Thu, 07 Feb 2008 17:52:51 +0000

We are about to build a house we wish to construct as close to Passiv Haus standard as we can. The walls are going to be 500 thick and we want them to have good thermal mass whilst meeting a U of 0.16. Can anyone suggest an ecconomical system to meet these requirements?

Make your own Rock Bog

Novy Mlyn — Mon, 22 Oct 2007 11:26:08 +0100

I want to publicise an idea I had while reconstructing our home, it will save loads of water and is really simple, and best of all free. Introducing: Rock Bog

Convert one of your toilets to a Rock Bog, a liquid only toilet, by putting a large stone in the bottom of it, then reducing the amount of flush by stones/bricks/water hippo in the cistern so that a clean 2 litre flush is achieved.

Background:
There is a problem with our drainage and water connection, which means that our indoor toilet is suitable for liquid only, and I have to bring in rain water to flush it (yes, obviously very inconvenient, and not a realistic alternative for our necessities), however I noticed that we were using huge amounts of water for flushing because the volume of water in the bottom of the toilet is so big, meaning that you had to go fill up the bucket for flushing several times a day. I know that there is an Austrian university which is developing a liquid only toilet which does not have a big u bend so only a little water is necessary to flush waste water through. My idea was to put some biggish stones in the loo to reduce the volume of water there. It's worked. I now need only a couple of litres to flush, rather than 5 or 10. The rocks also provide a visual reminder not to put anything other than liquids down the loo. I was thinking that this would work in households with more than one toilet because you could designate one to be liquids only, put yet more stones in the cistern to cut down the amount of water being flushed, but still keep the water clean. It would just mean that people would have to get into the habit of using different toilets for different occasions.

Any of you willing to give this a go!!! This is the second time I've told anyone about it (it's also posted on the green money saving expert forum!), so let me know what you think.

Green Building Accommodation Network

Novy Mlyn — Mon, 13 Aug 2007 16:06:22 +0100

I have noticed that there are several other users of this forum who are asking questions about green technology for accommodation which will be let out for holidays in the future.

It will be nice to see all this technology in action for myself, and I look forward to going on holiday to such places. My question is, though, in your opinion what is the best website for finding such places?

Is there already a good, working, green building accommodation network, or would anyone else be interested in setting up such a thing?

If yes, perhaps a facebook group is in order.

Insulating a sloping ceiling

ecology — Mon, 04 Feb 2008 23:05:05 +0000

We are in the process of upgrading a town house circa 1875. The top-floor rooms occupy roof space and the loft is very small with the chimney going through it. At present the loft hatch is too small to permit access to the loft space. Assuming that the loft becomes accessible, is it more effective to insulate the space between the roof felt and the rafters and would it be reasonable to assume that this could be done whilst leaving a recommended 50mm airspace, or would it be easier and more effective to insulate the sloping roof from inside the rooms? CAT suggest removing the internal plaster covering, fixing insulation material in and then adding another covering of wood to hold it in place. This would be a lot more work but would it be worth the extra effort? I have also read that insulated plasterboard could be used to fix to sloping ceilings. Basically we cannot decide how best to proceed and the Ecology Building Society is demanding evidence of work being carried out!

damp -proofing

fredster — Wed, 06 Feb 2008 13:21:42 +0000

i am about to buy a grade 2 locally listed brick built cottage circa 1820, partially built into a hill (clay). the timber & damp report required for the mortgage showed maximum damp. the firm that surveyed it specified wooden floors up and completely tank the building, then batten and board. the building was underpinned throughout in 1986, bituthane(?) was applied below floor level internally and new joists and wooden floors replaced on sleeper walls. a chemical dpc was added but nothing applied to the interior walls in the way of plaster even though this was specified. could i use a mix of french drains, air bricks, better guttering and electro osmotic dps. i really don't want to take up wooden floors and joists that are only 25 years old or ruin the building with batten and board. i am told the electro osmotic system will not work on the walls that are below ground level, is this true? i am buying the property from relatives who have lived there happily for 37 years and swore blind that there was no damp.
any advice?

