Efficiency increase on this old oil burner?

[swyman]

Bought my shop 7 years ago from my grandpa and it was built in 1974. I'm sure all this is original. Shop is 50'x100'x16' and the unit is 400k BTU. I would like to know if I were to buy a new heat gun assembly if it would be more efficient? The nozzle currently in it is a 2.5 gph so not sure on BTU output as it is a little smaller than the one I replaced a few years ago. I burn diesel in it also. Would I benefit from replacing this unit with a propane furnace? I know my insulation situation is not the best also so I need to do that also. Right now it just has 1" foam board over the purlins under the siding. It does have a steel ceiling but I have never been up in the attic so I am not sure what it up there. This is the way it was built and operated since new.... I have a bunch of work/$$$ to do! Attached is a pic of the unit plus one of it running and the inside of fire box. The fire brick has fallen out but my grandpa didn't replace it, told me the unit would have more heating surface area inside which kind of makes sense?

 

[matt_i]

I am thinking that's non-vented since I don't see a chimney.

If you have any access to natural gas, that seems to be the cheapest energy right now.

5000sf is probably in the 150k-200k Btu range (guessing here) and might be best served by two units instead of one large one.

Paying attention to insulation and trapping hot air (notoriously wonky for wanting to escape) is a worthwhile investment in my opinion.

Specifically regarding the fire brick, that seems to be a technique to keep surface temps down, for 2 reasons, 1) so the surface doesn't get too hot and burn things close by, and 2) so the metal doesn't get hot enough to prematurely oxidize and be slowly consumed at elevated temps. Without other alloys like stainless steel and even further, inconel, the life can be shortened.

 

[swyman]

There is a 50' chimney on the outside. The outside of the furnace doesn't get hot with the fans blowing, you can put your hand on it. I'm out in the country and there is no natural gas anywhere within 4 miles from me unfortunately.

 

[mygarageone]

The fire brick is there for a reason. It protects the combustion chamber from burning a hole in it from the flame.
That unit is so old , I doubt there anything you can do to increase efficiency .
You get 140,000 btu's from a gallon of fuel oil ,so at 2.5 your at 350,000 btu. Input.
I doubt your even getting half of that out in usable heat. 50-60 wasted heat up the stack.

You'll pay for a new replacement in short order.

You must be burning one hell of a lot of fuel ,

Insulation that building and you'll probably cut your fuel bill. In half and reduce your heat load by half.

 

[swyman]

The fire brick is there for a reason. It protects the combustion chamber from burning a hole in it from the flame.
That unit is so old , I doubt there anything you can do to increase efficiency .
You get 140,000 btu's from a gallon of fuel oil ,so at 2.5 your at 350,000 btu. Input.
I doubt your even getting half of that out in usable heat. 50-60 wasted heat up the stack.

You'll pay for a new replacement in short order.

You must be burning one hell of a lot of fuel ,

Insulation that building and you'll probably cut your fuel bill. In half and reduce your heat load by half.

What would be the best replacement once insulated? A set of hanging Modine propane units? I'm not in there everyday which is why I haven't done much with it but my fab business is picking up and I am in there more and more.

 

[mygarageone]

What would be the best replacement once insulated? A set of hanging Modine propane units? I'm not in there everyday which is why I haven't done much with it but my fab business is picking up and I am in there more and more.

That would be the cheapest way to go or you could spend a little more and do radiant tube heaters. For more comfortable when working.

 

[swyman]

That would be the cheapest way to go or you could spend a little more and do radiant tube heaters. For more comfortable when working.

Which one would have the quickest warm up time? It usually gets down to just above freezing in there but it does heat up to 60* rather quickly with the unit I have. Just don't know much about the radiant heaters. Which is more efficient, hanging or radiant?

 

[xjfish]

Thats a bad *** old fuel oil furnace. I had one also, worked great, was sad to retire the old overbuilt beast. I just had to retire the damn thing for economic reasons... (Nat. Gas)

Newer, more efficient fuel oil burners can be had for a reasonable cost...

 

[swyman]

http://s3.supplyhouse.com/images/products/large/b2007-1.jpg

I was thinking about adding this to my unit. I feel it would be a relatively cheap upgrade at the tune of $350, if it would give me better efficiency? Just not sure if I should go this route or get a couple propane Modines?

 

[Shop Specialties]

A large part of the efficiency of a heater is the firebox design. If the firebox is not extracting the heat and putting it into the room it is going up the stack. So it does not matter what burner you put on if the firebox cannot put the heat into the room.

