Boiler tempering for anti-condensation

[Old Timberguy]

I'm finally getting around to plumbing and hook-up between the three locations and several components in my wood boiler heating system. Very specifically I'm trying to determine my best option for a boiler tempering valve. After some research I had decided upon the Caleffi "Anti-condensation valve"
280966A
Size: 1"
Connection Type: Sweat
Max Temp (F): 140°F
Max Pressure (PSI): 150
Flow Capacity (Cv): 10
Material: Brass
Body Pattern: 3-Way
Application: Point of Source
Standards Met: ASSE 1017
This valve will be connected to a Grundfos UPS15-58 circulator on dedicted loop to my 500 gallon storage tank using 1" copper pipe. In theory the boilers function is to burn hot and heat the water in my tank with no other control interfering. Any demands from the various loads would be drawn from the storage tank. using a delta p circulator. My dilemma and question is whether this is indeed the best choice, and if not what suggestions could be offered. Unfortunately It turns out that this valve is made in Italy, and could be a couple weeks out minimum. Are there other options from a US manufacturer that would meet the same flow rates?
Thanks Rick

 

[maple1]

LK makes one too - would maybe come down to which one you could get sooner, if you're in a hurry. Think both have good reps. Check with boiler people who advertise on this site. There's also the Danfoss ESBE, that a lot use.

I've got an LK810 loading unit - pricey, but it works great. Pump stuck on startup last year, haven't tried this year yet. Not sure why but was an easy fix.

Re. your diagram, I might move the load pump to the bottom & pull thru the zones, and tie in the expansion tank just upstream from the load pump inlet. Think that's considered a good practice, in keeping inlet pressures up where they should be on the inlet side of the circ.

Also, if you're starting with depleted storage, your system won't see 180 water until all the water makes one pass through the tank. More like 160. Which could take a while if zones are drawing (at the same time the boiler protection valve is bypassing). And, you won't get much mileage out of your storage if you don't deplete it. So that all may or may not factor into sizing of your furnace coil. Just a mention.

 

[2Bits]

Old Timber Guy, I'm pretty sure Polar Furnace uses the Caleffi tempering valves on their G-Class gassers. They install one on each unit as part of their Connect-EZ assembly... Maybe give them a ring?

 

[NateB]

You may want to put some logic in that would turn off flow to the tank if the stats are calling for heat, and tank is below temp.

 

[Old Timberguy]

LK makes one too - would maybe come down to which one you could get sooner, if you're in a hurry. Think both have good reps. Check with boiler people who advertise on this site. There's also the Danfoss ESBE, that a lot use.

I've got an LK810 loading unit - pricey, but it works great. Pump stuck on startup last year, haven't tried this year yet. Not sure why but was an easy fix.

Re. your diagram, I might move the load pump to the bottom & pull thru the zones, and tie in the expansion tank just upstream from the load pump inlet. Think that's considered a good practice, in keeping inlet pressures up where they should be on the inlet side of the circ.

Also, if you're starting with depleted storage, your system won't see 180 water until all the water makes one pass through the tank. More like 160. Which could take a while if zones are drawing (at the same time the boiler protection valve is bypassing). And, you won't get much mileage out of your storage if you don't deplete it. So that all may or may not factor into sizing of your furnace coil. Just a mention.

Maple1 Thanks for the input. I checked out the LK version of this valve and they are made in Sweden, boy it sure is hard to find home-grown parts these days, I would have been more comfortable if there was a domestic brand available, but thanks for the option!

I took my drawing and erased the pump and made the alterations as you suggested, I'll include that copy to see if I'm hearing you correctly. I do understand what you're saying about the 180 water. This whole system is probably being assembled and used in a rather unconventional way. I'm a wood worker with unlimited access to waste wood cut-offs. The heating portion of this system is being used only to heat my workshop, which has both the radiant slab heat, and the fan coil. I'm hoping to maintain 50 degrees all winter but increase that to 65 degrees on the weekends. In theory the slab will make use of the low grade heat during the work-week, then on the weekends I have longer burn enabling the fan coile to quickly bring up the room temp. The indirect water heater is to be used intermittently also, it will we plumbed in series with my gas water-heater,serving as a tempering tank when not fully fired. In my mind at least, the trick will be in the control portion of the project. I have several temperature microprocessors and relays that will control the zone valves as my storage tank reaches certain temps.

 

[Old Timberguy]

Old Timber Guy, I'm pretty sure Polar Furnace uses the Caleffi tempering valves on their G-Class gassers. They install one on each unit as part of their Connect-EZ assembly... Maybe give them a ring?

Thanks for the input, I followed your lead and sent an email inquiry, Thanks

 

[Old Timberguy]

You may want to put some logic in that would turn off flow to the tank if the stats are calling for heat, and tank is below temp.

You are absolutely right on with that. Although my poor drawings don't show any of that, it is an equally complicated and important part of the project. thanks to Ebay and China in many cases, relays, temp sensors and microprocessors are cheap and fun to play with.

 

[Bob Rohr]

A two pipe buffer tank piping may work better.

Basically a large 1-1/5 in header at the top and bottom. These large headed become hydraulic separators allowing you to pull the loads without pump conflicts.

The biggest advantage of two pipe is heat energy flows directly from the boiler to the load when needed. If the system requires the full output from the boiler it flows into the header and to the zones. Flow starts going to the tank when the load gpm drops. The tank gets the % of flow not required by the system.

http://www.caleffi.com/sites/default/files/coll_attach_file/idronics_17_na.pdf

I think there is a sticky up top with a link to another NYSERDA presentation showing this piping.