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Heating with radiators vs in slab heat.

Freezing, well, you could run your circulating pumps full time when your boiler is off. Better protection would be glycol, but expensive. My neighbor ran out of wood this year, so it does happen, he did say, because of the total mass of heating medium, the boiler and the system held heat for several days after he ran out of wood. The outdoor boiler is a secondary heat source for him, so, really no inconvenience, however, the cost of wood fuel is beginning to set in.
Weil Mclain HE boilers, one of my favorites!!!!
 
I believe radiant heating from floor is best option for a new building. But to an existing structure? It's expensive. (For obvious installation issues.) Also consider your energy source? If you have natural gas. And in existing structure? Gas radiant overhead unit. Most efficient. And I believe safest choice.
 
I'm a huge fan of radiant in floor heat but like mentioned earlier it is a constant heat. Your boiler will be running all the time. If you do turn your thermostat down, you will probably need to turn it back up 4-6 hours or so to heat up the slab. I guess it all depends on how you use your garage. If you just spend time out there on the weekends, you could turn it back up on Friday and back down on Sunday. Radiators work well as you know. I like cast iron over baseboard/fin tube. The cast iron radiators provide heat longer at a lower temp (120°) where as fin tube needs to run at a minimum of 160° to be efficient and as soon as the zone pump shuts off, the heat does too. My 100 year old house has both types on 4 separate zones. We have a Weil Mclain energy efficient boiler that works well. It is surprisingly small and only heats a gallon and a half of water at a time. Out old cast iron boiler was probably 100+ gallons and not efficient at all. Your garage could be heated with a small water heater I bet.
I played around with the thermostat this winter, what I found was just set it where you want it and leave it. Leaving it set on 68 degrees means everything in the garage is up to temp vs everytime you turn it up it's on and off constantly until everything in the garage is up to temp.

Now I'm adding an addition that will mostly be for parking cars but serve as a body shop once in a great while. The main garage is 32×34 heated 24/7, this one will only need to be heated when I have a project going on.
 
Same idea here, have a Devilbiss paint booth in my shop, and do not have make up air. Actually, let my neighbor paint his son's pickup truck last Saturday. So in order to paint I have to raise my 12 x 12 a couple of inches to make up for the air, the booth is kicking out. I fan force oil heat my shop. Knowing we had to paint, I set the shop up for 24 hr 70 degrees pre warm before we started. Then once painting began, oil furnace runs right thru till we are done.
So, even if you heated the floor, you will still need some fan forced heating equipment, if you want to paint.
http://www.galletti.com/en/hydronic_indoor_units_446/fan-heaters

Something like above, is basic and simple, might even be able to find used.
 
Same idea here, have a Devilbiss paint booth in my shop, and do not have make up air. Actually, let my neighbor paint his son's pickup truck last Saturday. So in order to paint I have to raise my 12 x 12 a couple of inches to make up for the air, the booth is kicking out. I fan force oil heat my shop. Knowing we had to paint, I set the shop up for 24 hr 70 degrees pre warm before we started. Then once painting began, oil furnace runs right thru till we are done.
So, even if you heated the floor, you will still need some fan forced heating equipment, if you want to paint.
http://www.galletti.com/en/hydronic_indoor_units_446/fan-heaters

Something like above, is basic and simple, might even be able to find used.
There's a door that goes into the main shop from the addition so my thought was that I'd crank the heat up in the main garage then make a door plug with filters in it so I'd be pulling filtered warm air from the main shop. In my last paint booth it took very little air movement to move the fumes with the intake and exhaust on opposing walls so I'm hoping this will work out well?
 
You could add a water to water heat exchange so you only need polypropylene glycol in the one spot
only down side is plate heat exchangers are not cheap
 
You could add a water to water heat exchange so you only need polypropylene glycol in the one spot
only down side is plate heat exchangers are not cheap
Your reading my mind, was thinking about that yesterday haha.
 
In the far north fresh water lines run above ground so them don't freeze. Sure they have a layer of insulation but the only freeze protection is constant flow. Also warm and hot water will freeze faster than cold water. Could just placing an additional layer of tube under frost line were the temperature remains constant and a pump be the solution? Heating from 58 degrees would take less energy and time than heating from ten or 15 degrees. This would only require a valve off a zoned manifold right?
 
I vote for radiant...again! If you remember myself and another member tried to get you to put the tubing in the main garage just in case. Now that you have heating water available, radiant is a no brainer. Are you storing things you don't want to rust? If so, heating it at a minimum amount will keep things dry. Your car will thank you for it. And as far as radiant being slow, a 4" slab will start responding in about 6 or so hours, maybe less. You're never going to paint in an emergency, so turning up the bay the day before will not be a problem. The tubing is pretty cheap, and you don't have to hook it up right away. But you will. LOL

Also if won't freeze that quickly if you are already heating it because the slab will hold some heat for days. That will give you plenty of time to deal with running out of wood, break downs, or power outages.
 
Go with the in floor radiant. You will not regret it. I leave mine at 45 degrees all winter. It does keep the humidity off the tools and cars. Once it is warmed and stabilized it does not use much fuel (natural gas in my case). If I am going to be working in the shop I bump it up to 50 or 52. Only takes a couple of hours to get there. Mine is supplied from the house boiler and the complete system is filled with propylene-glycol (RV antifreeze). That is a one time expense. It is very efficient. I heat the 2800 sq. ft. house plus the 1250 sq. ft. shop from one 130000 btu wall mount boiler. This is in the Canadian climate as well.
 
