An un-ventable garage?

[Denkikun]

Hi Guys, Im a newbie here to the forum, and really appreciate that the Garage Journal exists!

I REALLY need some advice. I've been spending way too much time trying to figure this one out on my own....

I have a garage heating conundrum... I have a 1950s house with a garage under what used to be a covered outside screened in room. The garage is 24X20 with only 7 foot ceilings. all walls and ceiling of the garage are poured concrete. Walls are roughly 10 inches thick, ceiling is a concrete pad about 6 inches thick. I would like to heat the space to achieve a baseline 55-60 degrees in the winter. Since replacing the garage door with a new insulated one and those rubberized gaskets around the sides, I am able to hold 55 degrees inside when the temp is 30 outside.

This winter is the year to finish the father and son car restoration on the Triumph, so I plan to be in there a good deal, and would want to have 65 degrees with potentially zero outside for 2 or 3 hours at a time while working and try to keep a baseline of 55 or so.

I am trying to stay close to $500 for the installation (doing all labor myself)

I have looked at various options:
Ventless Gas heater.......... I'm sensitive to the smell of these, currently have one in there (see pic) that stinks, big time
Vented Gas heater......... I can't for the life of me figure out how I could vent one. I believe that my ceiling is too low for something like the Big Max or Hot Dawg heaters.... also for the overhead infrared heaters... ceiling is 7 ft 1 inch. I believe that this leaves me with only a direct vent wall unit or vertically oriented "wall furnace" with a top vent. The only options that I can see for venting are boring a hole through the slab above, somehow enclosing a vertical run of B vent through the sun room above and out through the roof of the house, or blocking out one of my glass block windows leaving a big space in the middle for a direct vent wall unit, or boring a giant hole in the concrete wall between my two glass block windows (looks like those units want a giant 11x11 inch opening!!), or trying to sneak a vent out the rear of the house next to the garage door that runs over the interior door to the garage... I think that I could figure out how to do this if I could find a wall mount vented NG heater that has a top or top/side vent rather than a vent directly out the rear of it..... I am totally stumped. Here are some pics of my situation... I have the gas hook up right there, just cannot figure out how to vent....

current stinky setup..


interior view of rear facing garage wall next to garage door - very little space above wooden interior door there to get a good rise across the run of the vent pipe


exterior view of that back wall next to garage door... pointing at the spot where vent would be - there is a soffit quite a ways off above...



Glass block window wall exterior - no soffit above, vent would be at least 4 ft below windows


Interior side of glass block wall

Electric heater....... I do not currently have 240V to the garage, and would have to add a circuit and run about 65 feet of wire to add this.. I was looking at a 5000 Watt heater, but am not sure that it would actually do the job... also concerned about the high cost of heating with the electric heater...

Apologies for the crazy long post here, and thanks so very much for any advice you might have!!!!

 

[ez-duzit]

Use electric heater(s) or vent through the glass block opening. A pro could quickly bore a vent hole anywhere you choose.

 

[rjn2649]

I've done it in the past, but a bit of time consuming. just get a 12" or longer hammer bit, and drill out the around the area you want, go from the outside in, then drill a bunch of holes in the area you want to knock out. Then chisel out the area.
I would get one of the least expensive SDS drills from harbor freight....YEAH I KNOW, but it's a limited use tool and will probably last for a job or two. I would strongly advise against the harbor freight bits, go with a quality bit and chisel. Go slow.
OR if you don't feel comfortable with that bit the bullet and pay someone...

Edit to add: going through the floor will be a *****, rebar and wire mesh will kill you, also I've come across conduit. Also since you already have a vent less heater, maybe you could just use a smaller (4" or so) vented exhaust fan and turn it on once a while to get rid of the smell?

