Green Building Forum - All Discussions

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Taking windows to the next level

pmagowan — Sat, 04 Feb 2012 16:05:10 +0000

Hi all, me again!

Some of you will remember that my plan for windows is a 28mm 3G Krypton filled unit (Ug 0.6-0.7) fitted in a modified sash frame set out into the EWI layer. In this scenario the main problem is the frame. I will have to create a large rebate to fit the units which would require clever use of a router and some skill. I have thought of another way and wonder what you guys think.
Basically I will split the frames (along the plane of the glass) and insert a 10mm insulating board of some type into the middle before sticking them back together with glue. This will make the frames deeper and thus make the rebate problem easier (no router required). It will also give a thermal break.

What material would you use as a thermal break and how would you stick them together?

Where can I buy 12mm square lengths of timber?

JT101 — Wed, 16 May 2012 07:32:02 +0100

I need to put a 12mm deep trim around my window frame so I can add magnetic strips to it, and then a sheet of perspex for secondary glazing.

Ideally, I need 12mm x 15mm x 6m, but 12mm square will suffice since it's more likely a standard size. Obviously it will come in shorter lengths than that.

Just can't seem to find anywhere that sells it. I've searched for "12mm square wood mouldings / trim".

What would I search for?

Thanks in advance

Treatment for a damp room

beelbeebub — Tue, 15 May 2012 22:16:38 +0100

Some advice would be appreciated.

It's not strictly a Green Building issue, but as there seems to be a god deal of expertise here it would be good to get some second opinions.

So the background.

I rent out a house on a steep slope. Due to the slope the house has a garage and "utility" along the downslope side, under the main floor slab. These spaces were created when the house was built in order to support the house above, so they are essentially "basement" type spaces. They were not built with a damp course or (on the retaining wall side) any damp proofing.

The tenant has (against our advice) been using the "utility" as a study type room (desk, books etc). The room has no windows, a small air brick and one (external door).

After a plumbing leak some years ago we installed a cheap "office" carpet at the tenant's request, his reasoning being to protect the concrete floor of the room which had had some tanking slurry applied (again in an act of good will to the tenant)

Recently there was another leak from the plumbing system (the exact circumstances are murky). Approx 1 bucket or so of water soaked into the carpet (the room is approx 3m x 4m)

The tenant had all his stuff removed (insurance job).

The carpet has been drying out over the last month, not helped by the fact the tenant tends not to open the door.

I was going to pop a dehumidifier in for the next week just to finish off the drying process.

When I was there 1 week ago, the walls and ceiling were fine, with no sign of mould or dampness). The carpet was mainly touch dry although in the corner closes to the leak it would leave a damp mark on your trousers if you knelt down. There were one or two small (about the size of a pea) "furry" things where I assume a crumb of sandwich or other organic matter had moulded over.

In my assessment a vacuum and a few days with the door open would see the place back to "utility" standard. The tenant wants the place upgraded to a full study but that's another tale.

The tenant wants (although he phrases it as "advises") the following work done (lifted from his email)

- The carpet is a vapour barrier. It is also effected by mould and spores. The carpet should be removed, placed in an airtight plastic bag and incinerated, as it is a health hazard. this should occur post swab samples collection.
Prior to any de-humidification they advise taking swab samples from the carpet and walls ceiling etc.

- All walls ceiling and exposed floor should be sprayed with an anti spore solution by means of a spray mechanism. The room then requires to rest whilst the process tales place.

- Once the spores have been killed the door should be opened to fresh air which will allow many air changes per hour. At this stage fans should be introduced for a two to three hour period. with the door open, assisting air changes.

- After this treatment spore samples may be taken and passed on to a laboratory for analysis.

- The next step would be post sample analysis is received to introduce axial fans and dehumidifiers plus a heat source with a closed door. Until the room has a low relative humidity and the walls floor and ceiling test out at an acceptable low relative humidity.

- If you are unable to carry out the above works and tests the appointed contractor appointed by Aviva can do so on my behalf and on charge it to you accordingly.

- Please be aware that the spore samples and analysis must be carried out by an ISO certified company, using appropriately trained operators with accreditation.

- I have been advised to tell you it would be dangerous and a complete violation of HSE regulations for you to do otherwise.

Does that seem a little excessive? To me it does, what does the voice of GBF think?

Filsolar - Solar Thermal

mzthomps — Tue, 03 Jan 2012 14:25:45 +0000

I've got two filsolar thermal flat plat style panels approx 2.1msq each fitted in 2005. During the recent install of some solar pv panels on the same roof, the solar installer noticed that both the panels had split .

