Green Building Forum - All Discussions

Food storage in a passive house

howdytom — Fri, 12 Oct 2007 09:53:53 +0100

It would seem that there's lots of talk about super insulated air tight passive housing, I assume they still use fridges/freezers(source of heat) to store perishable foods, why don't they have cellar/larder/cold stores ?

tom

Cement v Lime

Mike George — Tue, 16 Oct 2007 20:19:51 +0100

There is plenty of condemnation on the forum regarding anyone who dares to suggest using cement. While I understand that cement has a huge environmental impact, just how much better is lime?

Firstly there is the process. How does Lime compare with cement in terms of energy needed for production?
Secondly, how does lime compare in terms of energy use in transportation? Is there much lime produced in the UK?
Finally, what are the dangers to health of each?

Anyone care to take a stab at some figures, just wanting to further my knowledge

Dual heat source central heating

Thinfourth — Sun, 28 Oct 2007 11:50:20 +0000

Considering a new build house and thinking a few things over. firstly central heating

We are going to have underfloorheating and a big feck off wood burning stove. For sake of connivence we want to have a easily controlled option also for heating instead of having to build a fire every time.

So questions are

1 how to have two heat sources in one central heating system is this easy enough

2 How to even out the output of the log burner as it will be left damped down during the day and then when we get home it will be stoked right up and this will then produce way more heat then is needed so is there a way to even out this heat output and store it.

3 If the system temp gets too high is it easy enough to dump the excess heat to maybe a radiator range sat in the wood store

Solar DHW and Energy Conservation: Towards Whole Systems Analysis

Mark Siddall — Tue, 23 Oct 2007 13:02:50 +0100

I'm trying to get a better handle on the whole systems analysis of DHW and Solar Hot Water. The goal, if possible, is to show that water/energy efficiency measures plus SHW is cheaper that a Business As Usual model (I accept that simple efficiency will offer the least cost solution).

Is anyone aware of any studies that examine in detail 1) DHW use (litres/day or m3/annum) 2) actual the energy and water savings from efficiency features and design.

Ideally such studies would also cover heat losses from the DHW systems pipe work (adding insulation to pipes being and efficiency measure), elimination of dead legs etc.

Any help appreciated.

Mark

Where can I find a HUGE cylinder jacket?

Nick Parsons — Sun, 28 Oct 2007 09:07:26 +0000

I need a cylinder jacket (or more likely 2 or 3) for a sports pavillion cylinder approx 900w x 1500 high. Before we go to the 'cobbling something up' route, can anyone suggest where I might get a proprietary one? The (old, scraggy and largely useless) one that's on already is clearly a factory-made one - just a big version of a bespoke one. I haven't been able to find one by Googling, but then I am not that good at finding anything by that route. Can anyone help?

Thanks,

Nick

Sheeep wool insulation

david — Sat, 27 Oct 2007 21:12:06 +0100

Can anyone give me verifiable data on the manufacturing energy cost of sheeps wool and Rockwool/fibreglass insulations and the environmental impact of each product. I'm trying to come to a decision on which to use in my new house but there seems to be an absence of relevant data for these products.

I know which is the more pleasant to use but is this how I should choose?

I know that fibreglass and Rockwool are produced by melting glass and a mined mineral.
Is the glass recycled?
How much energy does each process use? How much co2 and other green house gasses are produced?

I know that sheep wool comes from sheep which need grass and concentrated feed produced using machines, artificial fertilizers produced from fossil fuels, some toxic chemicals such as formaldehyde and dips. Sheep also produce lots of methane which is a greenhouse gas. Cultivation and management produces co2.and more methane.
I'm assuming that the environmental cost of delivering these products is similar although perhaps sheep wool costs could be higher because of small scale decentralised production.
I'm sure that Rockwool and fibreglass production creates local pollution and environmental damage. I have read that sheep farming has destroyed some of our best upland habitats and prevents regeneration of woodlands. Fertiliser runoff pollutes lakes and streams.
How does one decide which is the greener insulation?

U values of ground bearing solid floors

tony — Thu, 27 Sep 2007 18:42:13 +0100

A U value is a measure of the heat loss in steady state. The heat lost from a solid floor should therefore not be the ammount calculated from the structural floor and the insulation alone but should also include any insulating properties that the hardcore, fill and sub soil layers may have.

It may even be that in the majority of cases no under slab insulation is not needed and only edge or wing insulation called for.

The tradition of only insulating walls down to floor level must also be called into question.