 

[Denkikun]

Thanks for the quick input! I was looking at the glass block windows thinking that it would be great to remove a few blocks and run a vent there, I installed those units a few years back myself, so would be totally comfortable going at those things. but I searched extensively online and couldn't find anyone venting out of glass block - plenty of dryers venting out of it but couldn't find anyone doing a heater. I'm in the city here, and have tried my best to understand local codes.. talking-to a guy in the neighborhood who is an inspector, he said to just follow the install directions on the heater. Only thing that I saw in various PDFs was that I need to be at least 4 feet from a window... wasn't sure if that meant I could be below one at 4 feet .... only other issue with venting out glass block is that I don't know what sort of heater besides a direct vent I could use to do that..... if a direct vent with vent sticking out the back I'd have to cover up the entire window... might make more sense to just block the window up (which I'd rather not do). I'm unaware of a heater that I could install with a 7 ft ceiling that could vent horizontally ....

 

[Denkikun]

I've done it in the past, but a bit of time consuming. just get a 12" or longer hammer bit, and drill out the around the area you want, go from the outside in, then drill a bunch of holes in the area you want to knock out. Then chisel out the area.
I would get one of the least expensive SDS drills from harbor freight....YEAH I KNOW, but it's a limited use tool and will probably last for a job or two. I would strongly advise against the harbor freight bits, go with a quality bit and chisel. Go slow.
OR if you don't feel comfortable with that bit the bullet and pay someone...

Edit to add: going through the floor will be a *****, rebar and wire mesh will kill you, also I've come across conduit. Also since you already have a vent less heater, maybe you could just use a smaller (4" or so) vented exhaust fan and turn it on once a while to get rid of the smell?

Thanks, just saw the addition above... yeah, I think you are definitely right about not going through the overhead slab (floor to sunroom) I don't mind the idea of opening up a hole in the wall, but I was blown away with how big they want the hole for those direct vent units (11x11 inches!)

 

[Jackfre]

I know you are new here, so just a word to the wise. When your start a post that includes a special car you have to introduce the car first with at least some pics, plans, mods and then ask your questions. Install a 9k btu mini-split. It will make electric heat affordable, give you great comfort year round. Perhaps best it will control the humidity so you don’t go down to the garage some spring day and find the tools covered in water. As to straight heat a NG or LP Rinnai EX-11 or 17 would walk away with this job. Core drill a 2.75” hold thru the concrete wall for the supplied vent. I did a ‘72 2002 when I lived in MA and it was so nice laying on a creeper with the heat blowing across the floor. MMmmmmm, it was good. Is yours a 6 or a 250?

 

[65ranchero]

Use electric heater(s) or vent through the glass block opening. A pro could quickly bore a vent hole anywhere you choose.

Yup!

 

[Denkikun]

I know you are new here, so just a word to the wise. When your start a post that includes a special car you have to introduce the car first with at least some pics, plans, mods and then ask your questions. Install a 9k btu mini-split. It will make electric heat affordable, give you great comfort year round. Perhaps best it will control the humidity so you don’t go down to the garage some spring day and find the tools covered in water. As to straight heat a NG or LP Rinnai EX-11 or 17 would walk away with this job. Core drill a 2.75” hold thru the concrete wall for the supplied vent. I did a ‘72 2002 when I lived in MA and it was so nice laying on a creeper with the heat blowing across the floor. MMmmmmm, it was good. Is yours a 6 or a 250?

Haha, okay, forgot what site I was on for a second there..... It's a 1974 tr6 that I actually did a frame off restoration on in 1990 when I was in high school (when I was supposed to be reading books, etc etc) The car's actually got a pretty good story... once I finished it in 1991 I moved out to Athens Ohio in the middle of nowhere on a gravel road... not being the right car for THAT situation, I sold it to a guy in Dayton Ohio who I didn't know and bought the correct vehicle for that situation, which was a 1970 Chevy C10 with a 350 out of a junkyard wrecker and a host 4 speed floor shooter with a granny gear....... fast forward 8 years and my brother found my triumph poking out from underneath a blue taro in a guy's driveway less than 2 miles from his hose in Dayton... so my brother bought it back for the same price I sold it for 8 years earlier. Then after driving around for a few years, my brother, who is a bit of a nut job converted the Tr6 to full electric using the giant electric motor from a 70s forklift and 12 SLA marine batteries... the result was a much slower than stock Tr6 with a range of 18 miles... nevertheless he autocross it a few times and used it to commute to work. Fast forward another couple of years and the car was sitting in his garage with batteries dead and he donated it to the "British transportation museum" that a guy is trying o start in Dayton - currently still a dark warehouse with about 50 or so British race cars or otherwise noteworthy vehicles ... so the car sat in the dark with all of its dead batteries and controllers, etc for a couple of years.... then my 5 yr old at the time son saw a little part of the yellow fender int eh background of a photo of me from about 25 years ago and wouldn't stop asking about it... made a call to my brother, and the darn car was back in my garage again - like a high maintenance boomerang! did another darn frame off this past 1.5 yrs... teaching the boy how to work on things though.....

