Comments on: Fireplace Building Science – Pros and Cons

By: Tim Campbell

Tim Campbell — Tue, 21 May 2024 21:13:09 +0000

In reply to Galen Wa. Yes, but the point is that in the process of rotting, trees release as much CO2 as if they were burned. So why not burn them?

By: Eric

Eric — Fri, 02 Feb 2024 04:07:23 +0000

Dr. Bailes- Sorry your heat pump didn’t keep up. I am guessing it’s because your design temp and hence a likely non cold climate heat pump was specc’d. in Colorado, the Cold Climate is a must. our non cold climate dual fuel where we removed the gas line obviously lagged at -10. but we felt alive and baked a lot.

By: RobertJ

RobertJ — Tue, 30 Jan 2024 00:30:21 +0000

In reply to Sam Simonetta. A house I worked on n 2007 went for the works, masonry heater, PV solar thermal and well insulated. When I spoke to him a year later he said if he had to do it over again, he would put the money for the heater into more insulation.

By: Sam Simonetta

Sam Simonetta — Mon, 29 Jan 2024 22:13:35 +0000

The type of wood-burner I found to work exceptionally well in the tight home we built in the Upper Peninsula of MI was a masonry heater (Tulikivi brand). The unit was made of soapstone and assembled on-site. This “small”, demonstration model still weighed about 1800 lbs. The idea was to burn a fire hot and fast, then after combustion close the dampers and allow the heat to radiate into the room. The heat would last almost 24 hrs. Though I plumbed in outside combustion air, I found I didn’t need it. As Allison did, I’d open a window only for the minute or two needed to start the fire, then close it. All continued to burn very hot and fast. As I recall, rated efficiency was in the 70% +/- range. Great for the coldest U.P. days and when the power went out – especially with the cast iron cooktop.

By: Galen Wa

Galen Wa — Thu, 25 Jan 2024 13:47:25 +0000

Of additional note:

Fresh plant agrofuel is a horrible source of energy as it’s BTU density is low.

You address indoor micro particulate pollution but not outdoor. Wood fires release micro particulates that are harmful. See any wildfire air quality advisories.

There is no surplus fuel. We live in a closed system. The sooner humanity grasps the full, long-term consequences of combustion in a closed system, the better off for all.

By: Allison Bailes

Allison Bailes — Thu, 25 Jan 2024 13:19:16 +0000

In reply to Brian. Brian: Yes, firewood needs to be dry, and I've got that covered. I've got a small woodshed I built in 2019 that still has wood in it from 2019 and 2020. I've got another covered pile that's been drying for a year and a half now.

By: John

John — Thu, 25 Jan 2024 03:09:59 +0000

I bump up the outside air and reduce the exhaust air on the ERV when the wood insert gets used because you made me OCD about make up air.

By: Dave Daly

Dave Daly — Wed, 24 Jan 2024 20:01:35 +0000

If you have an outside ash dump in an old fireplace, just open the ash dump doors outside and on the firebox floor and use sealed glass doors – that will provide all the combustion air you need and control PM – just be sure to close the doors after the fire goes out.

By: Galen Wa

Galen Wa — Wed, 24 Jan 2024 16:27:28 +0000

In reply to Tim. Dead trees rot. We live in (on) a closed system. All biomatter is recycled.

By: Brian

Brian — Wed, 24 Jan 2024 15:32:50 +0000

In reply to Mac McCabe. It will help pull more heat into the room, rather than allowing it to go up the chimney. But for an open fireplace, you will still not get much heat out of it compared to the amount of wood you are burning. To word it differently, if you burned the same amount of wood in an insert or a free standing woodstove, you would get a lot more heat. If you assume an open fireplace is about 5-10% efficient, an insert is about 60-75% efficient, and a free standing wood stove might be 70-80% efficient. Rough estimates and obviously depends on the unit or how your fireplace was constructed. A blower will bring more heat into the room in any of those scenarios. Many people don't use one on a free standing woodstove because they already get more than enough heat without it. Most inserts will still need a blower to heat a large area.