Do we need to be wasting so many resources on under slab insulation? It may even be that not insulating under most of the slab is a better way forward!

I'm buying a 15 tog duvet and wrapping myself in it .Is this green!!

susiespearing — Tue, 23 Oct 2007 10:09:37 +0100

Hi all.
I've been reading this forum for the past year in the hopes of gaining tips on trying to make the home we bought in March as enviromentally friendly as possible within the scope and budget of neccesary jobs.At the moment it runs from a solid fuel coal fed back boiler with a few storage heaters in hallways and the extension.
The house is a rural 3 bed in a row of eight down a private road,built in the early thirties and has a solid 9" brick construction with a dormer style bedroom window at front and back.
We plan(planned) to add oil condensing combi boiler( no gas in village) to heat and provide hot water since the immersion heater is old ,badly positioned and there is very limited space in the loft which meant the water tanks were housed in a bedroom and were keeping us all awake every flush of the loo.
Since requiring new lighting we also planned to install low energy downlighters and where apllicable low energy pendant fittings(since then read on here there may be problems with building regs). Ahhhh.
First thing we did was look into cavity insulation when we moved in which is where we discovered the solid walls.Next we planned loft insulation where we were told we would have to remove all the fibreglass that was stuffed into the eaves and replace the lot,which we will do.
Before we chose oil heating I spent hours and days reading up about the pros and cons of every type of heating from ASHP to biomass but every alternative has a double edged sword.Smoke pollution from wood burning,difficulty gaining pellets,cost of installation,ect.Yesterday I looked forward to my plumber starting finally on the oil system.He had asked buiding control to pop out and give him advice about siting the oil tank as we have only a narrow passageway at the side of the house and because of a long extension wih a further conservatory it wasnt possible to place the tank in the backgarden.It would have been 50mtrs from the tanker and ruin our narrow garden.
In line with my oftec registered plumbers advice we had replaced our fence panels with concrete panels and built a level sturdy base.Because my conservatory window was only 1.2mtrs from the tank we were told it's a no go.Despite my plumber explaining that we intended to surround the tank on three sides with fire barriers going slightly past the tank.Madness!! As i sit looking out at next doors tank fitted last year and directly next to the barrier fence and his shed it just seems totaaly unfair and ridiculous.Oftec had stated that although they cuoldn't pass it buiding control had more power to make exceptions and had phoned building control and told them that they regarded it as safe.
We have a 7k budget to update the heating and water and make the house more HIPS friendly.No room in the property for vast storage tanks(it was hard enough to find the space for the boiler),the kitchen is very narrow.
Is updated storage heating my only avenue?
Very depressed and at my wits end.

Cellar insulation

jonomunday — Thu, 25 Oct 2007 21:45:03 +0100

I am looking to insulate the ceiling of the cellar in my victorian terrace, which is also the floor of the living room. It consists of a wooden floor, joists 400mm apart, about 150mm deep.

I was interested in the Eco-Wool offer at B&Q. Would this be a suitable insualtor bearing in mind the need for airflow etc?

Also, what would be the best method of installing the insulation? I was thinking of holding it up with chicken wire or similar, what do people reckon would be the best?

Any help will be very gratefully received, as my feet are getting colder and colder!

Jono

UNEP GEO-4

fostertom — Fri, 26 Oct 2007 11:21:32 +0100

Definitive report just out: http://www.unep.org/geo/Docs/GEO-4AssessmentBrochure.pdf.
Don't know whether the condensed Summary for Decision-Makers is out yet, or have to plough through the full version.

Recycling: A step too far?

Bluemoon — Wed, 24 Oct 2007 22:50:12 +0100

Following links for an Alaskan sawmill attachment, I found this, what do you think?

http://www.bobvila.com/HowTo_Library/Converting_Shipping_Containers_for_Housing-Building_Systems-A2382.html

Wood pellet burner systems

tommy — Tue, 23 Oct 2007 18:30:26 +0100

I am in the middle of a complete refurb of a country cottage. There is currently no central heating etc. I am considering installing an Ofken wood pellet burner system as opposed a conventional oil boiler, tank etc (no mains gas in the area). I hadn't even heard of wood pellet burners until about a week ago, and am keen to gather as much info/ opinion on them as possible.

I like what I have heard so far in terms of their 'green' credentials and economy (v.s potential oil price rises), but am nowhere near being able to make a decision on whether this would be a sensible move. This will be my family home, expect to be there for a minimum of 10 years.

I would really appreciate all thoughts... Thanks in advance!