 

[Denkikun]

but back on the topic of heaters..... That's great to see that the Rinnai units only need about a 3 inch vent hole! Only issue there is that I' trying to spend about half that much money... everything that goes into the heater doesn't go into the car haha

 

[Copymutt]

Saw thru the wall.

The Most Important Do's and Don'ts of Concrete Wall Sawing

While performing the task of concrete wall sawing, one needs to be careful. Here, we will provide some do’s and don’ts. Read on to know more.

www.cadrillers.com

 

[Jagmandave]

I think I would run the 240 and either do an electric heater or a MiniSplit - you'll like the cool air on a sweltering hot summer day as much as the heat in winter. And when not using it for heat or A/C, it's handy for a welder too.

 

[rjn2649]

As I look at your heater, I also notice what looks like a lot of dust, and maybe fake logs? I would get rid of the fake logs, if possible, and clean out the dust from the heater...Just saying if you want to save money, you might be able to get the smells down and make use w/ what you got. I also know people hate those heaters, because they are not vented.

 

[Denkikun]

I think I would run the 240 and either do an electric heater or a MiniSplit - you'll like the cool air on a sweltering hot summer day as much as the heat in winter. And when not using it for heat or A/C, it's handy for a welder too.

Thanks Jagman, yeah, I have been thinking about this an option... so that I could have an easy welding connection point or fast charger for a future EV.... but it's sooo tempting to just hook up to that gas line that's right there... plus I think that I'd have an easier time installing the gas unit than I would wiring the 240 in. I'm currently in a trap trying to figure out the load on my main Electric panel ... it's tricky to figure out... ( I have 150 amp service) . If I were to do the electric, I'd consult with the elec permit guys in town and then get it inspected when I was done.

 

[Denkikun]

As I look at your heater, I also notice what looks like a lot of dust, and maybe fake logs? I would get rid of the fake logs, if possible, and clean out the dust from the heater...Just saying if you want to save money, you might be able to get the smells down and make use w/ what you got. I also know people hate those heaters, because they are not vented.

Thanks! yes, in fact recently the unit was turning off just after starting until I blew out the area around the pilot. I'm certain that there was all manner of stuff in there.... from grinding down the welds when I did frame repair.... I did clean off the logs and surrounding areas lately though.... still pretty stinky. another thing is that I while I'm cool with having the stinky heater on in there when I work, I'd rather not leave it on for long periods as Ive read about the massive amount of water vapor that invented produces

 

[Denkikun]

I think I would run the 240 and either do an electric heater or a MiniSplit - you'll like the cool air on a sweltering hot summer day as much as the heat in winter. And when not using it for heat or A/C, it's handy for a welder too.

Thanks, I do have an extra 120V line running right there that I could use for the mini split, but then again, those seem to cost $1K plus

 

[APEowner]

I went with ceiling mount electric IR heaters in my shop. There's some information on the install in my shop build thread which is linked in my signature below. I don't have any real numbers on run cost but I did notice a change in my electric bill after they went in. Apart from that I'm really happy with them.

 

[Denkikun]

I went with ceiling mount electric IR heaters in my shop. There's some information on the install in my shop build thread which is linked in my signature below. I don't have any real numbers on run cost but I did notice a change in my electric bill after they went in. Apart from that I'm really happy with them.

Wow! nice shop! I read that the IR ceiling mount heaters aren't supposed to be lower than 9 feet .... maybe I read too much, haha

 

[APEowner]

Wow! nice shop! I read that the IR ceiling mount heaters aren't supposed to be lower than 9 feet .... maybe I read too much, haha

Thanks! I've been enjoying working in it.

