Looking for some guidance on systems to use in an old property.

[Como]

To keep it simple we are in the process of buying a house that we know is going to need new systems.

5400 sqft
Triple brick, but badly insulated.
Forced air and water from Propane at $1,000 a month. No Natural Gas available.
Plentiful wood available locally at less that $100 a cord. Free if you clear it yourself - pine beetle.

Our plan:

Definite

Insulate, refurbish windows (Historic Building)
Wind power tied to grid.
All the usual options to minimise electricity consumption
PV not currently cost effective, wait for the next generation.
Solar Hot Water is cost effective, probably tubes as we will be high (9,500ft) and it can get very cold.

So we are thinking of:
Stainless Steel Wood Gassificaton Boiler, c 250,000btu, in a new building which would be big enough for all our systems and be insulated to the hilt.
Large water tank to provide storage fed by Boiler and Solar.
Water to be used for radiant heating and domestic hot water, initially it would be linked into to the forced air system as it will be a year or so before we can fit radiant baseboards. I have not seen a good US supplier, this is what I had in mind: http://www.discreteheat.co.uk/

So does the above make sense? We need a back up source, so I was thinking of keeping the Propane, would a separate Boiler be best, a few I have found allow dual fuels but then you may be limiting your choice. I was thinking with a big enough water tank, if you kept it fired up then you would be good for a weekend away, longer than that and you have the Propane making sure things do not freeze. There is also a wood stove in the main room, but I doubt if it is very efficient and certainly not placed to heat the whole house.

 

[begreen]

Moved to the boiler room. Is this a commercial facility?

 

[wallis54806]

It sounds like quite a project. I can't tell you anything about wood boilers. You say you are keeping the old windows, because it is an historic restoration. That being the case, if the house has cast iron radiators currently used with the hot water heating system I would keep them.

 

[Como]

Well the idea is it it will be a B&B;, so half and half. We want to make sure everthing makes sense from both a domestic and business erspective, a lot easier to sell a house as opposed to a dedicated B&B;.

I think from this issue of it will just count as a large house.

Original system seems to be stoves in each room, 12 chimneys as far as I can make out, no radiators and no evidence they ever had them. Stoves probably buned coal.

 

[Eric Johnson]

You might need an ASME-certified boiler for a commercial building, which a B&B;might be. I know that Tarms are ASME certified, and possibly Econoburn (bottom banner). The other Euro gasifiers comply with strict European standards, but they aren't recognized on this side of the pond, so that might be something to check out. I'm not sure about putting a Garn in a commercial building. That's another thing to check out, though if you put any gasifier in an unattached building, it might be a moot point.

Free wood is good wood. Since you would be burning pine, I recommend oversizing the boiler (less loading) and then put in a couple thousand gallons of hot water storage.

Personally, I think a wood gasifier will take care of all your heating and hot water needs. I would put the solar money into a big hot water storage tank. Other than making you feel better, I don't see the need for solar in your situation.

 

[Como]

I do not know the full load, I worked out that in winter they are burning half a gallon of propane per hour on average. I has been pretty cold. But it can get colder. Also they are probably not keping it as warm as we will need to.

The big imponderable is what the load will be after we have insulated etc, my guesstimate.

So 2,000 gallons or so of water storage, and the next size up Boiler, maybe 300,000btu's or thereabouts?

The idea behind the Solar HW is that it would give us hot water during the summer when we would not be running the furnace too much. And a 'free' top up in winter. Colorado gets a lot of sun. I saw an article were somebody had built a solar collector into the side of an outhouse, so I was thinking the extra cost might be more manageable.

 

[Eric Johnson]

If you have a big tank like that and a clean-burning boiler like a gasifier, then you can fire it up once a week and put enough heat in the tank to provide probably a week's worth of domestic hot water. I'm not knocking solar, just that it's a big expense and engineering challenge that really isn't necessary with the right wooburning setup.

More is usually better with hot water storage. Boiler sizing is less important with storage, IMO, because the buffer provided by all that hot water smooths over the problems you might have with a boiler that's either too small or too big. Generally you're ahead to undersize with a wood gasifier, because they work best when fired hard for sustained periods. But I'm thinking that if you have a big heat load and your ruel is bug-killed pine, you would want a bigger firebox, which typically means a bigger boiler. Mine is 205,000 btu/hour and it puts out an amazing amount of heat.

That's just my thought. Hopefully somebody else will share theirs as well.

 

[Como]

Thanks, that makes perfect sense.

 

[leaddog]

If you are talking stainless then you are proubly talking about a wood gun. They have a separate burn chamber in them for gas or oil guns. They can also be asme stamped but pricey. They seem to be a very well build boiler. Go with storage, the more the better as it will give you more options. An insulated 8x8x8 tank in the ground is about 2500 usable gals.
leaddog

 

[Nofossil]

I'll defend the solar concept for summer DHW. It's what I'm doing, and it's worked well for me. If you go that route, I'd consider breaking your heat storage up into multiple tanks so that you can heat a much smaller storage tank to higher temps with solar in the summer. 100 gallons at 135 degrees is useful. 2000 gallons at 100 degrees is not.

When you look at solar, don't look at efficiency in terms of BTU/square foot, look at BTU/dollar. A larger and less efficient panel may deliver a LOT more usable heat per dollar than the high-tech uttra-efficient panels.

I've got a writeup on my site - link in my signature below.

 

[Bob Rohr]

I'll second the SDHW. It shouldn't take too much of a system to supply most of your DHW through the summer months. Too much solar square footage can lead to the need for dump zones in the summer. Typical flat panels can and do work fine in snow country for DHWh

My mantra will always be to do some load calcs both for heating and DHW. There are plenty of top notch solar contractors in Coloado. consider hiring one to at least do the calcs for you.

These calcs are for a 50 solar panel job in Eagle, Colorado. A DHW system to provide 200 gallons of 130F DHW, spacing heating for 10,000 square feet of home with a 212,000 BTU/hr load at -12F.

Various graphs show Solar Fraction and Life cycle Savings, Monthly Solar fraction across the year, Solar energy available at the panel and Space Heating and DHW loads. Collector Slope and Solar fraction. % increase in natural gas against solar fraction and Life Cycle savings, and building heat loss against solar fraction and life cycle savings.

Good to have data like this before you tie a bundle of cash into a system.

hr

 

[Como]

That looks very interesting, Eagle is a few thousand feet lower, but near the same latitude of the property at issue and not that far away. Breckenridge would be the nearest town people are likely to know.

I take it that was for a new build suitably orientated, that's a lot of square footage, our main building is at right angles to due south, has a clear aspect, but still a 34ft width.

Just wondering what they use for back up?

Any recommendations for local contractors?, PM if not appropriate to post.