Ventless NG heater for a 2 car garage??!?

[AaronH87]

OK, so I have been wanting to heat my 2 car garage. I live in Lexington, SC. so it doenst get too horrible around here in the winter ( we see snow maybe once every year or 2, its sad ) so i really just want to make the garage comfortable to be in. I dont park in the garage. I have a NG water heater in the garage, so i have access to the gas line.

anyways, i have read alot of things about ventless heaters, and issues with humidity. I do NOT want to use an electric heater due to the power bill. I dont plan on having this on all the time, only when i plan on working/hanging out in the garage.

This is the heater i am looking to get.

ProCom Dual Fuel Vent-Free Blue Flame Garage Heater — 30,000 BTU

http://www.northerntool.com/shop/tools/product_200442160_200442160



for those people who have a ventless heater, what kind of issues have you had?

 

[dave67fd]

They will make everthing sweat. If that isin't an issue go for it.

 

[pfarber]

The humidity issue is more myth than reality. The myth being that burning NG or Propane, which is supposed to have H2O as he primary combustion gas will saturate the air, causing it to rain inside, or at least cause condensation.

In winter you WANT a high(er) RH. Warm moist air feels 'warmer' and avoids the health issues of very dry warm air.

You can run a humidifier (one of the ultrasonic jobs that blasts vapor into the air) full blast (about a gallon+ per hour) and not see any condensation issues.

Running a NG direct heater is putting nowhere near that much water in the air.

If it really bothers you, get an RH meter and open the door to the house if it get above 60-70%.. which it will most likely never do.

 

[Dick in Wisconsin]

What about carbon monoxide?

 

[pfarber]

'Water vapor moved through the system must be reduced to acceptable industry levels. Typically, the allowable water content in gas transmission lines ranges from 4 lb. to 7 lb. per MMSCF'

In Jan. 2012 my highest gas usage was 3.38CCF per day (average). So in ONE DAY I used 338 cubic feet of gas, for a whole house, in 24 hours.

If there is basically 1 lb of water (water is 8lbs) that means in ONE MILLION CUBIC FEET of natural gas there is 1 lb of water. So in 300 cubic feet there is point zero zero something.


Moral of story: Don't worry about it.

 

[DPelletier]

I've only been here a relatively short time ( although I've been doing my day job for over 20 years now) and I can easily predict that you will get a number of conflicting opinions on this subject every time it comes up.

So, with regards to ventless/direct fired gas heaters;

Pro's:
- quick recovery
- relatively cheap to buy
- no venting to deal with
- cheaper to run a NG heater than electric resistance heaters in most places (though propane may be even more expensive)
- very little electrical impact if you have no more space in your panel

Cons:
- introduce moisture and potentially the products of combustion into the space
- remove oxygen from the space
- gas piping costs (compared to electric resistance heaters)
- you need to be aware of the danger with some solvents and other products you might use in a garage or shop.


Now, there is no right or wrong answer and weighing the pros and cons is best done on a case by case basis. I often get asked what the "best" system is and the answer is always the same: it depends.

Personally for MOST garage/shop applications I avoid recommending ventless gas heaters due to the aforementioned negatives but the advantages are real an in the right application, they are a good choice. The right application (for my purposes) is a space with a very large interior volume coupled with a high amount of air exchange - usually from the regular opening of large OH doors.

Dave

 

[pfarber]

What about carbon monoxide?

Really? How many new homes are being installed, trouble free with direct vent gas fireplaces? How many thousands of home are being retrofit with direct vent natural gas heaters?

How many people are complaining of rain in their homes? How many people are dying from CO poisoning?

I need to open an web site that sells common sense. Heck I would give it away but most people still wouldn't know what to do with it.

What about gas line explosions? Gremlins? Dogs and cats living together? (<- Ghostbusters reference, double points for me)

 

[pfarber]

I've only been here a relatively short time ( although I've been doing my day job for over 20 years now) and I can easily predict that you will get a number of conflicting opinions on this subject every time it comes up.

