OWB Propane Backup - Ideas??

[hottubbrad]

I have a 250 gallon OWB sitting in an insulated shack 180' from my house. The lines run into the house for heating radiant and forced air etc....
I am interested in designing a propane backup. Initially, I thought of having the propane boiler in the house and have it switch on with a thermostat on the incoming water temp from the boiler outside. The disadvantage is that I have to run gas into the house, and a flue out and have an ugly propane tank near my house. Right now I am gas free (in the house) which means peace of mind for me. Carbon Monoxide....etc.

Now, I am thinking of having the propane boiler outside in the shack with the OWB. The issue is that the boilers I have done in the past are Closed Systems (pressurized). The OWB is Open.

Any thoughts on how to accomplish this outdoors with propane? I am open to new ideas and thoughts....

Thanks

 

[parkini]

You could use some three way valves and an aquastat that fire up the propane boiler and direct the OWB water through a HX in the propane boiler if/when the temp drops too low in the OWB.

 

[hottubbrad]

Does anyone know if there is a propane boiler that can work in an Open System? (or the ramifications of doing this)

Also, I thought of just having 2 zone valves that change the heating path from the OWB to the Propane Boiler. (I don't want to have to heat the 250 gallons in the OWB by propane.)

The planned system is for backup heat in the house AND shoulder season use when you do not need to light the fire.

 

[in hot water]

pool boilers are for open system and designed to be outdoor mounted.

I'm not aware of any high efficiency 90% outdoor units, due to condensate freezing issues. however.

Raypak and most of the copper tube boiler manufacturers have outdoor conversion kits available.

hr

 

[Chris Hoskin]

you could put a powervented LP boiler in the house and bury an LP tank so you don't have to look at it. Hate to see you suffering the heat loss of the underground piping when heating with LP.

 

[bigburner]

I use a raypack pool heater that was used on an open pool/now its used in a closed system, they work great and most have a built in by pass to keep it from condensation. You can tie a lot of things, I also have a 200 gal electric water heater, 6 tons w/w heat pump, and of course the wood boiler all tied together.