Long time lurker, first time poster. I have an early passive solar house (John Barnard Ecology House) that is extremely massive (entirely concrete) and relatively large (1700 sqft).
As such, I wanted to utilize the existing mass as the heat storage component of the system. Currently, there is an older Kickapoo Home Furnace that is no fun to work with attached to a 40 year old, extremely power hungry, inefficient air handler. I want to build a batch rocket system to burn copse feedstock (1-3" dia round wood bundles) with a jacket connected to the ductwork.
Like most conventional forced air systems, the send is from the floor, and the return is through the ceiling. My idea would be to reverse this flow to take advantage of passive convection across the stove heat exchanger, and distribute the heated air into the existing return ductwork that runs through the mass with end point fans. Schematic of ductwork.
What are some builds that are designed for intense heating of air rather than mass? Would it be something like a batch core in a barrel? I have two 300gal oil tanks I could use as a bell. Is there also a design that is more tolerant of damp or green wood?
Allot of the heaters on here rely on the mass also as a way of insulating the burn for higher burn temps. It would be hard to do a batch to heat air because not a tone of heat would go into your homes mass quickly so you might get really high temperature swings between firings that could make it more uncomfortable. A mass heater could actually slow down the temp swings and add comfort.
There may be some newer DC driven blowers that are less power hungry then your garden variety induction motor. I'm not referring to the ECM (electronically commutated) blowers that are mostly for maintaining a consistent pressure drop. I think there are some higher voltage brushless DC blower motors that draw a fraction of the power. My HVAC buddy was telling me about them but I haven't researched yet. I have a water coil in my HVAC that I cool my house using cold well water that I could also use warm water to heat with. I haven't used it for heating yet, I would like to get my blower wattage lower.
Anther option to consider is to go with a warm water coil in your hvac and build/buy a modern high efficiency wood boiler. You could then do a 1 day batch firing to a large storage tank if you wanted.
I thought the core temperature was maintained through the insulating properties of the refractory material or superwool?
My idea was to essentially have a core/riser or shoebox in a barrel in an air duct with convection assisted by end point duct fans driving the heat transfer.
The air heated by the riser barrel would deliver heat to the mass in the ceiling and floor through which the integral ducting runs. A bell made from flue tiles coupled to the exterior wall that the chimney exits would act to warm it and the insulated earth behind it, scavenging residual heat as the exhaust enters the chimney.
Unfortunately, outdoor wood boilers are banned in Connecticut, USA.
Last Edit: Feb 15, 2021 21:22:54 GMT -8 by apehead
TexasGonzo: Sooooo glad I found this site! Its always rewarding to find such a super group of folks! To any and all, feel free to PM me anytime. Thanks for having me!
Mar 11, 2019 18:56:41 GMT -8
jlmtech: GADGET: CONSIDER USING A JET PUMP INSTEAD OF A BLOWER FAN TO INDUCE DRAFT; NO CLOGGING.
Mar 26, 2019 8:19:28 GMT -8
michaelegan: i am unable to open the sketchup files on my mac. I used sketchup a few years back but apparently the company now requires a subscription. does anyone have any advice/instructions on how to use the program or how to view pictures without spending money?
Aug 20, 2019 18:41:48 GMT -8
mannytheseacow: michaelegan: download AutoCAD student version for free... import .SKP
Aug 23, 2019 13:33:44 GMT -8
topbaza: hi everyone, been searching all over net and this is were i need to be i think!!
Sept 28, 2019 6:16:25 GMT -8
anounaki: Hi, why I cant upload photos when I make new tread to this forum?
Feb 28, 2020 2:09:40 GMT -8
ahansen: photos under 1 mb not possible?
Jun 4, 2020 0:09:21 GMT -8
belgiangulch: Photo's are possible. They must be downloaded elsewhere and the image url (adress) is copyied.
Sept 14, 2020 7:26:15 GMT -8
belgiangulch: While creating a thread click on the small picture in the banner above the reply. A box pops up, paste the image url in the box. Pay no attention to the huge list of numbers and such.When you finish and hit reply your post with pictures will come up.
Sept 14, 2020 7:29:27 GMT -8
deadstarsstillburn: Hi there. I was directed this way by folks on the Permies.com website and am hoping I can get some information on how a total newbie can get started designing, siting, building, and not-dying-in-a-horrible-house-fire with a new RMH in a 160-year old home
Oct 21, 2020 6:52:10 GMT -8
deadstarsstillburn: The people over there recommended either a 6" batchbox or an 8" J-tube. I don't know what those are but am going to try to figure that out. What I need is a blueprint that I can scale to fit the need for my house. I have something likne 5000 square feet
Oct 21, 2020 6:53:00 GMT -8
deadstarsstillburn: but I do not need to heat all of it by any means. probably only need to heat half of that, maybe less.
Oct 21, 2020 6:53:15 GMT -8
deadstarsstillburn: moreover, the house has 3 storeys (large attic) so I assume if I get very efficient heating on the ground floor, that will go a long way toward heating the upstairs as well, no?
Oct 21, 2020 6:53:59 GMT -8
BenAlexanderT: Happy new year everybody. I wish you the best
Dec 31, 2020 15:06:14 GMT -8
Solomon: Anybody in Southern Oregon, in Jackson or Josephine counties?
Jan 16, 2021 21:54:43 GMT -8
gnomedome: i realsie this is from 2009
Apr 14, 2021 8:30:44 GMT -8
gnomedome: i realize this is from 2009 id love to see the photos from this ..as im looking to build a sauna soon similar to this .... if anyody sees this post firstname.lastname@example.org..... the photos in this post did not show up
Apr 14, 2021 8:32:00 GMT -8