So, with regards to ventless/direct fired gas heaters;

Pro's:
- quick recovery
- relatively cheap to buy
- no venting to deal with
- cheaper to run a NG heater than electric resistance heaters in most places (though propane may be even more expensive)
- very little electrical impact if you have no more space in your panel

Cons:
- introduce moisture and potentially the products of combustion into the space
- remove oxygen from the space
- gas piping costs (compared to electric resistance heaters)
- you need to be aware of the danger with some solvents and other products you might use in a garage or shop.


Now, there is no right or wrong answer and weighing the pros and cons is best done on a case by case basis. I often get asked what the "best" system is and the answer is always the same: it depends.

Personally for MOST garage/shop applications I avoid recommending ventless gas heaters due to the aforementioned negatives but the advantages are real an in the right application, they are a good choice. The right application (for my purposes) is a space with a very large interior volume coupled with a high amount of air exchange - usually from the regular opening of large OH doors.

Dave

Moisture into the space is wrong.
Combustion materials? Whatever that means is still wrong.
Removes O2 from the space? What proof do you have that its occurs?
Danger of solvents? What? Solvents aren't the problem, the VAPORS are, and any heat source will do.

Do do realize that direct vent doesn't mean that there is a 6 foot flame shooting out of the wall, right?

I really cannot believe the misconceptions and myths that about. Gas is going to be much more prevalent due to the lower price..... I'm gonna say that most of the people here are just flat wrong, or at best completely uninformed with respect to it. How many people even HAVE direct vent appliances? I do.

 

[brewchief]

Pfarber do you understand the difference between direct vent and ventless? It sure doesn't sound like it.

If there is only a gallon of moisture made from a million cubic feet of gas explain how come a 95% furnace gives off gallons of water a day.

Sent from my C771 using Tapatalk 2

 

[AaronH87]

Ok, so it sounds like i will be ok.

that being said, yall think ill be ok to tap into the gas line in that garage that feeds my water heater? ill do the work myself

 

[BlackdogJunkyard]

I have a vebtless rinnai heater in my 15'widex30'longx17'high garage. I have ZERO humidity issues. I have zero problems using spray paint in the garage while it's running. It has been zero issues. I even have an empire vented wall unit in my garage but it just doesn't crank out the heat like the ventless does. Not really sure why that is but whatever.
Ventless is fine.

Sent from my DROID X2 using Tapatalk 2

 

[AaronH87]

Awesome! thanks guys! (and gals)

 

[nehog]

'Water vapor moved through the system must be reduced to acceptable industry levels. Typically, the allowable water content in gas transmission lines ranges from 4 lb. to 7 lb. per MMSCF'

In Jan. 2012 my highest gas usage was 3.38CCF per day (average). So in ONE DAY I used 338 cubic feet of gas, for a whole house, in 24 hours.

If there is basically 1 lb of water (water is 8lbs) that means in ONE MILLION CUBIC FEET of natural gas there is 1 lb of water. So in 300 cubic feet there is point zero zero something.


Moral of story: Don't worry about it.

The moisture in a vent-less gas heater comes from products of combustion (natural gas, when burned produced CO, CO2, and H2O (that's water...)) It does not come from moisture contained in the gas.

 

[DPelletier]

Moisture into the space is wrong.
Combustion materials? Whatever that means is still wrong.
Removes O2 from the space? What proof do you have that its occurs?
Danger of solvents? What? Solvents aren't the problem, the VAPORS are, and any heat source will do.

Do do realize that direct vent doesn't mean that there is a 6 foot flame shooting out of the wall, right?

I really cannot believe the misconceptions and myths that about. Gas is going to be much more prevalent due to the lower price..... I'm gonna say that most of the people here are just flat wrong, or at best completely uninformed with respect to it. How many people even HAVE direct vent appliances? I do.

1) one of the products of combustion is moisture. period. This isn't my opinion, it's physics. If you want to argue that the moisture isn't significant in this application, then fine; if you want to argue that there is no moisture, then you need to go back to school.

2) What proof do I have that oxygen is part of the combustion process? really? see previous answer.

3) yes the vapor from solvents can be an issue and yes, the heat source matters. An open flame is more of an issue in this regard than a hot resistance coil.