My ceiling height is right at 9 feet but you're right, that might be an issue in your shop. I didn't think of that.

There are two issues with going lower. The first is, of course that you might get something temperature sensitive too close to the heater. The other is that the closer the heater is to the floor the smaller the area it will heat.

 

[PoorUB]

I wouldn't put a ventless heater in my chicken coop!

If those windows above the glass block window can open good chance you can not vent a heater under them.
Cold weather minispli, they build them to heat down to -30f, plus you get air conditioning.

 

[kelpaso1]

I wouldn't put a ventless heater in my chicken coop!

If those windows above the glass block window can open good chance you can not vent a heater under them.
Cold weather minispli, they build them to heat down to -30f, plus you get air conditioning.

LOL ya right! No mini is going to keep your garage warm at -30. Maybe above freezing but that's it.

 

[PoorUB]

LOL ya right! No mini is going to keep your garage warm at -30. Maybe above freezing but that's it.

Have done any minisplit research since our last discussion?

 

[kelpaso1]

Have done any minisplit research since our last discussion?

Umm err no. Heheh. Im just saying they dont put out a lot of heat in those low temps. Out here everyone has one. Most complain about poor heat output on really cold days. I'll stick with my wood stove.

 

[rjn2649]

SO now, back to the Trump...
Did your brother have the original engine and other assorted goodies ? Did it ALL pass to the guy in Dayton, then you? Or did you have to source all the other parts?
C'mon too many un-answered questions...

 

[PoorUB]

Ok, did some investigation, if the unit vents at lest 4 feet below a window you are golden. Table 7.1 here, Hot Dawg installation. I would figure out where you want to hang it, and hire a concrete cutter to bore a hole through the wall in the area of the glass block windows, or punch out one of the glass blocks.
Keep in mind with the smaller Hot Dawgs you can mount them upside down, there is no up or down. The heater will be below the seven foot limit, (But that is for commercial installations), but I don't see much of an insure with that other than it will be a head banger so put some shelves or a beer refrigerator under it so you don't walk there!

And buy a 30,000 BTU!! Anything else will be too large!!

Another consideration would be a 30,000 to 45,000 BTU high efficiency furnace, vents on PVC so that makes it simple, but you need to deal with condensate, plus it goes way over budget unless you can find a good used one, which is unlikely.

I should add, I don't like venting right up along side tha garage door, too close to the lintel over the garage door. I question the possible structural issues.

 

[Denkikun]

SO now, back to the Trump...
Did your brother have the original engine and other assorted goodies ? Did it ALL pass to the guy in Dayton, then you? Or did you have to source all the other parts?
C'mon too many un-answered questions...

Hahaha…. Yup, got the original engine from my brother as well. Going through it now… everything looks usable, just replace bearings, gaskets, etc. the engine has a milled head since my brother had been prepping it according to the old group 44 triumph race prep manual… als my cam had done putting do I grabbed a slightly hot one from Ted Schumacher at Tsi imports in Pandora Ohio. Last week I got my Toyota pickup truck 4 piston front brake upgrade… they bolt right on the tr6 and use same rotor!! Also have seats from a 1985 Miata S which have the separate headrests (look better in tr6 than the tall ones) It’s funny when you restore a car that you had restored 28 years ago…. You can’t ***** as much about whoever was in there doing the work before! Anyway the car was still in pretty good shape … that yellow paint is all original from my 1991 resto

 

[Denkikun]

Ok, did some investigation, if the unit vents at lest 4 feet below a window you are golden. Table 7.1 here, Hot Dawg installation. I would figure out where you want to hang it, and hire a concrete cutter to bore a hole through the wall in the area of the glass block windows, or punch out one of the glass blocks.
Keep in mind with the smaller Hot Dawgs you can mount them upside down, there is no up or down. The heater will be below the seven foot limit, (But that is for commercial installations), but I don't see much of an insure with that other than it will be a head banger so put some shelves or a beer refrigerator under it so you don't walk there!

And buy a 30,000 BTU!! Anything else will be too large!!

Another consideration would be a 30,000 to 45,000 BTU high efficiency furnace, vents on PVC so that makes it simple, but you need to deal with condensate, plus it goes way over budget unless you can find a good used one, which is unlikely.

