Froling wood boiler installation underway!!

[Grover59]

I have a small question, I am under the assumption that the froling has just the draft fan providing the air flow for the primary and secondary chambers. Individual flow to each chamber is controlled by the dampers.

Steve

 

[jebatty]

A word of encouragement: keep at it, you've got a top notch boiler that will do an excellent job once you get your wood and other settings right.

Call me skeptical, but I never would even try to burn red oak seasoned one year in my Tarm. My rule is minimum 2 years, but 3 years unless no other option. As to kiln dried wood, if other than high quality finished lumber stored inside, that may mean 17-19% MC, and then if it was stored outside, uncovered, could be higher; stored inside for a year could be 10% depending on your ambient humidity conditions.

I would suggest getting a half cord or so of truly very dry wood and working with that to tune the Frolig. Don't try to tune it with unknown wood, and plan for very dry wood for the future to assure that you get the performance the Frolig is capable of providing. High moisture content wood I believe to be the source of most gasification boiler performance problems. What does the Frolig manual say on MC? The Tarm manual recommends 15% or less.

Also, follow the rule that the most simple solution more likely will solve the problem rather than pursuing a more complex solution. That means one thing only: burn dry wood.

 

[jbastide]

Thanks for all the tips and encouragement. As it's our first experience burning only wood, we're still learning. Going to pursue dryer wood / biobricks to get us through this month.

Best,
Jesse

 

[Der Fuirmeister]

These shots are of the heat exchanger and the turbulator mechanism. The Froling has a total of 10 2" heat exchanger tubes with turbulators in each one. This is significantly more heat exchange than I am used to, and one of the reasons why the Froling never sees stack temps higher than 475�... I have yet to witness stack temps higher than 375�, and for most of the burn seem to hover around 300.

I'm not familiar with this unit. The temps mentioned seem higher than I'm used to seeing in our Wood Gun (245-285*, 305* max.). Is it a gasifier or a standard boiler? In another post you mentioned that you are a Biomass dealer. I'm curious, if you are a Biomass dealer, why did you install a Froling at home? What brand boiler are you replacing?

Some of my questions may be because I'm not familiar with all the boilers out there, but I thought I'd ask.......

 

[TCaldwell]

jd, have you run a run a brush through the flue lately. sounds more like the boiler could be inducing shutdown mode because of flue blockage. Also does the boiler do diagnostics on the o2 sensor, just a thought.

 

[jbastide]

I'd like to post an update on the combustion issues I'd been having with my Froling 20/30 since you guys offered some good advice on things to check out.

System: Froling 20/30 (running in 30kw mode)
650 gal. insulated thermal storage
passive solar
propane backup (never runs!)
exterior uninsulated masonry chimney with a square 6 inch clay flue

System was commissioned Jan 15th of this year during a cold snap. Noticed that I got several gallons of water due to condensation in the uninsulated flue. This was leaking out of the cleanout. In the installation manual, it does mention that condensation is a possibility.

In an effort to keep moisture down in the flue, I increased the minimum flue gas temp to 150 degrees C. No more condensation. However, by this point I had started looking at average residual oxygen levels during a burn and seeing levels between 14-18% for most of a burn. The primary damper would stay 99% open and the secondary would stick to 10% for the entire burn. This led me to believe that I wasn't achieving efficient gasification because of improper wood gas to combustion air ratios.

Folks suggested that I try some really dry fuel, so I managed to get some geobricks at my local paris farmer's union. I was still kind of surprised when the residual oxygen levels were still high (12-15%.) I burned them both alone and in conjunction with some of my less than ideal cordwood ('seasoned' in log form, cut and split on day of delivery in the Fall. I'm learning....) The burn was still not great.

Yesterday, I decided to try something new. Because outside air temperature was around 42 degrees F, I lowered the minimum flue gas temp back to 120C, thinking that any condensation problems might not be as bad as when it was really cold. I had a few geobricks on top of my cordwood, with about a half a load in the primary chamber. Residual O2 was in the 8% range during most of the burn. Secondary air was open over 25%, and primary air was choked down. This was working great!

Seems like the following are key to getting the Froling to work well with an exterior chimney.
1. Dry fuel
2. Insulated SS flue liner (or warmer outside temps!)
3. Keeping minimum stack temp at default setting (120) or not much higher to allow the boiler to reach gasification mode faster and not toss that heat up the stack

Thanks again!
Jesse

 

[DaveBP]

I'm a little surprised that Froling would even sanction an installation with an uninsulated exterior masonry chimney.

That really puts you at a disadvantage.

 

[TCaldwell]

can you put a insulated liner in the masonry flue, this might help in the long run.

 

[Willman]

Its all about proper seasoning of the fuel. 2 years cut split and stacked. Try to get some wood delivered before mud season (double up on qty. if possible) and start blocking and splitting. Stack in single rows in the wind for drying. then this time next year we can read your posts praising the awesome boiler you installed.
Check out the wood shed here for all things wood.

Will

 

[mustash29]

This thread is very inspiring to say the least. Thank you for the effort and insight on this (sexy) boiler. I'm looking forward to the day when I can have my very own thread similar to this.

According to the nice folks at Tarm, red & blue play nicely together.

This guy was installed in '96 when the house was built, it has served me very well over the years.

It's had an awful lot of help from this guy, but I'm sorry to say I do believe her days are numbered:

 

[skfire]

Good luck and take your time...

red and blue went well for my install
https://www.hearth.com/talk/threads/77159/

even though the Blue Buderus does not get much exercise anymore...the Red has taken over...
into the 5 month..and looking good.
and regarding the Tarm guys, highest compliments thus far.

Scott