Will 30k BTU be enough??

[SteelHorseHD]

Hi all,
I just have a quick question for anyone who might have an answer.

I have a 36x45 shop (1620 sq. ft.) with 10ft ceilings, R40 in the attic and R-19 in the walls. I dont have any windows but have two insulated overhead doors. My plan was to build an outdoor wood boiler to heat the house and the garage this winter but I have to save my money (getting married next year. I know, I'm stupid) For the meantime I would like something to keep the garage warm this winter because I finally finished the bathroom and plumbing, so I would enjoy a warm place to drink beer this winter other than being stuck in the house. I plan on installing 4 ceiling fans before the weather gets too cold to help circulate the air a little bit. I am thinking about installing one of those 30k BTU ventless propane heaters to just get me through this winter. I live in Illinois so the average temperature is somewhere around 30 degrees in the winter. The heater is supposed to be able to heat 1000 sq. ft. Do any of you think this will get the job done if I utilize my ceiling fans? I appreciate any input. Thanks.

 

[Zick]

I think it will be on the small side. Plus as a side note, I would not get one of those ventless propane heaters or else you'll have moisture issues to worry about.

 

[SteelHorseHD]

Thanks! I have heard that they cause moisture issues I Just wasn't sure how severe it gets. My first choice would be one of the Mr. Heater 75,000 BTU hanging units. I think it would probably get the job done but I just want to save as much money as possible because I will most likely only use it for one winter until I get the wood burner built. Thanks for your input.

 

[fabrk8r]

Look around for a used propane house furnace. A lot of times you can find one cheap that someone changed out for a higher efficiency model. Sometimes you can get one for free if you haul it.

Build a stand for it to get it at least 18" off the floor and vent it out the roof with "B"-vent using proper clearances. You can have a filter rack for the return and an elbow built for the top (don't use wood) at a sheet metal shop for a reasonable price.

 

[tabascokid]

I have a that heater, used it to heat my 3 car attached garage 28 x 40, 12 high, only used when I wanted to warm things a up a bit, replaced it with natural gas unit. I live in N. Ohio, winters get colder than 5. Still have the propane model looks brand new built by Procom bought from Grainger, if your interested let me know, hint: love to find it a new home (have to double check btu 25k or 30K), It warmed the place up, can't comment on moisture garage well insulated, 3 insulated 9x9 doors, 2 man doors

 

[Charles (in GA)]

In Illinois, no it won't do. In south Georgia, it probably would.

Charles

 

[regguy1]

Here's chart to help you choose correct size, they go by cubic feet. Looks like you'll need
90K Btu. With your good insulation you might wing it with a 75K.......


http://www.mrheater.com/upload/10-27-08 MH 2008 NT Heat Guide.pdf


75K on sale at NT:
http://www.northerntool.com/shop/tools/product_200316363_200316363

Modine:
http://www.djsonline.com/modineunitheaters.htm

Reznor:
http://www.djsonline.com/reznor_UDAP_Unit_Heaters.htm

 

[SteelHorseHD]

Thanks guys. I have found several used hanging units that range from 125k - 250k BTU. I Just don't know about buying a used unit. Everyone "claims" they still work but none of them are still hooked up.

 

[BadgerBoilerMN]

The volume of any structure is only one component of many - including inside and outside design temperatures, insulation (top, bottom and sides), windows and doors, ventilation, etc.- used to determine the heat load and size a boiler or unit heater.

It is silly to guess or depend on the WAG advice of your peers.

Before spending good money on any space heating equipment, it pays to have a professional perform a proper Manual 'J' heat load analysis. They look like this:

http://www.badgerboilerservice.com/images/SampleHeatLoadAnalysis.pdf

Ventless heaters are great as long as they are vented...crack a window or door so you don't wake up dead. As for building an outdoor boiler, better to buy one and get some help designing the distribution system.

Remember, 30m is the output of a vent-less space heater so 100% stays in the heated space, including the water vapor; a result of any fossil fuel conversion. The vent-less will likely keep the shed at 65F plus, if the doors are not opened much but moisture will be an issue.

 

[irisservice]

What is the cost of ventless?
i figure a unit like that would cost $300...
A MR. heater Big max would cost $500 for a 75,000 BTU

 

[fabrk8r]

The only reason I suggested a used furnace is because the OP wants something inexpensive to keep his shop warm enough to work in this winter.

The cost of a Man-J load calc is going to be more in itself than getting some heat in the place so the guy can work. He doesn't need the shop to keep a family of 5 comfortable. He needs to keep his fingers from freezing to his wrench handles and maybe keep his dog's water from turning into a block of ice and still be able to afford his upcoming wedding.

 

[SteelHorseHD]

The ventless heaters cost about $200. I think I might just bite the bullet and buy the Mr. Heater 75k unit for $500. It's a little bit more expensive but I'm sure I will be much more satisfied in the long run with it. I really appreciate all of your help on this.

 

[half_full]

The only reason I suggested a used furnace is because the OP wants something inexpensive to keep his shop warm enough to work in this winter.

No offense but the OP wants it warmed to drink beer. Any productive work is just an excuse to be out of the house

 

[Bojans]

I assume if you are talking about a wood burner you will have some type of radiant heat in the shop. The 75k unit will be a very nice for a quick warm up of the space if you keep it cooler when you are not out there.

 

[SteelHorseHD]

No offense but the OP wants it warmed to drink beer. Any productive work is just an excuse to be out of the house

Haha! you've got that right!

I assume if you are talking about a wood burner you will have some type of radiant heat in the shop. The 75k unit will be a very nice for a quick warm up of the space if you keep it cooler when you are not out there.

My plan was to just use a water to air heat exchanger and suspend it from the ceiling. I looked into the heated floors but to do it the right way it's just too expensive. I plan on keeping it around 50-55 when im not out there.

 

[caper150]

Not to hijack your thread BUT...... I have a 1300 sq ft shop with in floor heat that runs off of a 40 gal eletric hot water heater that I was told would be sufficent, but IMO is not and cost me a fortune to heat in the winter. Question I have is that I was told last year that I would never get an in floor system to comfortably heat my shop and that I would need a seconday heat source. I have a ventless heat system and was thinking of using that to help it heat the shop and npot break the bank but would I be able to run it constantly to be efficent????

 

[SteelHorseHD]

Well this weekend I was at my local Lowe's store and walked through the heater section just for the hell of it and ran across the Mr. Heater 75K BTU unit. It was the natural gas model but it was only $469. I can buy the propane conversion kit online for $25 and I also get a 10% military discount at lowes. Looks like thats what I'm going with!!

 

[58Yeoman]

I had a 30,000 ventless in my last garage, as 28x28 w/8' ceilings. I used a propane salamander heater to pre-heat the garage, then used the ventless to keep the temp up. It DOES put a lot of moisture in the air. In my 'new-to-me' shop, 24x40, I installed a mr. heater 75k. I haven't had a chance to use it in the winter yet, but will this year.

Not only does the ventless put a lot of water in the air, causing rust, but it can also stink to high heaven after a while.