50k Unit Heater Small Propane Tank.

[Lofty]

Hi all. New here. Im working on a unit heater for my garage and for this season I think I'm going to run it off a small (grill sized) propane tank. Is there anything wrong with this setup? I got browbeat by HVAC techs on Facebook about how I was going to blow myself up and propane isn't safe etc. The soft hose will go to a dual stage regulator on a tank. My heater has been converted for LP as per the instructions.

 

[gmcgeo]

a grill bottle can only produce 51,000 btu capacity. What will happen is that the tank will starve to create vapor pressure. You might get an hr or 2 before it shuts down.


Also, you should not use the rubber hose inside a building.

you need at least a 100# tank on the outside of the building, you can take the tank to a place monthly to fill but i think you will go through 23 gallon in a week maybe every 2 weeks


If your tank is inside at normal temps, you will see the tank last longer, however you should not have the tank inside. And that might be why your facebook ppl are saying what they said.

But then again you see ppl here with 20# tank with heaters attached to the top of them and heat the garage........ be safe

 

[Jackfre]

AM is correct. You may be able to get by but when it is really cold you will freeze up the regulator. Location always helps in these heating cooling questions so I’ll ask, are you in Minot or Miami?

 

[PoorUB]

It might work. One problem with LPG is the evaporation rate drops in colder weather. When you walk out to a cold shop and fire up the heater the tank will not evaporate LP fast enough to supply the heater. You could add one or two more tanks and T the gas lines together.

On the other hand more thanks add complexity and more chances for things to go wrong. also LPG tanks inside a building is against codes every where. Yes, people do it anyway!

Personally, I would find a couple 100 pound tanks and a rack to set them on, and leave them outside to shop.

Also keep in mind at full load your heater will use a bit more than 2 pounds and hour. A BBQ grill sized cylinder will run less than 10 hours assuming it would keep up. You will be spending a lot of time running for gas.

 

[Lofty]

a grill bottle can only produce 51,000 btu capacity. What will happen is that the tank will starve to create vapor pressure. You might get an hr or 2 before it shuts down.


Also, you should not use the rubber hose inside a building.

you need at least a 100# tank on the outside of the building, you can take the tank to a place monthly to fill but i think you will go through 23 gallon in a week maybe every 2 weeks


If your tank is inside at normal temps, you will see the tank last longer, however you should not have the tank inside. And that might be why your facebook ppl are saying what they said.

But then again you see ppl here with 20# tank with heaters attached to the top of them and heat the garage........ be safe

Thank you! Eventually, I want to get a 100lb or a 420lber and put it outside on the concrete behind the garage, however I just wanted to make sure this actually worked before I went and added the large bottles. I realistically think once the garage gets to heat and then I maintain it, it will be good. But this is good to know about the tank starving.

 

[Lofty]

AM is correct. You may be able to get by but when it is really cold you will freeze up the regulator. Location always helps in these heating cooling questions so I’ll ask, are you in Minot or Miami?

Im in wisconsin, so it get's cold as hell.

 

[Lofty]

It might work. One problem with LPG is the evaporation rate drops in colder weather. When you walk out to a cold shop and fire up the heater the tank will not evaporate LP fast enough to supply the heater. You could add one or two more tanks and T the gas lines together.

On the other hand more thanks add complexity and more chances for things to go wrong. also LPG tanks inside a building is against codes every where. Yes, people do it anyway!

Personally, I would find a couple 100 pound tanks and a rack to set them on, and leave them outside to shop.

Also keep in mind at full load your heater will use a bit more than 2 pounds and hour. A BBQ grill sized cylinder will run less than 10 hours assuming it would keep up. You will be spending a lot of time running for gas.

I was just going to do this until I verified the setup worked! But that is good to know, it's going to probably be a lot of running...
Ill have to just run piping to a stubout thru the back after I verify it works.

 

[TractorJeff]

Where abouts in Wisconsin? I have two 100lb tanks that I am no longer using. They last 23 days if you turn the heat down to 45 when not in there and up to 55 in use. PM me for more information.

 

[Lofty]

Sent you a pm TractorJeff! Thank you.

 

[Lofty]

So I got this snap double walled stuff in. You just pop it on, once you do can you spin it, or does it always have to be seam on seam? Seems odd that it's so easy to connect these, however I'm guessing it's better than single wall with screws.

Do you caulk these joints, tape them, etc?

 

[Firebrick43]

Hi all. New here. Im working on a unit heater for my garage and for this season I think I'm going to run it off a small (grill sized) propane tank. Is there anything wrong with this setup? I got browbeat by HVAC techs on Facebook about how I was going to blow myself up and propane isn't safe etc.

