Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
Pump Location on a 3-Way Mixing Valve
Alan (California Radiant) Forbes
Member Posts: 4,243
Comments
-
I'm no expert but shouldn't the pump be pulling from the mixing valve?0
-
I'm no expert but shouldn't the pump be pulling from the mixing valve?Yes, it should, but it seems to be working alright as it's been this way for years.8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab0 -
Pump needs to pump to the 3 way valve.
JakeSteam: The Perfect Fluid for Heating and Some of the Problems
by Jacob (Jake) Myron0 -
Sorry I don't understand is that thing under the yellow caution sticker a plate heat exchanger? Sorry Allen but can you explain the flow path. Thanks0
-
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab0 -
That's a strange configuration but I guess there's nothing wrong with it. Mixinging is 2 inlets and 1 outlet so it looks to me like it will work. I was confused but the piping on the HX. With Brazed plates are the in and out always on the same side and plate and frames they cross lile an X??0
-
As Dan always teaches, what goes into a tee must come out of a tee.
But with a 3 port fitting, how much goes which way. The path of least resistance thru the valve would see the most flow.
Or is the least resistance thru the FPHX and into that port of the 3 way.
Probably an un-predictable and very random temperature coming out?Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream2 -
Hot Rod: Do you think Julius Ballanco would know?8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour
Two btu per sq ft for degree difference for a slab0 -
PM magazine 2003 article that Siggy wrote about 3 way mixing valve Dos and Don'ts.Hot Rod: Do you think Julius Ballanco would know?
In that application it looks like flow is going into A and B but also through some pressure drop in the plate HX on one side. It obviously works to some degree? So enough flow of mixed temperature is getting to the load. Has the system been doing its job? Comfortably? Your loads are fairly low in that climate so mis-piped systems may be more forgivingBob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream1 -
Alan
You are not wrong with the forgiving hydronics. I told a customer who was getting 3- HTP 80 gallon tanks installed that piping the domestic water in a reverse return wont guarantee proper flow. Turns out based on the temp gauges I was wrong. That felt a bit like egg on the face. I know its not "right" but it works.Tom
Montpelier Vt0 -
I've seen that same mixer/pump configuration before as well. It was a new install done by the fuel company in press copper. It was a staple up radiant job, so I don't think they even needed any mixing. But it was working..... I kind of scratched my head too.Serving Northern Maine HVAC & Controls. I burn wood, it smells good!0
-
The delta-p across the fphe might imbalance the MV enough to not mix properly. Or it might work just fine if the delta-p is not that significant. From a "pump the cold" standpoint it makes sense at least.
Homeowners should know that there's always a big difference between "works" and "code" or between "works" and "best practice". Unvented DWV plumbing can work just fine, until it doesn't, not to code. 2x6 joists for a 2x8 span works fine, not to code. Strange that there are no building codes for radiant. Codes and inspections could improve the industry some day, clean up messes and actually make installer's jobs easier in the long run. When I've had radiant installs inspected the only thing they ever look for is a pressure test on the pex and the presence of a back-flow-preventer. I'd also have to admit that i've done plenty of "works" but not "best practice" things, and looking back would have rather had an inspector catch my mistakes.0
Categories
- All Categories
- 86.5K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 53 Biomass
- 423 Carbon Monoxide Awareness
- 96 Chimneys & Flues
- 2K Domestic Hot Water
- 5.5K Gas Heating
- 101 Geothermal
- 156 Indoor-Air Quality
- 3.5K Oil Heating
- 64 Pipe Deterioration
- 928 Plumbing
- 6.1K Radiant Heating
- 384 Solar
- 15.1K Strictly Steam
- 3.3K Thermostats and Controls
- 54 Water Quality
- 41 Industry Classes
- 48 Job Opportunities
- 17 Recall Announcements