Hot water heating options for small business

[duncang]

Evening all,

I wanted your thoughts, specifically, on how best I might be able to provide hot water for my bakery. I am setting up in a bog standard industrial unit, which I will most likely not be occupying for more that 4 or 5 years and therefore don't want to invest the earth into it, but do want to be as eco-friendly as possible.

All I need is to provide hot water on demand for hand washing as you come in to the bakery kitchen. I will also need to provide hot water for washing up not more than twice a day.

Final bit of information, I will be using a clay, wood-fired oven to do some of the baking in, the smoke from which will be evacuated out via a flue through the roof.

I am basing this all on the assumption that only hot water heating is required, not central heating as the oven will be providing this, passively.

Options and my thoughts on them:
- Solar thermal, wood love to, but requiring a minimal budget of £1500 and also not sure whether the roof would be able to support the load. I also need to be able to reverse any work done upon my leaving the premises.

- Boiler. Again, good, energy efficient options out there, but demands quite a lot of installation, a decent budget, and no gas readily available on site meaning a hefty connection charge.

- Wood burning stove. I like this idea, if there is a simple wood-burning stove that can be linked to a tank without too much trouble. Any thoughts? I could join the flue for this to the one for the oven to keep things simple and tidy.

- Instantaneous hot water heaters. I like the idea of these as they heat "on demand" and because we will be using relatively little. Have a look at these for example:
http://www.dealec.co.uk/brochure/acatal ... aters.html
The cons are that they are probably hugely inefficient at actually heating the water.

- Heat pumps. I know little about these and from what I understand could cost a fair whack.

My preferences have to be with either the instantaneous hot water heater, which I could maybe use in conjunction with some form of heat recovery from the smoke going up the flue from the oven, or with the wood burning stove provided I can find a simple one.

I look forward to hearing your thoughts!
Best regards,
Duncan

[pumpy]

Hi Duncan, i would think that your best bet is an instantaneous one, but instead of electric, howabout gas from a propane bottle [as used in static caravans,etc]. Maybe more expensive to buy, but certainly cheaper to run.

[camillitech]

Morning Duncang,

How about something like this, http://www.navitron.org.uk/product_deta ... 1&catID=77 there are several different sizes available and you could take it with you when you leave.

Good Luck, Paul

[contadino]

A friend of mine tried wrapping some copper pipe around the flue to his stove to collect heat from the smoke. I'm not sure of the exact outcome, but he then extended it to also collect heat from inside the firebox so I can only assume he wasn't getting sufficient heat from the flue.

You'll likely get plenty of space heating from the front of the oven. I assume you do most of your baking with the door closed? If so, the chimney will only be warm when you're firing. If you're in any doubt, maybe consider building the kitchen around the oven to get heat from all 4 sides - ours is kind of built into the back wall of our kitchen and it chucks out plenty of heat when it's going.

You could run pipe around the outside of the adobe and take heat from there, but that will mean the oven will cool down too quickly, so I'd rule that idea out.

[duncang]

Thanks all!

Some very interesting stuff here already... love the navitron kit, but not sure I would have the place to position it so it is south faceing without requiring a lot of piping from where it would be to where the water would be needed.
Gas-fired water heaters? Interesting, although that would mean adding another hazard to my fire assessment, something I am just learning about...let's see what I can dig up on them.
Finally, heat recovery, interesting stuff and I love the DIY aspect as if for nothing less it's a lot of fun, but I agree with you contadino at best it won't be very efficient, at worst it could cool the oven down which is not good.

What more thoughts? I am also interested in links to suppliers/websites you have used in the past as recommendations are going to be much better than just googling around...

Thanks,
Duncan

[mamos]

A back boiler in one of you ovens would be cool, I mean hot, oh, you know what I mean

mamos

[duncang]

Mamos - it would, although don't know how much heat it would draw out from the oven... may cool the oven too much to be able to cook in it....

hmmm, interesting stuff

[contadino]

Isn't there something in one of the John Seymour books with an English style baking oven? Rectangular box, firebox at the bottom with heat exchanger for water, and the separate oven above for cooking in?

I suspect, though, that you'll be producing more hot water than you'll know how to deal with...?

I can have a look later this evening if you'd like.

[duncang]

Contadino,
If you could that would be good...

Thanks!!

[contadino]

Yes, the bottom of page 287 of John Seymour's Self-Sufficiency book has a design for what he calls an all purpose furnace, that includes an oven and a back boiler. I don't have a scanner, but if you email me and I'll try to take a photo of it...