4) I'm not talking about "direct vent", I'm talking about ventless gas heaters that discharge the products of combustion directly into the space with no vent to discharge it to the outdoors. In a perfect combustion process, the appliance uses gas and air and an ignition source and creates heat, moisture and CO2. If it is less than perfect, then CO is an issue.

http://www.combustiontechnology.co.za/training/perfect_combustion.htm

http://naturalgasnb.com/cms/en/home/safety/carbonmonoxide/default.aspx


I own an institutional HVAC company which has been in business for 25 years, I have taken many courses on a variety of equipment and have installed virtually every kind of heater ever made. Believe what you will.

 

[DPelletier]

Pfarber do you understand the difference between direct vent and ventless? It sure doesn't sound like it.

If there is only a gallon of moisture made from a million cubic feet of gas explain how come a 95% furnace gives off gallons of water a day.

Sent from my C771 using Tapatalk 2

Agreed: direct vent = http://www.eehpatio.com/secondary pgs/DirectVent.html

ventless gas radiant heater =
http://www.spaceray.com/1_ceramic-radiant-heaters.php

Dave

 

[DPelletier]

Removes O2 from the space? What proof do you have that its occurs?

As an aside and assuming you ignore the physics, if you'll look at the link for the heater the OP proposes to use, you'll notice it comes standard with an "oxygen depletion sensor".....

 

[DPelletier]

While I'm at it, here is an excellent article on "Vent-Free Gas Heaters" including wall mounted heaters and fireplaces;

http://www.jlconline.com/Images/Vent-Free Gas Heaters - How Safe__tcm96-1154818.pdf

This should help dispel some of the misinformation about these kinds of heaters. Dave

 

[mmurphy]

With out the science. I have been using ventless heaters for a good 20 years and never had a problem with moisture. Humidity is to low in winter time here anyway.
Only draw back is if you use certain things such as paint, or a spray such as the wife using hair spray it will put out some nasty fumes as it burns off in the air around the burner. I never used one in a garage so I can not add to that.

 

[DPelletier]

With out the science. I have been using ventless heaters for a good 20 years and never had a problem with moisture. Humidity is to low in winter time here anyway.
Only draw back is if you use certain things such as paint, or a spray such as the wife using hair spray it will put out some nasty fumes as it burns off in the air around the burner. I never used one in a garage so I can not add to that.

For the record, I've never said that they can't work or always cause problems. Many people (like you) have had satisfactory results.

What I DO take exception to is the argument that they ALWAYS work fine or that the negatives/problems don't exist. As I said in my posts, they are a valid choice in some circumstances. OTOH, they negatively impact indoor air quality and aren't as safe as other kinds of heaters which is why the Province of British Columbia's Building Code does not allow these heaters on multi-family residential buildings and restricts their size on single family residential. I also believe that several states (Minnesota for eg.) doesn't allow them either.

An educated consumer can make the right choice for his/her needs but misinformation clouds the picture and can lead to poor choices.

Dave

 

[jeepman1]

just my 2 cents... .but a ventless heater will put out 1.5 gallons of water for every 100,000 btus produced. sooo their is definately water or water vapor their. i have seen several ventless heaters installed. i have also seen lots of cracks in sheetrock around the heaters due to excessive moisture.
if it were me i would at least buy a good co detector and put it in the garage with me. also keep in mind that this heater may burn clean enough when its new (it will still produce co even when new) but over time the burners will get dirty and this will cause the air fuel ratio to change and will cause higher levels of co. co kills. so what ever you do please be careful.

 

[Mike007]

I personally would go vent-less. You will always smell it. I installed one a customer had purchased a few years ago. It didn't rain, but the moisture condensed on the walls and ran down leaving yellow stains on the walls and puddles on the floor. I warned him. He now has a vented radiant tube heater.

 

[oldtractors]

I used a ventless NG one winter. It did smell - you could smell it in your clothes after being out there all day. It also created moisture. The moisture also seemed more corrosive than just high humidity. Part of the problem is that it wasn't heated all the time, so there was condensation on the cold tools. By the end of the winter, all of my machine tools had rust on them.