I would first insulate better before replacing the heater.

 

[86turbodsl]

Hey nice, Blissfield! I went to Blissfield High.

A modern boiler would probably be the only way to go on this, but for sure, insulation is the first step. Not sure what your insulation package looks like. Dad did tube heaters on his barn, he is on his second one, the first tube burned out.

FWIW, btu's needed depends on a lot of things. In the old days, for 5000 ft, you'd use a 300,000 btu furnace. That's 10X what my house needs now with good insulation. I do a 3000ft house with 35,000 btu heat pump. Insulate the building well, and your fuel source becomes much less important.

 

[LS6 Tommy]

No stack?! Falling refractory?! Time for a new, SAFE furnace.

Oil has the highest BTU content per equivalent unit...

Tommy

 

[930dreamer]

What about a waste oil furnace like clean burn, Lanair? I'd start with great insulation and go from there, here's a GJ member and a converted oil burner;

 

[Jackfre]

$350 spent on this unit is $350 wasted. It is grossly oversized, especially so after you insulate, which chould be your first step. Time for a new boiler.

 

[Radix2]

here is a way to look at it.

efficiency is basically how much heat goes up the chiminy vs how much goes into the room

if you did not have a chimney, and everything went into the room, your set up would be 100% efficient (do not do this !)

So for any upgrade, the question is, will it make your exhaust up the chimney cooler or make the heat going to the room hotter without making the exhaust hotter too?

It is hard to see something like a new burner making much of a difference on those items.

Efficiency comes from an effective heat exchanger, something your old unit does not have.

 

[swyman]

What about a waste oil furnace like clean burn, Lanair? I'd start with great insulation and go from there, here's a GJ member and a converted oil burner;

I would love one of those units but I only generate about 50 gallons/year. My brother in law has a large farm operation but he said they normally generate about 250 gallons/yr. I just don't think I could get enough used oil to survive a winter.

 

[swyman]

No stack?! Falling refractory?! Time for a new, SAFE furnace.

Oil has the highest BTU content per equivalent unit...

Tommy

The exhaust is power vented through the lower front of the unit and there is a 50' 12" stack outside.

 

[swyman]

Hey nice, Blissfield! I went to Blissfield High.

A modern boiler would probably be the only way to go on this, but for sure, insulation is the first step. Not sure what your insulation package looks like. Dad did tube heaters on his barn, he is on his second one, the first tube burned out.

FWIW, btu's needed depends on a lot of things. In the old days, for 5000 ft, you'd use a 300,000 btu furnace. That's 10X what my house needs now with good insulation. I do a 3000ft house with 35,000 btu heat pump. Insulate the building well, and your fuel source becomes much less important.

Really couldn't use a boiler as I'm not in there everyday so I would want to pay to keep the water hot while not in use. I went to Blissfield high also but graduated from Deerfield. Class of '91!

 

[Shop Specialties]

I would love one of those units but I only generate about 50 gallons/year. My brother in law has a large farm operation but he said they normally generate about 250 gallons/yr. I just don't think I could get enough used oil to survive a winter.

When you run out of waste oil you can use fuel oil in the same heater with zero issues. How many gallons of fuel oil are you going through now ? How much are you paying per gallon ?

A Clean Burn CB-3250 would be a good size for your shop. If you decide to insulate it very well you could possibly drop down to the CB-2500.

 

[930dreamer]

Any thought of a partition so as to not having to heat the entire shop? Can you get the oil from your Bil?

 

[86turbodsl]

Really couldn't use a boiler as I'm not in there everyday so I would want to pay to keep the water hot while not in use. I went to Blissfield high also but graduated from Deerfield. Class of '91!

Man, small world. My dad graduated from Deerfield. Class size of 12! You would have graduated with my brother.

I'd look at a waste oil furnace if it's possible to get enough oil.

Don't put any money into that old thing, and do the best insulation job you can afford. My 2c.

 

[swyman]

When you run out of waste oil you can use fuel oil in the same heater with zero issues. How many gallons of fuel oil are you going through now ? How much are you paying per gallon ?

QUOTE]

I'm on my 3rd fill up of 100 gallons. December was brutally cold and windy so it ran often. I have been paying $2.29/gallon here last 2 fill ups.

 

[swyman]

Any thought of a partition so as to not having to heat the entire shop? Can you get the oil from your Bil?