Luckily I have a letter from the solar installer which referred to a 10 year warranty on those panels, which they are following up on with Filsolar (albeit Filsolar rather slow to respond).

Apparently this is common. Anyone else had problems with Filsolar kit or flat panels?

Thanks,

Mark

MVHR and Natural Ventilation

Luke.Smith — Tue, 15 May 2012 13:32:54 +0100

Hi,

I'm doing a refurb of a bungalow and looking to go for new double glazed windows, IWI, 400mm in the loft and some kind of insulating overlay on the floors. In doing all this there is clearly an opportunity to go to town on getting the airtightness right down and retrofitting an MVHR unit (piece of cake to install with it being a bungalow).

So, if I've got good airtightness - lets say we get to about 3 m3/m2.h and I go for MVHR, I'll obviously need to go without trickle vents in my new windows. Could I also go for fewer operable windows to save on costs? How much cooling will the MVHR provide in the hot summer months? Could I strategically place operable windows to permit cross ventilation on the hottest days and get away with leaving some windows as fixed units?

C&F Customers' Group

alexsmb — Wed, 16 May 2012 22:28:08 +0100

I have started up a dedicated group for C&F customers. Have a look at http://groupspaces.com/CFCustomers

We have started putting up monthly turbine production stats too. Look at the tab at the top right.

The more people that join the more useful the information in the statistics, and the forum, will be.

Excess solar thermal heat ducted to AGS(pick this idea apart pls)

an02ew — Sat, 05 May 2012 09:35:46 +0100

Ok, so the plan is to oversize the solar thermal (ST) collectors and use two smaller solar cylinders as opposed to one huge one, the first (DHW) will take priority and reheat quick due to its size and the oversized ST collectors, when heated the second cylinder takes all the excess heat and ducts it away under the house into a AGS. the heat will be ducted in two separate 100m coils of under floor heating pipe rated at about 10 watts per/m so about 2kw each coil held in shape by wiring them to a cylindrical wire cage around 1m diameter and 2m tall, then backfilled with compacted sand and the new insulated floor system over.

The insulated floor slab will not allow the heat to rise up through the floor but deflect it under the very old cottage ( AGS pies placed up tight to cottage walls) which can well do with the all the heat it can get and with more mass than any other part of the build will also store the excess heat.

I realize that i should put more effort into the AGS with down stands of insulation and maybe even a concrete bund but it’s just a dump for the excess summer overheat. The idea is about having a solar DHW system that will quickly recharge summer or winter.

As always all comments good or bad welcome.

How much PV has the UK installed to date?

RobinB — Tue, 15 May 2012 12:32:19 +0100

Anyone know? thanks
RobinB

The five most important decisions to take before...

tony — Tue, 15 May 2012 08:11:02 +0100

If someone is trying to build an eco or energy efficient house, what do you think are the most important decisions he/she can make before the house is built?

loft insulation at front of house

telegramsam — Mon, 14 May 2012 16:22:50 +0100

I have just finished insulating the second of our two lofts (house built at the turn of last century) and realised that the very front of the loft/house which is very difficult to access between the rafters and is obviously totally exposed has not been touched in any way. Should I attempt to insulate this area as well do you think? Thank you for your thoughts.

New Build/Heating Design

matkat01 — Sat, 05 May 2012 22:12:53 +0100

Hi all

I'm a newbie here and my technical knowledge/understanding is limited but is improving all the time as I have spent quite a while searching this forum.

We are building a timber-frame closed panel house this year, which is 190m2 over 3 floors (using attic space). I know we are probably falling at the first hurdle in terms of being green due to the size of the house but it is very well insulated and airtight (with MVHR) and so should be very energy efficient.

Which brings me to my question...how do we decide on the best way to provide the heating requirements? We plan to have ufh on ground floor with rads upstairs and towel rails in bathrooms. We also would like a small (5kw) room-sealed wood burner in the living room for occasional use. I know this is a 'want' rather than a 'need' but this is non-negotiable as far as my husband is concerned.

The architect has specified a condensing boiler with megaflow cylinder. Ideally I would also like to install solar thermal and link this in. I have read lots of threads on here re. thermal stores and admittedly have got rather confused about whether we should use one or not. The budget is tight so cost is obviously an important factor. This may seem a silly question but who exactly am I meant to be asking these questions to? I want unbiased, independent advice on what our heating needs will be and the best way to supply them. I'd be grateful if anyone could point me in the right direction!

