Ventless NG Heater Experience

[lawfarm]

I had put up a post a few months ago requesting info on use of NG, ventless heaters in garages. Some positive responses, some negative responses. I was planning on putting in a vented heater and just living with having to cut a hole in a wall or roof, when a ventless heater fell into my lap, for free. So...I had to try it out.

My garage is a 2.5 car with rough drywall (taped and mudded but not sanded and finished), and pretty good insulation; newer construction (1yo). Ceilings are 10-12', and it is attached. I have a 30,000 BTU NG ventless heater mounted on the front wall of the garage, and to date, it is working pretty darn well. I have it set as low as it will go, which keeps the garage at about 50 degrees (F).

This weekend, it was -5, with 35-45mph winds, and the garage was comfy at 50-55 degrees. If I want to work in there, I can turn it up an hour or so early, and it will get as warm as you'd like. Adding a ceiling fan to circulate the air would definitely keep it more consistent temp wise, and would be a nice addition.

I've never had any air quality issues, and have monitored CO levels closely. Even with my tight garage, it isn't an issue (to date).

The other big complaint about ventless was the release of moisture into the air. It certainly does do that; my garage door is insulated, but still gets a bit of frost on the inside. I also have 1 double hung window in the garage that gets a frosting on it (on the wall opposite the heater). But there's no moisture on the walls, or on the tools, or etc. I do imagine that if I left the heat OFF and then turned it on and cranked it up, I'd have condensation on tools, as they warmed up. But with it on low all of the time, no issues. Also, the effect on my gas bill has been negligible...I just need to be vigilant about keeping the door shut.

My unit is not an 'infrared' unit; I can't say how well they work. But for my purposes, this works quite well. My old garage had a large forced air NG heater (from a mobile trailer) that could warm it up in minutes from any temperature to balmy. This doesn't have that capability. But it keeps the cars from freezing up, keeps my beer fridge from freezing, and keeps the garage a nice place to work, change, etc.

One funny thing is that I've noticed it really keeps the slab warm. I'm not sure if it is because the garage is attached, or why (or if it is in my head)...in my old, detached garage, I'd leave the heat off (unless I was anticipating a snow or was on call), and then turn it on when I needed to work in there. The air would warm up, but the floor was always FREEZING. In the new garage, the floor is surprisingly warm and comfy (it's around the air temperature...55 degrees or so).

Ultimately, I'd like to have a vented unit so I could have a bit more flexibility in where I set the temps (and to satiate my inner firefighter not liking the non-vented setup I currently have)...but for now, my heater is working well and I'm pleased with it. It certainly beats electric heat, and it beats kerosene space heaters or torpedo heaters for utility. Just wanted to do a follow-up post on the subject and give my thoughts.

 

[Sidekick]

when there is combustion , there is monoxide and it is cumulative. I am not a fan of "ventless" heaters having almost died of monoxide poisoning.

 

[6768rogues]

I agree with sidekick. No matter how you cut it, combustion provides the products of combustion. If you read the listing material that comes with a ventless gas heater, you will find that it requires a window to be open a specific amount. They are also sized in the listing to be safe, and following the instructions leaves you with a large space, small heater and a window open. Most codes do not permit them as a primary source of heat for the reasons stated.

 

[krooser]

Good info.

I don't heat the area in my shop that has the lift.... I just slide the door open that seperates the heated/non-heated areas if I need to use it. I've been thinking about a ventless heater to warm things up a bit over there... thanks.

 

[lawfarm]

when there is combustion , there is monoxide and it is cumulative. I am not a fan of "ventless" heaters having almost died of monoxide poisoning.

Yes, one does need to be aware of the limitations, I would certainly agree. But for a space like my garage, the system functions pretty darn well for what I need it to do. And yes, I've been monitoring the CO levels (with a 4 gas meter) and haven't seen anything even remotely concerning, at any elevation in the garage, even on cold days...but then again, I'm more precise than most probably would be. I think you'd be hard pressed to generate any even remotely significant CO level in an average garage with a heater of this nature, and that's based on first hand, objective testing with a known accurate meter.