Yes I have thought about getting a custom tarp made through a Tarp Stop which does tarps for Semi's. They quoted me around $600 a couple years ago. Only problem is I have been doing a lot of fabrication work which my saw and steel rack are in the back end. With the car lift in the North/front side of the shop there would be no room to bring the saw on the other side of the divider. I guess if I could come up with a way to roll it up could work. Also in the colder months I back the Steel delivery truck into the shop and close the doors while we unload and it takes up a good 60'. This could possibly be my best route, could get away with insulating only half.

 

[swyman]

Man, small world. My dad graduated from Deerfield. Class size of 12! You would have graduated with my brother.
QUOTE]

I graduated with 19 but 1 was a migrant so really 18! Who is your brother?

 

[American Locomotive]

What's the specified nozzle size? There are a couple of tricks you can do to squeeze more efficiency out of the furnace. One them is to turn the pump pressure up while going down in nozzle size. This improves the spray pattern while keeping firing rate the same.

There are charts that correlate nozzle flow and pump pressure to maintain firing rate. Sometimes going down in overall firing rate helps too. This isn't something you should try yourself though. You'll need a furnace guy with proper test and measurement equipment to dial the furnace in with a nozzle change.

As mentioned, I'd probably insulate first before messing with the furnace.

 

[swyman]

What's the specified nozzle size? There are a couple of tricks you can do to squeeze more efficiency out of the furnace. One them is to turn the pump pressure up while going down in nozzle size. This improves the spray pattern while keeping firing rate the same.

There are charts that correlate nozzle flow and pump pressure to maintain firing rate. Sometimes going down in overall firing rate helps too. This isn't something you should try yourself though. You'll need a furnace guy with proper test and measurement equipment to dial the furnace in with a nozzle change.

As mentioned, I'd probably insulate first before messing with the furnace.

A few years ago my friend who has works in the commercial HVAC field brought me the 2.5 nozzles as the one we took out was a 3.0 but we did not make any changes to pressure??? Maybe we should have? I think now from the advice from the members I am looking at Clean Burn heaters. It would be great to be able to burn both used oil and fuel oil with the same unit....didn't know you could.

 

[American Locomotive]

Any change of firing rate requires retuning of the furnance.

 

[930dreamer]

You could find a couple of big a$$ wood stoves.

 

[LS6 Tommy]

The exhaust is power vented through the lower front of the unit and there is a 50' 12" stack outside.

Ah. That's why I asked. Still need to fix the refractory wall, insulate the building, get the right size nozzle, set the proper firing rate and you should be good to go.

Tommy

 

[Shop Specialties]

When you run out of waste oil you can use fuel oil in the same heater with zero issues. How many gallons of fuel oil are you going through now ? How much are you paying per gallon ?

QUOTE]

I'm on my 3rd fill up of 100 gallons. December was brutally cold and windy so it ran often. I have been paying $2.29/gallon here last 2 fill ups.

So between you and your BIL oil you could have at least made it this far on waste oil this Winter. Waste oil has a higher BTU content and the heater blows HOT air. 300 x $2.29 = $687.00 saved if you burned the waste oil readily available. With the Clean Burn metered pump you will be able to burn 80/90w to diesel fuel without making any adjustments.

 

[swyman]

So between you and your BIL oil you could have at least made it this far on waste oil this Winter. Waste oil has a higher BTU content and the heater blows HOT air. 300 x $2.29 = $687.00 saved if you burned the waste oil readily available. With the Clean Burn metered pump you will be able to burn 80/90w to diesel fuel without making any adjustments.

Any reason to stay clear of units on craigslist? I have seen a few on there and most come with all the tanks, pumps and other accessories. I'm sure I would have to do a rebuild but couldn't be to much could it? I am really liking this idea!

 

[swyman]

7

You could find a couple of big a$$ wood stoves.

NO WAY! I just sold my Central Boiler last year......don't get me wrong, it worked great but it consumed way to much of my time to keep it fed. I sold it to my BIL and bought a coal boiler to replace it and that has worked out wonderfully!

 

[Shop Specialties]

Any reason to stay clear of units on craigslist? I have seen a few on there and most come with all the tanks, pumps and other accessories. I'm sure I would have to do a rebuild but couldn't be to much could it? I am really liking this idea!

First check with the Clean Burn dist in your area if he has any used rebuilt heaters for a good deal. That way you still get service after the sale. Craigslist heaters can be 50/50. If you want to send me some ads you are looking at I will try to help you as much as I can so you make a good purchase. To bad you were not closer to Montana.