Question on Mr. Heater Products

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wtrgp32

New Member
Hearth Supporter
Jan 21, 2007
2
Hi guys!

I'm writing from Central New Jersey. I have a pre-fab modular garage / workshop on the property. It's about 38' x 26' x 8'. The WALLS are 8' at the eaves rising to 10 feet at the peak. It's got a large overhead door, but this isn't opened during the winter. It's got one standard-sized door and four windows. A portion of the garage is used for the storage of two riding lawn mowers, two ATV's and a small go-cart.

I've enclosed a small area about 10' x 15' with a heavy gauge plastic drop cloth, and use this area as a wood-working shop. I purchased a Edenpure heater (the large one) with the expectation that it would heat the area, but I was wrong. It doesn't put out enough BTU's to do the job.

Right now, it's about 30 degrees or so during the day, although it sometimes gets colder in the middle of the winter. I don't plan on spending much time out there if there's a lot of snow on the ground, but I'd like to do some light carpentry out there from time to time.

I'm interested in the Mr. Heater MH42T Triple Heater which mounts to the top of a 20 lb propane tank.

This is the item.

My question is - Do you think this will suffice for heating in the cold weather? Do you think it would be safe with the plastic drop sheeting? Another concern is the possible presence of gasoline vapors from the lawn equipment, but I don't that's a real threat.
 
I have a house that is under construction here and thats what I use. Wont heat the whole house (2000' ) but keeps the area Im working in warm enough ( at least until the temps drop into the teens.) It will light stuff on fire so be careful where you put it and be sure there are no gas leaks on your equipment. One negative, It eats propane like a pre EPA wood stove eats softwood. On high mine goes through a tank in about 10 hours.
 
How does the BTU rating of the Mr Heater unit compare to the old inadequate heater? Their MH40 (40K BTU?) heats up to 850 sq ft.

Just looking at Mr Heater product manual sheets, they say

"This appliance is unvented and must be used in a well ventilated area".

and

"Do not use this heater in a space where gasoline or other liquids having flammable vapors are stored or used".

So their you go.

Aye,
Marty

Grandma used to say, "The only substitute for using good judgement is years of appropriate positive experience."
 
I investigated a lot of different heating devices for my 24x24 garage that is really an off-and-on workshop. If I follow your explanation, you want to use an on-demand heating device to add a little warmth if you decide to do some work in the shop. That was my goal too.

That triple head unit will heat that space, but propane will put out some fumes. I have a single head unit and it puts out some noticeable fumes in the whole 24x24 space after an hour or so. It will bother some people more than others. I'd use a CO detector though if you go the route of any propane device. Also, those are radiant heaters and work best when you will be warmed by the direct radiant energy (meaning you have to stay close enough). Eventually it will warm the air though. 3 head unit is oversized for that space - I'd go with the single or double.

I also tried several other types of propane heaters. Mr. Heater makes a short squat round unit - I took it back. I also tried one of the forced air units that blows out the heat. What I eventually realized (duh) was all these propane devices had combustion byproducts that didn't make them suited to a close environment. It burned my eyes, bothersome smell, etc.

I ended up buying a Berko "red cube" 240v electric heater. It is about 1'x1' square. I have to run it awhile before heading out to the garage, but it gets the job done. Here is a link: http://www1.epinions.com/content_125008187012

I also have an old kerosene heater. I grew up with kerosene and am not as bothered by the fumes as some folks. I think they put out less combustion byproducts, possibly due to less actual combustion. Regardless, it takes a while for it to warm up the space but is my preferred method if I have some advance notice that I might spend a while out there on a project.

Wow, I didn't intend to write all this. Sorry. I may as well finish. There is another negative side affect of fast warm heaters. They heat the air rather quickly, but then you have LOTS of condensation onto your cold metal tools. Surfaces like wrenches, bandsaw tabletops, etc. will develop condensation and can rust. I found it really annoying. It seemed to happen worse with the propane, probably due to the H20 created as a byproduct of combustion.

Electric heater - requires 240v you may not have. But your small 15x10 space might actually get by with an el-cheapo 1500 120v heater.

Kerosene - takes longer to heat up than the high output propane heaters, but less disagreeable fumes IMHO.

Propane - fast heat. Good to keep somewhat near you if you will stay mostly in same area like sitting on a stool at a bench. Worse fumes I believe due to more actual combustion..
 