Insulating below timber floor boards

tosca — Wed, 06 Feb 2008 21:07:25 +0000

I've recently moved into a 1901 house with a horrible laminate floor ontop of a suspended timber floor, the amount of cold air coming through the floor is shocking so as a urgent job I intend to rip up the laminate, and replace with a wooden floor (not yet sure what type). Here is the real part that i'm confused about - I am intending to use Kooltherm K3 boards to insulate under the floor which should be ok to fit due to a 2 meter space below, however what should I do above the floor boards between the new flooring ?, I assume that I will need to use some sort of insulation for sound and for levelling without impacting on the boards ability to be well ventilated.

Thankyou,

Labyrinth / earthtubes with MVHR systems.

Neil — Wed, 06 Feb 2008 10:30:06 +0000

I'm trying to research under-slab labyrinths or embedded earthtubes as a method to pre-warm or pre-cool supply air for a MVHR system in a passivhaus build.

I've seen various examples and references in past years and always thought itt makes a lot of sense, and am now starting to look a bit deeper with a view to proposing the technique in a current project.

Wondering about optimum depth, passivhaus.org suggest earthtubes @ 1.5m, same as GSHP loops, but can this be reduced in underslab situations so tubes are above foundation level [making it much simpler]. And whether the GF slab / wings / sub walls should be insulated? - I think probably yes to preserve that pre-warm / cool differnetial?

Any memnbers used these techniques ?

Point of Use Instant Electric Water Heater to replace Immersion Heater

edwinvanek — Wed, 06 Feb 2008 09:29:45 +0000

In have recently replaced the immersion heater and tank in one part of my house (supplying family bathroom and kitchen) with a solar hot water tank with 4m2 of solar panels, linked to oil condensing boiler, wood stove with back boiler and back up small immersion heater.

I also have a shower room in another part of our house which due to the shape of our house is too far away to connect to the other system. As we only use this shower on ocassion I am planning to replace the second immersion heater / tank here with a point of use instant electric water heater connected directly to the mains pipe so that I only heat the water if I need to use it and I can remove the water storage tank in the loft of our house which is exactly over our bed as well as the hot water storage tank /cupboard to create a bigger spare bedroom.

I have been looking at the Zip's and Redring's but I am not sure which brand or how many KW's to go for ( they seem to be 6, 9 or 12 KW for single phase). The unit will be 2 meters from a basin and 4 meters from the shower. This means that I can leave the shower mixer and tiling as it is. I would be grafeful to hear from any of you who have any experience with these units. Thanks very much for your help.
Edwin

Parasitic energy usage

tony — Tue, 05 Feb 2008 18:46:19 +0000

Parisitic energy usage, as pointed out by PaulT --the planned and inbuilt ditching of huge ammounts of heat out of homes via extractor fans.

How is this in any way, shape of form compatible with the present government stated policies of energy reduction and so called carbon saving drives?

dynamic simulation of heating

funcrusher — Tue, 05 Feb 2008 22:22:15 +0000

Does anyone have any knowledge concerning dynamic simulation models of domestic heating?

There is continual discussion of thermal mass, woolly jumpers, solar gain, insulation, heatstores, recovery systems, glazing, curtains/shutters, wind chill, UFH, rads, responsiveness, numerous devices and fuels for providing heat, control systems, etc. What has always struck me is that protagonists always assume a â€˜steady state systemâ€™ on a 24/7 basis, and ignore the fact that in reality conditions vary day/night, seasonally, and randomly. Plus social use varies enormously, both as between households and within households from day to day.
Generally, heating systems are designed to meet a worst case scenario, or at least a 95% worst case, â€˜efficientlyâ€™. In fact, that means that for the overwhelming majority of the time even in winter periods they are greatly oversized. This implies under-used capital cost and possibly low efficiency when light loaded. Common sense suggests a better principle would be to install a smaller highly fuel-economic system at less capital cost to meet base needs, with a low capital cost but fuel-expensive system (eg electric) to meet peak loads. Furthermore, the conventional steady-state system may not be optimum when confronted by need to respond to unpredictable demands.

