Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Plumbing => Topic started by: Mjf3487 on October 04, 2016, 05:45:57 PM

Title: Connecting to indoor boiler options
Post by: Mjf3487 on October 04, 2016, 05:45:57 PM
I'm installing a used outdoor boiler to my indoor oil boiler. I will be using a heat exchanger. The Indoor boiler has a coil in it to heat domestic water and a single zone to heat the house. At this time I'd like to leave that alone

I'm thinking the simple option would be to add a second zone to indoor boiler and run circulator 24/7 through the heat exchanger. This should keep indoor boiler up to temp all the time allowing me to have hot water all the time and heat whenever the house calls for it.
The negative would be running 2 circulators 24/7.

Does anyone see a problem or possibly a much better option?
Title: Re: Connecting to indoor boiler options
Post by: mlappin on October 05, 2016, 08:45:53 AM
Unless they are especially large inefficient circulators you most likely won’t notice it in your electric bill, the savings from what you’re heating with now compared to the electric used by the circulators should be offset greatly by savings in your heat bill.
Title: Re: Connecting to indoor boiler options
Post by: Mjf3487 on October 05, 2016, 10:05:09 AM
Ok that's good to hear

What are most people doing with similar setups?
I haven't had great luck researching it

Thanks for your help
Title: Re: Connecting to indoor boiler options
Post by: Roger2561 on October 05, 2016, 10:57:22 AM
Can't answer your question as to what most people are doing but what I did is put a circ at the oil burner drain that pumps water to heat exchanger.  The T&P valve for mine is on top of the oil burner so I put a "T" between the T&P valve and oil burner.  I attached the return line from the heat exhanger to the side of the "T".  The circ runs 24/7.  I don't see that must rise in cost for the time it's running.  Good luck with your project.  Roger   
Title: Re: Connecting to indoor boiler options
Post by: hondaracer2oo4 on October 05, 2016, 11:05:57 AM
Rogers solution is pretty simple without having to add another zone onto your zone supply and return manifold but most drain and tp valves are only 3/4 diameter which means you lose a lot of flow reducing your btu capability. Since you only have one zone for the whole house I assume that th house isn't huge and you could probably get away with just using the drain and tp valve.
Title: Re: Connecting to indoor boiler options
Post by: Mjf3487 on October 05, 2016, 05:01:43 PM
Rogers solution is pretty simple without having to add another zone onto your zone supply and return manifold but most drain and tp valves are only 3/4 diameter which means you lose a lot of flow reducing your btu capability. Since you only have one zone for the whole house I assume that th house isn't huge and you could probably get away with just using the drain and tp valve.
You are correct, it's a small house. Single level, roughly 1200sqft
Title: Re: Connecting to indoor boiler options
Post by: RSI on October 05, 2016, 09:55:16 PM
3/4" threaded pipe is the about the same size inside as 1" pex so it shouldn't be that bad. Using larger pipe and fittings except where it enters the boiler should get decent flow.
Title: Re: Connecting to indoor boiler options
Post by: slimjim on October 06, 2016, 05:43:41 AM
The golden rule that I use is for each gallon of water flow per minute, you can effectively extract 10,000 BTU's so if you can get a flow rate of 7 gallons per minute flow rate through 3/4 inch pipe ( which is really pushing the estimate with the 90's ) then you can extract 70,000 BTU's. If the oil boiler is rated at 70,000 BTU,s and it does the job well, then you should be OK.
Title: Re: Connecting to indoor boiler options
Post by: fireboss on October 06, 2016, 07:03:23 PM
Not to hijack this post but I will lol! But thanks to Rodgers post here and me reading the manual over and over again I think I figured out my problem from last year that you guy's help me with!   I have my loop running backwards I am pulling from the heat exchanger  to the bottom of my oil burner.  I think it should be going the other way ! The manual and rodger says so. It does OK until the real cold nights but I am sure I will have no problems when I reverse the flow! What do you think?
Title: Re: Connecting to indoor boiler options
Post by: Roger2561 on October 07, 2016, 11:43:08 AM
Not to hijack this post but I will lol! But thanks to Rodgers post here and me reading the manual over and over again I think I figured out my problem from last year that you guy's help me with!   I have my loop running backwards I am pulling from the heat exchanger  to the bottom of my oil burner.  I think it should be going the other way ! The manual and rodger says so. It does OK until the real cold nights but I am sure I will have no problems when I reverse the flow! What do you think?

fireboss; Looking at what you described, I believe yours is backward.  At the drain, I installed a "T" between the oil burner and drain bib, this way I'm sure I had a way of draining the oil burner if I had to.  I also put isolation valves before and after the circ for the time I need to service it, I don't have to drain the oil burner of water.  You must already know this but make sure the flow direction from the oil burner is opposite that of the flow from the OWB when connecting to the heat exchanger.  Keep us posted of the outcome.  Roger  PS:  One small thing - there's no "D" in my first name.   ;)   
Title: Re: Connecting to indoor boiler options
Post by: mlappin on October 07, 2016, 02:15:56 PM
  PS:  One small thing - there's no "D" in my first name.   ;)

There is now :thumbup:
Title: Re: Connecting to indoor boiler options
Post by: fireboss on October 07, 2016, 06:56:37 PM
Sorry about that Roger ! So I switched my flow to night thank God for shark bites fittings it took longer to drain the oil burner ! And yes I no about the opposite flow thanks for double checking this drove me nuts for years ( not sure if this is the end of it) but those real cold close to zero nights I was maxed out ! I started with a,40 flat plate exchanger   then went to a 100 plate and didn't gain a degree so went from a 007 to a 14 and didn't gain anything so thank to Roger post I think I found my problem I won't really no till the winter !
Title: Re: Connecting to indoor boiler options
Post by: fireboss on October 07, 2016, 07:00:26 PM
PS  if slim looking for a helper  Roger is your man he is wasting his time at his teaching job  he should be on the magic bus lol!
Title: Re: Connecting to indoor boiler options
Post by: slimjim on October 08, 2016, 06:01:53 AM
He would be welcomed anytime!