Thanks

Wind farm noise in court

CWatters — Mon, 04 Jul 2011 19:37:49 +0100

Wind farm noise goes to court..

http://www.dailymail.co.uk/news/article-2011162/Wind-farms-whoom-whoom-whoom-noise-drove-mad-farmers-claiming-3m-tell-High-Court.html

Quote:
Lawyers for the couple say they are now seeking an injunction to bring about modification of the operation of the wind farm, plus some £400,000 damages to compensate them for the noise nuisance that has blighted their lives.

Also in the Telegraph..

http://www.telegraph.co.uk/earth/environment/8615569/Noisy-wind-farm-drove-couple-out-of-their-home.html

and The Times but that's subscription only.

Whole roof solar thermal

jemhayward — Tue, 17 Feb 2009 19:38:34 +0000

I'd like to put 4m2 of flat panel solar heating on the roof of my barn, but the listed building people are not impressed. They want smaller, but that isn't going to work, so I was thinking of installing a very long run of pipes just under the tiles in the ventilation space, with the aluminium flanges used for underfloor heating to hold it all together. Apart from the complexity can anyone offer any comments on how well it might work. I'd have about 14m2 of roof to play with.

MVHR Controls

Pugliese — Wed, 16 May 2012 09:07:30 +0100

A question for all you out there with MVHR.

What are the best and most useful controls?

I am thinking that I should have humidity sensors that auto switch the unit to boost in every bathroom so that they switch to boost when having a shower etc and possibly another humidstat in the kitchen. Also a central boost switch downstairs maybe linked in with the kitchen one.

Also summer bypass - good idea?

Right to privacy?

JSHarris — Sat, 12 May 2012 16:17:52 +0100

We have a small problem, regarding the positioning of windows in a new build. In the original planning approval, a neighbour managed to convince the planners to prevent a first floor window being fitted in an elevation that would overlook a small part of their garden (not any windows in their house). The nearest edge of the neighbours back garden in question is just over 20 metres away, and across the other side of a lane (their garden backs on to the lane). The neighbours house has it's gable end facing, and directly on, the lane and has no windows. Between their garden and the wall of the new house where I'd like to fit a window there is a single storey pitched roof garage, around 3.5 m high at the ridge.

I've searched the planning portal and other places for advice, but can't find anything that defines any "right to privacy". In this instance I'm not at all sure there really will be a clear view from the window to their garden, anyway, at least not at anything below about head height, as the sight line will be limited by both the garage roof ridge and the hedge at the edge of the lane (which is around 2.5 m high).

I can't easily fit obscure glass, as the window in question is in the living room and looks down on to a small area of garden between the house and the garage. My view is that 20 m from their boundary, plus the intervening garage and hedge, is sufficient to provide a reasonable degree of privacy. It's perhaps worth noting that the area of the neighbours garden that could possibly be overlooked is a rockery, with no area for sitting out, etc.

Has anyone tackled this sort of thing with the planners and managed to win any concessions, please?

Has anyone read the Green Deal Consultation?

Nick Parsons — Thu, 15 Dec 2011 09:52:26 +0000

....and do you feel happy with it? For example, has anyone got from it a better idea than I have on how expensive (big, tricky) EWI jobs will ever meet the Golden Rule without an ECO bigger than I guess will actually happen?

LENR again

CWatters — Fri, 13 Jan 2012 09:11:58 +0000

I still hesitate to post info on LENR (AKA cold fusion) but this is on a NASA web site aimed at facilitating technology transfers to industry...

http://technologygateway.nasa.gov/media/CC/lenr/lenr.html

That link also features on the home page...

http://technologygateway.nasa.gov/

FiT Provider

jms452 — Mon, 14 May 2012 09:56:36 +0100

We are hopefully having PV installed this week and I have spent the weekend reading through my current electricity supplier’s Fit info.

I was annoyed to see that if I want to change electricity supplier in future I also need to transfer my FiT provider to the new company.

http://www.npower.com/idc/groups/wcms_content/@wcms/@resi/documents/digitalassets/fit_information_booklet.pdf (p4).

I will probably find that they aren’t the best deal when our already low usage drops and I would like to avoid reams of paperwork every time I want to change electricity company.

I don’t really fancy transferring to utilities warehouse for a strings attached short term sweetener.

I have spoken to good energy who I saw mentioned positively on other forums and they seemed helpful and don’t restrict me from changing electricity supplier but admitted it could take 9 weeks for me to get the cash after submitting meter reading! Is this normal?

Any recommendations (you can whisper if you feel more comfortable).