To take a very simple illustration: assume a house on a winterâ€™s day needs 200W per degC temperature difference. With a target of 20degC the heat loss might be 6kW at 6am, declining to 2kW at 2pm and then rising to 5kW by 10pm etc. If we heat by hot air, we can have extremely rapid comfort response whenever there is occupation and if the house is low thermal mass we lose (ie waste) little heat when unoccupied by simply switching off. If we use UFH the reverse is true â€“ we have to heat more or less continuously because response is poor. If occupation is say 2hrs am and 4hrs pm, we might get away with say 30kWhr with a hot-air system but need more like 100kWhr with UFH. Even if UFH is produced by a cheaper device eg heatpump, it may be a case of using expensive equipment to produce cheap heat and then waste it.

Throw in all the variables I have mentioned so that heating and cooling of thermal masses etc is factored in â€“ well it makes an immense model to construct. But surely that is what we need: not analysis of a steady state bad winterâ€™s day, but a seasonal profile of how the system(s) will behave so we can optimise to individual circumstances â€“ just as we might select a tractor, car, van, lorry, ship, train, bicycle or aircraft for transport?

Energy from the Earth's atmosphere?

Peter A — Thu, 31 Jan 2008 20:12:08 +0000

I was reading about the satellite that is due to come back to Earth and part of the article stated that the temperatures created by something like this re-entering the Earth's atmosphere were akin to those on the surface of the sun, seemed an extraordinary claim but I guess it must get pretty hot. The thought then struck me could this energy be harnessed in some way, appreciate might be out of the reach of us ordinary people and perhaps you might use more energy putting something up there in the first place.
Am I losing the plot or do you think in years to come there could be potential, polite responses please...........and no I haven't been drinking!

loft conversion & dormer & building regs

pdurkan — Tue, 05 Feb 2008 20:56:01 +0000

hmm - I'm v. confused. Bought our 3-bed semi with converted loft & dormer & self-closing fire door. My local building control say that the function of the door is to protect an occupant from a fire elsewhere in the house. However, I wondered if it might also be to reduce the updraught experienced when the door is open, which is presumably a fire hazard.

The reason I ask is I thought about installing a vent above the door as the ventilation in the conversion is very poor (unless there's a strong south-westerly) - building control say no, not without an automatic fire detection system. The room is mainly for guests, so now I'm thinking, on the balance of probabilities (likelihood of a fire whilst room occupied by heavy sleeper vs need to ventilate).... leave the door open - got to be the best green option ???:confused:

Underfloor Heating

albacore — Sat, 13 Oct 2007 14:43:07 +0100

We were talking to heat-pump suppliers at the ExCel Homebuilding Show recently. As I understand it, the ideal layout for the underfloor heating pipes would be different depending on whether a heat-pump or gas boiler was the source. While we do like the idea of a heatpump, there is no way we are going to be able to afford it at the time of the build. The plan was to have a gas boiler for one boiler's lifetime (is 15 years a reasonable assumption?) and reconsider a heatpump at that point. How crucial is the difference in pipe layout to the efficiency of either system? We are planning a thermal store with solar input. Does this affect the calculations?

Thanks as always for your help.

Welsh Energy Sector Training - Launch Events

tobble — Tue, 05 Feb 2008 17:14:59 +0000

Hello

I'm working on a project managed by the Welsh School of Architecture (Cardiff University), including research partners from Bangor University, Swansea University, and the Institute of Grasslands and Environment Research, and the University of Glamorgan. It is sponsored by KEF (the Knowledge Exploitation Fund). The aim of the project is to promote the rapid commercialisation of research and increase the skills, knowledge and expertise capital in the industry, through education, training and CPD. The project is being launched at three event across wales, the first of which is on the 13th February (next wednesday) near Cardiff.

The attached invitation has more details including how to register for the events. Anyone with an interest in renewables and energy efficiency in Wales is welcome. We are also still looking for appropriate organisations to hold information stands at the events. If you are interested in this please email me:
toby DOT cambray AT gmail DOT com.