 

[tatra]

do you open your garage door on a semi rgular bsais?................could be why you don't get a reading of any co..........possibly in a closed enviro, it may show up as it accumulates as staed before...............i too am in need of a new heating system and have thought of radiant or forced air............currently have an electric forced air furnace and may just buy a new one to replace that so as not to have to deal with piping etc.........thanx for taking the time to write the review...........

 

[kbs2244]

What is the advantage of a ventless over a vented?
First time cost?
I would go with a used 80% vented from a HVAC contractor before I would go with a new ventless.
They are junk to them when people upgrade to the 90 plus % units.
A lot of time they will give them away.
The most I ever paid was $100.00, but that was delivered as he was on his way back to the shop from takeing it out.

 

[euromade]

My First post on this foruum...
Just purchased and installed a ventless 30,000 blue flame heater by Mr. Heater. It is a unit with a fan and termostat.

I have a 3 stall garage, well insulated.
DOES ANYONE KNOW HOW MUCH natural gas does this unit burn? I guess how many cubic feet per hour does it burn? How much is it going to add to my montly bill?
Thanks!

 

[oldgoat]

I put a ventless one in my 22 x 26 insulated garage. It did build up moisture though and I also then put a portable dehumidifier in. I did leave it on last winter for a couple of months on about 50 deg but found out that it does use quite a bit of gas. I do have a tester with alarm and have never had a problem with it even coming close to having high levels. I also think that it takes along time to bring the temp up if left off. It was suppose to be able to heat 1000 square feet. For occasional use I have no problem with it and considering what I was quoted for a forced air unit it made sense to use in my case. Also if the electricity goes out it still is functional.

 

[logguy]

A 30k btu vent free heater will use about 30 cubic feet of gas per hour. The cost of gas varies per location.

The reason we are told to open a window is for make up air for combustion. They tell you to open a window because there are some people that will put a 30kbtu vent free gas heater in a 8x10 room. If that room is very tightly sealed, you could have problems with not enough oxygen for combustion. There is a sensor that will shut the unit down when O2 levels get below 18%. Most garages that I have seen are not that tightly sealed though.

 

[HoosierBuddy]

There's quite a lot of misinformation in this thread.

Ventless heaters, when properly maintained, furnished with adequate combustion air, etc. do not produce carbon monoxide. All of them now sold included an oxygen depletion sensor which monitors for a drawdown of oxygen in the combustion air and will shut the heater off if any is detected. Many ventless heater companies are specifically manufacturing and marketing ventless products for garages. This is not a case of someone using something designed to do "X" in a "Y" situation. These heaters are being used as their manufacturers intended.

To answer the question about cost, in the US right now natural gas is selling for (very roughly) $11 per DTH. That would work out to a cost of $.33 per hour for burner on time. If the heater never gets the garage up to temperature, that would cost $8 per day. If the garage is well insulated that won't be the case...but the cost will be "substantial" in any cold weather climate.

The size of the heater has very little to do with the cost to operate. The biggest concern is the heat loss of the structure being heated and the number of hours the heat is on.

I have heated a garage with a ventless heater and I was not satisfied because of problems using solvents around the heaters, excessive water output, insufficient heat output, and the fact they are an ignition source for a fire either due to proximity to a solid combustible or if there is a gasoline spill in the garage.

For heating, they are "better than nothing" but they aren't as good as a vented heater that is properly sized for garage.

I'd point out to everyone that I actually own and use 2-ventless heaters in my home...an unvented gas log set and a space heater. We use both of those to supplement regular heating with a furnace and our hydronic heat in another part of the house. They are a great backup source of heat (as they don't require any power to operate) but they are completely unsuitable as a primary sorce of heat. I don't mind using them an hour or two a day...but running them more than that can lead to all sorts of problems...especially with humidity. I'm not "against" ventless heaters...they just aren't my preference for use in a garage.

Phil