Really, you should not use a flexible gas hookup as a movable hose, it doesn't appear to be bonded, your using a rubber hose inside a building, and your using an unapproved regulator inside a building that isn't vented properly. Yes your chances of blowing yourself up are much greater than if you did things right.

The soft hose will go to a dual stage regulator on a tank. My heater has been converted for LP as per the instructions.

You heater's instructions say to install in accordance with all applicable codes and you are nowhere near there.

 

[Lofty]

Really, you should not use a flexible gas hookup as a movable hose, it doesn't appear to be bonded, your using a rubber hose inside a building, and your using an unapproved regulator inside a building that isn't vented properly. Yes your chances of blowing yourself up are much greater than if you did things right.


You heater's instructions say to install in accordance with all applicable codes and you are nowhere near there.

Fair enough.

I was starting with a small cylinder because I was worried about using a bigger cylinder outside.

I will run hard line outside to a 100lb tank (or two) instead.

Thanks for your input.

Since you seem to be an expert in this area, can you answer my question on the type b vent connection?

 

[PoorUB]

Since you seem to be an expert in this area, can you answer my question on the type b vent connection?

Pretty sure that B-vent does not met codes for that heater.

Do you have the instructions for the heater? My bet is it requires stainless venting.

 

[Lofty]

Edited: let me double check this

 

[Firebrick43]

So I got this snap double walled stuff in. You just pop it on, once you do can you spin it, or does it always have to be seam on seam? Seems odd that it's so easy to connect these, however I'm guessing it's better than single wall with screws.

Do you caulk these joints, tape them, etc?

You just line up seam to seam, making sure the locking tab came through(I cant see) and twist until the x aligns with the seam below(appears to be right on the bottom joint)


No you do not tape, or caulk. The chimney support plate should clamp onto the bottom section at the ceiling and keep it from turning

 

[Lofty]

Pretty sure that B-vent does not met codes for that heater.

Do you have the instructions for the heater? My bet is it requires stainless venting.

Looks like it only needs stainless for commercial? It's a MHU50.

 

[Lofty]

You just line up seam to seam, making sure the locking tab came through(I cant see) and twist until the x aligns with the seam below(appears to be right on the bottom joint)


No you do not tape, or caulk. The chimney support plate should clamp onto the bottom section at the ceiling and keep it from turning

Thank you!

 

[PoorUB]

Looks like it only needs stainless for commercial? It's a MHU50.

Read the previous page. It says no to B-vent.

Section C - horizontal venting - General

Pretty sure all of this style shop heaters require stainless Cat III vent, ( for horizontal venting) . B-vent rots out pretty fast so it is not accepted.

 

[PoorUB]

You just line up seam to seam, making sure the locking tab came through(I cant see) and twist until the x aligns with the seam below(appears to be right on the bottom joint)


No you do not tape, or caulk. The chimney support plate should clamp onto the bottom section at the ceiling and keep it from turning

Why bother? B-vent doesn't meet the manufacturers requirements.

 

[Lofty]

It says SINGLE WALLED B VENT

this is double walled b vent.

Maybe I am wrong but I thought this complied... wtf

 

[Firebrick43]

Why bother? B-vent doesn't meet the manufacturers requirements.

I realize that now that I know what heater model it is.

It says SINGLE WALLED B VENT

this is double walled b vent.

Maybe I am wrong but I thought this complied... wtf

B vent is only applicable for vertical chimney. It appears to me that its a horizontal chimney and therefore must be stanless cat 3

 

[Lofty]

Well this is going very well.

Thanks for the input everyone. I wish they made adjustable 45* cat 3 vents locally but I will look online to achieve this.

How annoying.

 

[PoorUB]

I installed and service HVAC for years. When it comes to an install, I swear most anyone can do it, if they read the instructions!

 

[Lofty]

I see other threads where the single and double wall confusion comes in for this exact model. To be fair.....

 

[PoorUB]

Well this is going very well.

Thanks for the input everyone. I wish they made adjustable 45* cat 3 vents locally but I will look online to achieve this.

How annoying.

Menards is probably your only hope to buy CAT III venting. There is some online vendors too, but returns would be a hassle.

 

[Lofty]

Yeah, not sure what to do about this now since there's no adjustable 45s in cat 3. I think I'm boned.

 

[PoorUB]

Well this is going very well.

Thanks for the input everyone. I wish they made adjustable 45* cat 3 vents locally but I will look online to achieve this.

How annoying.

That is where experience comes in to play. Someone that does this every day scopes out the venting situation, gas and electrical before starting and may mount the heater to make his job easier.

 

[gmcgeo]

Yeah, not sure what to do about this now since there's no adjustable 45s in cat 3. I think I'm boned.

Cat 3 is needed, however you can get away with this for a couple months until you can replace.

