Here's the zero-energy blurb from the drawings of a current Planning Application. It's an ambitious extension and uprate of a 1985 bungalow, including a 10.5m x 8m x 3m high room with roll-away glass on two sides. The site is a SW slope with full sun exposure from dawn to sunset, on the edge of a Devon village, facing open country. The building has empty cavities and no underfloor insulation - ideal for AGS inter-seasonal subsoil heat storage!
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A Zero-Fuel project in Mid Devon

A pioneering demonstration that will attract much publicity.

Techniques that could take most of UK's building stock 'off-grid' for heating ventilating and cooling - houses, flats, offices, factories .....

This 1980s bungalow is ideal for uprating by the AGS approach.
AGS is ANNUALISED GEO-SOLAR - download www.greenershelter.org/TokyoPaper.pdf for a simple explanation of the principles and how it's done.

AGS buildings collect plentiful summer sun heat and store it in several metres of dry subsoil below and around the building - enough, when retrieved, to provide the entire winter's heating. Zero bought-in heating fuel is needed, therefore zero Carbon dioxide is produced.

Other inter-seasonal heat storage methods are expensive, hi-tech and yet struggle to retain a full winter's worth of heat, and so require fuel from Jan/Feb on.

AGS (Annualised Geo-Solar) subsoil storage easily retains the full winter's heat requirement, by low-tech, near-passive means. As a gentle, steady process, an AGS building takes 2 or 3 years to fully charge its subsoil with stored heat; thereafter performance improves year on year. Subsoil effectively provides its own heat-retaining insulation around the storage zone.

AGS collects summer sun heat by a variety of means, as suits the individual building. There may be solar panels, but principally the building itself collects sun heat through big windows, and is arranged to conduct that heat away to subsoil storage, so avoiding the usual overheating. Consequently AGS buildings often have large windows, by current standards - but nevertheless use zero fuel and produce zero Carbon dioxide.

AGS buildings are insulated and airtight to the highest standard, well beyond current Building Regulations requirements.

The technical details are being fine-tuned by computer simulation, using EDSL Tas dynamic thermal modelling software - visit www.edsl.zenwebhosting.com.
Its performance will be verified by simulating its summer sun heat intake and its winter heat losses through the course of years of actual weather data.
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As we move into that fine-tuning, and working drawings, I shall no doubt be putting many questions and requests for advice, insights and expertise to this forum. I'll appreciate all feedback.

Heavy curtains etc, but not really relying on that. Triple glazed. The point of storing your own private supply of CO2-free heat, is that there's no particular limit to how much you can collect and store, so you can afford to 'waste' a bit where there's good reason to, while conserving to highest standard elsewhere. It's a free and easy alternative to mean little minimise- everything and save-everything Passivhaus! Ideal for e.g. hotels. Obviously a balancing act, between practicable summer collector area (windows and panels) and winter loss (windows) area.

Thankee kindly Jeff

Wouldn't it depend on the water table ? how would you guard against saturated ground taking all the heat away ?

Posted By: fostertom
AGS (Annualised Geo-Solar) subsoil storage easily retains the full winter's heat requirement, by low-tech, near-passive means. As a gentle, steady process, an AGS building takes 2 or 3 years to fully charge its subsoil with stored heat; thereafter performance improves year on year. Subsoil effectively provides its own heat-retaining insulation around the storage zone.

Doesn't storing the heat year round present overheating problems during the summer? I could understand that AGS would work fine in both summer and winter if the heat storage was precisely at opposite phase to the seasons - store the heat in summer and wait for it to arrive at the building in winter. And don't store anything in winter so that you don't have heat arriving in summer. But this seems to suggest that the heat will be stored year round?

Posted By: fostertom
AGS collects summer sun heat by a variety of means, as suits the individual building. There may be solar panels, but principally the building itself collects sun heat through big windows, and is arranged to conduct that heat away to subsoil storage, so avoiding the usual overheating.

Letting the summer sun into the building in summer seems counterintuitive. Surely using a solar collector would be better?

mmmm......
so how is it 'taken away to storage as it arrives' and 'injected' ???