Insulating mortar

tony — Sat, 20 Oct 2007 18:53:16 +0100

A lot of people are still using aerated concrete blocks to build with. In my opinion these are naff! They crack and move arround too easily, are brittle, insubstantial and of too low thermal mass. I wont use them, instead I use medium or heavy weight blocks. But when I use mine I use mortar of the same thermal properties as my blocks but them that use aerated blocks use thermally bridging mortar-- crazy or what?

Is there such a thing as insulating mortar? Surely if the blocks can be insulating then shouldn't the mortar be as insulating? (even though I hate aero blocks it only seems common sense to me to have matching mortar) then again there it a sad lac of common sense in the way we build so it is not a surprise.

Low energy lighting in new builds and renovations

Richard Waite — Mon, 20 Aug 2007 21:58:40 +0100

I'm struggling to find regulations / guidance on fitting low energy light fittings (i.e. compact fluorescent bulbs) in new builds / renovations. I know that people are still installing old-style fittings which means years of high energy lighting to come. I'm thinking of spots and recessed light fittings, especially the small GU10 downlighters. To get the equivalent brightness of a halogen, you need a longer low energy (cfl) bulb and so a longer fitting - but I know that people are still installing fittings which will not take the longer cfl's (without the bulb sticking out). The longer fittings are available.
The question is, do people have to fit cfl-compatible fittings and if so, can you tell me where I can find the regs / standards on lighting?
Many thanks.
Richard

Silver foil insulation

oiseaux — Mon, 15 Oct 2007 20:05:45 +0100

I know its not the most greenest of insulation materials, but in my particular situation it really is the only alternative if I want to see my green oak rafters from below. I see that Actis still do a version here in France which uses sheep wool and they claim a u value of 6.1. What do you think?

Esse Cookers

jdpatton@dnet.co.uk — Fri, 19 Oct 2007 20:54:07 +0100

Hi there, I was hoping someone here might have some experience of the Esse Gas Cooker/Stove with the Catalytic Flue. The Rayburn I bought has failed to cope with our prevailing winds and I thought the Esse might be the answer. But I am unhappy paying the Â£3.5K based solely on the salesmans blurb. Does anyone know of anyone who has one??
Many thanks,
Jeff.

Steady state predictions of heat losses through solid floors

Mike George — Fri, 12 Oct 2007 23:39:59 +0100

I remember reading somewhere [can't remember where] that using steady state calculations; the maximum heat loss through a ground bearing slab is predicted to be around 10% of the total for a building. Obviously this varies with the introduction of insulation. Is the 10% figure correct? If so how much of a saving is made by the introduction of insulation and how quickly does the saving diminish as u-values are reduced? At what point do steady state calculations predict that the otimum level of insulation will be reached?

Anyone care to have a stab at some ball park figures?

Green Building Magazine

Keith Hall — Thu, 24 May 2007 17:50:49 +0100

Nearly ready

My cold loft

Joinerbird — Fri, 19 Oct 2007 15:10:26 +0100

Hi there Greenguys.
I have one of those questions things for you.
I have finally looked up into the loft of my new house. Its big and cold. There is 100mm of pinkish mineral wool down already, so I intend to lay an addtional 200mm (criss crossing of course) Will that do? I know its 270mm, but with the existing 100mm down already....
And.
I am used to seeing nicely renovated loft spaces with good bratherble felt or trad felt and vents. But in my space, there is rafters and tiles. Thats it. (1934 house, 2 hips, semi) I noticed that some of the crap that was left in there by ex resident was damp and mouldy. Is there a danger of the roof becoming damp? There are no vents in sofit or ridge. I can see daylight in some points, but not gapping holes. Can breatherble felt be added to underside of rafters? Will it help? Am I worrying about nowt?
Thanks guys, any comments welcome.

Free sustainable building events from 12th Novembers

GBP-Keith — Fri, 19 Oct 2007 18:51:45 +0100

The first in a new series of free debates examining ways of improving the
sustainability of regional buildings and improving the lives of communities gets
underway next month.

Organised by the architecture centre for the North East, Northern Architecture,
the initial event is being held on 12 November at Newcastle Civic Centre and
will look at sustainable cities.

It is the first of five over the next five months that will raise the level of
debate about how the North East should respond to climate change and increasing
pressure on resources, whilst constructing and maintaining long-lasting
buildings and places.

Latest figures suggest that 50% of all the UK's carbon emissions are generated
by buildings and structures, while the building design and construction industry
creates a third of all waste.

