Anybody here have a concrete block wall shop they heat?

We're in the process of building a garage here at the house. It'll have a small office space above it. The garage portion will be roughly 30 x 30 and the walls will be made of concrete filled CMU block. It'll have insulated garage doors on one side (one single and one double) and a few insulated french doors that open to the yard on the other. The ceiling will be spray foam insulated a well.

My main concern is heating the space in the winter. Do you guys have any similar garage spaces? If so, how do you heat it? Do you think I'll have any heating issues since it'll have a spray foamed ceiling?

My dads shop was the same dimensions. I worked out of his shop for 20+ years. His was only filled on the front wall and front corners (door side). 30x30x12' ceilings. Home-made metal doors non insulated. The attic was only partially floored for storage which made heating a bitch. After a few years we finally covered the un-floored portion with sheet foam insulation and it wasn't that bad after that. Winter in Alabama is so short we never got too carried away on sealing and insulating. We were more concerned with making sure the belt and bearings were maintained on the wall fan.

We used a combination of kerosene jet heater for quick warm ups in the morning and propane infrared heater for steady heat after the initial chill was gone.

I'm not sure why you are filling the CMU with concrete, unless it is a building code thing, but here in the Northeast the most common way to insulate CMU walls is by filling them with Perlite. It is small balls and you pour it in as they are building the walls to get maximum density in the wall. It works very well here. I'm not sure of the "R" factor but has to be better than solid concrete. Hope this helps.

In floor heat here. I have a 60 gallon electric hot water tank that heats the floor. 3 zones, no noise, no sparks and a nice warm shop from October/Nov to May 1. 24x30 garage, My walls are 2x6, the slab is engineered and insulated on the outside and underneath. It's fully insulated/dry-walled with R60 blown in the ceiling.

Worried about heating in winter???? You live in New Orleans!!!

Did I mention I hate snow and cold......

dfree383 wrote:Worried about heating in winter???? You live in New Orleans!!!

YES I AM!!!!!!

You've been to my other shop. I can't heat that place with enough propane to get the thermometer to move!!! All that hot weather the rest of the year has me spoiled...

I heat 40x40 steel building 10' wall open ceiling with propane. Days like today, 9* this morning and pretty stout north wind, it needs a little help from the ready heater! If we have normal temps,high 20's at night and 40 or so during the day, the little 30,000 btu wall heater does ok and don't cost a lot. Where you live you'll see benefits from that insulation in the hot months! AC!!!!!

I would definitely go with radiant floor heat in the slab. You'll have to keep an eye on the weather and start warming it before the cold hits, but it also works well in the summer to keep it cool.

I use a 175,000 btu propane heating in mine (40x65), and it has been in a tug of war with Mother Nature for the last few days. But mine is an insulated metal building with tall walls. It will keep it warm enough to knock the chill off, but not enough to shed the jacket.

I would check on the VAL6 Portable Radiant . We heat a 50x60 with 14' walls here in Wyo. with one , it was -19 deg with a 30mph winds this weekend and it would warm the building up enough to work with out a jacket .

jeffgfg wrote:I'm not sure why you are filling the CMU with concrete, unless it is a building code thing, but here in the Northeast the most common way to insulate CMU walls is by filling them with Perlite. It is small balls and you pour it in as they are building the walls to get maximum density in the wall. It works very well here. I'm not sure of the "R" factor but has to be better than solid concrete. Hope this helps.

I am going to go out on a limb and say it is for strength. We are in hurricane country here.

i heat a 100'x60' with my 165000 btu reddy heater burns about 5 gallons of deasil a day it was in the 20s last night and around 35* today took about 20 mins to get the chill off and after about 45 mins my jacket came off. Once the temp inside get up I set the thermostat on it will cut off and on. I will find out tomorrow how it will work with this small winter storm coming through got to set a new engine and trans in the 57 chevy I am working on restoring.

jasonf wrote:

jeffgfg wrote:I'm not sure why you are filling the CMU with concrete, unless it is a building code thing, but here in the Northeast the most common way to insulate CMU walls is by filling them with Perlite. It is small balls and you pour it in as they are building the walls to get maximum density in the wall. It works very well here. I'm not sure of the "R" factor but has to be better than solid concrete. Hope this helps.