I should add, Ido't ike venting right up along side tha garage door, too close to the lintel overthe garage door. I question the possible structural issues.

Thanks Poor lUB! I really appreciate all the info! Very interesting to know that the hit dawgs can flip, also that the height is likely okay. I had found a nice 35k floor standing Dayton unit that stands 27 inches tall with top vent that I was pondering …. I’m now going to go down the hot dawg rabbit hole…. Haha It’s weird that I can’t find anything online about people venting out of glass block windows… it seems like a pretty obvious option …

 

[Denkikun]

Hahaha…. Yup, got the original engine from my brother as well. Going through it now… everything looks usable, just replace bearings, gaskets, etc. the engine has a milled head since my brother had been prepping it according to the old group 44 triumph race prep manual… als my cam had done putting do I grabbed a slightly hot one from Ted Schumacher at Tsi imports in Pandora Ohio. Last week I got my Toyota pickup truck 4 piston front brake upgrade… they bolt right on the tr6 and use same rotor!! Also have seats from a 1985 Miata S which have the separate headrests (look better in tr6 than the tall ones) It’s funny when you restore a car that you had restored 28 years ago…. You can’t ***** as much about whoever was in there doing the work before! Anyway the car was still in pretty good shape … that yellow paint is all original from my 1991 resto

Sorry, 1995 Miata… haha

 

[PoorUB]

Thanks Poor lUB! I really appreciate all the info! Very interesting to know that the hit dawgs can flip, also that the height is likely okay. I had found a nice 35k floor standing Dayton unit that stands 27 inches tall with top vent that I was pondering …. I’m now going to go down the hot dawg rabbit hole…. Haha It’s weird that I can’t find anything online about people venting out of glass block windows… it seems like a pretty obvious option …

No problem with the glass block. The vent pipe needs clearance to combustibles and the glass block isn't going to catch fire! It could just as well be brick.
Just be sure of your clearances to the windows above.

Great that you have gas handy too!

If you want to get picky about it that unvented heater you have is not in code. It needs to be at least 18 inches off the floor in a garage. Gas fumes tend to linger at the floor so the concern is that a heater sitting at floor level has a better chance of igniting the fumes instead of a higher mounted heater.

Not sure what Dayton unit you were looking at, but if it is a natural draft unit you need B-vent pretty much straight up, you probably can not vent it out the wall.

 

[Denkikun]

No problem with the glass block. The vent pipe needs clearance to combustibles and the glass block isn't going to catch fire! It could just as well be brick.
Just be sure of your clearances to the windows above.

Great that you have gas handy too!

If you want to get picky about it that unvented heater you have is not in code. It needs to be at least 18 inches off the floor in a garage. Gas fumes tend to linger at the floor so the concern is that a heater sitting at floor level has a better chance of igniting the fumes instead of a higher mounted heater.

Not sure what Dayton unit you were looking at, but if it is a natural draft unit you need B-vent pretty much straight up, you probably can not vent it out the wall.

Thanks, I’m sure that the Dayton unit I was looking at (used) is natural draft… come to think of it, I also read something about venting on a wall with prevailing wind…. That’s the case with my wall (the one with glass block windows). So maybe a power vent is best . I’m checking on the $800 price tags a bit though

 

[Denkikun]

Thanks, I’m sure that the Dayton unit I was looking at (used) is natural draft… come to think of it, I also read something about venting on a wall with prevailing wind…. That’s the case with my wall (the one with glass block windows). So maybe a power vent is best . I’m checking on the $800 price tags a bit though

Sorry, I’m “choking” on the price, not checking haha

 

[yeldogt]

I'm with Jack on this ... I always use the cabinet heaters. Easy install through the wall .. sealed combustion .. heat down where you need it. Comes in the correct size vs what people typically use. Yes -- more $$ to purchase. It's all in the box ... vent included.

My brother and I did a bunch of Triumphs ... mostly 4A's and 250's ... we did do two 6's. Better seats ...

