Adding gassification boiler to an existing propane fired boiler system.

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huffdawg

Minister of Fire
Hearth Supporter
Oct 3, 2009
1,457
British Columbia Canada
Hello gents.

I have a buderus propane boiler that supplies hot water to five infloor radiant zones, seven 6' radiant baseboards and DHW.
system controlled by honeywell aquastat.
-there is 1 pump for radiant flooring
-1 pump for higher temp. baseboards.
- 1pump for DHW which has priority.
it is a closed system.

I am thinking about tying in an EKO or something similar.

Where would be the best place to tie into the existing system.

My explanation of my system is probably very vague.
I will be able to make up a drawing and post pics.
When I get off this ship and get home!

Thanx in advance for any hints or help.

Cheers Dale
 
Huff,

If you have room to do storage which would give you more efficiancy check out the Simplest Pressurized System folder. I currently have a Eko 25 and Munchkin Contender propane boiler and running a simialr setup. Right now I run my boiler in the evening and run on storage during the night and day. Heating 1,800 sq. ft., DHW and Hot Tub. During the winter and burn in the evening and then again in the AM. When it get's below 0 I have too add wood during the night.

Good luck and this is the place to get info.
 
I have my OPB tied in the way CB shows using a wrap around pump, my oil beast stays 175 all the time and only comes on if the water temp from the OPB drops below 140. A simple set up but not the best, some guys here use all kinds of electric valves and sensors to not heat the gas/oil boiler until the wood boiler is cold.
 
huffdawg said:
Hello gents.

I have a buderus propane boiler that supplies hot water to five infloor radiant zones, seven 6' radiant baseboards and DHW.
system controlled by honeywell aquastat.
-there is 1 pump for radiant flooring
-1 pump for higher temp. baseboards.
- 1pump for DHW which has priority.
it is a closed system.

I am thinking about tying in an EKO or something similar.

Where would be the best place to tie into the existing system.

My explanation of my system is probably very vague.
I will be able to make up a drawing and post pics.
When I get off this ship and get home!

Thanx in advance for any hints or help.

Cheers Dale

If I was dealing with something like that, and I understand your setup properly, I would probably put a T on one side of the existing boiler and a switching valve on the other so that I could pull the water from either the propane boiler or the wood boiler storage tank. I would then make a separate loop from the wood boiler to the storage tank. This would use your existing pumps and plumbing for the loads, and allow you to feed the load either from the storage tank or the propane boiler, and add one pump and a mix valve for the wood boiler loop that heats the storage. The storage would act like a giant hydraulic separator to isolate the wood boiler from the rest of the system.

Gooserider
 
Thanx Gooserider
So would the water in the storage tk and the wood boiler be non seperated.
And Im also assuming that the lp boiler aquastat logic would figure out that the lp boiler doesnt need to fire when
heated water is coming from a heat exchange coil in the storage tk.

Cheers Huff.
 
huffdawg said:
Thanx Gooserider
So would the water in the storage tk and the wood boiler be non seperated.
And Im also assuming that the lp boiler aquastat logic would figure out that the lp boiler doesnt need to fire when
heated water is coming from a heat exchange coil in the storage tk.

Cheers Huff.

If using pressurized storage, the wood boiler, storage tank, LP boiler, and house loads would all be part of the same pressure system, and share the same expansion tanks - this does have the minor downside of requiring BIG expansion tanks, but that isn't a huge issue. Having pressurized storage has other advantages that can make up for the headache of the larger expansion.

If doing non-pressurized storage, I would plumb it a little bit differently, but still do a similar setup, in terms of the general system layout. However I would want to do some extra stuff to allow using the same HX in the storage tank to both charge and discharge it...

In terms of the interaction between the wood and LP boilers, I would want to set up the plumbing so that the LP boiler would NOT see heated water when running off the wood side - running hot water through a boiler that isn't being used is just wasting energy. There are a lot of different options to control the two boilers and switching between them. One simple method is to put a second thermostat in place, one for each boiler, and set the LP boiler stat to several degrees lower than the wood stat - if the wood side is keeping the house warm enough, the LP thermostat will never call for heat... Another is to put an aquastat or other sensor on the wood side wired to turn the LP boiler off as long as the wood is above your working minimum... There are many other ways as well, ranging from the very simple to the quite elaborate...

Gooserider
 
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