Each event will feature a panel of experts from within and outside the region
talking about the many complex sustainability issues that concern regional
architects, engineers, planners, developers, policy makers and others.

The first one kicks off with a panel of experts from design and business
consultancy firm Arup, urban planning and design practice Urban Initiatives and
UK's leading sustainable transport charity, Sustrans looking at ways of creating
long-lasting and eco-friendly neighbourhoods featuring carbon free buildings and
energy efficient systems.

They will also discuss how these impact on people's lives and the first time
house buyers market, and propose guidelines for planners and other professionals
trying to create more sustainable communities and cities.

The full programme is:
Â· 12 November, Newcastle - Sustainable cities
Â· 11 December, Durham - Sustainable buildings
Â· 16 January, Sunderland - Sustainable communities
Â· 12 February, Middlesbrough - Sustainable resources
Â· 18 March, Gateshead - Sustainable futures

All events 6 - 8 pm. Admission free but booking required. Call 0191 260 2191 or
visit www.northernarchitecture.com/events

Range cooker

David Salter — Thu, 18 Oct 2007 14:32:34 +0100

Range cooker

Flat-pack housing, is this the way forward?

Mike George — Sat, 06 Oct 2007 22:09:37 +0100

Read this today-
http://business.guardian.co.uk/story/0,,1961670,00.html#article_continue

Any thoughts? the article is a little lacking in detail

Understanding Energy in Buildings - Basic Principles

sallyh — Thu, 18 Oct 2007 18:50:14 +0100

IMPORTANT INFORMATION Course at RIBA 25th October (see previous posting). It has been decided to make this first course a 'pilot', and the charge has therefore been reduced to Â£117.50 inc VAT. All participating will be encouraged to provide feedback which will inform the later courses. For more information and to book log onto www.carbonlite.net

How to prevent having to use LPG central heating so much

David Salter — Thu, 18 Oct 2007 14:53:48 +0100

We recently moved to a largish,2700 sq ft, south facing bungalow in Sussex and want to cut down on the amount of LPG,which was already installed before we arrived, used to keep the central heating system going.

The roof space is fully insulated and the cavity walls filled and all the windows double glazed.

We added a 30 tube evacuated solar panel in the summer which provided all the hot water required without having to resort to the LPG.

We now want to get rid of the old cooker and replace it with a Rayburn/Esse type one
a/ to cook from
b/ to heat the kitchen
c/ help warm up the cylinder water so that the LPG does'nt have to kick in so frequently to keep the central heating upto temperature.

Would I be rigt in thinking that I need a 3 coil cylinder to take the 3 heat sources, ( Solar,Rayburn/Esse,LPG) and that by investing in a Rayburn/Esse to help boost the water temperature in the cylinder that the call on the LPG will be far less?

Would a 3 coil water cylinder be the same as a heat store?

Would a Dunsley Neautraliser need to be fitted?

What would the best arrangement be to save on the use of LPG?

Do not want to go to the expense of taking the LPG out,and also want to have the comfort factor of the Rayburn/Esse.

Any information would be gratefully received, and if any plumbers, who live near Battle, East Sussex, would be interested in plumbing in the Rayburn/Esse please get in touch.

Rgds DES

Understanding energy in buildings.

sallyh — Sun, 14 Oct 2007 18:15:02 +0100

Understanding Energy in Buildings - 25th October at RIBA, 66 Portland Place, London W1B 8AD
This course is open to architects, architectural technicians, builders, developers and anyone who is involved with the design and construction of buildings and needs to enhance their understanding of:

Â· How buildings work as systems particularly with respect to energy and environment
Â· New and traditional building technologies available for managing energy in buildings
Â· How to design buildings as a complete energy system and so deliver low energy standards in, for example, the higher levels of the Code for Sustainable Homes and the forthcoming Code for non-domestic buildings

The course will relate to Building Regulations, AECB Standards, compliance methodologies including SAP, other assessment procedures and the Code for Sustainable Homes.
Â£352.50 inc VAT per person (AECB member)
Â£470 inc VAT per person (non-AECB member)

http://www.carbonlite.org.uk/carbonlite/training.php

cavity wall insulation

rae — Fri, 03 Aug 2007 17:55:57 +0100

Hi All,

Dh and I have talked for a long time about getting cavity wall insulation.
My limited knowledge goes back to when I first heard about people having formaldehyde-loaded stuff pumped into their walls and then suffering headaches.
Since then I have just tarred all cavity wall insulation with the same brush and always resisted it.

However, it is becoming apparent in the home we are in now, that it really could help us make our home more energy efficient.