 

[Bruce Amacker]

Don't go ventless, the humidity is terrible. I have a 30k non-vented in a 3 car garage and when I run it the engine assy in my classic car sweats to the point water is nearly dripping from it and rusting all external components.

It's basic chemistry, not myth, and anyone who argues has not had the time to experience the truth.

Put in a small overhead FA furnace vented through a stack.

PS this is also a problem with kero- I used torpedoes to heat a 900sf garage for years and it ruined my tools- all rusty from the humidity generated by the combustion.

 

[pfarber]

While I'm at it, here is an excellent article on "Vent-Free Gas Heaters" including wall mounted heaters and fireplaces;

http://www.jlconline.com/Images/Vent-Free Gas Heaters - How Safe__tcm96-1154818.pdf

This should help dispel some of the misinformation about these kinds of heaters. Dave

This is pretty much what I said.

But the empirical stories of 'rain' are followed by this:

"This extreme example represents a
misuse of the equipment that violates
all industry recommendations"

Ventless (putting combustion gasses into the room) is no more worse than using a humidified, that can, put a gallon of water in the air in an hour.

If you don't believe my, read the cited article... it says what I did.

 

[DPelletier]

This is pretty much what I said.

.

Sure. OK, I'll let the oxygen and water in the gas comments go. The bottom line is that ventless gas heaters have some negative traits and whether those traits are a problem for you or not depends on the circumstances and your expectations.

Dave

 

[DPelletier]

There are five elements in a proper HVAC system. They are; temperature control, filtration, fresh air, humidity and circulation (prevention of stratification).

Let's see how a ventless gas heater stacks up;

temperature control: yep

filtration: no

fresh air: double no. not only does it not provide fresh air, it lessens the indoor air quality in the space

humidity control: no, it introduces humidity at an unchecked rate.

circulation: no

A simple home forced air heating system addresses all five. Now, not all garages have the same utilization and, in fact, I'd argue that they are used in widely disparate fashions... therefore you need to weigh the positives and negatives of every system based on the situation.

I'll use my latest garage as an example; it is an attached double with a workshop. it is approximately 734 sq ft with 11' ceilings. It is used as:

- storage for my wife's daily driver
- storage for my collector car (very seldom driven)
- a workshop and tool storage area where I perform a variety of automotive, small engine and household projects but no real painting, welding, grinding type projects (I have a 5000 sq. ft. metal fabrication shop for that stuff).

I have natural gas available in the garage wall. approximately 50% of the walls are shared with the home and above the garage is a heated bonus room. The forced air heat runs to this room run concealed in the garage ceiling space.

Recent temperatures right around freezing show the garage (with no heat) keeping around 14 - 15 degrees celcius and 44 - 47% RH. I have been using a small 1500watt electric heater when I want to bump it up to 17 - 20.

After considering cost, complexity, maintenance, energy costs and comfort, I have chosen to use a Dimplex 2KW electric heater in conjunction with a 300 CFM exhaust fan hooked to a humidistat with a fresh air intake c/w BDD on the opposite wall.

This sytem is inexpensive to purchase and easy to install. Energy consumption isn't a huge issue given the small load.

temperature control: yep

filtration: no (though I could easily install a filter on the incoming fresh air)

fresh air: not continuously but just like many houses, the humidity will rise and kick on the EF depending on setpoint.

humidity control: yes

circulation: yes, but not well: heater has a propeller fan and exhaust fan will be used if paint or solvents are being used.

....just an example of some of the things people should think of when deciding on any heating system.

If my shop was a stand alone welding or automotive shop, I'd go in a completely different direction; probably radiant tube or in floor hydronic with an exhaust system.


Dave

 

[Mike007]

I personally would NOT go vent-less. You will always smell it. I installed one a customer had purchased a few years ago. It didn't rain, but the moisture condensed on the walls and ran down leaving yellow stains on the walls and puddles on the floor. I warned him. He now has a vented radiant tube heater.

Duh. Fixed my previous post.

 

[DPelletier]

Duh. Fixed my previous post.

We knew what you meant.


