Viability of "green" technologies in domestic setting

Hello,

I'm looking for any reliable source of information on the fashionable green technologies that can reduce my "footprint". Saving money over, say, a 10 year period might be nice.

My limited reading on this tells me the best investment is insulate to within an inch of one's life - but allowing for adequate ventilation to avoid condensation. Living in a solid-walled Victorian end-of- terrace the classic cavity wall insulation is not available to me. Is there any way I can make a reasonable estimate (U-values?) of the current heat loss through external walls versus the heat saved (heat loss rate reduced I guess) for the current uninsulated walls against a "certain" thinkness of internal wall insulation. My thoughts are to take the walls back to bare brick and insulate from there. Although probably more effective, there is no way I am going to cover the original external brick work with cladding of any kind - and there might even been planning restrictions on that.

I'm also going to investigate rain water harvesting for using to flush loos and/or washing machine. I already collect rain water in butts for watering the garden. It may turn out that is a cheaper and better use for the water.

Regards

Clive

Reply to
Clive
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Burgers. Lots of them.

Reply to
Adrian C

Yes, definitely.

Proper insulation versus 9" brick is about a 40:1 heat loss reduction.

You wont be able to go 'full proper'..but you should get *overall* heatloss down by a factor of 4 or so.

Why take back? plaster is a modest insulator..or is it a question of space?

I would point out one major issue.

Building control.

If you do anything notifiable the BCO if he is a total dimwit may say that you have top go the whole hog, and get the walls up to modern standards. That's about 50m of insulant (celotex/kingspan).

What you are looking at is total dry lining of every wall with Celotex and foil backed plasterboard.

The roof will need LOTS of insulation. And try and put boarding on top to stop the wind whistling through it if you use rockwool. This is the absolute bets cost/benefit use of money. It heap and it does a lot.

Draughtproof every door and window. This is a huge gain also. And costs peanuts.

Then attend to the walls. This is starting to get expensive, but really makes a difference, if they are suspended wood. Tack town hardboard and re-lay carpets, or best of all, lift floors, put celotex between joists and relay.

Then fit thick interlined curtains.

If you have an old boiler, upgrade it.

Last and least, fit double glazing. Its almost the worst use of money, but if you have done everything else, you might as well.

The best use or the water is to let it soak into the ground to replenish the water that everyone uses.

Watering the garden does that, I suppose using rainwater to flush the loo at least saves pulling it out of the ground to do that. But I wouldnt say its a huge saving.

Reply to
The Natural Philosopher

Best and easiest is to clad the outside. There can be big airleaks in the gap between the ceiling and the floor. A Maplin infrared thermometer showed me a heat loss at the top of my walls where they were thinner due to the roof slope. My bible is

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're canadian where they have big heat differences!

[g]
Reply to
george [dicegeorge]

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both a good read

Agreed.

You have the choice of insulating inside or outside. Yellow House has a good discussion of each. Generally outside is better, if it's at all practical, but most of us (myself included, with an 1880s end terrace) end up going internal.

Yes, it's not too hard. Best done through a spreadsheet, because then you can set up a model and adjust the parameters to re-run it easily, rather than calculating from scratch each time.

Flush is the big one - washing machines are fussier and just aren't using that much water these days.

The favoured option seems to be bath/shower grey water as a loo flush, rather than rain. It's on my to-do list: when I upgrade the current outside loo to become an indoors / outdoors downstairs loo, I plan to flush it with grey from the bathroom above. As I have height to work with, I can avoid pumping. The main issue with these systems is a timer on the grey holding tank - if it isn't used quickly, it's dumped in favour of a white water (or potentially rainwater) cistern fill.

The problem with rainwater harvesting for flushing is the seriously large volume required, and the long storage times. Although the school behind our house has such a system, it requires a massive tank farm to hold the water.

Reply to
Andy Dingley

Water collection: Britain is awash with water. The cost and energy use of supplying it via pipes is trivial. Collection and reuse are only very useful if youre on a water meter. Use greywater in the loo, and rainwater for the garden. Aerators on shower & basin reduce hot water use.

Double glazing: retrofitting this just doesnt pay its way.

Boiler: if its old, keep it, unless its a very low efficiency type. New ones are much more efficient, but have much shorter lives and much lower reliability. TCO generally favours the old ones.

Walls: Cavity walls were used in Victorian times, they jsut weren't the default wall type. So its worth drilling to see what you really have. If not, then any thickness of polyisocyanurate onto the walls is going to really help. But if you can use acvity insulation, do, it has advantages.

Floor: suspended tmiber floors can be taken up, insulated and relaid.

Solar: Forget pv. Thermal can be made to pay its way if the design is good.

Collect all burnable rubbish and burn it in winter, if you're desperate to be green and have a fireplace.

NT

Reply to
Tabby

When I was replacing my roof I put rainwater collecting tanks in which I use to flush the toilet. It has a manual mains water feed tap (haven't got around to automating it), and I only ever have to use it occassionally in summer. I've manually filled the tank four times so far this year.

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Reply to
jgharston

patio. The downspouts will be connected to a common drain that will connect to a sand trap then into the storage tank. I've considered putting a ball valve low down in the tank to provide automatic top-up in times of low rainfall. Discharge from the tank will be into a drainfield designed to handle the worst forseeable storm drainage.