Can anyone tell me what is used now? Is it safe (I don't mean do the Government and service provider's tell us so, I mean is it *really* safe)
I'd like to know what impact it might have on the health of the people in my home and the environment please.

many thanks
Rae x (slightly paranoid it would appear :surprised:)

Underfloor insulation

Hugh Roberts — Sun, 14 Oct 2007 18:43:49 +0100

Hi,
I am about to renovate an 1890 end terrace house and have read lots about cavity wall insulation and from previous experience I would prefer to leave the cavity empty so am looking where else I may be able to counter this. The ground floor has a decent void underneath and I was wondering whether there is any advantage or disadvantage to fixing kingspan/celotex between the joists or would it be better to insulate on top of floorboards before carpet/wooden floor goes down.
Secondly I intend to retain old sashes and want to draftproof them. I understand that if i remove the openers i can route a groove and fit a draft strip. Any tips on this, where can i buy the draftstrips and is there any system that is particularly good.

Thanks

Hugh

Clearing wall cavities - help!

Hugh Roberts — Fri, 12 Oct 2007 20:57:41 +0100

We have just bought a victorian terrace and have a clear problem with damp at the bottom of the walls - (rising damp?) We are against the idea of injecting silicon and want to try all other angles first.
My understanding is that we need to identify any possible drainage problems which may be introducing damp, sort out the seventies windows without trays, and also to clear the cavities to ensure the dampcourse is not bridged.
So to the question! How do I approach the clearing of the cavities? Is it easier from inside or outside? Do I take a brick out above the dampcourse? How far apart should I remove bricks - is it the distance I can reach?! And do I need to replace the prevous brick and wait for the mortar to dry before I do the next one? All help on dealing with damp without recourse to chemicals very gratefully received.
Hugh

Ground floor slab/insulation.

AndrewJwaters — Tue, 09 Oct 2007 20:40:08 +0100

My agreed spec for the make up of the ground floor slab [ To a barn conversion] is as follows:-
Mot type 1
Dpm
100mm conc
50mm cellotex
Wet UFH
50-75mm screed
Floor tiles

My question is :-
Any advantage in increasing the 50mm cellotex to 100mm thick?
Thanks.
:cool:

Underfloor Insulation(wooden Floors)

Howard Frey — Mon, 15 Oct 2007 05:34:04 +0100

I would like to insulate underneath my sanded and varnished pine floor boards without having to pull them all up first.

I had the idea of taking up a couple of boards and taking gardeners netting to the under sides of the joists then filling the space between the joists with rockwool insulation.

I'm just a little concerned that this would prevent any air flow to the underside of the f.boards as the joists are 100 mm deep and the rockwool 100 mm thick. the varnish on the top is Johnson's Traffic Cote.

Any thoughts advice much welcomed

Advice on rafter spacings

oiseaux — Tue, 09 Oct 2007 09:48:08 +0100

I have just started to load the roof on my previously mentioned garden room, and I am now concerned as to whether I have got my rafter spacings correct. I am using green oak rafters, 2.6 metres long at 45 cm centres. The tiles are terracotta, with a weight of 75 kg. per sq metre. The first section I have installed shows a deflection of 3mm at the midway point. Is this acceptable or should I increase the number of rafters and to what centres. Thankyou for any advice.

THERMAL MASS

Richard Oxley — Wed, 13 Jun 2007 18:52:44 +0100

Further to the informative article on the Benefits of Thermal Mass in the latest Green Building Magazine I am interested to know if a solid wall with internal insulation was modelled, as this would separate the thermal mass from the living space and possibly provide a clearer picture of the value/performance of thermal mass. I would be interested in the results for any such modelling.

Hot Air

albacore — Mon, 15 Oct 2007 17:45:15 +0100

Does a heat recovery ventilation system have to compensate for the fact that hot air rises? The systems I have looked at all deliver the warm fresh air at ceiling level. Is the flow-rate sufficient to even out the temperature or does living with the system mean warm ears and cold feet? As even ears (for some of us at least) are considerably below ceiling height, does that mean there is a lot of unused warmer air at ceiling level?

Any views on what it is like to live with one of these systems from someone who has done so would be very welcome.

calculating current radiator outputs

mitchino — Fri, 12 Oct 2007 20:26:37 +0100

Is there a formula or online calculator available whereby I can measure all my current radiators and find out their outputs? I can find outputs for similar sized radiators from manufacturers online catalogues, but is there an exact method?