Thanks

John

GRP roof coverings

owlman — Sat, 12 May 2012 12:50:46 +0100

Does anyone have any experience of GRP as a lead roof substitute. It's for a small pitched roof.
For instance does it look OK, and how does it weather? The longevity seems fine, and all the components/mouldings etc are readily available. Is it easily applied? What about flashing to a house wall?
Any advice greatly received. Mike

Heating controls - compatability

Sigaldry — Mon, 14 May 2012 13:47:44 +0100

Anyone know enough about heating controls to advise is it possible for a larger dwelling to use time and temperature zone control (Domestic Heating Compliance Guide requirement for dwellings over 150m²), with both a delayed start thermostat and a weather compensator.

One set of SAP software I use seems to allow all three together and gives a benefit, but the other software I use doesn't allow the delayed start option with time and temperature zone control. Not sure which set of software is wrong.

Appreciate any feedback...

Aerogel: Building control approval.

JTGreen — Wed, 09 May 2012 14:01:35 +0100

In our "extension + refurb" of our solid brick end terrace we've insulated everywhere (loft, underfloor, cavity walls of block and brick extension, EWI where possible to solid wall, IWI where not possible).

For the IWI we've used mostly 75mm celotex, but on a couple of walls where we don't have space we've used aerogel - the type laminated to a magnesium silicate board either 49mm (40mm aerogel + 9mm board; on the internal face of an external wall of an alcove where the window is < 50mm from the wall - we're already cutting into the architrave a bit here) or 29mm (on the wall overlapping the EWI and on the chimney breasts which project into the rooms, both to avoid cold bridging. The chimney breasts will be filled with more insulation, either surrounding the flue or completely filled).

My problem is that our inspector from Building Control has never heard of aerogel and has asked for BBA certificate etc... This was a bit of a shock to me, given that I thought aerogel was a pretty much accepted product (i.e. appears on energy savings trust publication CE71 as amongst the 'highest performance' insulation materials). I have asked the manufacturers to email the data to building control, but they have been a bit slow about doing so.

What happens if building control won't sign off the use of aerogel insulation in these fews areas where celotex would have been impossible? Am I looking at a huge expense of having it removed?

Passivhaus Specifications & Details

davidfreeborough — Mon, 19 Oct 2009 11:56:19 +0100

I plan to build a house to Passivhaus standards and I am in the process of looking for a plot of land. After a number of months harvesting information and recommendations from the AECB, this forum & other sources, I have developed the attached specification. Note there are a number of different tabs for structure, windows & doors, HVAC, U values, etc.

How is an architect likely to react to receiving such a detailed brief? Can you recommend an architect in the East Anglia region with experience of low energy homes who would be interested in taking such a brief? Any thoughts on the specification itself?

David

Lower CO2 cements (GGBS or PFA etc.) in 25kg bags?

TimSmall — Sun, 13 May 2012 22:10:14 +0100

Hi,

I'm getting to the bit of my refurb where I'll start using a chunk of concrete in foundations and floor slabs.

Ideally I'd like to use Ground Granulated Blastfurnace Slag (GGBS), or Pulverised Fly Ash (PFA) to displace some of the portland cement, in order to reduce the environmental impact.

So, the question is, where do you get the stuff (readymix is easier I understand, but the site makes that problematic).

So far, I've come up with (localish):

Some cements which are sold as sulphur-resistant e.g. blue circle "sulfacrete", which is 35% (I think) PFA, but is a bit pricey (£8+? for a 25Kg bag).

http://www.lafarge.co.uk/CementProductBrochures/Cement_in_Sustainable_Construction.pdf

Similarly, some other "CEM II/B-V" cements (21% to 35% PFA) are available I think, but I haven't found any prices on them from local suppliers.

Not so local, but cheaper (I'd probably go 50/50 portland/GGBS with this) - GGBS at £6 for a 25kg bag from some lime specialists:

http://www.buildinglime.co.uk/price.html

Anyone happen to have come up with a better lower CO2 cement? I don't know how "portland-limestone" cements compare embodied CO2-wise either...

A bit of info:

http://www.greenspec.co.uk/greening-of-concrete.php

http://www.lafarge.co.uk/CementProductBrochures/Cement_in_Sustainable_Construction.pdf

http://www.cemex.co.uk/re/pdf/lt-cementitious.pdf

Anyone done this research before and come up with anything?

Tim.

p.s. Looked at limecrete, but can't really do it with my budget or timescales unfortunately...

soaking wet chimney in thatched stone cottage

Buzzfan — Mon, 14 May 2012 20:01:55 +0100

Would any experienced experts mind offering me any advice re a severe damp problem in a brick chimney penetrating a thatched roof? The chimney has always been damp, but the problem seems to be getting worse, & none of the local builders seem to know how to remedy - or more specifically, they all contradict each other, and I don’t think they have dealt with chimneys in a thatched roof before.

