Vented Propane Shop Heater..

[3 Phase Lightbulb]

I'm looking at some of the larger vented Propane shop heaters and was wondering if it's possible to run them with a 40lb Propane bottle? Or even a 100lb Propane bottle?

Specifically I'm looking at this 75,000 vented Propane garage heater:

http://www.mrheater.com/productdetail.asp?id=793&cid=148

The specs say it has a 1/2 inch LP gas fitting and nothing else. Does anyone know if I'll be able to hook up a small Propane (40-100lb) bottle to something like this? Is there a special hose/kit somewhere? I realize it's not going to last very long with just a small bottle.

-Adrian

[CCWKen]

The part I read says that it comes with a gas conversion kit. That might be cheaper, if you have gas service. With LP at full rating, a 20lb. bottle may last only 4-5 hours.

Since it's vented, it has to be mounted. You might check this option: Universal Hook Up Kit - Stock #: F271239

You'll probably have to run a copper line to it. 1/2" is going to pass a lot of gas!

I have one of their 3-burner heaters but that's in a "well vented" barn.

[3 Phase Lightbulb]

Is "LP" the same type of Liquid Propane that you get for your average 20-30-40lb bottle? I've seen references to "Propane Gas" and "Liquid Propane" and I'm wondering if there is a difference?

I want to mount a good Propane heater in my garage up high, and vent it outside with a vertical vent kit, but I just want to make sure I can run it with a propane bottle, and not with a propane service (I.E: Metered Propane). Is there a difference?

If a 20lb bottle will run 75,000 BTU for 4 hours, that would be great! Basically I just want to heat my garage on Saturdays this winter for 6-7 hours. I don't mind filling a 40lb propane bottle every weekend.

I'd love to get a wood stove but I don;t want to give up any floor space. I like the idea of mounting a large Propane heater with a vent.

-Adrian

[cntryboy1289]

Not sure where you live, but where I am from, you can rent a 250 gallon tank for like $50/year plus your gas. I wouldn't try to tell you not to do what it is your trying to do, but a 75,000BTU furnace will use up a 20# bottle in a hurry when you have to heat a cold shop and a 100# bottle won't last for more than 2 weekends. If it runs for an hour, it would just about use up the gas in the 20# bottle and it will most likely have to run that long in a shop unless it was well insulated. Even running back and forth to get 25 or 100 gallon bottle filled will be more than having the tank set up and you will burn close to a tank of gas if you do much work even just on Saturdays this winter. I would opt for the ease and simplicity of using their tank and having them come to you to fill it.

Yes, you can plumb off the smaller tanks and hook them directly up to the heater, they all use the same size connections off the tank and you can use whatever size piping is needed according to your code with the proper gas line connections with a shutoff valve. I would just hate to have to pick up and lug round the 100# bottle each time I needed gas myself.

[Your Old Dog]

When I looked into this years ago I was told to stay within sizes consistant with a propane grill as a guide. Many grills are 35,000 btu running off 20 lbs tanks. It has to do with the gas vapor rate out of the tank. You might want to check with a propane company but my guess is they will suggest 2 100 lb tanks in a manifold arrangement for 75K unit will be the most efficiant. (it might also make a nice backup fuel system for emergency use)

[Tin Falcon]

Propane gas vavor rate. The problem with a high demand rate on a small tank is that as the lp vaporizes it cools the tank . As the tank cools the vapor pressure lowers. This reduces pressure to your regulator. In laymans terms the tank will freeze.Solution bigger tank or manifold multiple small ones. I used to run a stove and gas water heater off a 20 lb tank in a cabin for weekend use. You could probly use two 40lbs manifolded togetherlike they do on rvs.Work safe do your homework.

[Tin Falcon]

Propane gas vavor rate. The problem with a high demand rate on a small tank is that as the lp vaporizes it cools the tank . As the tank cools the vapor pressure lowers. This reduces pressure to your regulator. In laymans terms the tank will freeze.Solution bigger tank or manifold multiple small ones. I used to run a stove and gas water heater off a 20 lb tank in a cabin for weekend use. You could probly use two 40lbs manifolded togetherlike they do on rvs.Work safe do your homework.

[rws]

I run a 35000 BTU Modine vented LP heater in my wife's greenhouse. I have three 100# tanks, and have a "switching" regulator so it will switch to the full tank when one runs out. When one is empty, I hook up a full tank, when the next runs out, I take two at a time to refill while running on the last tank.

For a heater of that size, you'll run yourself to death refilling tanks. Believe me, I get tired of the way I do this small heater.

Depending on what the cost of propane does this winter, she may be out of luck this year, and all the plants in the house!

