Is Ecobuild going mainstream?

[kenneal - lagger]

Just got back from three days at Ecobuild at the Excell Centre in docklands. Full of eco bling but there were one or two really good stands. The people who were selling double glazing a few years ago and heat pumps two years ago are now selling PV panels; suits and ties, smart hair and orange. You wouldn't want to buy a second hand car from them so why buy a PV panel?

Another reason it must be going mainstream is the number of stand sporting scantily clad ladies. Well, I assume they are ladies!

The AECB was giving out badges saying "Never mind the Green Wash, join the AECB!"

There was a wide range of free seminars from out and out green wash to informatives about eco refurb and Passivhaus design. A friend of mine went to a conference session with Dr Alice Roberts as main speaker. He's not sure what she said but she looks better in person than on the TV! Apparently Tony Juniper, who chaired the session seemed to agree.

There was an Architect talking about the problems caused by all the regulations that prevented her designing buildings as she would wish! Thank god for the regulations is all that I can say. Unfortunately she is in a majority in the architectural profession at the moment.

Another Architect asked what problems were encountered with mold growth in Passivhaus buildings because of the high levels of insulation and the air tightness. He left after being told there isn't a problem because the internal structure never gets cold enough to cause condensation because of the elimination of cold bridges and the overall insulation thickness and there is continuous low level ventilation. He left in a huff with his sidekick who also obviously didn't believe what he was told. Can't convince everyone I suppose. I should have asked him if he knew a bloke who went by the name of The Inspector?

Was it worth spending three days there? For the seminars, yes. For the exhibition, no. If you sat down with the guide and map and picked out what is not bling you could do the rest in a day or less.

[Blue Peter]

Another Architect asked what problems were encountered with mold growth in Passivhaus buildings because of the high levels of insulation and the air tightness. He left after being told there isn't a problem because the internal structure never gets cold enough to cause condensation because of the elimination of cold bridges and the overall insulation thickness and there is continuous low level ventilation.

Is that true even if the house is filled with wet washing?


Peter.

[Ballard]

Ha Ha, I was sitting in on that talk, I wonder if I sat next to you...

Didn't learn much, it was all a bit basic and superficial, aimed at the novice I thought.

The show is completly mainstream now, they should organise a 'fringe eco-build' with all the really intresting stuff in it.

[kenneal - lagger]

They have to spread the good stuff around to get the "people in the know", i.e. us, to look at the rest of the rubbish, Ballard.

I was the guy with the white hair and beard about three rows from the front on the left side. I annoyed the panel by saying that I had built a well insulated lightweight house that I couldn't keep cool. I think that talks on Passivhaus design are either really simple or incredibly complicated. The design details are quite simple and then you get to PHPP which is complicated and you need a computer to work through it.

A friend and colleague attended the lecture by the architect complaining about regulations.

[kenneal - lagger]

Another Architect asked what problems were encountered with mold growth in Passivhaus buildings because of the high levels of insulation and the air tightness. He left after being told there isn't a problem because the internal structure never gets cold enough to cause condensation because of the elimination of cold bridges and the overall insulation thickness and there is continuous low level ventilation.

Is that true even if the house is filled with wet washing?

If you fill the house with wet washing you put the MVHR system on boost until the water vapour is cleared. If you have got any sense you would only hang washing in the wet areas or in communication areas near wet areas. Because warmed air is introduced into the living areas and extracted from dry areas the moisture doesn't then get into the living areas.

Even if it does because you're drying washing in the living room any condensation would happen on the windows rather than the walls because even the triple glazed windows used in PH construction will loose heat much quicker than the walls and so will be the focus of condensation formation.

The only real problem that has been found with PH construction is that because the heating in very cold periods is via warming the incoming air the bedrooms tend to be at the same temperature as the living rooms. This makes them too warm so it is now advised to put some form of heating into the living areas rather than use an inline heater battery in the MVHR system.

[SleeperService]

I'm probabily being thick but what is PHPP?

I'd listen (or rather watch and listen) to Dr Alice Roberts reading a Haynes car manual

[Mr. Fox]

what is PHPP?

Passive House Planning Package

I wired a new ecobuild few years ago (used it for a NICEIC inspection, too).

All that ducting made me feel like Bob Hoskins in 'Brazil'. If doing it again, I might look at acoustic/physical isolation of the heat exchanger/fan box more closely - although I'm probably being over-fussy, as it was still a lot quieter than a gas central heating system, even on 'boost'.

I had to put circuits in to every room for electric heating (as spec'ed by the architect). At the end of the build, I guess money was getting tight, so I left on the understanding that they would call me and I would return to fit the heaters at a later date when it the weather got colder.

A year or so later when I bumped into the chap, I asked if he wanted them in and he declined, as it never got cold! There's a woodburner in the lounge - used infrequently - which more than did the job for the whole house.

Hopefully by now it's getting mainstream enough that architects can stop wasting good cable.

[SleeperService]

Thanks for that. I'd googled but didn't understand the context, your link is much more helpful

If you want to see cable overuse have a look at a French system. Everything heads back radially to a distribution board, each on a seperate fuse (or breaker now I suppose). I think they had to factor in the weight of cable

[adam2]

I know of someone who has a relatively large and very well insulated house with heat recovery from extracted air.
Not quite passive haus, but approaching it.

The home is off grid, with 12 volt extract and supply fans with a heat exchange system.
Stale air is extracted from the kitchen, bathroom and toilets via 2 speed fans, the extracted air from each fan is passed through a vehicle radiator.
Water with antifreeze is pumped through the radiators and becomes warmed by the warm,stale extracted air. The incoming fresh air is warmed by a vehicle radiator in the supply air duct. The various vehicle radiators being connected together with wide bore insulated copper pipe, with forced circulation by a low power 12 volt pump.

The whole house is heated by a small wood stove with a thermal store. No central heating radiators are used, just a simple loop of wide bore iron pipe around the entire house. The limited heating surface thus provided is ample in view of the good insulation.
Wood or other fuel is needed, but the amount is small in relation to the size of the house. The woodstove is only designed for one or two radiators, but easily heats the entire house via the pipe loop.
The fresh air supply is slightly warmed by the heat exchange arrangement described. It is warm enough for bedrooms, and the fresh supply to the main living room is at low level next to the wood stove.

[Adam1]

I was at Ecobuild too and would echo Ken's comments. There is good stuff there but thinly spread.

Re mould, I got asked that question on Saturday when a group of architects and interested individuals from Holland visited us in our retrofitted Certified Passivhaus. We have zero problems with mould now, whereas before it was a nightmare in the house (admittedly the structure was in a terrible state before the building work) but we also had cold spots everywhere, each a perfect breeding ground for mould spores.

We have been hanging all our clothes indoors and it has only had a beneficial effect in that it helps to keep the relative humidity within healthy limits.