Please see below 2 jpeg photos of the chimney, and at the top of the first photo a small link to a pdf elevation.

The brickwork in the attic below the thatch is soaked, damp has caused rot in joinery below, and is coming through the plastered stone wall supporting the brick chimney.

We'd like to use the chimney for a wood burning stove, and know this is risky in a thatched house without a steel liner. I also suspect that a liner would prevent the flue from drying out. I could make it into an open hearth fire as this would have lower gas temperatures, but my building insurance would be invalid if the chimney caught fire unless lined. I dont have to use the fire, but would prefer to if possible.

One suggestion is to spary the brick with numerous coats of clear water sealer/repellant once the brick dries out this summer.

Another is to put a cowl over the chimney pot.

Another is to totally remove the brickwork back to the inner step and fit a steel cavity tray across here at level 6

Can any experienced old school expert types offer any advice please? Id rather not receive conjecture suggestions from any well meaning types who arent certain :shamed:

thanks in advance

MVHR units

borpin — Sat, 12 May 2012 14:57:59 +0100

I have a quote from AllergyPlus for MVHR. Looking through the recovery units on their website https://www.airflow.co.uk/Products?category=pg_VUNI&catdesc=Top-Connection-Heat-Recovery-Units I am wondering what the difference between the £400 and £2.3K units could be as air rate seems about the same. I have been offered the DV90 SE but am interested in the Duplexvent 71. Is the former really worth the extra cost? The main difference is that the DV90 I think has a variable speed motor and the 71, 3 fixed speeds. The DV90 also has the option of a 900W heating element and frost protection. As the unit will be inside a warm roof I do no see that as a requirement.

I also not that these units only have 2/3 year warranty which for a £2.3K item is a bit poor.

Knocking £2K off the install is extremely attractive! So, what have I missed?

Modulating boilers - whatever happened to them?

andykent — Mon, 07 May 2012 13:51:07 +0100

I need to replace my ageing combi boiler, and had planned to get a modulating one to complement renewable sources I plan to add in the future. That is, a boiler that adjusts its heat input according to whether the feed water has been pre-heated.

I'm surprised to discover very few models showing up on an online search, and only two, old, hits for "modulating boiler" in this forum. The main domestic manufacturers (Worcester Bosch, Baxi, etc) don't seem to have added a modulating offering. A few use modulating pumps, but only Alpha and Atlantic (the latter being ugly sods you wouldn't want in your house) seem to have true heat modulation.

Are modulating combi boilers an idea that just never caught on? (if so why?), or has it been replaced with some magic new technology I've missed? Or if it's still a goer, what are the good, robust products?

Thanks,
Andy

Any recommendations for RWH firms in Derbys/Yorks?

Nick Parsons — Mon, 14 May 2012 10:10:19 +0100

That's it! Helpful, flexible people. Supply and fit or supply and commission only. We have an exg concrete tank which could arguably be re-lined but may be more trouble than it's worth.

MVHR Constant Volume or Pressure

borpin — Sun, 13 May 2012 19:56:56 +0100

Looking into MVHR units and have come across a reference to "constant volume or pressure" for the Sentinel Kinetic Plus.

Quote:
Normal; Airflow based on system pressure. Airflow reduces as system pressure increases. Constant Volume; Maintains pre-set airflow irrespective of system pressure. Constant Pressure; Maintains system pressure by adjusting airflow when constant pressure dampers open or close.

CXan someone explain the practical effects of the different approaches? Is this unique to this model?

Selection of suitable replacement heat source for multifuel stove

abundantearth — Sat, 05 May 2012 11:16:16 +0100

We are currently looking to replace our Aarrow boiler stratford T50 b after ONLY 7 years..it has sprung boiler leak and help welcome as Aarows attitude is well we only guarantee for 3 years anyway..also any experience of this!!!

So we are now looking at what to install , we have solar thermal feeding into our system. We had originally looked at pellet boilers and woodchip. we do not really have suitable outside space . but any options considered

3 way valve or 4 way pros and cons

freemp31 — Tue, 01 May 2012 19:54:32 +0100

Orlan Super 40kW - Laddomat - 3000L store. That's the input side sorted.

All OK so far. But when it comes to the output I feel as though I'm in the dark still. Obviously the 90C flow needs mixing down to -say -60C for the rads and UF manifolds, and ideally I would be looking at a motorized valve with temp sensing, but what are the pros and cons of either a 3 or a 4-way valve setup (biggest diam pipework I can manage to minimise flow/return turbulence and safeguard stratification, and something like an Alpha pump, obviously)?