 

[Jackfre]

Thanks for the info. Really nice for you and your son to work together on this. Has to be very rewarding. My car after the 72 was a 75 2002 Turbo. The Turbo was written up in the December ‘09 issue of Bimmer. I am out of cars now living vicariously through projects like yours. I have absolutely no self discipline and just burn the bank down with each car. Even by my somewhat loose standards I was and remain nuts So proud! If you are planning on staying in the house for the foreseeable future a better quality climate control product is worth the expense. At this point you are stuck in the “Cheap heat or cheap heater” quandary. A 9 or 12 k mini-split will run on 15 amps. The thing about the Rinnai too is that I could pull a Rinnai in about 15 minutes, patch the hole and move it to the next place

 

[yeldogt]

Thanks for the info. Really nice for you and your son to work together on this. Has to be very rewarding. My car after the 72 was a 75 2002 Turbo. The Turbo was written up in the December ‘09 issue of Bimmer. I am out of cars now living vicariously through projects like yours. I have absolutely no self discipline and just burn the bank down with each car. Even by my somewhat loose standards I was and remain nuts So proud! If you are planning on staying in the house for the foreseeable future a better quality climate control product is worth the expense. At this point you are stuck in the “Cheap heat or cheap heater” quandary. A 9 or 12 k mini-split will run on 15 amps. The thing about the Rinnai too is that I could pull a Rinnai in about 15 minutes, patch the hole and move it to the next place

I briefly had a 68 -- my brother had a Tii -- think it was a 72. He only let me drive it once.

 

[Denkikun]

Thanks for the info. Really nice for you and your son to work together on this. Has to be very rewarding. My car after the 72 was a 75 2002 Turbo. The Turbo was written up in the December ‘09 issue of Bimmer. I am out of cars now living vicariously through projects like yours. I have absolutely no self discipline and just burn the bank down with each car. Even by my somewhat loose standards I was and remain nuts So proud! If you are planning on staying in the house for the foreseeable future a better quality climate control product is worth the expense. At this point you are stuck in the “Cheap heat or cheap heater” quandary. A 9 or 12 k mini-split will run on 15 amps. The thing about the Rinnai too is that I could pull a Rinnai in about 15 minutes, patch the hole and move it to the next place

Wow! 2002 turbo, that's excellent! I've been really into water cooled VWs for the past 20 years or so... most recently a 2003 1.8t manual Jetta wagon.

 

[Denkikun]

Okay! based on the excellent info that everyone offered (thanks so much) I am now focused on either a direct vent wall unit or running 240v electric to the garage and doing wither a 5000 or 7500 Watt heater... I'm trying to figure out if I have capacity in my main elec panel and actually need just a bit more advice.... I would plan to do my own electric work but pull a permit and have it inspected. However, the first step is the load calculation... I have an automated worksheet that the inspection folks gave me, but I am a bit stumped on one section...
--- could someone offer some support in determining the "HVAC LOAD".... it's asking me for the wattage of my air conditioning and furnace respectively...... I have a natural gas furnace and AC.. there is nothing I can find on the units that suggests wattage load... I suppose that the AC wattage is to the outdoor compressor/condenser unit? Any help here would be GREATLY appreciated

I'm looking forward to actually helping someone else out on here in the future, as I have been the recipient of mucho info and advice, THANKS! My areas of specialty are Japanese language, Building modern sheds, retaining walls, and British cars - Vespas - KTM - Honda CB750

 

[Max]

The HVAC load should be the sum of what the interior and exterior units pull. To a very gross level you could look at each of the breakers to get an upper limit of the power draw. A better way would be to look at the labels on your unit (or maybe online specs for your specific unit). Asking in the electrical forum will get better info from the sparkies there also.

 

[Denkikun]

The HVAC load should be the sum of what the interior and exterior units pull. To a very gross level you could look at each of the breakers to get an upper limit of the power draw. A better way would be to look at the labels on your unit (or maybe online specs for your specific unit). Asking in the electrical forum will get better info from the sparkies there also.

Thanks, Max ! You're right! I will ask over in the electric forum. Appreciate your help

 

[PoorUB]

Max load on a breaker is 80%, so it the unit needs a 20 amp breaker the max load is 16 amps, but the actual load is certainly less.

safe would be to add up the recommended breaker sizes and go with that.