I am considering installing a Garn to replace my old OWB.   My current wood boiler feeds into a gas boiler in my basement, and the gas boiler controls the 3 heating zones.  It should be a pretty straight forward connection as far as I can tell.  Does anyone know where I can get a more detailed picture of how the Garn works.  I'm getting pieces here and there, but find I am wishing for a manual of some sort.  I've done most of the wiring and plumbing in my house and would like to do as much of the installation as possible.  Even if I end up hiring someone to do the installation I would like to know what I'm getting into.

Thanks much

haarstic,

As Tattooz said, each install is going to have it's own details, so there is no single "way" to install the GARN, but his diagrams give you a good idea of one alternative.  Feel free to go through the pages on my site (link in my signature below) to see how I did it.

I think that two books should be required reading for anyone considering installing a GARN themselves.  Dan Hollohan runs a web site called www.heatinghelp.com  He has published several books relating to HVAC function, theory, design, and installation.  Get a copy of "Pumping Away" and "Primary-Secondary Pumping Made Easy".  These are invaluable in understanding your options, and the pros/cons of those options, when designing your installation.

The integration should be straigtforward, since you already have an OWB integrated into your existing in-house system.  However, keep in mind that you cannot locate the GARN outside, unprotected, like a typical OWB.  You will need to shelter and insulate it, since you are heating and storing 1500+ gallons of water (or more if you go with a WHS2000).

Sign up for the forums over at www.hearth.com, like Tattooz mentioned.  Good people and tons of experience and info.  Search for GARN and you will learn much.

Jim and Tattooz,

Thanks much for your excellent information, it is just what I am looking for. The diagrams are very helpful, and I will definately pick up those books you mentioned and check out the other websites.   I'm planning to spend the rest of the winter learning as much as I can about the Garn and installation with my system so that when the time comes I am not hit with unexpected costs and situations. 

I've looked at other gasification boilers, and from what I can see the Garn fits the bill for me.   It seems to have all the options I want:  heat storage, the ability to burn almost any kind and size of dry wood, and a simple operation.  An inside location is also desirable for me as I'm getting older.

Again, your help is much appreciated!!!

J

I am also in the design process of building a house.  I have looked at all the other wood boiler/gasifiers and believe the garn is the way to go for me.  I do have a question for all.  Is it common practice to put a garn indoors?  From what I have read and seen, it seems everybody has theirs outside.  I am still in the design process of my house and would like to put mine inside.  Is it possible?  I am thinking that the weight may be an issue.  But again I am preplanning and can be ready for it.

Seems to me the unit would be more efficient if it were in the house.  I'm going to enclose mine in an attached building, no going outside to fire, no heat loss in the pipes.  I would make sure you can close the boiler room from the rest of the house in case of escaping smoke, and of course the mess the wood pile makes.  The weight shouldn't be a problem if you can prepare for it.

 Here's a couple pictures of one installed inside a finished building. I'll figure out how to post them here some day..........

http://www.hearth.com/econtent/index.php/forums/viewthread/32167/

NOTE: This is a repost because the other one did not copy the line breaks.  That was using Safari, this is using Firefox.  Someone should share how they get pictures to show up in their replies.  Sorry for the duplication. 

Here are some guidelines that now accompany the manuals.  It points out all the unique things to be considered when installing a GARN unit.


IMPORTANT GARN® INSTALLATION GUIDELINES
========================================

Congratulations on your purchase of a GARN hydronic wood heating unit. While the design and operation of the unit is
very simple, it contains several innovative and novel design elements that will impact how your system is designed.


SPECIAL DESIGN CONSIDERATIONS:
-----------------------------------------------------
Before you finalize the design of your system, be sure to read this manual and pay specific attention to the following
items:

 NON-PRESSURIZED WATER STORAGE - This is a non-pressurized water storage system and as such requires
careful attention to:
o how pumps are sized
o where pumps are located in relation to the storage tank
o where pumps are located within the distribution system
o and how pumps are controlled.

 PRESSURIZED EXHAUST FLUE - The GARN unit uses a blower to provide efficient combustion and heat
exchange. This requires all flue connections to be sealed to prevent exhaust gases from entering an interior space.

 STORED HEAT - The temperature of the water in the storage tank will vary depending on frequency of burning
and the rate heat is removed from storage. Your system should be sized for the LOWEST expected system water
temperature. The lower the system water temperature, the more effective your storage becomes. Many
conventional heating components are marketed based on 180 F water temperatures. Make sure your components
are selected based on their performance with lower water temperatures.

 METHOD OF HEAT DISTRIBUTION - Water-based heat storage systems work well with all heat distribution
options. However, the specific need for heat will suggest one type of distribution over another. Properly sized
radiant floor heating works exceptionally well with water-based storage systems, however, the requirement for air
filtration or conditioning may dictate the use of hot water coils in an air circulating system (NOTE: Heating coils
should NOT be added to forced air systems that use a high efficiency furnace with plastic flue pipe). Other design
considerations may point to some form of radiator that uses the hot water directly. Several different methods can
be combined, but care must be taken so they all work equally well with the temperature of water available.

 METHOD OF CONTROLS - There are certain control designs that work best with a water-based heat storage
system. Carefully read the entire manual for options that will work best for your application.


GOOD ENGINEERING PRACTICES:
-------------------------------------------------
Any heating system that circulates heated water from a heating device to its point of use can benefit from incorporating the
following good design practices:

 PROPER SIZING OF DISTRIBUTION PIPING - Many times a smaller size pipe is chosen to save on installation
cost; however, undersized piping can dramatically reduce how efficiently the heat is distributed. Often, the
required heat cannot be delivered regardless of the selection and sizing of other systems components. This is an
error that can only be corrected by replacing the undersized pipe.... a very expensive option.

 PROPER SIZING OF PUMPS - Many people do not understand how to select a pump that matches the
requirements of the system. Use the charts in this manual and those supplied by pump manufacturers to insure the
selection of the proper size and model of pump. Consideration must be given to both the head loss and gallons per
minute required at the lowest expected temperature.

 PROPER SIZING OF HEAT EXCHANGE EQUIPMENT - Equipment should always be selected based on the
system water temperature available and other components in the system. Be careful of “rules of thumb” that
appear too good to be true.