I vote for radiant...again! If you remember myself and another member tried to get you to put the tubing in the main garage just in case. Now that you have heating water available, radiant is a no brainer. Are you storing things you don't want to rust? If so, heating it at a minimum amount will keep things dry. Your car will thank you for it. And as far as radiant being slow, a 4" slab will start responding in about 6 or so hours, maybe less. You're never going to paint in an emergency, so turning up the bay the day before will not be a problem. The tubing is pretty cheap, and you don't have to hook it up right away. But you will. LOL

Also if won't freeze that quickly if you are already heating it because the slab will hold some heat for days. That will give you plenty of time to deal with running out of wood, break downs, or power outages.
Lol, I don't regret not putting in it the main garage seeing how what I have keeps the garage nice and toasty, keeps the floors at a minimum of 62 degree in negative zero temps, costed very little and also allows for propane backup and central air to be added.

In the addition it makes a lot more sense, no fans, filters or motors for dust to get in and no moving air to kick up dust in the paint. Now to start researching how to properly route and zone it.
 
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Go with the in floor radiant. You will not regret it. I leave mine at 45 degrees all winter. It does keep the humidity off the tools and cars. O



Are you saying that if you get one of those warm days in the winter & you throw open the garage door, the floor won't sweat?
 
Are you saying that if you get one of those warm days in the winter & you throw open the garage door, the floor won't sweat?

As long as the floor is the same temperature or warmer than the damp air, it will not sweat. The floor also needs to be installed properly with insulation and vapour barrier underneath, which is actually building code in some areas.
 
Devon if you decide what you want to do let me know...I can draw up the in-floor schematic for the tubing...I used the 6" wire mesh in my concrete pour and tied everything for the floor onto it.
Nice thing is if you make an actual accurate diagram of what your going to install and then install it that way you always know pretty much where they are in the floor in case you ever wanted to attach something else to the concrete...
Here's what I used...my runs were 300' long each...with a total of 4 runs...I concentrated the perimeters closer together as that is where the main heat loss takes place and then spread them apart further in the center of the slab...
Depending on the size you may be able to get away with 2 300' runs which would mean you only need a manifold for 2 connections...
My slab was 28x40 but the inside dimensions were more like 26x38 due to the 12" block walls...

Along with insulation under the slab you will also want to insulate the side of the block or footer to prevent heat loss through the end of the slabs...

No progress on mine in a while...I'd like to get everything for the heat finished up before this winter...

Let me know as it does take a while to draw everything out and then move it around to get equal lengths....

I have no formal design experience for this as I just copied a floor plan that was used on a commercial project I was working on...then tweaked that around to make it work for what I needed...

Pex_layout.png 6  9-22-16.jpg 8-24-16 (4).jpg 8-27-16.jpg 022.jpg
 
Devon if you decide what you want to do let me know...I can draw up the in-floor schematic for the tubing...I used the 6" wire mesh in my concrete pour and tied everything for the floor onto it.
Nice thing is if you make an actual accurate diagram of what your going to install and then install it that way you always know pretty much where they are in the floor in case you ever wanted to attach something else to the concrete...
Here's what I used...my runs were 300' long each...with a total of 4 runs...I concentrated the perimeters closer together as that is where the main heat loss takes place and then spread them apart further in the center of the slab...
Depending on the size you may be able to get away with 2 300' runs which would mean you only need a manifold for 2 connections...
My slab was 28x40 but the inside dimensions were more like 26x38 due to the 12" block walls...

Along with insulation under the slab you will also want to insulate the side of the block or footer to prevent heat loss through the end of the slabs...

No progress on mine in a while...I'd like to get everything for the heat finished up before this winter...

Let me know as it does take a while to draw everything out and then move it around to get equal lengths....

I have no formal design experience for this as I just copied a floor plan that was used on a commercial project I was working on...then tweaked that around to make it work for what I needed...

View attachment 751132 View attachment 751133 View attachment 751134 View attachment 751135 View attachment 751137
I appreciate the help, I started another thread to gather thoughts and posted my preliminary plans lol. As for my layout it's extremely simple, a 24x24 with a 16' garage door centered on one wall. I saw some routing plans that I'll post once I have a better connection but it's basically a spiral layout. One run will run around the complete perimeter spiralling back to the center where in returns then the next just inside of in then another?
 
I drew up a quick schematic but after thinking about it I know it is wrong...You are attached to the existing shop on one wall...that would mean you could lessen the frequency of the runs in the floor in that area being as the loss is much less...I was told not to get runs greater than 300' using the 3/4" pex piping... After drawing it out I'm pushing 300' on two runs and end up with an 8x8 or so in the center with ho heating...
I was trying to do even runs with an even number of manifold connections...Just trying to avoid needing to buy a 4 connection manifold when you may only need 3...preferably only 2
I'll move it around a little and see what 600' of piping looks like with less heat along the existing shop wall...

If the foundation is a 6" block the interior dimensions change to 23x23 which also will change the length of the runs...

If you get a chance sketch me out something primitive but accurate and we'll see how it works out...
 
I drew up a quick schematic but after thinking about it I know it is wrong...You are attached to the existing shop on one wall...that would mean you could lessen the frequency of the runs in the floor in that area being as the loss is much less...I was told not to get runs greater than 300' using the 3/4" pex piping... After drawing it out I'm pushing 300' on two runs and end up with an 8x8 or so in the center with ho heating...
I was trying to do even runs with an even number of manifold connections...Just trying to avoid needing to buy a 4 connection manifold when you may only need 3...preferably only 2
I'll move it around a little and see what 600' of piping looks like with less heat along the existing shop wall...

If the foundation is a 6" block the interior dimensions change to 23x23 which also will change the length of the runs...

If you get a chance sketch me out something primitive but accurate and we'll see how it works out...
Will do but yes 23'×23' inside, its's pole style.
20171112_163934.jpg
 
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