Foam Insulation and Halo-Carbon Green House Gas Emissions

Mark Siddall — Fri, 15 Jun 2007 17:16:44 +0100

â€œNet climatic impact of solid foam insulation produced with halocarbon and non-halocarbon blowing agentsâ€ by L.D. Harvey is a study that examines the embodied energy and emissions payback for insulation. In particular polyurethane insulation using either HCFC 141b, HCFC 365mfc or n-pentane as blowing agents are considered. The study is based on a climate with 4000 degree days (and a range of other assumptions to numerous to mention here) are considered. Two performance levels of insulation are considered RSI 3.0 and RSI 10.0. Conclusions are that: -

Â· The emissions payback for RSIs ranging from 3.0 to 6.5 and blowing agents HCFC 141b and HCFC 365mfc are between 22 and 39 years respectively.
Â· For an RSI of 6.5 payback are in excess of 40 years and an RSI 10.0 marginal payback times are in excess of 100 years!!!
Â· n-pentane (Global Warming Potential of 7) has marginal payback for RSI 10.0 of 25 years.
Â· Harvey notes that the embodied energy payback for foam insulation with an RSI of 6.5 is 8years and for an RSI of 10.0 is 11 years.

Referring to the above data, given that an RSI of 3.0 is a U-value of 0.30, if you ensure than the GWP is less than 7 it is bordering on acceptability i.e. CO2 equivalent emissions are likely to be recovered within its life span.

Referring to the EE of cellulose and low-density mineral fibre the authorâ€™s graphs show payback within 0.25-2years. You will note that this payback is substantially less than the CO2 payback for the foamed insulation i.e. the difference is >22years at an RSI of 10....or U-value of 0.1. So, from a holistic environmental stance Harvey concludes that foam insulation in high performance low-energy houses is counterproductive.

This noble conclusion is obviously is easier said than done. The use of foam insulations in low-energy homes is almost a requirement for technical reasons if no other i.e. to support floor slabs etc. In this light a balanced approach is surely the most reasonable. Minimise the use of foam insulations wherever possible.

It is very clear that the GWP of the blowing agent should be <5 (as BREEAM/ECO-Homes requirements.) Some manufactures now claim to use such blowing agents with a GWP of 3. Ideally a GWP of <1 should be specified (but I'm not sure whether that is technically possible at this stage.)

The EE payback for High Density Mineral is circa 20 years. In this light the gap between foam (
For your own copy of these findings please follow this link:
http://www.geog.utoronto.ca/info/facweb/Harvey/Harvey/aspapers/Harvey%20(2007d,%20ClimateTradeoffs_Insulation).pdf

In a nutshell I guess the deeper lesson, beyond GWP, is that low-density insulation is best....all this kind of suggest that SIP Systems have a major hurdle to cross....

Mark

Veneered external doors

Chris Wardle — Sun, 14 Oct 2007 19:33:01 +0100

Anyone know of the best treatment to weather proof an oak veneered external door? Something clear would be preferable as I like the look of it as it is.

average energy requirements

mitchino — Sun, 14 Oct 2007 20:11:17 +0100

Does anyone know where can I find figures/statistics/calculators for average domestic household annual energy requirements? I'm in Scotland so figures for there would be best. Thanks for any help.

Therma Fleece

richy — Sat, 13 Oct 2007 14:17:11 +0100

Not much information on the Green Building Store for this material.

What thickness is equal to 100mm king span?

What thickness of warmcell 100 is equal to 100mm kingspan?

Using floors as thermal mass

Mike George — Sun, 23 Sep 2007 07:35:00 +0100

Posted By: Jeff Norton (NZ)

I am involved with designing and overseeing the construction of some lightweight buildings on ICF foundations/slab on grade homes. Timber construction suites our conditions well as we have plenty of timber plantations and sheep's wool to insulate them.

A well insulated building requires minimal heating and a lot of NZ has dry well draining ground ideal for thermal storage. The light weight building can us the ground as the thermal mass by insulating the foundation edges and with wing insulation. The trick is to balance the energy demand of the house with the sites passive and active solar harvesting abilities and sizing a thermal store to blend the two.

These homes are design to maintain a minimal internal temperature of 18 degC year round (from solar, occupied or not) and with additional spot heat when required. Most clients want a fire place in the living room any way.

By having the 3 elements to work with (load, mass and generation) you can look for the most cost effective solution, passive house standard construction might be to expensive compared to solar panels or compacted hardfill!

Because every site/project is different, I always push for a good simulated computer model of a design at concept stage to establish the future path.

