DOWN FIRING A BOILOER

[butternut]

LOL! ... I wasn't drinking when I wrote that title either! :grin2: Speed typing with two fingers has it's down side


I dont know as I am ready to put everything I know on the subject out there but I am bringing it up because I am seeing this practice more and more over the last few years up north. I would like to hear your opinions and views on the subject.
I understand that there is a vast wealth of theory and opinion to be had on the subject and I would be glad to elaborate my views but for now... let me hear your story.

I have to scoot and will be back later. hope this is a thread that will be worth reading when it hits it's end.

[beenthere]

Been done for a long long time here.

If down fired too much, they will use more oil.

[butternut]

Been done for a long long time here.

If down fired too much, they will use more oil.

That is a given but I am looking for some opinion based on experience and theory. A discussion with merit in other words.

[beenthere]

Ok. Down firing to save oil works. Have to give consideration to boiler piping gain on many older systems. If you don't, you be under fired and use more oil. Also need to double check what retention head a Beckket burner has to make sure you can set the burner up properly for the new firing rate. Too large of a head, and you won't get good combustion. It will have a high CO.

[snupytcb]

before you do this you need to determine, as close as possible, the exact btu's needed. and if it has an indirect, make sure it has priority option. as been said, do not go less than the burner is rated.many variables are on the table when you do this. have you applied for pro yet? it would make this alot easier on us.

[beenthere]

before you do this you need to determine, as close as possible, the exact btu's needed. and if it has an indirect, make sure it has priority option. as been said, do not go less than the burner is rated.many variables are on the table when you do this. have you applied for pro yet? it would make this alot easier on us.

Yeah, specially since we have a Pro Oil Burner forum.

[butternut]

before you do this you need to determine, as close as possible, the exact btu's needed. and if it has an indirect, make sure it has priority option. as been said, do not go less than the burner is rated.many variables are on the table when you do this. have you applied for pro yet? it would make this alot easier on us.

Been awhile waiting on the Pro upgrade. Guess everyone is out working.

[butternut]

Yeah, specially since we have a Pro Oil Burner forum.

Yeah....So I have heard. Still waiting

[billg]

Not only do you have to make sure burner is set up for the lower firing rate (end cone and static plate) but the combustion chamber is sized correctly (This can be a pita in units with just a target wall or no liner at all) and flow through heat exchanger controlled (sometimes smaller venting or baffling). And this is only on the firing side not to mention the heat transfer side.

[tlj000]

If down fired too much, they will use more oil.



Care to expand on this?
If you have proper combustion and less heat going up the chimney how could you use more oil.

[beenthere]

Care to expand on this?
If you have proper combustion and less heat going up the chimney how could you use more oil.

A burner burning 1 GPH running 24/7 uses 24 gallons. A burner burning 1.5 GPH running 14 hours only burns 21 gallons in that same 24 hour period. At 1 GPH if the burner never shuts off but just maintains the set temp, it uses more oil. At 1.25 GPH, it may only run 16 hours, and then it would only be using 20 gallons in that same 24 hour period. Its a fine line between just right, and too little.

[beenthere]

Been awhile waiting on the Pro upgrade. Guess everyone is out working.

Seems there is no info on you applying. Send it in again.

[tlj000]

A burner burning 1 GPH running 24/7 uses 24 gallons. A burner burning 1.5 GPH running 14 hours only burns 21 gallons in that same 24 hour period. At 1 GPH if the burner never shuts off but just maintains the set temp, it uses more oil. At 1.25 GPH, it may only run 16 hours, and then it would only be using 20 gallons in that same 24 hour period. Its a fine line between just right, and too little.

I’m missing something here.

Let just say the burner is 100% efficient.
If the load requires 1gph running 24 hrs. that would be 3,336,000BTU/24hrs
Your examples of nozzle and run times and gallons don’t add up to this.
I would also hope that by decreasing the nozzle size you would increase efficiency by lowering the stack temp.



341901

[beenthere]

I’m missing something here.

Let just say the burner is 100% efficient.
If the load requires 1gph running 24 hrs. that would be 3,336,000BTU/24hrs
Your examples of nozzle and run times and gallons don’t add up to this.
I would also hope that by decreasing the nozzle size you would increase efficiency by lowering the stack temp.



341901

My run times were times pulled out of the air as examples. But aren't far off.

1.5 X 14 = 21. 21 X 140000= 2,940,000
1.25 X 16 = 20, 20 X 140000 = 2,800,000
1 X 24 = 24, 24 X 140000 = 3,360,000

The savings of the higher firing rate comes from the off time.

The lowest stack temp is not always the most efficient set up. When the firing rate gets too low, heat transfer rate drops since there isn't enough heat. Unfortunately so does stack, which leads to a false high efficiency reading.