[dhammer]

I'll second what Tin Falcon says, depending on where you live you might run into pressure problems with a 20 lb or even a 100 # cylinder. In addition the cost per gallon in a 20# cylinder is higher than having LP delivered to a bulk tank.

Propane contains about 90,000 BTU/gal, a 20# cylinder contains slightly less than 5 gal liquid LP.

I'm hanging a LP heater in my shop too but might not use it too much this winter.. the price of LP is on the rise.. $1.60/gal today.. tomorrow who knows?

[Ian B]

The freezing problem can easily be solved - just stand the bottle in front of the heater!

Joking aside, when I'm running a large burner tip off a propane bottle, I usually stand the bottle in a large tub of warm water - this effectively cures the freezing. Maybe a quick waft with the torch would work too...

Ian

[Evan]

"Maybe a quick waft with the torch would work too..."

Yeah, it'll find leaks for sure. You'll need at least a 100lb bottle (or equivalent) to avoid the freezing problem. 75,000 btu is a fair amount of input. I've used propane to heat my shop in the past and found this out the hard way.

See here:

"Rule of thumb for heater tank sizing is: 75,000 BTU heater needs minimum of one 100 lb tank..."

http://www.nbmc.com/lpchart.html

[3 Phase Lightbulb]

I wonder if two 40lb bottles on a manafold would provide more linear pressure than one 100lb bottle. I like the idea of putting smaller bottles on a manafold because the smaller bottles (<100lb) don't need a permit in my state and are easier to throw in the back of my truck.

[Al Messer]

I bought a vent-less wall mounted Propane heater from Lowe's about three years ago with which to heat my shop-- 25' x 42' . I have it attached to a 250 gallon tank with a 1/2" Copper line threaded through PVC to protect it. I only have to fill the tank in the Fall and Spring. I still have about 55% left from last filling.

[ARFF79]

Adrian

That looks almost identicle to the one hanging in my garage/shop. Last year I used just under 900 gallons of gas, Nov.-May. The building has about R-30 insulated walls, but the roof insulation needs to be redone and increased. Bldg size is 24x32x10 under eaves and the unit is fed from 2- 100 gallon manifolded tanks. I live in a creek valley so moisture is a year round concern especially in the spring and late fall from heavy dews and frosts. I keep the thermostat set for 40* unless I am working in there long term or have a project needing paint,then I boost it to 65*.The rest of the summer it is turned off. You will use less gas if you keep the temp. constant as opposed to heating it up for a few hours each week as everything in the space needs to warm up as well. Keep moving at 65* and you can get quite warm. The biggest use of gas seems to be on extremly windy days. With standard garage doors, it just seems to suck the heat right out. After re-insulating the roof I will probably replace the doors with insulated ones.

I use a local service to fill the tanks. they own them and all piping to the building connection. I paid a one time fee for tank rental and installation, but your suplier may be different.

Also check you building codes. Here in Pa.,I can daisy-chain as many 100 gallon tanks together as I want and keep them right next to the building, but if I install a 250 or larger tank, I must place it at least 25 feet from any structure and bury the feed line under ground, below the frost line. Go figure. I believe the fire hazard is the same if not greater on a manifolded system as opposed to a single source.

[dfeeney]

I just finished installing a Mr Heater vent free infrared heater in my shop. The heater is 25,000 BTU and I am using a 100lb tank. The walls and ceiling are insulated. I used rigid insulation for the garage doors. My shop is 24x24.

The Mr Heater people swear that it should keep my shop hear in Maine heated.

So far I have just kept the temp set at 55*. The nights so far have been in the mid- to low forties and hasn't been running very often.

I guess I will see how well it works very soon!!

[3 Phase Lightbulb]

I think the ceiling in my garage/shop is around 14' high so no matter what I use to heat it, I've got a lot of wasted heat up high before it starts to fill up and start comming down. My garage doors are not insulated either so it's going to be a battle tring to heat it this winter.

-Adrian

[Evan]

You need a ceiling fan.

[3 Phase Lightbulb]

I was just going to wear stilts, but a ceiling fan would definitely solve the problem.

[ARFF79]

After you install it, get a couple of sheets of fiberglass duct board and form some ducting so that the heat is blowing down towards the floor. Yes it will rise to fill the ceiling, but it will give you some circulation and help warm your tools and the floor sooner.

[robinssm]

My LP company gave me this formula for the Pikes Peak area 7500', however the efficiency of your heater and your insulation will have a play in this as well. Take the BTU rating "130,000" divided by "91,500" this will give you the amount of LP consumed per hour "1.42......" in gallons.