Jeff's post prompted me to start this new thread.

In the UK we are ever pushing for lower and lower u-values in floors. Clearly insulation is needed for suspended floors. However, it seems curious to me that while the principle of using thermal mass in walls is generally acceptable it is not really taken advantage of in solid floors. I have long considered a similar method to that suggested by Jeff above, I.e. continuous cavity insulation down to formation level. It is after all acceptable above ground, and has been advocated as an alternative to conventional floor insulation in CIBSE Guide A. ' Insulation wings' could be added to minimise heat loss further. Should this type of construction be adopted in the UK? If not, why not?

GSHP - why have I been on the phone all day ?

tomlin — Thu, 11 Oct 2007 20:02:13 +0100

As part of my self build in the far north west of scotland, I've been seriously considering a ground source heat pump.
Having contacted several manufacturers I have been disappointed with the response I have received. My experience so far is that ;
- I get no response from flling in enquiry forms on supplier websites
- Telephone contact is not much better - promises of returned calls aren't honoured
- Suppliers happy to quote but dont have their own installers and don't or can't provide installers covering the Highlands
- Suppliers offer to 'train your plumber' - Im sorry but that doesn't inspire confidence (no disrespect to plumbers intended)

If this is the response to a pre-sales enquiry, Im starting to question what level of post sales support will be available. I wonder if this is to do with geography or the fact that this is an imature technology in the UK ?

Has anybody a good story to tell of installing GSHPs in the Scottish Highlands before I give up and go for an easy but not at all green option?

Temperate timber

Danb1203 — Wed, 10 Oct 2007 14:08:22 +0100

Hi all,

i've been asked to do some reasearch into temperate timber - and how it is the first choice as a material for sustainable construction within the UK.

So I thought i'd post it on here and see if any of you lot would have any knowledege or information on this, or even a view.

All thoughts would be helpful

many thanks

DPM material for under UFH - whats the alternative?

geegee — Tue, 09 Oct 2007 19:30:21 +0100

Firstly, can anyone explain why a damp proof membrane is necessary under a water-piped underfloor heating system? My architect is insisting it is not necessary but all other websites I have consulted on construction tecniques seem to include one as standard, above the subfloor but below the insulation surrounding the pipes.

Secondly, whats the alternative to PVC - is there a more ecological option or is this just one of those things we just have to accept for practical reasons? And what about the material for the pipes? (oh dear, this being green can be very challenging for us novices).

For interest, my system will be powered by biomass from locally sourced waste material, the insulation is natural compressed cork board topped by a layer of concrete (oops) and the finish either local stone or FSC-certified engineered oak board. It would seem a shame to have to use polluting plastic for the DPM, although I understand there isn't an alternative to the concrete layer over the pipes.

Any advice would be much appreciated.

Heat exchanger connecting vented and pressurised heating

bryand — Thu, 11 Oct 2007 10:24:18 +0100

Hi
Han anyone tried to transfer heat from an independent vented heating system (wood stove with 34,000 btu boiler with coil plus big rad) to a closed pressurised system (wood pellet with rads and underfloor) using a heat exchanger? I am just about to get the stove and am a bit nervous!! Can anyone see a problem with such a system, so long as a stat on the stove gets the pumps in the two systems running? The heat exchanger would be placed on the return pipe back to the boiler.

Thanks

Off Site renewables no longer eligible for zero carbon homes

Olly — Fri, 05 Oct 2007 17:13:37 +0100

An article in Building today says that offsite renewables will no longer be permitted for zero caron homes.

http://www.building.co.uk/story.asp?storycode=3096695

With regards to the CfSH, this only relates to energy for appliances, all energy for SAP (heating, hot water, pumps, fans etc) has always been required to be produced on site.

The implications are that this will make code level 6 projects virtually impossible on many sites, and prohibitively expensive on most.

I'm not sure how this will pan out, I'm currently working on a code level 6 project, and I can tell you that if we need to provide energy (electricity) for appliances on site then we're in serious trouble, there's only so much electricity you can produce on a small site, we already have lots of PV to offset the carbon from the biomass heating/hot water and MVHR, I simply don't think there will be enough roof area to produce the quantities of electricity required. Wind is simply not an option with planning, leaving biomass CHP as just about all that's left and that is simply unproven at this scale (35 units) and the load profile is also completely wrong.

Is this simply due to concerns that the take up of zero carbon homes for stamp duty exemption will be too high?

