Last year, I posted about my relative success using a 30K ventless NG wall-mounted heater to keep my 2.5 car garage warm (garage has 12' ceilings, fully insulated, attached to house, about 20' deep and 27' wide). The good: 1) cheap; 2) efficient; 3) never had any air quality issues, even with it running at full tilt for a few hours (checked it with a calibrated 4 gas meter); 4) no holes to cut / easy to install.
The bad: 1) I used it to keep the garage 'warm' (40 degrees), and if you wanted to go from 40 degrees to workable (55-60 degrees), it took a LOOOOONG time; and, 2) the moisture was noticeable (if you left a wet coat in there to dry, it never really dried.
Soooo...I bit the bullet and bought a Big Maxx 45K forced air NG furnace, and installed it a few weeks ago. Heater is installed in corner of garage ceiling, pointed towards garage door. Here's my basic review:
Comparison of Vented / Non-Vented: The difference is much greater than I had thought. The most obvious difference is drying; the garage is noticeably drier. If I'm snowblowing and get my jacket wet, it dries in the garage now. So do wet cars, puddles, etc. It is worth it for this benefit alone. Also, if I want to go from 'warm' (40) to 'workable' (55-60), I can do so in about 10 minutes. With the Big Maxx, I did a horizontal, thru-wall vent, which was easy to install. I wouldn't go back. The vented is clearly louder than the ventless (as it has fans), but I actually like that...I can tell when it is running, and keep a better eye on gas consumption. The forced air vented unit also pushes the heat around the garage much better, and I think it is thus more efficient; the whole garage temp remains pretty consistent, and heat spreads well. Verdict: Although the ventless did work for my application, the vented is clearly, clearly much better.
Acquiring from Northern Tool: Shipping was fast and easy, unit arrived undamaged. I did buy the thermostat and vent kit that they recommended and, in retrospect, I would not do that again. With the 45K unit, you only require a 3" vent. I'd go to the local home improvement store and buy 3" piping for the vent, make a smaller hole, and not spend 3x as much on the Northern vent kit (that uses 4" piping and a 3" to 4" increaser to accommodate the 45K BTU unit). Also, the Northern thermostat was a complete joke. Accurate to within 35 degrees or so. I wouldn't waste my money on that. I ended up buying a Honeywell programmable thermostat on sale for $16 that works perfectly. Verdict: Northern's sale price on the heater was great, and the unit arrived quickly and undamaged. I'd skip the vent kit and thermostat and buy those locally.
Quality of the Big Maxx: After having it for 3 days, the electric motor on the forced air blower started making a bad grinding noise. (Sounded like a blender full of marbles). I contacted Big Maxx and they sent out a replacement motor, free, pronto (as you'd expect). Replaced that, and it's been running perfectly ever since. Reasonably quiet, and the right size for my application. (75K would have been overkill). The motor shouldn't have failed within 3 days, but at least they were prompt in sending out a replacement motor, and the replacement seems to be working perfectly. No other complaints at this point. Vibration isn't an issue. (Mine is mounted somewhat uniquely; one side is screwed to the ceiling joists, and the other side is hooked to a higher part of the ceiling with chain. Seems to work fine). I do wish the mounting rails were a bit sturdier, as mine bent a bit during install. Verdict: So far, so good. Initial problem overcome quickly, and I look forward to many years of good heat.
Overall: Installing the ventless unit encouraged me to run NG to the garage, which was good, but the vented experience has made me wish I had started with this setup last year. No comparison; the forced air is much, much more useful. I have read some on here now talking about the need for sealed combustion heaters in garages. Certainly, they could be more efficient and potentially safer, but I feel comfortable with my unit (we've used similar furnaces in many similar environments for years), and am pleased with the outcome.
The bad: 1) I used it to keep the garage 'warm' (40 degrees), and if you wanted to go from 40 degrees to workable (55-60 degrees), it took a LOOOOONG time; and, 2) the moisture was noticeable (if you left a wet coat in there to dry, it never really dried.
Soooo...I bit the bullet and bought a Big Maxx 45K forced air NG furnace, and installed it a few weeks ago. Heater is installed in corner of garage ceiling, pointed towards garage door. Here's my basic review:
Comparison of Vented / Non-Vented: The difference is much greater than I had thought. The most obvious difference is drying; the garage is noticeably drier. If I'm snowblowing and get my jacket wet, it dries in the garage now. So do wet cars, puddles, etc. It is worth it for this benefit alone. Also, if I want to go from 'warm' (40) to 'workable' (55-60), I can do so in about 10 minutes. With the Big Maxx, I did a horizontal, thru-wall vent, which was easy to install. I wouldn't go back. The vented is clearly louder than the ventless (as it has fans), but I actually like that...I can tell when it is running, and keep a better eye on gas consumption. The forced air vented unit also pushes the heat around the garage much better, and I think it is thus more efficient; the whole garage temp remains pretty consistent, and heat spreads well. Verdict: Although the ventless did work for my application, the vented is clearly, clearly much better.
Acquiring from Northern Tool: Shipping was fast and easy, unit arrived undamaged. I did buy the thermostat and vent kit that they recommended and, in retrospect, I would not do that again. With the 45K unit, you only require a 3" vent. I'd go to the local home improvement store and buy 3" piping for the vent, make a smaller hole, and not spend 3x as much on the Northern vent kit (that uses 4" piping and a 3" to 4" increaser to accommodate the 45K BTU unit). Also, the Northern thermostat was a complete joke. Accurate to within 35 degrees or so. I wouldn't waste my money on that. I ended up buying a Honeywell programmable thermostat on sale for $16 that works perfectly. Verdict: Northern's sale price on the heater was great, and the unit arrived quickly and undamaged. I'd skip the vent kit and thermostat and buy those locally.
Quality of the Big Maxx: After having it for 3 days, the electric motor on the forced air blower started making a bad grinding noise. (Sounded like a blender full of marbles). I contacted Big Maxx and they sent out a replacement motor, free, pronto (as you'd expect). Replaced that, and it's been running perfectly ever since. Reasonably quiet, and the right size for my application. (75K would have been overkill). The motor shouldn't have failed within 3 days, but at least they were prompt in sending out a replacement motor, and the replacement seems to be working perfectly. No other complaints at this point. Vibration isn't an issue. (Mine is mounted somewhat uniquely; one side is screwed to the ceiling joists, and the other side is hooked to a higher part of the ceiling with chain. Seems to work fine). I do wish the mounting rails were a bit sturdier, as mine bent a bit during install. Verdict: So far, so good. Initial problem overcome quickly, and I look forward to many years of good heat.
Overall: Installing the ventless unit encouraged me to run NG to the garage, which was good, but the vented experience has made me wish I had started with this setup last year. No comparison; the forced air is much, much more useful. I have read some on here now talking about the need for sealed combustion heaters in garages. Certainly, they could be more efficient and potentially safer, but I feel comfortable with my unit (we've used similar furnaces in many similar environments for years), and am pleased with the outcome.
trust me it's like a disease.