[3 Phase Lightbulb]

I bought the Mr. Heater Big Maxx 75k BTU/Hr unit with the Horizontal Vent Kit, Thermostat, and Universal Hook up kit. I'm not sure what other fittings I'll need, but hopefully it should be straight forward when I have the unit in hand.

Does anyone know what the average price is to buy/rent 100lb bottles? Any idea what the average price is to fill a 100lb bottle? Any idea how long (in hours) a 100lb bottle will last with the unit always on?

-Adrian

[Your Old Dog]

We need to renew this thread mid-winter. I'm using wood but wanted to go to either Natual Gas or propane if it's not too expensive. (For what I paid for my stainless steel 3-layer chimmney I could have put in a vented wall heater on each wall. What the hell did the pioneers do before triple wall stove pipe? I need it for insurance purposes. $79.00 for 1- 3 foot piece)

[This message has been edited by Your Old Dog (edited 10-05-2005).]

[dfeeney]

It cost me $250 for the complete installation. The 100lb tank cost around $250 to fill.

[3 Phase Lightbulb]

<font face="Verdana, Arial" size="2">Originally posted by dfeeney:
It cost me $250 for the complete installation. The 100lb tank cost around $250 to fill.</font>

Wow, you pay $250 to fill a 100lb tank (~24 gal)? If so, you're paying ~$10/gal for LP! You might get more BTU's from of burning $1 bills http://bbs.homeshopmachinist.net//wink.gif

[Evan]

Something way wrong with that. It cost me about $16 CDN to fill a 30 lb tank. About $10 of that is the fill charge.

[This message has been edited by Evan (edited 10-06-2005).]

[3 Phase Lightbulb]

I got my Big Maxx heater, a horz vent kit, a universal adapter kit, and a 100lb propane bottle ($64 to fill, and $.33 per day rental from my welding supplier).

Now I need to find an ~11 inch (wc) water column LP regulator. Anyone know of a good online supplier for the 11" WC regulator, and other things I'll need like a gnd joint union, plugged tap, drip leg, etc... ?

-Adrian

[CCWKen]

A heating and plumbing supply store should have everything you need. (Not Home Depot--Go to a supply house.)

The ground union is steel or iron but I don't know why you would need that for a propane setup. You can ground the tank and the regulator has a union type connector. The heating unit should already have a ground via the cord/wire. A union is just so you can remove a section of "pipe" without disassembling the whole works.

Plugged tap- A plug tap? or Ground plug tap?

Drip leg- This is nothing more than a drop from a Tee. Normally it's about 12" long with a valve on the end. It allows you to drain condensation from the gas line. Usually not needed for propane.

Geez Adrian, this project looks like it's running into some buck$. An extension from the house system may have been cheaper. http://bbs.homeshopmachinist.net//eek.gif

[3 Phase Lightbulb]

Ken,

Yea the local hardware store didn't have the right regulators.

The heater is a vented system that is permanently mounted in my shop and I've never done any propane plumbing before so I want to have some fun and install it to code. The installation manual shows what parts I need/etc.

My house furnace is Oil/Forced hot water and already has 4 zones so I don't want to add a fifth.

-Adrian

[CCWKen]

Yikes! I feel for you guys up North with oil heat. I remember those days but fuel oil was only $.26/gal. back then.

[3 Phase Lightbulb]

I installed my vented shop heater today:

http://www.bbssystem.com/pictures/heater1.jpg

http://www.bbssystem.com/pictures/heater2.jpg

-Adrian

[JIMofalltrades031]

Looks good so far Adrian. Make sure you install the rest of the venting properly. By going horizontally out you have to make sure you go vertically far enough to get clean air above the roof line or the heater will have problems venting and you will get CO poisoning. Also I would look into getting a 120 gallon tank as this size is fillable from a bulk delivery truck.(this will save you a considerable amount of money in cost per gallon). If you stay with the smaller tanks I can't help but think that the price would be better at your local propane supplier as he probably supplies your welding supplier. You will like the heat. But you will get higher humidity in your shop. Heating up and then letting it cool down will play havoc with your steels and tools.

Jim (Hank Hill's brother in Deland) http://bbs.homeshopmachinist.net//biggrin.gif

[3 Phase Lightbulb]

<font face="Verdana, Arial" size="2">Originally posted by JIMofalltrades031:
Looks good so far Adrian. Make sure you install the rest of the venting properly. By going horizontally out you have to make sure you go vertically far enough to get clean air above the roof line or the heater will have problems venting and you will get CO poisoning. Also I would look into getting a 120 gallon tank as this size is fillable from a bulk delivery truck.(this will save you a considerable amount of money in cost per gallon). If you stay with the smaller tanks I can't help but think that the price would be better at your local propane supplier as he probably supplies your welding supplier. You will like the heat. But you will get higher humidity in your shop. Heating up and then letting it cool down will play havoc with your steels and tools.

