Outdoor Wood Furnace Info

All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: coolidge on May 16, 2016, 06:28:35 PM

Title: Radiant or Hot Air
Post by: coolidge on May 16, 2016, 06:28:35 PM
I have radiant in my slab in the garage, I also have a 50,000 btu modine type hot air blower that I don't use but is stubbed up. Would it be beneficial to hook the air handler up for a faster recovery or just run the lower temp radiant?
Title: Re: Radiant or Hot Air
Post by: schoppy on May 16, 2016, 11:37:55 PM
I have a hanging forced air in a 24x40 garage I used for years before I put up my 50x60 shed. I put in-floor in the shed and keep it at 50 degrees. You can't beat the in-floor heat for even heat which doesn't have the big temp swings of forced air. Also you have the damp moist floor surfaces with forced air unless you leave the heat on all the time. The key to very efficient in-floor is to have insulated it very well during construction, underneath and perimeters. My choice would be in-floor anytime. Good luck.
Title: Re: Radiant or Hot Air
Post by: slimjim on May 17, 2016, 03:45:35 AM
I would use them both, that new Chevy probably won't want to start when it's cold out, you should have bought a bus!
Title: Re: Radiant or Hot Air
Post by: coolidge on May 17, 2016, 05:12:32 PM
I might need that new truck to pull you up the hill in June.

I think I will hook up the modine when work slows down.
Title: Re: Radiant or Hot Air
Post by: slimjim on May 17, 2016, 05:24:11 PM
Ahhh the old cornfield caddy will get her in there, are you going to be ready in June?
Title: Re: Radiant or Hot Air
Post by: coolidge on May 17, 2016, 06:42:25 PM
Yes, shut down last week, will drain and get things disconnected, maybe I can get it moved of pad.
Title: Re: Radiant or Hot Air
Post by: slimjim on May 18, 2016, 03:42:16 AM
Any idea what you will be doing with the old one? I might have an experiment for you.
Title: Re: Radiant or Hot Air
Post by: mlappin on May 18, 2016, 07:29:34 AM
I’d like to have radiant in our shop someday, father would really like to have it as the air handlers mess with his ears, he has tinnitus.

I’d like to have it but the current shop is both too small and too low to get either combine in, also too short to do anything but park the hopper bottom in.

I’d prefer to actually build a new shop thats actually large enough to handle everything we want to do instead spending all the time unloading all the shelves, moving those out, tearing all the old concrete out, digging down (most likely by hand) to properly install the perimeter insulation, etc. Father just wants to cut a few slabs out and place the tubing in those and skip the insulation around the perimeter. Just won’t believe me when I tell em if your not gonna do a radiant slab right it both not worth doing at all and may take more to heat than it does now.

With our current shop radiant would be nice, but air handlers actually work better as it may be weeks at a time were all we do is walk int the shop to grab a wrench or something else, if were not using it I keep it at 45, if I have a few big projects coming up then I keep it at 65 during the day and 50 at night, maybe even 70 if we are painting. Not viable to change temps all the time with radiant, if I was going to keep it the same temp all the time, much more insulation would be required.
Title: Re: Radiant or Hot Air
Post by: GUSWHIT on May 18, 2016, 02:38:56 PM
In my previous life, we had both the radiant and an overhead airhandler/modine type.  We only ran the overhead one when we would open the big garage doors open to get things in and out.  We could kick them on to take the chill out of the "air" quickly rather than waiting for the slab to eventually warm the room.  I'm sure you guys can imagine what the room air does when you open a 20' wide 16' tall door to get a piece of equipment in or out. 
Title: Re: Radiant or Hot Air
Post by: agriffinjd on May 18, 2016, 04:47:41 PM
I don't like the fact that with radiant in-floor heat, you waste btus by mixing cold water into the hot water to reduce the temp before it's pumped into the floor tubes.  So even if it's a nice even heat, I just couldn't live with the thought that I wasted btus like that. 
Title: Re: Radiant or Hot Air
Post by: slimjim on May 18, 2016, 04:51:41 PM
You are not mixing cold water, only mixing down the extreme heat from the hot side with tempered return water, no BTUs are wasted!
Title: Re: Radiant or Hot Air
Post by: coolidge on May 18, 2016, 04:54:04 PM
It definitely doesn't take long for the shop temp to drop when the door is open, I will hook up the air handler before winter.

Slim, what you got for an experiment?
Title: Re: Radiant or Hot Air
Post by: slimjim on May 18, 2016, 05:08:53 PM
Call me!
Title: Re: Radiant or Hot Air
Post by: mlappin on May 18, 2016, 08:32:03 PM
I don't like the fact that with radiant in-floor heat, you waste btus by mixing cold water into the hot water to reduce the temp before it's pumped into the floor tubes.  So even if it's a nice even heat, I just couldn't live with the thought that I wasted btus like that.

It’s not really wasted, if anything mixing it with cooler return water from the floor, you’re actually stretching the BTU’s out that you have.