OT: more eco home problems

[sm_jamieson]

More eco home problems:

It keeps saying they are "super-insulated" without any info. I bet they aren't, at least not to Harry's standard.

Simon.

[ss]

aren't, at least not to Harry's standard.

I was just reading about those super efficient houses in Bradford that have £1600 elec bills and water is `harvested` which I presume is rainwater. Anyhow this got me thinking for those that are on a water meter (I am not) Would it be feasible and safe to collect rainwater from the house roof and maybe shove it through a filter and into your main water tank with an overflow to take any excess away, thus cutting down on metered water usage. Would it be practical, although I am not a plumber it sounds like it would be easy and cheap enough to plumb in.

[Andy Burns]

Hmmm, I'm not on a water meter, I wonder about a water-powered turbine to generate some electricity :-P

[Dave Liquorice]

Well it says those on the bio-mass system are up the HMGs highest standard and the other just slightly lower. So not Harry's 2' thick expanded polystyrene but still pretty good. Those PV panels are far too small to produce anything useful, they are even small for a solar thermal collector.

I suspect a box ticking exercise in the design, we must include X, Y and Z to get get the "deliverables" and "draw down" the grant monies. No thought in how the technologies work on their own or with each other. And finally the technology installed by ordinary sparks, plumbers, etc who haven't be trained in the installation and proper commissioning of the kit.

[Dave Liquorice]

Well you could but "they" would take a dim view of it if you were likely to ingest it, which includes breathing the mist in a shower. You could fit the same sort of kit that is supposed to be fitted to private spring/well water supplies. UV lights, fine filters etc. But at a couple of quid a cubic meter is it worth it? Harvested rain water is generally only used to flush the bog.

To get the most benefit you'd also need to know when it was going to rain far enough in advance so the tank was more or less empty by the time it did rain. If you keep the tank topped up with mains water there is no space for rain water... I guess you could just have a large tank and when it's empty use a bucket of mains water to flush the loo.

[Tony Bryer]

Here on new houses using roof water for WC flushing is quite common - there's a large tank beside the house which is topped up from the mains if the level drops too low.

In rural areas where you don't have rainwater and a bore may not be possible, roof water is run through a basic filter and used for all purposes including drinking. Our rain is probably less polluted than in the UK and where I've seen this done there is a corrugated metal roof which doesn't collect the algae and moss that a tiled roof would.

[ARW]

Guess what I wired up today:-)?

Although it was underground and not just a tank beside the house.

[dennis]

You just fit a larger tank and set the mains float switch to a low level.

[ARW]

the "The bulk of the storage tank remains empty ready to admit the water from the next rain shower" bit.

And today was the first time I have seen one/wired one up.

The harvested water will be used for the 9 toilets and the 2 dishwashers. It was at a largish house that I have just second fixed.

[Tim Lamb]

Our second house, built in 1907, had (still has) a brick soft water well. By the time we got there the *tank* room had been converted to a small bathroom and the downstairs bog to a cupboard.

>

[Tim Streater]

I don't have a "main water tank". I'm on mains pressure everywhere with an expansion chamber next to the boiler for the CH. So no pipes in the roof and no tanks and no holes in the upstairs ceilings.

What I do have is 700 litres worth of water barrels connected to the downpipes. Cost about £100 or so, and given the amount of water we want to use on the garden, 700 litres is a woefully inadequate amount of storage space. I reckon it'll take about 50 years to provide payback. When it rains I don't need them and when it's dry there's not enough.

How big is your "main water tank"? Probably take about 30 mins to fill it from rain. You'd need to get all your washing and everything else fitted into a short period of time in order to take serious advantage. Good luck persuading the teenagers to take their shower *now*.

[Tim Streater]

Prolly generate less than harry.

[Dave Liquorice]

Hadn't fully thought it through but why bother with float switches and solenoid valves? Just bend the arm of the float valve down. B-)

Bogs, OK. Dishwashers? I know they get pretty hot so will probably kill most pathogens but I'm not convinced. After all if they have a problem with the mains water they recomend a ten minute rolling boil before drinking it (after it's cooled...).

[Brian Gaff]

You would need two tanks for that one supposes and could only generate when you had enough water in the upper tank. sounds like its not going to be a goer unless your house is about 300 feet tall. Brian

[Andy Burns]

Not if I use mains pressure and send the output through a heat pump and then down the drain, I'm sure harry won't mind if it pushes his water bill up a little.

[tim.....]

In what way do you think using rain water for your washing machine, flushing the loo etc doesn't cut down on your metered usage?

tim

[tim.....]

IME of looking at bill from flats that have communal heating, the charges for maintaining the system swamp the fuel charges by a very large margin.

They may help to "save the earth", but they don't provide users with lower bills.

tim

[RobertL]

one thing to consider is using the rainwater (or borehole water) only for flushing the loos and perhaps bathing and using the mains water for cooking/drinking.

one extra benefit is that the sewerage charge (usually higher than the water supply charge) is also based on the supplied-water meter so that would go down as well even though the rainwater was actually going into the sewer.

For amusement, here is a water-powered lift

Robert

[Martin Brown]

aren't, at least not to Harry's standard.

But I doubt if that is the root cause of the problem. If you look the houses have *one* token cosmetic solar panel and some are installed at right angles. It would be interesting to know which way is north.

What is killing this scheme is almost certainly that when there isn't enough sun it reverts to crude electric immersion heaters which is just about *the* most expensive way to heat water or heat a home. It was flawed from the outset as should have been obvious to energy audit.

I have yet to find anyone that has done OK with ground or air source heat pumps in the UK. Air source is fine for dumping heat outside a building but tends to freeze up in winter if you try to do the opposite. It is too damp here and the sun doesn't get high enough.

Recycling of rainwater is trivial and should be done on all modern build for water that is not required to be drinking quality. Most homes built in Belgium have had this feature for decades.

[Martin Brown]

Yes. That and electricity costs seems to kill ground source heat pump systems that on paper would otherwise make good sense until you try to run them. The ongoing maintenance costs seem to be exorbitant.