I am going to go out on a limb and say it is for strength. We are in hurricane country here.

Yep, that's the only reason. Being 100' from the banks of Bayou Barataria means it may get flooded at some point. Although it's sitting on a mound of dirt that's about 11' above sea level.

The shop space I rent now is the middle 30' wide section of a 90' x 30' long building. It's 30' deep with a cinder block wall on one side. The rest is insulated metal, but the ceiling height is about 18'. The new garage will have natural gas plumbed into it.

Heating a tall shop is a PITA. I keep wondering if there isn't a way on a shop with tall walls to effectively get all the "wasted" heated air gathering up high to circulate back down to floor level. I had thought about using ceiling fans in a tall shop and reversing their direction during the winter, but.....

I know that ceiling fan makers say you should run them in the winter and reverse their direction (to supposedly circulate the house's warmer air at the ceiling back down to floor level). But to me while using the ceiling fans in the winter and reversing them might make the air temp in the house "feel" more even, I sill get a chill from the fans moving the air when I try it.    

.....That kinda makes me think that if this idea was applied on a bigger scale in a tall shop the "up-high" warmer air would in fact get circulated back down to some degree. But I'm guessing you would also probably still get a "chilled feeling" from the fans moving the air.

How tall are the walls? I put overhead infrared heating in my 30x28 in Canada. It is quite popular as it is more affordable then in floor heating.

Ceiling height will be 10' at the lowest point. The ceiling will actually be the spray foamed floor of the second story...

So what happens to an in-floor water heater circulating system (I'm guessing PEX tubing is used in the concrete floor?) in the summer time? Do you just flip the breaker off to the water heater & pump and let the water in the water heater/system just sit? Or does the water have to be drained every summer?

DILLIGASDAVE wrote:So what happens to an in-floor water heater circulating system (I'm guessing PEX tubing is used in the concrete floor?) in the summer time? Do you just flip the breaker off to the water heater & pump and let the water in the water heater/system just sit? Or does the water have to be drained every summer?

Curious as well. Aren't there geothermal systems that pump that water back underground to cool it off in the summer months?

Radiant floor heat would be my choice if money wasn't an object but it's just not in the budget...

jbozzelle wrote:

DILLIGASDAVE wrote:So what happens to an in-floor water heater circulating system (I'm guessing PEX tubing is used in the concrete floor?) in the summer time? Do you just flip the breaker off to the water heater & pump and let the water in the water heater/system just sit? Or does the water have to be drained every summer?

Curious as well.  Aren't there geothermal systems that pump that water back underground to cool it off in the summer months?

Radiant floor heat would be my choice if money wasn't an object but it's just not in the budget...

Yes, cool water in the summer keeps the slab temp down. Geothermal would be the first option. I know that cost is higher, but only at first. If you keep the shop till you can't work in it any more, it will pay for itself.

It cost me $1000 to have the pex put in before the slab was poured, $350 for the electric hot water tank on sale and $500 cash to the plumber who hooked it up. He brought a commercial circulation pump and all the fittings he needed. Zero maintenance for 12yrs now. I don't use it to cool my slab in the summer. I would put in a heat pump for that if I ever build a new shop. My garage is on a budget that costs me $103 per month for the year and most of that is heating it in the winter. I average 30-50Kw/h per day through the winter when the heat is on.

DILLIGASDAVE wrote:So what happens to an in-floor water heater circulating system (I'm guessing PEX tubing is used in the concrete floor?) in the summer time? Do you just flip the breaker off to the water heater & pump and let the water in the water heater/system just sit? Or does the water have to be drained every summer?

You typically run some type of antifreeze in case the power goes out or the boiler is not on.

Have you thought about a waste oil furnace? My shop is 40x50 and heat with it during the winter in Western NY it keep it heated to around 70 and I have 16 foot ceilings. Clean burn makes them