j sigs

Peter E Johnson wrote:

j sigs wrote:
Peter, thank you!  I'm not sure Im following you 100%.  What would you suggest for a thermal mass?

Also, if the boiler is outdoors, and only burned for a few hours a day, wouldn't I need MORE antifreeze on the outdoor side?

Again, thank you for your input!  I'm not an engineer so sometimes the concepts don't jump right out at me as obvious.  Regardless, I thank you!

There's no way I could buy a shell and tube heat exchanger, cant afford it.  If I could scavenge one from the junkyard, possibly, but even then I don't really know enough about them to know what I'm looking for.   I've seen some built out of old electric water heaters.  I could possibly pull that off.

The thermal mass would still be the 300 gallon tank.

It sounded to me like you wanted to pump water out of the 300 gallon tank to the rocket mass heater which would require a lot of antifreeze to stop it from freezing.

Doing this project on the cheap is a good way to get the BOOMsquish. The only place I've ever seen a used shell and tube heat exchanger for sale was at an auction at a shut down oil refinery. They're not very common outside of heavy industry.

Edit: The MSPaint picture came out really small.

initially i just wanted to wrap a copper coil around a heat riser or something and plumb it via pex al pex (because that's what I have on hand) and go right into the 300 gallon tank.  but it's the copper coils around the heat riser that sounds like everyone is saying is a bad idea for the BOOMsquish factor.  still thinking about the most effective heat exchanger...

how about this, i followed your lead with MSPaint lol, and I left a bunch of things out butttt...with some strategically placed valves and a pump with both inlet and outlet manifolds AND a lets say 10-ish gallon "glycol bypass tank" (just made that up lol) you could eliminate the need for 150 gallons of antifreeze and also ditch the tube and shell heat exchanger? just switch over to glycol mix when finished with my batch burn.  that way if overnight temps drop a 50/50 mix gets you protection down to -34 deg F which is well beyond my needs here in CT

what do you think?  

Peter E Johnson wrote:A shell and tube heat exchanger would probably be the best way to go. You wouldn't need a "high" pressure 300 gallon tank for your thermal mass, and since you're planning on putting the boiler outdoors it would require a lot less antifreeze on the outdoor side of the system. It would require two pumps, one for the higher pressure boiler side of the system, and one for the low/no pressure thermal mass side.

Peter, thank you!  I'm not sure Im following you 100%.  What would you suggest for a thermal mass?

Also, if the boiler is outdoors, and only burned for a few hours a day, wouldn't I need MORE antifreeze on the outdoor side?

Again, thank you for your input!  I'm not an engineer so sometimes the concepts don't jump right out at me as obvious.  Regardless, I thank you!

There's no way I could buy a shell and tube heat exchanger, cant afford it.  If I could scavenge one from the junkyard, possibly, but even then I don't really know enough about them to know what I'm looking for.   I've seen some built out of old electric water heaters.  I could possibly pull that off.

again, haven't had enough coffee yet, but.....

is it logical to think that if I had a water jacket from a boiler, I could mount it somewhere on/in either a RMH or a waste oil burner, in a way that would reduce the boomsquish factor?

The ultimate goal is to spend less money on oil in the winter.

Here's what I've been thinking about in case anyone is wondering where I'm going with all this

I have a pretty regular source of waste oil.

I was thinking of either 1. a waste oil fired RMH or 2. The blue flame style waste oil burners.

Burning manually outdoors about 15' from the house

Batch burning with manual firing of the boiler and monitoring the burn in person i.e. no automation.  I would burn for a few hours at night after work, say 6-9pm loosely monitoring temps, etc

collecting the heat via water and some type of heat exchanger on/in the burner

pumping the water via a Taco pump

building a 300gal tank indoors to hold hot water

heating at least one zone (master bed/bath, 2 smaller bedrooms) up to about 67 deg F 24/7 throughout the winter

Heating the zone via a separate Taco pump and baseboard hydronic heaters


Probably a lot of little details I haven't mentioned or forgotten because of lack of coffee!

Thanks in advance.



For reference, I'm in CT Zone 6a in a residential neighborhood.  House was built in '86.  Currently have a Burnham V8 Oil fired Boiler w a beckett burner.  I average about ~800 gal of oil usage per winter.

Hello all,

 Just getting my second cup of coffee here so maybe my brain isn't working right yet. Butttt....what's the feature/s of a residential oil fired boiler that makes it safe enough to run inside a home?  It's not a large amount of fluid per zone, there are zone valves that could fail, pumps that could fail, etc.  I assume there are safety features on these pumps and valves that shut the burner off if anything fails?

I know anyone looking to heat water with a RMH is warned (rightly so) of the "boomsquish."  It seems most are pointed towards the tank over the RMH design (Tim Barker or Geoff Lawton design)

Just wondering the difference between a boiler and any RMH water heater design that's been proposed?

John

Thanks in advance!

interesting.  what will you face the outside with?

Interesting.  What's the inside of your "doghouse" made of?  I'd like mine to be movable as well

Hi

TL;DR:  Looking for a material that won't off gas at high temps.  Temps you would find 2" from the top of a barrel stove.  I would be breathing the air, don't want to die or get sick!  

