Outdoor Wood Furnace Info

All-Purpose OWF Discussions => Plumbing => Topic started by: BigAlsc on October 08, 2015, 06:36:57 PM

Title: Pipe size versus flow
Post by: BigAlsc on October 08, 2015, 06:36:57 PM
I'm doing the calculations on my system using charts off a link previously provided on this site. I have approx. 425' of 1" pex pipe and fittings on a comparable grundfos 26-99 pump through a 30 plate exchanger. Was considering going to 50 plate but now seeing that may need to go to 1 1/4 pipe also. Looking to get more heat transfer but chart says 1" pex a only gets 7 gpm flow. Will a 50 plate change the transfer if only getting 7 gpm?
Title: Re: Pipe size versus flow
Post by: RSI on October 08, 2015, 08:56:34 PM
7gpm is a fairly average flow rate for most systems.
What type of insulated pipe are you planning on using? If there is a pex-al-pex option, or a 26mm/32mm pex option, I would consider that since the price is usually lower than 1-1/4" and it isn't that much smaller.
Title: Re: Pipe size versus flow
Post by: mlappin on October 09, 2015, 08:02:08 AM
When I did the shop I ran the numbers three times, was actually cheaper with the lower prices on smaller pumps to pay for the 1 1/4” pex instead of running 1” pex.

Depending on what your going to use for underground pipe, upgrading to Logstor instead of using a standard 1” pex might be a very wise decision.
Title: Re: Pipe size versus flow
Post by: mlappin on October 09, 2015, 08:07:57 AM
Now that I’ve thought about it, it was definitely cheaper to pay for larger lines and run smaller pumps, I’m wanting to say I saved around $400.

One pump to feed the flat plate HX, then three more running eat exchangers in the shop. One pump feeds 1 1/4 line to the east wall where it tees to 1” line and each of those goes to a HX under the benches. Another goes to what used to be a cold corner of the shop to an air handler that used to be a gas furnace, a fourth goes to another air handler/old gas furnace thats on casters so you can aim it under a vehicle that your working on.
Title: Re: Pipe size versus flow
Post by: BigAlsc on October 09, 2015, 09:28:00 AM
Been running a few years with it. Didn't know all this knowledge was here at everyone's disposal before I installed everything. I bought the boiler used with plate exchanger and put 1" five wrap pipe in  myself not knowing what I've learned from everyone. Just trying to improve. Don't think it would be cost effective to remove 200' of 1" and replace with 1 1/4. Thought maybe 50 plate would be a more economical improvement. Does more plates equal less resistance?
Title: Re: Pipe size versus flow
Post by: RSI on October 09, 2015, 10:02:24 AM
More plates do have less restriction but you probably won't gain much going from a 30 plate to a 50 plate. If you had a 20 it would probably be enough difference to be worth it.