 

[Mainiac Mat]

Post #21 in this thread shows some pics of my Modine HD60 install, which is very similar and the instructions clearly spelled out Cat 3 stainless duct for a horizontal flu.

Here's a link to the place I purchased it from. Scary thing is that I only paid $239, just two years ago. That's a 53% price increase

The good news for me was that installations <4' horizontal run allowed you to pitch down so condensation drains out the pipe to the vent cap, and thus a drain line with a water trap was not required.

 

[Mainiac Mat]

I already had two 120 gal LPG tanks supplying the house, so I teed off of the tank line to a separate regulator on the exterior garage wall.

I plumbed it all myself with black iron pipe in the walls and yellow clad stainless flex to the unit itself. But I had a young guy from church who works HVAC for his dad (and just got his gas card) come and do the hook up from the tank to the regulator, and to check the pressure drops at the internal gas valve for me. This wasn't extremely complicated, but it does require a manometer setup with the correct fittings.

I was his first official LPG job and he was very reasonable.

 

[TractorJeff]

I bought my B-Vent parts at Menards. (Don't quote me) I thought the 90 could be spun around to make whatever Angle was necessary?
I would have to go out to look to be Correct!

 

[beemerphile]

Im in wisconsin, so it get's cold as hell.

I knew Wisconsin was cold, but I thought hell was hot ???

 

[PoorUB]

I bought my B-Vent parts at Menards. (Don't quote me) I thought the 90 could be spun around to make whatever Angle was necessary?
I would have to go out to look to be Correct!

B-vent, yes, but for his application he needs stainless Cat III.

 

[Lofty]

Just wanted to update this. I got it fired up and it runs great. The B vent is going to have to stay for now. This is completely powered down when not in use and is only on when ill be out working. It's also on a detached garage.

Code regulations aside, they used to run these like this pre 2009. I think an inspection each year on the b vent would suffice. Will be adding a CO and explosive gas alarm / detector too.

Asking the real questions now, even if the vent breaks how different would that be from running a propane torpedo heater in a garage? Isn't that similar?

I ordered a manometer to ensure the pressure is set to spec.

 

[gmcgeo]

A torpedo heater needs a lot of oxygen to run efficient and safely, you can still get co poisoning from it if garage is not giving enough oxygen.

Same with that heater, if vent broke all CO gasses go into the building and it recirculates back into the unit causing incomplete combustion then causing higher and higher CO in the building. This would happen with a torpedo heater too if not getting enough oxygen.

 

[RoninB4]

A torpedo heater needs a lot of oxygen to run efficient and safely, you can still get co poisoning from it if garage is not giving enough oxygen.

Same with that heater, if vent broke all CO gasses go into the building and it recirculates back into the unit causing incomplete combustion then causing higher and higher CO in the building. This would happen with a torpedo heater too if not getting enough oxygen.

-After working on cars outside during Winter in Chicago for several years I rented a house with a separate garage. Still too cold to work in so I bought a kerosene torpedo heater, worked great. After one particularly long night of working under the car I fell asleep in the garage with the heater on. Woke up to the torpedo heater going on/off combustion and I found it difficult to breathe. The garage was quite drafty but the torpedo heater had burned up all the oxygen, I was likely very close to death from carbon monoxide poisoning. It's sneaky, you'll never know it's approaching, and you just go to sleep. Be wary of combustion indoors.

 

[Lofty]

Ronin that is very scary. I hate those torpedoes. Thanks for all the answers here, that makes sense. I've learned alot from you all here and I appreciate it.

 

[TractorJeff]

B-vent, yes, but for his application he needs stainless Cat III.

SORRY! You are right! It is CAT 3 stainless I installed, not B-Vent.
Brain should have been in Gear before Fingers were engaged!
I still think the 90 will spin to a 45?
I need to go look.........

 

[PoorUB]

SORRY! You are right! It is CAT 3 stainless I installed, not B-Vent.
Brain should have been in Gear before Fingers were engaged!
I still think the 90 will spin to a 45?
I need to go look.........

CAT III stainless is welded, at least I have never seen an adjustable elbow. Pretty sure it doesn't exist.

 

[Firebrick43]

Just wanted to update this. I got it fired up and it runs great. The B vent is going to have to stay for now. This is completely powered down when not in use and is only on when ill be out working. It's also on a detached garage.

Code regulations aside, they used to run these like this pre 2009. I think an inspection each year on the b vent would suffice. Will be adding a CO and explosive gas alarm / detector too.

Asking the real questions now, even if the vent breaks how different would that be from running a propane torpedo heater in a garage? Isn't that similar?

I ordered a manometer to ensure the pressure is set to spec.

Are you hobbyman22 brother by chance?