Solid blocks to all internal walls and like you say concrete floors -- how about planks? I would forget the steel frame and if you really cant build with blocks and bricks then how about pouring it all?

Wide fully filled cavities --- solar panels on the roof and an inter seasonal thermal store -- passive solar design and thence no boilers or heating needed.

Hope it gets off the ground.

What do you think an inter seasonal thermal store is then? like the ones in Alberta or N Europe but smaller could easily work. All I was thinking of was a water tank underground under the building.

Tony,

for an apartment building a reasonable store could be put in place with an internal swimming pool - it could be solar heated in summer and a heat pump could extra heat in the winter. However, if you do the calculations, it's surprising how much water is needed for an entire season - infeasible for most houses that's for sure. I did post the calculations on an earlier thread but the search function isn't showing it.

Just to put it into perspective, a 10,000l heat store made out of water requires 11.6kwh to raise it by 1C. So a 20C differential will give you 233kwh - that obviously won't last very long. OK, let's say you have a swimming pool that's 10m long, 3m wide and 1m deep on average (that's a fair sized pool btw). That's only 30,000l and so a 20C differential will store 700kwh. If your heatload is only 5kw, that's enough heat for just over 5 days. See the problem? It takes a huge amount of thermal mass to make inter-seasonal storage possible. For fun, I recently calculated the thermal mass of the cylinder of rock that surrounds the borehole of the ground source heat pump that I use for heating. Allowing the cylinder to touch the property line gave a mass of around 40,000 tonnes - the heat capacity of this was just enough to supply all the heat I need for winter after making some simple assumptions on the termperature differential from the start of the season to the end (it's more complicated in reality due to ground water movement etc. - I just wanted to see how much heat was stored in that cylinder of rock). This gives you an idea of how much thermal mass is required for inter-seasonal storage at least in my climate (which, of course, is more severe than the UK - but not by as much as one might imagine in terms of heating degree days per year). 40,000 tonnes of limestone is equivalent to 1752381l of water (correction for different temperature differentials used) - this is a cube of water 12m per side (not too bad I suppose) or a swimming pool 29m x 29m x 2m deep. This might just be feasible for an apartment building (though a pool 100 feet by 100 feet would be pretty large!).

Paul in Montreal.

Tony,

sounds interesting! How do you plan on extracting the heat from your pond? Presumably you're not going to let it cool below the minimum you want inside your building if you're going passive. Problem is as the store gets cooler, the rate of extraction of heat also becomes less in a fully passive system - could make for some chilly days in early spring. Your 150,000l will store 3500kwh if you heat it by 20C - you might get by if your heat loss is really low - 3500kwh will give you an average of 1.6kw continuously over 90 days. Have you done any modeling? Charging the pond may be an issue in the less-than-sunny UK climate. Preventing overheating should be straightforward - but it depends on what your heat delivery system is. I'm currently looking at RETScreen (this is a renewable energy modeling package from Natural Resources Canada) and hopefully will be attending the training course in Montreal in January - it would be interesting to see what can be done with this kind of localized inter-seasonal store. Any more info you can provide would be appreciated.

Paul.

I cant make my hot 2000 do anything useful for me. Walls -- 100mm solid concrete / 300mm fibreglass batts in cavity/ 100mm brick or concrete block. roof mega insulated exceptionally low air leakage, MHVR, triple glazed low E (our way round) windows, below ground insulation down the outside of the walls of the basement to 2.2 m then horizontal for 2 m sideways with the second level lower part of the basement 10m x 6m x 2.5m deep filled with water as thermal store. Basement floor insulated to try to stop heat coming up from the thermal store. Solar hot water system too. Rainwater shower, washing machine and composting WC.

Do I have any hope -- weather aprox as London England. House facing SE solar porch outside thermal envelope front roof 45 with roof windows to bedrooms and 1.25m high walls. Overhanging front eves to give summer shading with the possibility of additional active shading, sun screens to roof windows and fans from porch to/from house.

The porch will be oak framed and likely single glazed -- interested Biff?

No but if i cant get 2k going how will i make 3000 work for me?

Posted By: fostertomThanks to others' original steer on this forum, esp. James Norton and/or Jeff Norton (NZ), I'm currently designing extension and re-ordering of a client's house in Devon, on AGS lines, which we'll Tas-model before pressing GO (and before convincing the Bldg Insp). I'm in touch with John Hait, who is sadly not well enough to provide me with consultancy; still trying to contact Don Stephens.

I bought the John Hait book, good read and in simple terms so I can understand it!

http://www.EinsteinCode.info to buy the ebook

Thx

There's a secondhand copy of "Passive Annual Heat Storage" from an American bookseller for £15.79 on www.abebooks.co.uk

Difficulty with trying to meet level 3 is that information available is patchy and contradictory. It may be a better strategy to go for tradable points from other sections