I can see that the calculated depth etc will hopefully avoid the heat escaping at night in the summer, but will this not involve a lot of digging or drilling to get it down there. You are also then reliant on getting the calcs right to get the timing right with no control at all. Would it not be simpler to store it under subfloor insulation closer to the surface and then control the release as it is needed ????

Posted By: TerryWould it not be simpler to store it under subfloor insulation closer to the surface and then control the release as it is needed ????

That is one of the options, but an unnecessarily crude one, which misses out on opportunities for neater performance. It's akin to the 'big tank of water' approach to storage (except the tank's full of soil) which has so far proved expensive, leaky of stored heat, and requiring lots of plumbing, valves, pumps etc and fuel to run same. It's possible to minimise the latter, get semi-passive operation, and possibly even a nett surplus of captured heat, if only there was an easy way to turn that into electricity to sell back to the grid!

Posted By: Benjmaking it airtight/super insulated

Not difficult!

Posted By: BenjWhy is this particular building ideal for AGS?

Orientation, sun exposure, garden space around, 1985 bungallow so straightforward modernish construction in good condition, built just at the last moment before under slab insulation and cavity fill came in, well drained non-clay deep subsoil.

Sounds great fostertom. A couple of questions.

1. Doesn't the ground/subsoil around the house for a a good few metres need to be kept bone dry to store the heat effectively? Will this involve large amounts excavation/moving outbuildings/paths etc and laying some kind of waterproof membrane?

2. What do the internal surfaces need be to collect and transfer the heat for storage? Will wood suffice?

3. Sounds very similar to PAHS, is this the same thing?

I have been cogitating on something very similar. This is an extension of solar heating. You have bought the panel, pump,controller, double coil DHW tank and hot storage tank. Its August and the whole system now has to dump heat cos' all the stores are up to temperature.
What I was thinking about was to bore 4" diam holes from 1m out from the house walls pointing inwards so at a depth of say 7m they are terminate 2m inside the houses foundations. Now you install a concentric water pipe. 4" outer copper pipe then a 3" plastic pipe with a 22mm plastic pipe inside that, filling this gap with foam. The 4" pipe has its end sealed and is stuffed into your bored hole. Pumping the excess hot water down the centre pipe to the bottom of the hole, the water returning via the gap between the 4" Cu and 3" plastic pipe. Now your excess hot water is warming the soil under your house.
The reason for using pumped water is that the warm subsoil will not loose heat directly back into space if the water is turned off.
The meditteraneum church effect, causes the suns heat to be conducted into the ground during the day but also allows the heat to escape at night.
The marginal cost of my system over a solar water heating set up, would be boring the hole, bit of specialized pipe and an extra panel, say £4k. The outcome would be zero heating bills. Sounds a better deal then GSHP.
Any comments?
Frank

chuckey, you've dead-heated with us on the concentric idea! but why such high spec? 4" copper?!! plastic outer and inner, no 3rd item, no insulation might not make such good thermal contact, but let the water loop round a few times .... Would you blanket the ground for a distance around with insulation, to prevent the heat shortcutting up to the outdoor ground surface? How would you go about boring multiple holes? What do you mean by

Posted By: chuckeyThe reason for using pumped water is that the warm subsoil will not loose heat directly back into space if the water is turned off.

What's

Posted By: chuckeyThe meditteraneum church effect, causes the suns heat to be conducted into the ground during the day but also allows the heat to escape at night.

The ideas are starting to flow, there must be numerous ways of balancing heating load, solar gains (active & passive) and heat storage of a house.

A good driver of a dynamic simulation software package (& with a copy of a Rawlings price guide) should be able to design a house for every location with minimal heating.

Chuckey's sounds like a good option too.

Fostertom

If modifying an existing building to be super insulated and airtight is "easily done " then why am I finding it a nightmare to specify a brand new building which will be the same.
Would you just wrap the whole thing in celotex?

I think you've summed the whole thing up in "B".
Seems to me all of the technologies discussed here have their advocates and non believers. Just when I think ive got the design sorted I read another post which swings me in the opposite direction.
Are there any proven Passivhaus standard multifoil insulated buildings ?

not sure about the insulation bit! never mind super insulation.