Outdoor Wood Furnace Info

Outdoor Furnaces - Manufacturers with NON EPA-Certified Models Only => Shaver Furnace => Topic started by: ambonci on November 25, 2015, 07:10:02 AM

Title: circulator location
Post by: ambonci on November 25, 2015, 07:10:02 AM
I am wondering how many shaver owners have the circulator located on the bottom port of the stove, pumping from the bottom instead of the top.  I think there are many benefits to running off the bottom.  including:  pump should never loose its prime, more head pressure, less chance of pump cavitation,and returning the colder water on top.  I'm looking into doing this soon.  I read on a shaver install sheet that they recommend moving pump to the bottom port.  just curious if anyone has done it and what they experienced for pros and cons.

Thanks.
Title: Re: circulator location
Post by: mlappin on November 25, 2015, 11:42:29 AM
On the G series they pull off the bottom and return to the top.

I built a waste oil boiler last fall and pull from a quarter of the way up from the bottom and return to the top. I have a Ranco in the top to act as a high temp cutoff and it always reads a few degrees of what the temps are pulling from the bottom. Seems to mix very well this way, but I’m also moving a LOT of water. Have two BG-25’s supplying water to my heat exchangers around the shop and a Grundfos 26-99 feeding a fifty plate heat exchanger, so mixing of the water is inevitable.
Title: Re: circulator location
Post by: ambonci on November 25, 2015, 06:16:10 PM
I have a grundfos 26-99 feeding a 50 plate exchanger and a 30 plate for my DHW.  I did the swap today and it seems to be working nice.  I do have another circulator on back of OWB feeding off the top and returning on the bottom, this loop is for my garage heater.  I'm a little worried that one is feeding from bottom and one from the top.  I never had a problem with the garage loop.  should I be concerned about one feeding on top and one on the bottom?
Title: Re: circulator location
Post by: Steinacher Sales on November 27, 2015, 07:54:11 AM
Some of Shaver's earlier install manuals said to put draw from the bottom and return to the top. They changed back to drawing from the top and returning to the bottom. The hotter water is always at the top. Just makes sense that heat rises.

You are right you have to keep your furnace full of water! Another reason would be getting lime or other sediments from the water sucked into the port and pump when drawing off the bottom.

In all it will work both ways!

Greg Steinacher
618-401-0726

Title: Re: circulator location
Post by: ambonci on November 27, 2015, 06:55:33 PM
doesn't the head pressure change when moving to the bottom?  More head pressure the better correct?
Title: Re: circulator location
Post by: Steinacher Sales on November 30, 2015, 06:26:53 PM
Yes there will be greater head pressure. It shouldn't make any difference how it pumps though. Those little pumps are amazing to what they will pump. But, as you mentioned before it will not go dry at the bottom.

Greg Steinacher
618-401-0726
Title: Re: circulator location
Post by: RSI on November 30, 2015, 06:30:50 PM
It will make a difference on the pump inlet pressure. It is important to have a little pressure at the inlet if you want the pump to last. It will make no difference at all on head pressure after the pump.
Title: Re: circulator location
Post by: ambonci on December 01, 2015, 05:02:36 PM
I was worried about longevity of pump feeding from the top that's why I moved to the bottom.  You guys just assured that I made a good decision.  Thanks guys.