S I units

tony — Sat, 06 Oct 2007 14:00:28 +0100

I get wound up extraordinarily by the awful use made of units in general and we should be getting "with it".

In the 1970's the UK adopted 'SI' (system international) units

We should only talk about meters, kilograms and seconds and combinations with factors of a thousand allowable

Thus centimeters are not SI units, meters or millimeters or kilometers are.

Feet and inches are definitely out, as well as inches only which are more so, as are fractions of inches.

BTU's no way --- Watts (W or kW) etc are the ones to talk in terms of

Kilogrammes, degrees Celsius or may be Kelvin too

Should we clean up our act on here? What do we think.

Ground source or LPG boiler for underfloor heating?

EdF — Thu, 10 May 2007 09:13:23 +0100

I'm shortly to install underfloor heating in an outbuilding conversion which will make a 2 bedroom bungalow. The house will probably be occupied by only two people and our intention is to rent it for a few years and then move into it ourselves .. We had intended to use a ground source heat pump as we have a large field next to the property. However, I understand the heat pump will use nearly 3KW of electricity all the time it's running, but I do realise that one 'gets out' about 9KW. Underfloor heating has to be left on for long periods, days rather than hours and I fear that our energy consumption may work out more than at present. We certainly don't use 3KW of energy constantly now. My wife and I live in a large house which has LPG wet central heating with radiators, installed before we bought the place. We only have the heating on in three rooms for a couple of hours in the evening and morning in the winter, our main heat source being a large woodburner in the sitting room. As I get into my dotage, however, in about 10+ years time I don't want to have to cut 4 tons of wood a year (we live in the Highlands and are surrounded by managed woodland and there's a ready supply of firewood not suitable to go to the mill). The very high cost of a heat pump and underground loop is also a main concern, and I am concerned that we will never see a return on the extra cost and in the meantime the electricity bills may be much higher than at present.
I would be interested in opinions as to which way to proceed. At the moment we favour the UFH with an LPG boiler, with the possibility of changing over to a ground source heatpump in a few years time should the cost fall. I cannot afford the extra cost of electricity generation to offset mains useage. I can see UFH with a heatpump would be a boon if one has a large house to heat most of the time and one has very high heating bills, but I am sceptical about it in our case.

Heating Solution Advice Please

learner — Fri, 01 Jun 2007 23:07:07 +0100

Hi
My wife and I are buying a small farmhouse that we would like to extend. DHW and central heating for 5 radiators is currently provided by a solid fuel Rayburn Supreme which I believe is rated the same as the current 355SFW model. Despite the info on their website, I am nonetheless suspicious that the Rayburn may struggle when the number of radiators increases to 9. Additionally, we will not light the cooker in the Summer and an immersion heater will be expensive. Here are 3 options that I am considering:

1. Add solar heating panels to help provide DHW (especially in Summer). Add solid fuel stove in new lounge. Accept any shortcomings in central heating.

2. Add solid fuel stove with boiler in lounge to help Rayburn with DHW and heating. Use immersion heater in summer.

3. Add oil fired boiler to work alongside Rayburn when necessary.

We are Rayburn virgins so any informed views would really help us to decide on the best solution. There seems to be a huge difference in energy rating depending on whether you use wood or smokeless fuel? Thoughts and alternative ideas gratefully received.

Rob

Lammas eco village refused

Nanuls — Tue, 09 Oct 2007 14:47:07 +0100

Bad news for Lammas, who've had their plan for an eco-village in Pembrokeshire refused by the councils planning commitee. It was the first to be submitted under the council's new "low impact development".

http://news.bbc.co.uk/1/hi/wales/south_west/7034371.stm

experimenting with papercrete/paper adobe

applecheeks — Tue, 09 Oct 2007 17:48:35 +0100

Hello all,
I want to build a domed room in my garden with a kind of verandah attached. Sounds posh but it won't be, I want to be hidden, comfortable and soundproofed while I am there so I can write music and practice guitar.
I like the idea of papercrete and paper adobe, but as I am in Wales and we get a lot of rain, am wondering what is going to stand up best to the weather.
I don't really want to use cement at all, but I am wondering how little I can get away with in a papercrete mix that would still make it weatherproof and strong. Failing that, is there another plaster of some kind that I could use, but add a weatherproofing substance to the mix? Grateful of any help you can give me.
Thank you!
Applecheeks

Fixings to green oak

oiseaux — Mon, 08 Oct 2007 11:23:47 +0100

What sort of screws should I use to make a fixing to green oak, zinc plated seem to react in a corrosive manner. Many thanks