E-Classic 2300 temperature

[firechief]

First of all Happy Thanksgiving to all.  Hope you're eating plenty, watching some football and taking naps.
I'm wondering about the temperature setting for my 2300.  I've only had it up and running about 10 days now and the temperature is set at 165 degrees.  I'm just heating my home which is about 2500 square feet.  We currently keep the house at 70-72 depending on the time of day and who is home.  Is this temperature good for my situation ?  It seems to be working well.  Under what circumstances would I bump my temp to 170 or 175 or even 180 ?  Not really sure how that works.  Would really appreciate some feedback.  Also, while I'm yakking, what exactly is "bridging" of the wood and how do I best avoid it? I appreciate all the help from this forumn and the members to my questions being new to the OWB experience.  Thanks.

Jim

[solidwoods]

Your system performance is a matter of how is the house temp is  vs. fuel consumption.

If you wish to reduce fuel consumption, increase heat radiation and lower the water temp.

Because:
When water temp is increased, fuel efficiency is reduced. 
So if a unit can be run at a lower temp it is more fuel efficient,, but you have to "equal and opposite reaction" with more heat radiation.  Not a bad trade off since the radiation equipment is a fixed price.
Just a 50' coil of 3/8" dia copper tube behind the couch has a big effect (or 200' in the furnace duct).


Fuel bridging is a hole in the fuel (in the burn chamber). 
It's a big deal in constant feed chips but not so much with whole wood.  If its a problem with whole wood then the fire box needs to be redesigned (cause we put fire in a box over 150yrs ago and we should be able to design that by now for the $ charged).

[dva]

Taking a lesson from hydronic heating with conventional units, most manufacturers recommend a circulating water temperature average of 180 degrees. When I asked my group of people who claim to be knowledgeable in the art, I got the between 175 and 195 answer. I set it to 185 as a result.

But I do not have a lot of time behind the wheel of this either, so other opinions might be helpful to all of us.

Happy holidays!

[MudBud]

For outdoor temps above 40 degrees I have been using 175.   For temps under 185 seems to work the best that I have used in the last year.

[stumper]

It all goes back to thermodynamics.  Lower water temps increase effiecency of the heat transfer in the boiler but decreases the effiecency of heating the home and domestric water.

In my case the driving factor is the temp of the domestic hot water.  I have my hot water tank set at 165 so I run my boiler at 185 (180 on to 185 off).

As I recall a problem and discussion from college there is relatively little differences in effiecency with the heat transfer based on water temp in an engine.  efficency gained or lost in transfer to the coolant was off set by the transfer at the radiator.  The was a bigger differnce in pressurizing the system and that is not an option for us.

Lower temps will reduce heat lost through the insulation of the boiler and the thermo-pex, the same way a lower temp in the house decreases the heat loss through the insulation of the house.

The default from the factory is 185.  I suspect they chose this as a default because it is a good compromise with all the factors in play.  If is were signifacently more efficent at 160 that would likely be the default.

[firechief]

Thanks for the replies.
I'm guessing I'll need to bump my temperature up a bit.  I guess my biggest concern is running out of wood for the winter.  This first year will be a gauge for me as to what I will use each year going forward.  I'm hoping my 7 cords of dried hardwood will last through at least March.  Cheers.

Jim

[dva]

While I'm certainly not skilled in thermodynamics, I would guess that just increasing the temperature of the unit is not directly related to how much wood you'll eventually burn. Heat load on the system will play the biggest part, me thinks.

A higher boiler temp may result in a shorter inside heating cycle and vis-versa but the BTU's needed to heat the space may stay constant or about constant.  165, as you had your set for is lower than the norm, but who's to say it isn't right for your situation?

Like I said, I based my setting on reading recommendations for all of the boiler companies I could fine, including conventional system companies. I would however be prepared to burn more wood than you think you'll need in your first year - ie don't get caught short. Next year you'll be in a much better position to judge.  Enjoy your your warm and cozy holidays!

[Highlander]

So i have been experimenting since this post started. My temp has been set at 185 since i started burning. This was at the dealers recommendation. I consistently burn about 1/2 to 1 wheelbarrow of wood in a 24 hour period. I changed my temp to 175 and have found in the last 2 days my wood consumption increased considerably. Almost 3 barrows full. Heat draw has been about the same so i dont think that has anything to do with it. I reset it to 180 today. Ill see how much that changes the wood consumption.

[stumper]

I just read in the new manual I just received

"NOTE: It is not recommended to set the controller below 185 F."

No reason was given.

[island]

The reason 185 is the norm is because central boiler finds that the chance of condensation in your firebox is minimal at this temp.Just read the new owners manual cover to cover,it also shows how the wood burns from the bottom up,so the top of the wood pile actually dries from the heat,before it burns.Any temp lower may create condensation which may create corrosion in firebox which may create failure!
At 185 you also get more hot water as a bonus.I have set mine from 180 to 185 not worth taking a chance of losing 10 grand on the furnace.I also found if you load smaller amounts of wood,twice a day it limits bridging problems,only bridged once this year.

[firechief]

Thanks for the replies,
I did read that information in the new manual, so with that being said I will bump mine up to 185.

Jim