Solar water heating

On 13 Mar 2006 11:45:16 -0800 someone who may be snipped-for-privacy@care2.com wrote this:-

That rather depends what the aim of the design is. In my view reducing running costs and so reducing greenhouse gas emissions is at least as important as anything else. That does not mean it is the only consideration.

Reply to
David Hansen
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By an Italian.

Reply to
Mary Fisher

Computer program.

Reply to
Steve O'Hara-Smith

OK. Since I caused the confusion, let me explain why I thought that the cost (or savings; sorry for the misunderstanding) was extremely low :

Here is a 'saving' calculator for DHW :

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have a 1-family home, using a 50 gallon tank with about 65% overall efficiency, using about 60 gallons HW per day. Gas-powered. Northern California natural gas price (retail) is around $1.50 / therm. So, I see DHW cost of about $350/year. That seems right extrapolating my summer gas bills (when I use gas only for HW).

Now, expected savings using solar DHW should be beteen 50% and 80% of DHW usage (seen this at various web-sites). So I should save between $175 to $280/year. And note that I an on the low-end of the consumption scale, using nat gas for DHW in a small household, using front-loader European washer, and water-saving shower heads and such. Most people use a lot more than me, and many use electric DHW heaters, which essentially double the cost.

So, once again : how did you get to savings of just £20 / year ?

Rob

Reply to
Rob Dekker

Considering 50' of 1/2" nominal piping contains less than a gallon of water, and US machines use many gallons, the cold, stagnant water has little overall affect on the filled temperature.

daestrom

Reply to
daestrom

I certainly would. For example, a two story house with basement. The hot water heater is in the basement (NG). Should we 1) carry laundry up/down two flights of stairs everyday to reach the washing machine from the main bath and bedrooms, or 2) install the laundry upstairs in a hall closet area between bedrooms and bath.

In (1), we have less than ten feet of piping from heater to machine, but constant 'stockpiling' of laundry waiting to be carried up/down. In (2) we have ~30' of pipe and much more convenience. And since the machine is only rarely set to use 'hot' versus 'warm' or 'cold', the savings of 20' of piping is quite miniscule compared to the labor of hauling laundry up/down two flights of stairs.

Some may consider putting the machine in the basement 'sensible', but they

*obviously* aren't the ones that do laundry in their home ;-)

daestrom

Reply to
daestrom

On Mon, 13 Mar 2006 22:18:00 GMT someone who may be "daestrom" wrote this:-

Why?

Reply to
David Hansen

That is where the furnace is.

Reply to
Cosmopolite

You would have to live in a 500 sq ft house to have less than 50' of copper plumbing.

Point made though.

little

Reply to
Solar Flare

Not in the Americas

machine.

Reply to
Solar Flare

On Tue, 14 Mar 2006 00:04:18 GMT someone who may be Cosmopolite wrote this:-

Does it have to be there?

Reply to
David Hansen

Some people have secondary circulation pumps and dead legs that are not 100 foot long. In fact a secondary circulation pump can pay for itself in water saved and less electricity used in hot and cold fill domestic appliances. And voila, always instant hot water at the taps. No price can be put on that.

Reply to
Doctor Drivel

European machines are far more energy and water efficient. They don't have a large bath of water in them. Water content in the most highly efficient is very low these days.

Reply to
Doctor Drivel

The UK has the smallest, pokiest most expensive houses in the developed world. Space upstairs to fit a "laundry room"? We only dream of such things. A basement? That's Hollywood man! If we had basements we would have them done out in pink.

Reply to
Doctor Drivel

Away from the living areas. It makes sense. Make the basement a utility area.

Reply to
Doctor Drivel

The message from "Doctor Drivel" contains these words:

URAnAlienAICM£5

Reply to
Guy King

On 13 Mar 2006 11:40:44 -0800 someone who may be snipped-for-privacy@care2.com wrote this:-

See this or another thread running at the moment.

Reply to
David Hansen

And yet my home is 2000 sq.ft., and there's about 15' of pipe between the washer and the water heater. You must have been thinking of 500 sq.ft. homes in your own neighborhood, eg 10 X 50', with the washer near the rear bumper and the hot water tank near the hitch.

Wayne

Reply to
wmbjk

Well, that's a gross exaggeration, as we have energy efficient machines here in the USA (modeled after the European ones, no doubt) that are very close in efficiency. I have a Sears front loader washer that takes

1/3rd the electric and water of my previous unit.
Reply to
Steve Spence

On "average" they are far more efficient here. But best of breed on both side may be ~equiv. The likes of AEG make the most efficient.

Reply to
Doctor Drivel

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