What do the rest of you have and what do you prefer for the electronics?

Mike up North... what do you have?

Funny how just when you think you're out of the choice mine-field, you realize you've had the map folded, and there's another page!

p.

Excellent little Android app for range and height.

Joiner — Tue, 08 May 2012 13:19:24 +0100

Waiting for the rain shower to stop and a mooch found this little app...

http://www.androidpit.com/en/android/market/apps/app/kr.sira.measure/Smart-Measure

Just calibrated it and tried it in here and it's surprisingly accurate. When the rain stops I'll have a play in the garden with objects of known height and distance.

Simple things! :wink:

(Oh, and it's free!)

What can i do with 3 damaged PV panels ? any ideas

jamesingram — Fri, 02 Mar 2012 17:52:53 +0000

I've got 3 x 250W panels (freebies) that have the glass broken ( its toughened so currently still all together)
I presume they work , but haven't tested them yet.
I was thinknig of sticking some clear lament film over them to hold them together and waterproof them a bit
perhap a new sheet of glass bonded on top will be better.
Anyway, dont think I'll add them to my existing grid tide system but was thinking of sticking them on the shed roof and mucking about with them in some way , any ideas , seems a shame to bin them.

cheers Jim

Nu-Lok roofing feedback

PeterStarck — Sun, 06 May 2012 09:53:53 +0100

Borpin
The main roof is hipped and there are three dormers which are hipped. There are two single storey extensions one is mono pitch and one is gabled. Originally I wanted the hips and ridge mitred. Unfortunately the timber frame was badly constructed with different angles on the various pitches which only came to light when I started battening the roof. Therefore all the items connected with mitring? the tiles were not needed. I ended up with dry fix ridge and hips. The verge trims didn’t fit well with the deep aprons on two of the dormers and I made some from ali angle.
I’ve never tiled a roof before but I battened and tiled the mono pitch extension and it was straight forward. I asked Nu-Lok to tile the main roof as winter was approaching. It took them months to finish my job partly because the company ran out of tiles which I then learned came from Malaysia and not Italy as I thought.
At the time I bought the materials Nu-Sustainable was in Northants and the roofing materials were stored in Swindon.
Nu-Sustainable offered a roofer for two days to train me.
It’s an easy diy system for a straightforward roof.
If I can help with anything else just ask.

Useful resource

Joiner — Sun, 24 Apr 2011 11:15:58 +0100

I've given this thread a generalised heading for ease of recall.

Any useful links to information resources that will show up on a 'search'...

http://www.planningrenewables.org.uk/resourcebank/index.cfm

Silicone smoothing tool

Joiner — Sat, 12 May 2012 09:31:17 +0100

Where can I get one of these?

[IMG]http://i49.tinypic.com/2dlr682.jpg[/IMG]

I've had this one for more years than I can remember, it came from Screwfix then but is no longer available from them. All anyone does nowadays is the silly finger-shaped tool that makes more mess than it's supposed to prevent, whereas this one leaves a clean profile and squeeges off the excess to leave a clean margin. Excellent for working into profiles.

Mine has had it at last, the tip starting to separate. :cry:

It's a plastic handle and the squeegy end 'clips' into it.

Thanks.

Airtightness around old beams

zebra — Thu, 10 May 2012 22:25:34 +0100

17th Century timber framed house - from inside to out will have: lime plaster, 15mm woodwool board, OSB as airtightness layer, 100mm thermafleece between studs, 100mm Steico woodfibre breathable EWI, propriatary lime render.
Question is this - the ring beams goes around the room at eaves height and protrudes into the room further than the studs. Originally the wall was lime plastered on laths over the studs, but the ring beam was left exposed. I want to do this again. I've shown a picture of the ring beam coming through the OSB layer.
The plan will be to complete the airtightness layer by sealing around the ring beam with airtightness tape. This will be crucial to stop air leakage. Has anyone tried doing this, and do they have any tips? How effective will it be?
Thanks!

The lure of PVC windows

Shevek — Sat, 17 Mar 2012 22:22:34 +0000

We're in the process of getting window quotes and I suspect (98% recycled) PVC is going to be hard to pass up.

Can you give me some solid reasons why we shouldn't go with this option?

3G / Passivhaus PVCu window options

TimSmall — Wed, 28 Mar 2012 22:23:27 +0100

I've come across a couple of companies manufacturing and supplying Passivhaus Institut certified (PHZ) 3G PVCu windows in the UK (BTW, I'm reasonably familar with the pros and cons of PVCu vs timber etc. and have decided on PVCu for this project for various reasons, having used timber high-spec (at the time) 2G in the past).

