Question for the Gurus,.

ALH_4

You might want to do an economic analysis on that before going too far.

Ericjeeper

Outside woodboiler

Ok I currently heat with fuel oil bock. and Six solar panels to back that up.Ok on cloudy days, I want to hook up a woodfired water heater,..Open. I was thinking just adding another heat exchanger to my 600 gallon buried tank.But Man that dude holds some serious gallonage..Glycol is costly..
I was wondering if I could do a drainback system, as the boiler will only be fired on cloudy days.Thinking of using a sump type pump,feeding into the bottom of the tank and a return up towards the top.I do realize I would have to cap off the tank.But it would still be open back to the storage tank,therefore could never build pressure.
Am I nuts?I can set it right on the slab over the storage tank.and piping would be direct to drainback.If I would use a basement type sump pump would the 110-130 degree temps hurt it?
Or would I be better off just doing a close glycol loop? for a heat exchanger?trying to keep this safe and simple too.Thanks
Link to my solar setup photos.
http://www.pbase.com/ericjeeper/solar

Josh M.

Sounds like alot of work to me...

Ericjeeper

I have zero dollars in the boiler itself.

I used an old woodfired furnace. and welded it into a 30 inch diameter section of boiler tank. Well ok I have 30 dollars worth of wire and gases.
So You can see I am not spending 8 k to assist my solar. just a few hundred.. I have 600 tree tops to cut up. I have cut and given away 30 truckloads of wood so far. I might as well unload some at my house huh?

[Deleted User]

Think about this scenario...

You've started the pump, which can usually handle relatively high temperatures. You start a roaring blaze in your wood boiler and start pumping and dumping all those free btu's into the storage tank. Now all of a sudden, for what ever reason, the power goes out. Now all the fluid drains back from the boiler into the drainback storage tank reservoir. You now have a dry fired boiler. Glowing, red hot pre melt down condition boiler. Suddenly, the power comes back on and the sump pump turns on and hits the glowing red boiler with relatively cool water. What do you think, or let me re-phrase that , where do you think the boiler will end up?? Your roof, your neighbors roof, your neighbors back or front yard, or the street...

Not a pretty sight is it.

I only mention this because I have seen it happen too many times to recount, and none of them ended up being a good scenario. Sad thing was, the owners were warned of the potentials in all cases, but decided to go forward with their ideas anyway.

Can you tell I'm not a big fan of wood fired boilers?

Fortunatley, no one has died in my cases, but they certainly could have. You're playing with dynamite here. Be EXTREMELY careful...

ME

Ericjeeper

I understand that

But with no power The damper door falls shut.Therefore all but eliminating the fire?The fire without the damper door held open by the activator will basically just smolder.. Granted it will still be hot, but I would think far from red hot.
I will take what you suggest into account.
What about some sort of lockout for the pump. lets say it lost power and would require a manul over ride..is there such a critter? Thanks

Joe_75

Woodfired boilers are as safe as the manufacturers make them or in this case as safe as the HO makes his. I have installed many WF boilers and have ran my own for almost ten years without incident. I also know of a great many more that have not had feed water flash to steam as you have mentioned. Most WF boilers use a NC damper so that when power is lost they shut down tight. I have seen some off brand and home made ones that are not safe and could have problems. I would not recommend this home made boier/storage tank idea. I would personally recommend a solid namebrand boiler with the proper controls.

[Deleted User]

I'm certain there is...

but you have too many moving parts, and all it takes is one to go bad to cause a major problem. Damper sticks open (it happens), trip strip fails to trip (it happens too), pump locks up for no apparent reason (happens WAY too often).

A simple surge suppressor strip would keep the power to the pump off after an outage. But still, too many things to consider for me. I understand your need to lower your overall fuel bill, but there is a safety threshold to be considered in the evaluation process that is CRITICAL.

But it is a free country, and you are a responsible adult. Just be aware of the consequences.

NIMBY (Not in my back yard)...

ME

Ericjeeper

Ok I will put a glycol system in

Ok you all have convinced me to do a closed loop with glycol, I have the manifolds. and 1 inch tubing. All I will need to buy is a few hundred feet of 1/2 inch non barrier pex.And some SSC crimp rings.
Ok Now can someone recommend a good multi speed pump?
cast iron will be fine. Does anyone happen to have a used goldline differential controller forsale?with sensors.
I will weld in a well into the tank to drop a sensor into the reservoir.I already have a well into the storage tank.
I do not plan on burning a fire 24/7 Just on days when it is cloudy.
Thanks for the input/.I might be a tightwad.. But I am not going to be an unsafe HO.