Temperature differential off & on

[Cantrellc123]

I've read a good bit about the new EPA OWB that are soon to be here. While their goal is admirable, the chosen path to achieve this is at the very least questionable.
This had me thinking about my OWB and the temperature differential between the preset temp and the temp that activates the fan. The differential on mine is 5 degrees. What if this differential were increased to 20 degrees? A I understand it, start up is the time of worst pollution. So with a greater differential, the length of burn time would be increased thus reducing emissions.

Good idea, or bad idea?

 

[John R]

My OWB runs 30° difference between on and off.

 

[benp]

I personally don't think it will be an issue.

I imagine the temp differential will be according to each manufacturers design to optimize for the best efficiency for that stove model.

 

[gary s]

It will vary with different stove designs and also demand. My P&M ML30 likes a small 3-5 degree differential.

 

[Poston5]

My hardy likes a low differential, I leave it at 5 degrees.

 

[Cantrellc123]

So are you guys saying you've tried different settings in order to settle on the 5 degree differential?

 

[gary s]

So are you guys saying you've tried different settings in order to settle on the 5 degree differential?

This is my 5th year with my OWB and I tried several settings, here is what I like and how it actually works. 176 on 180 off, the water temp drops to 176 and the blower comes on, if it's been idling long the temp may drop to 174 before it gets roaring again then fire roars until it reaches 180, blower shuts off but hot glowing wood takes the water temp up to 184. Now those numbers will vary with how much and what type wood but not much. For domestic how water I don't want too much of a differential.

 

[Poston5]

So are you guys saying you've tried different settings in order to settle on the 5 degree differential?

I have played with it and found the small differential seems to maintain a nice burn in the boiler. I have had issues on warm days (50 degrees or so) with keeping the boiler lit. I noticed when my differential is low it fires more often therefore getting a better burn. I really can't see a difference in heating with the higher temps, even when it was in the negatives I left it at 160.

 

[sam-tip]

20 degree differential here. 175 to 195. Any larger and the burn temps go down at the end of the burn. But that is my boiler. Each boiler is different. To many factors to consider. Mine burns different on windy days. Different with soft vs hard wood. If I put the wood to far to the back of the boiler.

 

[StihlFroling]

Every OWB is different, there is a sweet spot for each one. Plus your wood and weather also effect this.