The options I've found a pretty similar - one is based on the KBE System_88mm profiles, and one on the Rehau Geneo profiles.

http://www.passiv.de/komponentendatenbank/files/pdf/uebergang/zd_rehau_rehau-geneo-phz_en.pdf

http://www.passiv.de/komponentendatenbank/files/pdf/uebergang/zd_profine_kbe-system_88mm-passivhaus_en.pdf

The prices I've quoted for both systems from different suppliers are very close - at around £250 inc VAT per m² (based on a small ~4 m² order - 2 windows) both are tilt+turns.

Going for the non-PHI option on the KBE cuts it to £160 inc VAT per m² - the glazing units are the same in both cases.

The differences between the two System_88mm options seem to be some extra seals, and a few bits of "platinum" EPS in the profiles - the steel reinforcement may also be a different shape. In both cases, the glazing units are the same - 4/16/4/16 with two planitherm panes, and argon fill (Ug = 0.6).

So you pay a lot for the extra PHI piece of paper, and a few bits of EPS and EPDM... Grr.

Additional cost for the PHI certified version: £375

Savings over 30 years (assuming 8p per kWh average over that time span for gas CH, and the relatively mild Brighton south coast UK climate) approx: £110

Although that calc doesn't take into account any additional losses from the less air-tight construction of the non-PHI certified option. I've absolutely no idea how much difference that'd make (Brighton is relatively windy, and it's half way up a hill, facing into the prevailing wind). Any ideas?

Has anyone come across any other suppliers (or UK profile options) for high-spec PVCu windows?

Anyone have any opinions on the relative qualities of the Rehau vs. KBE profiles?

Ta,

Tim.

SPAM

Joiner — Sat, 12 May 2012 11:14:13 +0100

What constitutes spam (as in the forum type)?

Two types: financial and prejudicial.

Financial: Someone who simply advertises their company's existence without materially contributing to a wider understanding of the subject under discussion

Prejudicial: Someone with an apparent although not openly declared (as in company name) financial interest who comes onto the forum and invites people to contact them off-post about an issue of general interest or concern, thereby removing consequent discussion from the open forum and depriving others, current or future, of the information subsequently discussed.

We know from the good examples on here that there is often a time when an enquiry gets so specific to an enquirer's particular situation that to continue in open forum would be of no material use to anyone else. Fine. I have myself been contacted via a whisper and carried on detailed correspondence over very specific matters, although where anything arises that might be of more general interest I'll copy it to an open post within the original thread. It's a question of judgement and whether you have the scruples to observe forum etiquette.

Carve-up

fostertom — Wed, 09 May 2012 11:22:45 +0100

The lambs in the fields out of my window - chasing around, jumping for joy - until 2 days ago, red stumps where their tails used to be. Now they're crushed, moving like sluggish sheep, sticking close to mummy, running away from us instead of coming to the fence with innocent curiosity. Their joyfulness has been terrifyingly ended by routine brutality. Shortly they'll be lamb chops. It should make the meat eaters amongst us shudder. Along with the fact that they've already consumed 7 times the resources compared to growing a comparable veggie diet, and farted methane equiv to megatons of CO2. World food shortfall? GHG crisis?

Breathing Window

adwindrum — Wed, 09 May 2012 19:42:45 +0100

Will pick the obvious mans brain about this when I go further down the route, but thought I would see if anyone not selling one had any thoughts about it.

It seems to make a lot of sense to me.

Positives, no ducting, highly efficient, works with windows open.
Negatives ?

http://www.viking-house.co.uk/fine-wire-hrv.html

http://www.breathingwindow.org/

Fully filled cavity wall with AAC block - interstitial condensation

ondrejg — Thu, 10 May 2012 15:33:15 +0100

Hi, I tried to model a simple cavity wall with facing brick, 100 mm mineral wool and AAC block (0.18 W/mK) inner leaf in BuildDesk U and it shows an interstitial condensation risk according to BS EN ISO 13788. As far as I know this type of wall construction is widely used so I don't understand how it is possible that it does not pass the condensation risk check. Am I doing something wrong? Can anyone help me to understand this?

Masonry stoves and the The Clean Air Act

Shevek — Mon, 23 Jan 2012 13:36:41 +0000

When you're in a smokeless zone how do you go about getting a bespoke masonry stove certified as an "approved appliance" for wood burning?

4.00kWp pv system price

tony — Tue, 08 May 2012 18:46:03 +0100

What is the going rate for 4.o kWp solar pv system now?