Dave

 

[stingry]

OK, I'll jump in here. I installed the exact same heater that the OP proposes to use in a 24 x 24 attached garage. It is well insulated with 2 insulated 7x9 overhead doors. I live in western NE, where it is fairly dry and rarely dips below 0 degrees in the winter. I used this heater one winter and here is what I observed:

Yes, it produced moisture even in our dry climate. The windows in the garage would condense moisture to the point it either froze on the windows or ran down the wall.

It produced a noticeable odor which I found to be quite objectionable!

After it ran for a day or so, the flame would turn yellow and would not burn consistantly, signs of oxygen deprivation. Eventually, it would shut down. Yes, I realize this is from not having enough outside ventilation, BUT why have a heater that you have to open a friggin' window to have it run properly?

I no longer use this heater.

These are my own personal experiences with this heater, you decide.

Cheers
Steve

 

[BadgerBoilerMN]

DPelletier is the only smart guy in this thread. (OK, a couple of honorable mentions).

Ventless gas-fired space heaters can be a serious hazard if misapplied. They do not have their own source of combustion air, which means they compete with the occupants for O2 and creature CO when not satisfied. If your garage is fairly loose you may not notice the considerable and quantifiable water vapor produced when any fossil fuel is converted.

I don't know any gear head that thinks moisture is a good thing in shop.

If all of this flies in the face of "your" common sense, just remember, dumb luck is for dummies.

If you are on a budget a direct-vent tube heater or unit heater if you must, with combustion air supplied from the outside. The closer and tighter the space the more important combustion air is. Since I will wager that few in this blog have a combustion analyser to assure their appliances are not making CO, the simple, cheap, shortcuts so often proffered on this sight should be taken with rock salt.

 

[AaronH87]

I do have access to the tools to meter CO levels as well as other products of combustion

 

[BadgerBoilerMN]

If you got'em smoke'm!

 

[AaronH87]

Perks of working for the Fire department full time and living in my stations response area

 

[koditten]

I had a ng heater for 1 winter before I got my floor heat going. I had no problem with humidity or CO. You will be fine heating the garage with your centers heater. The warm glow is nice too.

KO

 

[jmarkwolf]

Time to start thinking about heating garages again, particularly in Michigan.

I'm building a new detached 28ft x 30ft garage, to compliment my attached 22ft x 24ft garage, and am deliberating as to which heater to put in it.

I put a 30,000btu ventless NG (natural gas) in my attached garage 15 years ago, and it has worked great. The heater is a bit overkill for the room size, and never needed more than a couple "clicks" over "low" to heat the room.

But this time I consulted "Garage Journal" for the current wisdom on such matters and find that ventless heater opinions are not very complimentary, citing humidity, CO (carbon monoxide), and oxygen depletion.

As far as CO, I've always had a CO monitor in my attached garage, and the only time I've ever seen the reading higher than 0.0 is when I drive a car in or out. It always returns to 0.0 after several minutes.

As far as humidity, I've never noticed any rusting on anything (tools, aircraft, cars) in the garage in all this time, although the single double-pane picture window does seem to condense more than normal. I just chalked it up to a "builders grade" window, but an now wondering if it's something more. In any case, a suppose an inexpensive dehumidifier could eliminate that issue.

As far as depleted room oxygen, occasionally opening or cracking a door will replenish oxygen levels, will it not?

An alternative of course is to use a more conventional vented furnace, but then you have to deal with flues and stacks, and will need more BTU to compensate for heat losses out the exhaust.

So, I'm debating with myself as to which way to go, and not winning the argument.

 

[Todd.Brock]

I have a vent free fireplace in our basement. It *****. I hate it. It stinks and I used it twice. Now it's just for hanging stockings at Christmas.

To me, the hard part of a NG heater is the NG. I would have run one in my garage , except NG is at the opposite end of the house. I would make a chimney hole in a heart beat.

I ended up going with electric. My vote is vented.

 

[Zurawskt]

So I will jump in a say I just ordered a tube heater and will have to vent it, after all the time I spent looking at all the options it seems like there is no good reason to use a ventless heater unless you plan on SPOT heating in a VERY well ventilated area. What's the big deal with running a vent pipe, piping is cheap and many forced air units are power vented, you can vent horizontal or verticle. Seems to be the lazy way to go ventless, just MHO.