add-on wood boiler piping

MikethePlumber

i have an oil-fired boiler w/ primary secondary loop; priority demand for the indirect water heater and would like to add a wood boiler to the system

i have some idea about the piping but would like some further input

also any ideas about the wiring would help

thanks

mike

john walsh_2

add-on

I"m going to be doing the exact same thing in upstate NY. My set up is the same with primary secondary in the existing heating system which I installed according to "pumping away" by Dan over 12 years ago. I'm going to cut into the primary loop with two 1 inch tees close together and pipe the supply and return of the wood boiler into these two tees. I'm going to seperate the oil fired boiler from being part of the primary loop and pipe it into the primary loop the same way using two tees cose together. Then at the wood fired boiler I'm going to use a thermostatic bypass valve to allow the wood boiler to heat up quickly before delivering heat to the  heating system. I'm going to go lo tech on the wireing I think, I'm just going to use a doubble pole switch at the  wood boiler. Up will turn on power to an aquestate in the wood boiler that connects on a temp rise which then goes to the wood boilers' pump (that way when the wood boiler goes cold the pump won't be pumping system water into a cold boiler) while also disconnecting power to the oil fired boilers' gun. Down will shut power to the aqestate and turn it on to the oil gun.

 Of course everything is subject to how I feel on the day but that's the way I hope to do it .

John

Chris S

add on boiler

I have a similar system to what you are both describing.  I piped my boilers in parallel,  into a Caleffi hydrosepaerator, eliminating the primary loop.  This way either boiler can supply heat.

For control,  I installed an aquastat in the supply line to my heating loads, which breaks on rise.  I use this aquastat to break the low voltage signal to the fossil fuel boiler. 

As for boiler protection, I installed  and later removed a Danfoss thermostatic valve, in favor of a variable speed circulator.  - Hot Rods idea.  Read planty about all of this at hearth .com in the boiler room. 

My wife sets the thermostats at T presently, since we are no longer paying for fuel.  T=  tropical,  i wear shorts at home.

L'town Radiant_2

Just a thought,

you fellas might also keep in mind that many, if not most  wood boilers are open systems, so when connecting to existing traditional closed loop hydronic system, you will need to sperate the wood boiler by way of a heat exchanger or confirm that there are no ferrous components in the existing system.

john walsh_2

energy storage tank

Very important detail! Also  according to John seiganthaller in his book "MODERN HYDRONICS" he recommends burning a charge of wood HOT and FAST catching and storing the BTU output in a storage tank. He  says that's the best way to get the most out of seasoned fire wood. But for now I'm going to connect it in to the existing system closed circuit and burn small amounts of wood with all stats at B for Bermuda until I get a feel for what a charge of wood will do, and when funds allow, I will get me an EST(energy storage tank) and have the wood boiler open to atmosphere. What do you think?

Charlie from wmass

what boiler are you putting in?

Tarm, Kerr, and Buderus are closed systems you can put in the basement with their own dedicated chimney flue. The others that are open need to go in the back yard. A heat dump/ sorage is the way to go with wood boilers though. 2 good hot burns a day will take care of most homes in the dead of winter. This means a need for room and funds to pay for the sorage tanks. They are both closed systems and open tubs.

TonyS

Here is a link to something that will help

http://www.cmxshow.com/docs/CMX_CIPHEX-wood_solar.pdf

john walsh_2

wood boiler

Thanks Charlie and Tony. Great stuff!