DHW heat recovery

JSHarris — Mon, 24 Oct 2011 14:15:08 +0100

The "Solar thermal or PV? ASHP or burnt fuel of some kind?" thread has drifted off to a discussion on waste heat recovery from DHW, so I thought I'd summarise all I've been able to dig up on this topic so far in one thread. If nothing else it may help someone who later uses the "search" function.

I've found (thanks to tips from others) two shower waste heat recovery devices, the Recoh-Vert (at a reputed £575 + VAT) and the itho Shower Heat Recovery Unit. Both are very similar, essentially just two concentric copper pipes with the warm waste water running down the centre and the cold water feed running up the outside. Both look as if they need to be mounted vertically to perform at their best.

The other solution I've found is from Earth Save Products and looks like it will recover waste heat from any warm water source in the house. It's called the Heat Squirrel and consists of a 120 lt tank, buried beneath floor level, with a heat exchanger coil inside, through which the cold water feed to the DHW system runs.

The performance claims for the shower waste heat recovery systems indicate that they may reclaim 50 to 60% of the waste heat from shower water. I've not seen any data for the Heat Squirrel, but suspect that it might be a bit better, as, despite the lower overall waste water temperature, it has what looks to be a more efficient heat exchanger. As incoming cold water is almost always a fair bit colder than the inside of the building envelope, this system seems to have the potential to preheat incoming water much of the time, even if only by a modest amount.

The last option is a DIY shower waste heat recovery device, made from ordinary large bore copper pip and some fittings. This is almost certainly the lowest cost option, as even buying pipe and fittings from your local plumber's merchant should allow a unit to be built for less than £100.

Overall I'm leaning towards a combination pre-heating system for cold water feeding the DHW system. The Heat Squirrel looks to be a good option for recovering low-grade heat from mixed waste grey water, but the shower heat recovery system looks more effective at recovering the higher grade heat from a shower, perhaps. I'm seriously thinking about using a combination of a home made shower waste heat recovery device along with a Heat Squirrel buried in a well-insulated cavity in the slab, with a suitable access hatch. Cold water would come into the house and have a direct feed to the cold taps, with all the rest going to the Heat Squirrel, and then on to the shower heat recovery device before feeding the DHW system.

Any thoughts?

underfloor - below floorboards retrofit heating?

Gavin_A — Tue, 08 May 2012 15:18:46 +0100

I'm just seeking opinions as the the viability of retrofitting an underfloor heating system actually below the floorboards, probably with a metal plate to spread the heat across the floorboards, with a foil faced air gap, then probably 150-200mm insulation between the joists below the heating pipes.

This'd be for a low energy refurb of a community building, so large hall space where the middle of the room is a long way from any radiators on the wall, and I want to use the wall space for 100-150mm kingspan anyway, which'd involve moving the entire heating system, and we'd be looking at full underfloor insulation anyway, so... just wanting to assess the viability of actually retrofitting low temp wet underfloor heating in his way.

I make it something like a U value of 2-2.5W/degree, which'd give us a potential of 17kW heat input if we used the entire floor area, but more realistically something like 4-6kW would be about right.

My concern is with the thermal inertia of the wood. I can calculate roughly the heat capacity of the floor itself, but have more difficulties when it comes to knowing how fast it would cool down / what it's starting temperature will be at the point it starts warming up, so how long it'll actually take in practice to get up to temperature on a daily basis.

So I was just wondering if anyone had practical experience of something similar /looking for a sanity check on it really... thoughts?

online learning tools for U-Value calculations

alistairm — Thu, 10 May 2012 12:13:17 +0100

I am currently using Energy Design Tools for u value calculations and condensation calculations.

The calculations are ok and i have a reasonable grasp of using the program and its many flaws and glitches.

I often have problems with interstitial condesation and am looking to get a better understanding and knowledge of the problems how to overcome them.

I am also very interested in Passiv Haus and have looked into becoming a Passiv Haus designer but wish to gain more knowledge and a solid understanding of the basics before I pursue that avenue any further.

Any help or links to teaching aids / tutorials etc would be great

Thanks in advance

internal wall insulation

woodcutter — Mon, 07 May 2012 17:00:56 +0100

Hi All
has anybody had any experience of using Calsitherm insulation on external (and internal we are attached to a chapel) stone walls.
I would like to let the external walls 'breath' but not sure if this would be necessary on the 1st floor internal walls which seen dry. On these walls I am thinking of using Celotex type insulation. Any comments?
regards
W

Official C & F turbine AEPs

gavstamp — Fri, 03 Feb 2012 16:25:21 +0000

Has anyone seen the official C & F wind turbine AEPs? I have been trying desperately to see what these turbines can do but cannot find any of their official MCS data. Can anyone help?