Reply to
Steve Firth

Umm .. Anglain Water know how to charge;!...

Reply to
tony sayer

Details of how here:

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Reply to
John Rumm

In some places. Here in Cambridge it rained last week which was the first significant rainfall since February. It was similar last year. But that acts against a rainfall collection scheme: you'd need huge storage tanks for

3 months' water, while underground is a vast aquifer used for free to store water.

It's a different story if you live in a hard-rock geology area in the north, though typically there are still some aquifers available (eg sandstones or fractured rock) and much more rainfall to start with.

Greywater makes sense, particularly for the garden. Flushing with greywater can work, but is moderately complex since it shouldn't be stored for more than 24 hours.

Water from washing machines and dishwashers shouldn't be used on the garden: the detergents are too harsh. Normal soap and washing up liquid is fine.

If you have particularly high water bills, fitting a septic tank may reduce sewerage charges (the biggest part of the bill) if you can prove this to the water company. If you're not on mains drainage then you'll need to do this anyway. Note it's worth thinking about split tanks, one for 'black' water (toilet material) and one for greywater (with dishwasher/washing machine output) - the detergents will harm the bacteria breaking down faecal material, and an excess of water input may swamp them.

OTOH plugging draughts from (eg) wooden sash windows is cheap and makes a difference. If you have metal framed windows, there can be a significant cold bridging effect (and associated condensation), though probably not enough to make it worthwhile replacing the windows just for that. There might be some kind of insulation that can be applied to the inside of the frames.

That assumes it's gas. If you aren't on mains gas, then there's a bigger range of choices.

You might think about replacing open flue gas boilers (where oxygen is taken in from the room - which will burn warm room gases and draw in cold exterior air through leaks in insulation: the house is one big convection cell) with those where the boiler air intake/flue are wholly external.

PV is only worthwhile if you're off-grid for some reason. Though it might pay on the FIT scheme, it won't pay without the subsidy.

Better if you can have a fireplace that can be airtight-sealed when not in use, or will burn behind glass, so that your room isn't exposed to the chimney draught (the convection cell again). There are some modernistic fireplaces that do this (and eg have fans to distribute heat/oxygen better)

- I'd be interested in opinions/experiences.

If you do have a fireplace, think about where the wood is going to come from. Central London isn't known for its forests. If it's local (eg freshly cut from a nearby wood) where are you going to store it to leave it to dry out?

Theo

Reply to
Theo Markettos

We get 56" a year rainfall, that's a vast amount. Water companies lose vast amounts through leaks for one simple reason: it isnt worth fixing them. Regional varitions arent an issue, there's enough for everyone.

Some areas of the world are short of water, we, if anything, have too much, and conservation for its own sake is simply pointless. Conservation of heated and metered water does make sense.

NT

Reply to
Tabby

This is pelleted wood, which is a different kettle of fish from burning locally coppiced wood, but it has some interesting numbers for CO2 output (ie actually applies what appears to be sensible methodology for CO2 calculation, not just vague handwaving). They run the numbers for quite a few scenarios (eg Swedish/Scottish wood, sea/road haulage, locations of depots, etc):

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Reply to
Theo Markettos

Don't know where you are, but there are vast differences in rainfall across the country. Cambridge/East Anglia being at the low end, about 25" IIRC. At one time I lived in Cumbria and got data from the water authority (we operated a rain guage for them). Between Carlisle and Seascale there was vast difference in rainfall, about 5:1.

The south eastern part of the UK is short of water, partly due to overpopulation, but also low rainfall. The north west has a surplus. Unless teh high costs of pumping can be vastly reduced then regional differences do matter.

Reply to
<me9

think UK average is 60",East Anglia generally 30" or less.

yes.

Reply to
The Natural Philosopher

I would not really consider replacing a boiler until it fails beyond repair. I can't imagine you would ever recoup the cost of a new energy effecient boiler in its lifetime.

IME all solar power in this country is disappointing. It's just not sunny enough.

Reply to
Mark

Its more than enough rain. So much that its stayed unmetered for decades, so much that people dont even bother harvesting roof water, so much that almost noone bothers recycling grey water. Its only vague green ideology thats caused metering to come in, and the possibility of a price hike in the process.

NT

Reply to
Tabby

cavity

I shall have to have a look at that site.

Trouble is it mucks up the external appearrance, in our case 17th C rubble stone. We are just moving from the we must do somthing to plans & prices stage of gutting the house and lining with 50mm of celotex/kingspan. Along with moving staircases etc...

(heat

against a

Or one of the many online heat loss calculators. I found several when checking that a 1.5kW radiator would be enough to keep a sensible sized room warm. Watch what external temp some use, one I found used

8C! They are basic and don't give a great choice in wall types but you can at least get an idea of the saving between 9" solid brick and 9" solid brick with 50mm celotex/kingspan. It will be a lot...

Insulated lining to all external walls will give the biggest saving but is very disruptive to do. Have good loft insulation, there isn't a great deal of difference between 100mm fibre with 22mm chipboard over the top and 200 mm of fibre. I think "they recommend" 250mm of glass fibre these days but that last 50mm is really getting into the realms of diminishing returns.

Make sure the windows aren't drafty and consider double glazing.

I can't see much point in rainwater harvesting but then we aren't on a water meter...

Reply to
Dave Liquorice

You're installing an escalator?

Reply to
Huge

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