Jim (Hank Hill's brother in Deland) http://bbs.homeshopmachinist.net//biggrin.gif</font>

This unit has an exhaust blower so there is no need for any vertical venting. The Horz vent has a 1" rise per 12" of run and extends about 12" away from the house terminating with a vent cap.

I don't expect the humidity to change at all since it's a fully vented system. All of the moisture from the propane combustion is blown outside so I'm not adding any moisture.

-Adrian

[Evan]

What Jim said about the larger tank. Around here you can get a 250 gal tank delivered and set up for free with first year rental free and only $65 US a year rental after that. Bulk propane is $00.50 US per pound here right now.

Check your code for minimum distance from an exhaust stack to an opening window.

[This message has been edited by Evan (edited 10-23-2005).]

[3 Phase Lightbulb]

I only need heat for a couple of hours on the weekends and only for a few months (Dec, Jan, Feb, Mar). Renting the 100lb tank for 4 months will cost me $40, and propane is 64 cents a pound. I can always switch to bulk later, but I'll see how things go this winter. I'll be very happy if I get four weekends per 100lb tank (~8 hours per weekend).

-Adrian

[snowman]

Adrian,

I'm with the others, only because 100lb tanks are a bitch to move.

I dont like laying down any tank to transport, I'd much rather have the "jug" that they sell, but I honestly dont think we are allowed to have them in this town....something with the zoning. I dont know.

I do like my 100lb, I have it hooked up to the grill. I've had it on the grill for two years and I think it's still half full (probably should check before that part of the yard gets snowed in).

Just make sure you put your tank someplace that's easily accessible...and find some way of loading and unloading with ease.

Heat is nice, my father in law is working in the garage right now, installing the corn burner. I plan to run it four days a week...start it up on Wednesday evening, shut it off on Sunday (my ratrace job non-working days). I am geeked to have cheap heat this winter! Plus I can buy all the corn for the year now, and deduct it from my business taxes.

-Jacob


-Jacob

-Jacob

[3 Phase Lightbulb]

<font face="Verdana, Arial" size="2">Originally posted by snowman:
Just make sure you put your tank someplace that's easily accessible...and find some way of loading and unloading with ease.
</font>

I've got my 100lb tank right near my garage door. Swaping them out is no big deal. In fact, my 300 CF Argon bottle for my TIG machine feels more heavy. You can see my white tank temporarly connected to the heater in this picture:

http://www.bbssystem.com/pictures/heater3.jpg

-Adrian

[Evan]

http://bbs.homeshopmachinist.net//eek.gif

[Your Old Dog]

Adrian, you sure you won't void out your home-owners insurance by having the propane in the house? Might want to make an anonomous (sp)call...

[3 Phase Lightbulb]

I suppose I could put it outside but then I'd have to build a little house for it. Right next to my Oxy/Act setup seems like the safest place http://bbs.homeshopmachinist.net//smile.gif


-Adrian

[3 Phase Lightbulb]

I LOVE IT!

I installed a pair of ceiling fans to circulate the hot air from my shop heater and I've got a digital thermostat controlling the temperature. I can play in my shop all winter in a t-shirt. The 75k BTU unit heats up the garage very quickly and seems to be very efficient. I think the ceiling fans make the system work so well.

http://www.bbssystem.com/pictures/heat.jpg

-Adrian

[dfeeney]

I was just reading my post on the cost of installing and filling a 100lb propane tank. I was just a little off on the price.
The cost to fill it was $115.00. My bad.

Also, an update on my infrared heater. The temps the last few nights has been in the low teens and the days have been around 25-30 degrees. The temp in my shop has been at a constant 65 degrees and has only been running for just a few minutes every hour or so. I couldn't be happier with it.

Dan

[QSIMDO]

Dan, what heater do you have please?

[3 Phase Lightbulb]

I've been working in my shop all day. I even opened up a window for about an hour while I did about an hour of TIG welding. It nice and warm in the shop and it was around 30 outside today. It's more comfortable in my shop now than it was this summer with the heat. I'll need to get A/C for the shop this spring.

-Adrian

[dfeeney]

Here is the link http://www.northerntool.com.

The model number is: F272100, cost is $299.99

[3 Phase Lightbulb]

I also bought my heater from http://www.northerntool.com

Item# 172645

-Adrian