 I'm building an outdoor wood fired forced hot air furnace.  Picture a woodstove in a doghouse.  The woodstove heats the air in the doghouse.  There are 6" insulated inlet and outlet ducts that go to a basement window that will be fashioned with some type of flange.  There's a 6" duct fan inside the basement that pushes air from the basement through the duct into the bottom of the doghouse, moves up around the woodstove, and returns to the house via the 6" duct at the top of the dog house.

I'm building the doghouse out of metal studs and using rockwool insulation to keep the heat in.  It's basically a 3'x3'x3' cube.  The woodstove is a barrel stove.  It protrudes out the front of the doghouse just a tad to ensure there's no mixing of conditioned air and combustion gasses when I start/load the stove.

I planned on using some old duct stack as the inner facing of the metal stud walls.  Then I realized that the duct work was galvanized.  My research says galvanized over 400deg F will off gas zinc fumes.

I basically need 5 sheets of material that are 30"x38" for the sides and the roof.  I had one piece of sheet metal that I used for the floor already.  I have at least 4" of clearance from the stove to the inside of the doghouse around the bottom and sides.  I accidentally measure my uprights studs a bit short and only have about 2" of clearance at the roof.

I'm in Connecticut, zone 6a.


My question to you all is what material can I use to construct this doghouse?

I'm looking for something cheap and readily available that won't off gas at high temps.  Things I've thought of are:

-Aluminum flashing.  Is it coated?  Can I burn/wash off the coating?
-Durock?
-Durock covered with aluminum foil or flashing?
-Can I used the galvanized duct?  I've heard of soaking it in vinegar to remove the zinc but the pieces would be too big to soak; I don't have a container large enough.
-Just leave the rockwool bare?  no walls?  maybe filter the heated air coming back into the house for tiny rockwool fibers that might fly off?


Any input is much appreciated!  Feel free to ask any questions!

Thanks, John

Here's a screenshot I took of David's data.  I wish it was a bit clearer, sorry!  The vertical lines represent one day and I assume it's 12am to 12am.

But from what I can tell, after about 15-20 days (I'm okay with the lag) the peak temps are at noon or shortly after and peak at about 150-160 deg F.  They seem to bottom out around 110-130 (again, after 15-20ish days) somewhere in the early hours of the morning.  

Keep in mind, David's barrel is outside.  I can only imagine getting smoother curves at higher temps when the barrel is placed in my basement.  Even at 110, it's still just sitting there radiating heat, right?

I hear you when you guys are saying one barrel may not be enough. And yes, 3 panels in parallel is my plan.  

John, I rent this flat, so I'm not switching to gas.  I'd love to know what type of electric pump you use to push the hot water around in your HWS system.  I've been thinking about something like that for a while now.

I'm not sure I'm even going to bother with a thermostat.  I would like to place a fuse inline though.  No batteries, no controllers, simple, cheap.

And I know what you all are going to say, "try it and let us know!"  haha, that's what I love about this site!

Thanks All!

John C Daley wrote:Couple of questions;
- What is a basement apartment
- What is delta
-  What temperature do you actually want?
- If the thermostat is set at 55, why is the room 62?

John

It might be a slight language barrier here, I see you are from Australia. Do Australians call apartments "flats" like the British do?  A basement apartment is a flat in the lowest level of a single family home.  Built in the foundation of the home.  I hope that helps.

Delta is a fancy way of saying "change" or "difference",  commonly used in the sciences.  ex.  67-62=5; therefore the delta is 5.

I'd like the temp to be somewhere around 67 deg Faranheit

The room naturally stays a bit warmer due to it being embedded in the ground. The heat will come on if the temp drops below 55.  62 is bearable, but 67 is much more comfortable.  The goal is to be more comfortable.

Hope this helps!

Hi all,

 First off, may apologies. I didn't know where to post this.  Also, I always try to do some research before I post so I don't post redundantly but I couldn't find anything.

I live in a basement apartment in Connecticut (Zone 6).  It's about 8400 cuft (30*40*7) of open studio space.  We have oil heat here with baseboard hydronic and I'm trying to reduce the oil bill and mostly, be warmer.  The thermostat hangs out around 60-62 during the day.  It's set at 55.  So naturally, it's about 62 down here.  66-67 is super comfortable down here.  I'm only looking for a Delta of about 4-7 degrees.

If you are familiar with David Poz on Youtube he did a comparison of PV vs. Solar Thermal a few years ago.  He uses both technologies to heat their respective 55 gallon barrels with about 50 gals of water in them.  For the PV he wires direct to a DC 48v 1500 watt water heater element. WIth direct wiring the heating element only gets powered when the panels are generating enough voltage to power the element.  Both of the barrels are outside in February behind his solar array.  He insulates both barrels with some foil faced insulation, I didn't catch the R value, sorry.  After a few days he's getting temps in the 150-160 range with the PV system.  Keep in mind, these are outdoors, in February in Massachuesetts.

Here's a link to one of the videos in the series he does about PV vs. Solar Thermal: https://www.youtube.com/watch?v=KVeGummoXS0&t=2s

My thoughts are this.  I basically want to do the same thing but the barrel will be inside.  I'm not going to insulate the barrel.  I might put a fan lightly blowing some of the heat that radiates from the barrel off of it.  The water temp should get  higher seeing the barrel is indoors.  I realize the barrel temp dips when there's less sun.

But am I wrong to think that this will raise the temp of my apartment?  I'm just trying to think this through.

Thanks in advance!

John