btu oil vs btu water

realolman

I am hesitant to broach this subject, but I cannot see what is wrong with what I am doing or thinking. I would like to keep this as simple as possible and I think it can be kept simple.

This is a concerning a Burnham V74 that originally had a 1.10 GPH nozzle.

#1. I am only interested in how much oil I burn and how much that burned oil raises the temperature of the water in my boiler. I don't care about anything else.


#2. My boiler contains a fixed volume of water. I closed the valves on my boiler so there would be no circulation, and ran the burner with two different sized nozzles... a 1.10 GPH and a .65 GPH both @ 140 psi. I set both of them using an electronic analyzer.

#3. I ran the burner for 5.55 minutes ( 5 min 33 sec )with the 1.10 nozzle and waited until the temperature peaked. This firing raised the temp of the boiler water 77°F

#4. I did the same thing with the 0.65 nozzle, running it for 5.05 minutes. When the temperature peaked, this firing had raised the temperature by 74°.

#5. Assume my boiler contains 12 gal water, and oil @ 140,000 btu... Based on oil burned vs. water temp raised, I'm thinking the 1.10 nozzle to be 43% efficient and the .65 nozzle to be 78% efficient.

Which nozzle do you want in there if it's your boiler?
Am I saving fuel by downfiring?