I also have a 10x12 room in my garage that I heat with a 110v electric oil filled radiator. Although it is well insulated. does take a bit to heat up but keeps it plenty warm even when its 20 outside.
 
If you are using power tools, watch the sawdust and the flame. It wouldn't be a problem with hand tools since the sawdust is heavier or plane curlies drop to the floor, but a table saw will put a fair amount into the air.

A woodworking board like woodnet.net may be able to offer more specific advice.

Matt
 
Thanks for the Quick Responses:
Marty-the BTU ratings for the two devices you questioned are
EdenPure Heater-Rated at 5000 Btu while the Mr Heater is up to 42,000 Btu' thats quite a jump.
The EdenPure however has a fan built in with a rating of 105 CFM,while the Mr Heater of course
has no fan.The fan didn't really seem to help/
You fellows answered a lot of Questions for me,and for that I thank you. I'm still kind of up in air
a little. I'll have to make my decision as to rapid heating (How quickly I'm able to start working in there) and safety. I'd would love to put a wood or pellet stove in, but I would be uncomfortable with
having that "smoldering", on it's own overnight. Plus the fact a stack outside would upset the
neighbors,I'm sure. Probably the local authorities also.Anyhow Thanks again-I'll be back.
 
wtrgp32 said:
Thanks for the Quick Responses:
Marty-the BTU ratings for the two devices you questioned are
EdenPure Heater-Rated at 5000 Btu while the Mr Heater is up to 42,000 Btu' thats quite a jump.
The EdenPure however has a fan built in with a rating of 105 CFM,while the Mr Heater of course
has no fan.The fan didn't really seem to help/
You fellows answered a lot of Questions for me,and for that I thank you. I'm still kind of up in air
a little. I'll have to make my decision as to rapid heating (How quickly I'm able to start working in there) and safety. I'd would love to put a wood or pellet stove in, but I would be uncomfortable with
having that "smoldering", on it's own overnight. Plus the fact a stack outside would upset the
neighbors,I'm sure. Probably the local authorities also.Anyhow Thanks again-I'll be back.

Question: if what Marty said is corrct that this heater should NOT be used in a confined space, what "decision" is there to be made? There are no "trade-offs"......the manufacturer is saying (between the lines) that if you use it in a confined space it may kill you.....
 
castiron said:
wtrgp32 said:
Thanks for the Quick Responses:
Marty-the BTU ratings for the two devices you questioned are
EdenPure Heater-Rated at 5000 Btu while the Mr Heater is up to 42,000 Btu' thats quite a jump.
The EdenPure however has a fan built in with a rating of 105 CFM,while the Mr Heater of course
has no fan.The fan didn't really seem to help/
You fellows answered a lot of Questions for me,and for that I thank you. I'm still kind of up in air
a little. I'll have to make my decision as to rapid heating (How quickly I'm able to start working in there) and safety. I'd would love to put a wood or pellet stove in, but I would be uncomfortable with
having that "smoldering", on it's own overnight. Plus the fact a stack outside would upset the
neighbors,I'm sure. Probably the local authorities also.Anyhow Thanks again-I'll be back.

Question: if what Marty said is corrct that this heater should NOT be used in a confined space, what "decision" is there to be made? There are no "trade-offs"......the manufacturer is saying (between the lines) that if you use it in a confined space it may kill you.....

Propane heaters use lots of oxygen. The warning to not use in a closed area without a source of fresh air. You will see the same warning on non-vented gas wall heaters for your house. Their they usually say to crack a window in the room. Same thing applies to RV's with radiant heaters. I like the heat from a propane heater, but they are expensive to run. So I use some kerosene heaters.

I have a 12 X 15 room that I usually close in the back in the winter. If I need to use it even to store work for a few days to keep it warm, before I can get to it. I use a 23K Btu, radiant heater, not the convection type. Usually, a tank full of kerosene (1.9 gallon) will last two or three days. This warms the furniture and then warms the room. I can regulate it down to about 8K Btu. An hour at high and turned down it will keep a constant 64* even in the teens outside. Unfortunately it's been single digits and lower here lately, so the door is closed and the thermal curtain is draped and secured. I let customers pay for the heat to store their stuff at home and I pick up the day before I start to work.
 
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