A freind of mine managed to run out of oil. He has a forced hot water system that uses heating oil. He asked if he could use diesel fuel from his truck. I’m pretty sure he can but wasn’t possitive.
Any problems with doing so?
I think so, but this will be much more expensive since he’s paying transportation tax on the diesel and isn’t buying in bulk as he would if he were buying heating oil. Not a HVAC man, though…
Yeah, it’ll work. Red dyed home heating oil is pretty much identical to #2 diesel; albeit quite a bit less expensive; the reason heating oil is dyed is to aid in preventing people from using it as fuel for cars and trucks, since transportation taxes have not been paid on it. But if you absolutely need it and can’t afford the minimum that heating oil suppliers have (usually 100 gallons), go for it.
Remember, if you ran your tank out, you’ll probably have to bleed the air out of the line before your burner will fire up. There’s should be a valve for this purpose at the oil pump on the burner.
I imagine for him it is a money issue of some sort. He wanted to know if it would work and if it would get him through the night. I told him I thought it would work but call Bob(a HVAC guy I know) to find out for sure. I always seem to be the elected person to ask home improvement/maintenance questions to.
Another question to add, his truck might have a 40 gallon tank. If he takes 10 gallons how long can he heat a home for? I havn’t paid much attention to my own oil bills other than noticing it costs alot. I figure the tanks hold 250 gallons for a reason.
That’s going to vary wildly, depending on the size of the home, how well insulated it is, how cold it is outside, what temperature he sets the thermostat for and other factors. If it were me, I’d turn off radiators in all but essential locations and keep the thermostat fairly low during the day, say around 60, and turn it down even lower at night and just throw a bunch of blankets on the bed. Really, anything he can do to conserve heating energy will help.
Have him look on his furnace nameplate and read the BTU/hr rating, and then the rest is a trivial calculation. Generally oil furnaces are not modulated but run flat-out (off/on) so you can assume he would need the BTU/hr rating. Assume 100,000 BTU/hr heat input furnace, then assume 130,000 BTU/gallon for diesel, and you get:
100,000 BTU/hr / 130,000 BTU/gal = 0.77 gallons/hr
10 gallons / 0.77 gallons/hr = 13 hr
If the heat output is what is given on the nameplate, then you’ll need to include the efficiency factor to work back to the gallons. You might assume an 80% efficient non-condensing furnace as a low-end rating to be conservative.
100,000 BTU/hr / 0.8 = 125,000 BTU/hr heat input needed
125,000 BTU/hr / 130,000 BTU/gal = 0.96 gallons/hr
10 gallons / 0.96 gallons/hr = about 10 hr
Right, but he probably wants to know how many days it will get him through, which depends on the factors I listed previously. The furnace isn’t going to burn for 10 hours nonstop, unless he leaves all the doors and windows open. Knowing that you’ve got 10 hours total running time doesn’t help much if you don’t know how much the furnace is going to cycle on and off.
It’s a good enough answer for me. My freind might care for more info. My curiosity has been satisfied. Thank you both.
My post did not contradict anything you said in this thread. I provided some actual calculations that the OP could use to determine a worst-case fuel usage. The OP’s friend could possibly look at the total fuel oil use per month if they have it on a bill or meter, divide 10 into that and multiply by the number of days, and get an estimate that way.
I will remind the OP that despite what Wikipedia and other online sources may imply, diesel fuel is not exactly the same thing as FO#2. I cannot find web-linkable cites that say there is a caution against using them interchangeably in home furnaces, but I did contact some friends in the industry about this today, in an attempt to actually try to answer a GQ with hard data. Sadly, I have failed to find much to offer - the results of my conversations ranged from “you can probably use it” to “don’t know.” I contacted a friend at the DoE about it and he said “it’s not recommended, but I’m not sure it would do any harm. I’d make sure that they have good CO detectors because the (furnace) orifices may not be calibrated to ideal combustion, but it’s probably close enough.” I know that it is not recommended that you switch it out in gas turbines without adjustment and calibration, and the EPA may require a recertification of your CEMs, but for home use…the results are unclear.
I’ll offer a non-web cite (so we know that probably means it has no value…) from page 700 of “The Chemistry and Technology of Petroleum”, by James G. Speight, wherein it says:
…which to me implies that it’s saying you can use diesel oil in a home furnace, but not home heating oil in a diesel engine - since a home furnace doesn’t really care about the cetane number AFAIK.
I didn’t say it did. I was just clarifying the point for the OP.