The WEST website will go live in the next few days:
www.welshenergysectortraining.org

Toby

underfloor heating connection to a existing rad systems

jamesingram — Wed, 30 Jan 2008 23:02:29 +0000

Hi
After a little advice on Single room packs
I've fitted these add on units several times to existing rad full pumped systems
You plumb in the flow and return and it blends it down to a suitable temperature and then pumps it round the ufh pipe .
I think they are normally wired up to the boiler to come on when there is a call for heat
or perhaps they have a flow switch that starts up the pump, I cant remember

Anyway we've fitted a condensing combi boiler and I've over sized the rads ,with the idea of having a lower
flow and return temperature, as I understand they are more effiecent the lower the FR temp.
now if we run the FR at say 40o could we do away with the add on unit and just run it straight in the ufh ?

alternatively could we use a standard thermostatic valve to mix down the FR and then run it into the
ufh all off the boiler pump, the main flow would be mixed with the ufh return and then become the ufh flow

reasons for this are
not having to purchase the unit ,( Â£300)
no additional pump runnning cost
simpler
the house is a 3 bed semi ,the ufh pipe is approx 100m, 7 rads on the system , boiler 27 kw

I realise there are lots of calculations that would allow me to answer this question
but I was just after people general thought on the idea as sometime calculations and what you can actually do are different things

Thanks for your thoughts

Jim

UFH + underfloor insulation

krishna — Mon, 04 Feb 2008 19:20:42 +0000

I started asking this question in the "Best place to put a radiator" thread but felt I shouldn't really hijack that thread, so. On jamesingram's advice I looked at the articles on floors in the latest issue of GBM. Good stuff. But I'm still not clear on a couple of things. There is an illustration of a refurb with some insulated floor with UFH pipes. As james suggested, looked very similar to what we are trying to do. However I am a little puzzled. There was a cross section diagram which showed joist depths extended, with breathable roofing felt attached to base of the extended joists and the spaces filled with 100mm depth of warmcell on top of which was some PUR boards supported on battens attached to base of the original joists. But the photograph of the same job showed the joist 'extensions' running at right angles to the original joists, the roofing felt draped OVER the lower joist extensions and battened along the bottom of the original joists, before filling with warmcell. Hmmm... I can't quite work this one out.

Where is the best place to put the felt and is breathable felt the best thing to use? I was planning extend my 4" joists by a further 4", but with timbers run underneath at right angles. Then staple the membrane along the bottom of the extended joists and let the insulation (Warmcell) fill the spaces to a depth of 100mm, including letting it go in the 4" gap below the original joists. Then batten and place the PUR boards above and lay UFH pipes on the board insulation. Then 20mm solid wood flooring above. Any problems with that?

The man from building control thinks I am mad and wasting my money (too much insulation he says). He is also not sure about using breathable roofing felt (or any roofing felt) or building paper under the Warmcell as he says they haven't been tested or approved for the task. Any advice on that one?

Any ideas how to convert a wind driven sign to produce electricity?

Nick Rat — Mon, 04 Feb 2008 21:39:30 +0000

I've recently acquired a garage forecourt type wind-driven sign and
i'm keen to see if it's possible to produce electricity from it.Its a
2 blade savonius looking structure.It turns on a vetical shaft with
some bearings located in the base.Has anyone done this before?Any
ideas or top tips would be greatfully received.Cheers

Plumbing systems

krishna — Mon, 04 Feb 2008 18:40:14 +0000

Plumber has said he uses solvent welded waste and drainage pipes because push-fit leaks. I'm inclined to go along with it for underground or under floor drainage because it'll be under the house and I don't really want to have to deal with any problems there, but when it comes to the waste pipes, or even the soil stack, doesn't push fit make green sense? As in you can make changes or reuse bits if you need to?

air to air heat exchangers

therackals — Sat, 02 Feb 2008 22:42:07 +0000

Hoping to set up air to air heat exchangers on my house this year (trombe wall/ thermosyphon type). Anyone in the UK tried this yet? Results?
Regards
Hayden

Green Building Software

richy — Sun, 03 Feb 2008 21:25:38 +0000

I'm looking for some board cutting software. It makes sense to make the best use of ones materials from a green point of view! But so far I've failed to find anyhing. Can anyone help?

Wood generated acid rain?

tony — Tue, 22 Jan 2008 15:05:06 +0000

Burning wood always releases Sulphur Dioxide into the atmosphere

We used to be concerned about acid rain -- is this no longer a concern?

Will we need to add sulphur fertilisers to our woodlands in order to grow timber or doesnt the natural sulphur run out

Where does the acid rain fall? Is Canada sending us acid rain?