My Garn Barn....
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Looks Great, I have a GARN 2000 heating two homes. I fire the unit twice a day, 0500 and 1700 adding one load after the intial load. Works great. There are some tricks to it (load the wood toward the back of the fire box and don't burn to much small wood at once you will get puffing). I made my own pipe as suggested by GARN which saved a ton of money $3.50 per foot total (1 1/4" pex 1" solid insulation and ABS pipe) works great. Also had trouble finding 1 1/4 fitting had to purchase a WATT crimping tool. $$$$
Tat,
Are you supplying off the top and returning in to the bottom of the Garn? And on your loop farthest away from the Garn, are you sucking from the plate heater?
Are you supplying off the top and returning in to the bottom of the Garn? And on your loop farthest away from the Garn, are you sucking from the plate heater?
Hey Garn..
1) Yes supply from top Return to Bottom.
2) I am at a stand still right now.... We are having some varied opions about pump placement. Tomorrow AM is the big Pow wow with all the right people. will have a much better Idea tomorrow night.
P.S. Take a look at my photo... Pumps to High...?
1) Yes supply from top Return to Bottom.
2) I am at a stand still right now.... We are having some varied opions about pump placement. Tomorrow AM is the big Pow wow with all the right people. will have a much better Idea tomorrow night.
P.S. Take a look at my photo... Pumps to High...?
Tattooz said:
Well, I hope Heaterman chimes in on this cause we discussed this awhile ago about where to supply/return. Mine is set up sucking off bottom and returning to the top. He agreed with me and that is what a old manual of a garn said, but I was wondering if that is right. I notice that when my unit is not under load that my temp gauges split about 10*F from top to bottom. I'm afraid that if it went the other way the spread would be much greater and I might possibly boil over sooner when firing.
I don't know about sucking through the plate hx and a Y-strainer is the best setup. I think I would want to push to the hx and strainer where the water is colder-Is that loop closed? I guess that would define where the pumps goes too.
I am glad you and Jim K are posting your installations along with your questions. The information you are providing as well as gathering is helping me immensely. Garnification brought up some good questions for thought. I will be posting my plan soon. What software are you using for your schematic? I just have a simple line drawing program.
Hello, The hx placement I found to be the easiest and most efficeant is to pipe the return of your exsiting boiler counter flow through a hx. If you have a fin tube system there is no need for a extra pump and you don't have to put a close loop in. I don't have schematic but will make one and post in a few day. Pipe losses are important, if you have a standard fin tube system Place you pump in you GARN barn, through a y strainer and check valve, to the home with a hx plumbed into the return line of you boiler. Very little line losses, very efficent. Also if the GARN is located at a height great enough above the exisiting heating system you may not have to put a hx in, just convert to an open system. Hope this helps
Don L said:
It is counterflow, in that diagram... (the colors used just make it less obvious, I think, but the pumps point the right ways)
Joe
Tat - I think the pump on the GARN may be too high. I have mine mounted equivalent to about a foot above the bottom of the GARN, but pulling water from the upper bung. That is the way GARN/Dectra is now instructing owners to install the pump. Depending on your pump size and flow rate, you may be OK with respect to cavitation or suction boiling. What is your elevation?
I'll have some updated pics of my P/S loop posted next week. I am pulling water for the secondary house loop about a foot from the Tee on the primary. I am pushing my water ~125' to the HX where the strainer is mounted in the basement about 5 feet from the oil furnace. The furnace circulator will push water through the return leg and into the HX, counter flow to the GARN water. Pretty standard stuff, AFAIK.
Data: I am using a Grundfos UPS 43-44FC three speed on the primary. It is a low head, high flow pump. It will give me more than the 14GPM I'll need for all three secondary loads, and keep the return water warm. Based on the pump curve and my calculated head loss, I don't expect to need to run it faster than the lowest speed setting.
I am using a Grundfos UPS 26-99FC three speed on the house secondary. I have a lot more head loss due to pipe length, fittings, and the 20 plate HX. However, I still only expect to use it on low speed.
The second and third loops will be using a more typical Grundfos 15-58 on each loop.
I just hope the tech that helped me pick the 20 plate HX was right.
I'll have some updated pics of my P/S loop posted next week. I am pulling water for the secondary house loop about a foot from the Tee on the primary. I am pushing my water ~125' to the HX where the strainer is mounted in the basement about 5 feet from the oil furnace. The furnace circulator will push water through the return leg and into the HX, counter flow to the GARN water. Pretty standard stuff, AFAIK.
Data: I am using a Grundfos UPS 43-44FC three speed on the primary. It is a low head, high flow pump. It will give me more than the 14GPM I'll need for all three secondary loads, and keep the return water warm. Based on the pump curve and my calculated head loss, I don't expect to need to run it faster than the lowest speed setting.
I am using a Grundfos UPS 26-99FC three speed on the house secondary. I have a lot more head loss due to pipe length, fittings, and the 20 plate HX. However, I still only expect to use it on low speed.
The second and third loops will be using a more typical Grundfos 15-58 on each loop.
I just hope the tech that helped me pick the 20 plate HX was right.
BrownianHeatingTech said:
Boy, am I glad I read your post twice as I was focusing on the color rather than the direction arrow within the pump symbol. The installation is now clear.
Thanks Joe!
tat. that looks much better with those modifications,do you still have room to insulate them after a test fire
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