Wood heating pros and cons
 

http://ecorenovator.org/forum/attach...1&d=1390495575

I got an email from HomePower today and this was one of the links in it. I love the idea of growing my own heat in my back yard. Anyway, its worth a read:

Efficient Heating with Wood | Home Power Magazine

The main problem with pellets is the very fine ash dust inside the stove. Another problem is the plastic bags and water seepage. I have see a system with a 5 ton storage hopper that can be filled with a vacuum, but the furnace (which is for a radiant floor system) still has to be manually cleaned out.

My family heated with wood for several years when I was in high school. A small (1100sq ft) cape house took ~3.5 cords of mostly apple and maple. That required a good size shed and a lot of hauling. The land my parents owned was ~14 acres that was an old apple orchard; with approximately 150 Baldwin trees and all sorts of volunteer trees. There were 5 of us with strong backs, and we did it with a chainsaw and splitting maul and a large Gardenway cart, a homemade trailer for the family Volvo.

The chimney needed cleaning and I'm sure the soot was there, but not too bad. The chimney was a triple insulated metal 8" flue with an straight vertical run of ~18'-20'.

Wood heat is lovely, the sounds of the crackling fire just so nice. But not so the other heat it takes . . . hauling it in and cleaning it out.

For many years we heated with wood (Michigan) and we used efficient airtight stoves (Vermont Castings). But compared to our geothermal heat pump; it just does not compare.

I do have a backup pellet stove, in the fireplace, for emergency heat and the use of pellets is FAR better than chunks of wood.

But thinking about it, all that splitting of wood, decades ago, probably prevented me from killing someone. Splitting wood, when it is about zero, jacket off, is very rewarding as the frozen wood just cleaves apart. Great exercise, good for the mind.

Wood when burned, is still a huge contributor to CO2 and the EPA has recently announced yet another hike in woodstove mandated efficiency.

Steve
conflicted as I love burning wood, but also realize the problems

In the grand scheme of things, wood burning is as CO2 neutral as the natural decay of organic material in a forest.

-AC

Hydro to Heat Converter - Panoramic

I'd buy this bad boy if I could afford it. This is the only hydronic fireplace I've found available in the US. There are tons of European makes.

Hook it up to a buffer tank, with some geothermal/natural gas in tandem. Enjoy the fireplace and save heating costs at the same time.

Make one.

-AC

>.................

Last summer I installed a combined wood and solar heating system for a client of mine. He bought a second hand hugely overrated wood burner, a boiler rather than a glass fronted nice to have in the lounge burner. He soon discovered it was too powerful for his house.
I added a 1000L buffer storage tank and 4 solar panels to his system. the buffer tank also supplies domestic hot water.

The system works wonderfully. He lights is boiler for a few hours every 2 or 3 days or as needed and it supplies heating and hot water. He has his own supply of wood from olive and carob trees.
https://www.oeg.net/en/tank-in-tank-...ion-g516005400

A couple of important things to be aware of with any wood burner with a back boiler is that you must ensure it has a way to circulate the water to ensure that there is no way the water will boil and that the water tanks don't usually have a very high working pressure so are not really suited to closed systems.

Also they can consume a lot of wood! Sometimes the Kw rating of the burner is given based on burning coal not wood. The wood rating I have seen on some burners is 30% lower than the rating when burning coal.

Acuario

Do you know if there is any kind of specification that came with that storage tank that describes the rate of heat loss from the tank?

-AC

I'm sure the manufacturer has something but I've not seen it. The tank came with a 15cm thick foam jacket to wrap round it - when I first saw it I thought it was a mattress! There was also a thick foam cap.

The tank is installed in a small purpose built room which also reduces the overall heat loss although energy efficiency wasn't the top priority in this project as the fuel cost is almost nothing.

Acuario

A few years back I saw a photo blog of a home build where they installed what looked to be a huge polyethylene water tank, something like this. A guy climbed in the manhole and installed a big coil of copper tube, I think it was anchored with string.

The tank was placed in a small room not much bigger than the tank, just off the garage. After plumbing the connections, including a drain line out to the garage, they filled the entire room with blown cellulose.

I love the idea of growing my own heat in my back yard

Great when you are young and have kids at home, not so much when older<G> .

We heated over 5000 sq ft with wood for over 30 years. When DW hit 55 (closer to 2 decades ago than one!) she said she was tired of hauling wood when I was gone on business trips. This was after the kids were grown, we use to pay them 50 cents to start the fire when they got home from high school.

Anyway, GSHP and air-air now, but actually have a big fire today as it is supposed to get to the teens tonight.

Have never paid for wood, used to burn close to 10 cords per year. Water wall fireplace with circulating water.

Anyway, just keeping the fire going yesterday seemed like a chore, hard to recall we did it as a matter of course for so many years.

However, say 35 years, average of abut $1000 utility cost not spent, say about $60K-$70K not spent and grown made it worth it.

Thinking that way, having our own well and septic ($80 mo here for water and sewer) was another $50K saved/invested!!!

5000 sq ft... isn't that about the size of a bowling ally?

-AC