Taco mixing valve with outdoor reset

[barkeatr]

Im headed towards a 4 way mixing valve to help protect my boiler from cold return temperatures. What does the outdoor reset sensor do? does it sense a drop in temperature outside and respond? with my high mass system it would need to be checking the weather forcast as the current temperature is too late!

barkeater

 

[stefan66]

Im headed towards a 4 way mixing valve to help protect my boiler from cold return temperatures. What does the outdoor reset sensor do? does it sense a drop in temperature outside and respond? with my high mass system it would need to be checking the weather forcast as the current temperature is too late!

barkeater

4-Way? I use a three way to meter in hot water from storage to my slab
It kicks up the temp aprox .4 degF for every 1 deg. drop outside (below 70F.).
Remember your house is already warm and your mass is also.
As soon as the outside temps drop, it starts increasing the temp inside.
That is why all your loopszones should service the perimeter(outside walls) first.
The only variables not worked into it are the wind speed, as it increases heat loss through the windows.
and whether you are getting any solar heat into areas , again windows.

 

[barkeatr]

i believe the 4 way will also help me protect my boiler from T below 140...although i need to study diagram to figure out why.

 

[Clarkbug]

Barkeatr,

Could you instead put in a heat exchanger to help with your boiler issues?

If you piped the feeds from the boiler into one side of a Hx, and then put the house on the other, a strap-on aquastat on the return to the boiler with a setting of say 145 could interrupt the circulator on the house side. That way the boiler wouldnt get too cold, and your house could still run 115 water back to the heat exchanger. The aquastat would be an open on fall model, and could just interrupt the circuit there.

It would mean that you would have a closed loop inside that needed expansion and makeup, etc., so thats something to consider.

 

[in hot water]

with a 4 way, properly installed and controlled by a reset control you can get constant circulation. So the valve is always trying to match the heat loss of the building, the pump never shuts down. With that setup the high mass is a great match, the slab is always warm without overshooting. Adding indoor sensor input dials it in even better, so if you have large internal loads, parties, etc, the indoor sensor corrects.

You get return protection also by simply placing a sensor at the return pipe at the boiler, the 4 way modulates to assure the temperature you dial in. 4 ways have been mostly replaced by variable speed pumps with delta t logic, but it is still a great control logic.

hr

 

[PassionForFire&Water]

I find this very interesting and like to learn more about this
Does anybody has some schematics or can share more info?
Thanks,

 

[barkeatr]

marc, here is one link. i will send you more as i dig through the parts for this.

http://s3.pexsupply.com/manuals/1261149024134/20641_PROD_FILE.pdf

thanks for the explaination "in hot water" this makes total sense ! the internal sensor might help with my over mass house.

 

[ewdudley]

I find this very interesting and like to learn more about this
Does anybody has some schematics or can share more info?
Thanks,

http://www.pmengineer.com/Articles/Feature_Article/2002/09/30/Injection-Versus-4-Way-Valves

 

[barkeatr]

Barkeatr,

Could you instead put in a heat exchanger to help with your boiler issues?

If you piped the feeds from the boiler into one side of a Hx, and then put the house on the other, a strap-on aquastat on the return to the boiler with a setting of say 145 could interrupt the circulator on the house side. That way the boiler wouldnt get too cold, and your house could still run 115 water back to the heat exchanger. The aquastat would be an open on fall model, and could just interrupt the circuit there.

It would mean that you would have a closed loop inside that needed expansion and makeup, etc., so thats something to consider.

clarkbug, i understand what you say, this is a possiblity...when you say "your house" do you mean the fuel oil fired boiler? Im not sure how 115 water woudl still get cycled back to the house. Interesting concept.

barkeater

 

[Clarkbug]

Barkeater,

What I was thinking was that you would essentially make two different loops, one that is from a heat exchanger to your Profab, and then one from your house to the heat exchanger. You could keep the return line to the Profab above 140 with an aquastat that turns off the circ pump on the interior loop.

Sorry for the confusion earlier, what I meant was that the cold water coming from the slab could still hit the heat exchanger (essentially what it is doing right now to your boiler) without any other changes to your interior piping.

 

[barkeatr]

TEETHING STAGE...ha, I LIKE IT.

i essentially have what you say in a system but my house loop basically is a sidearm to a hot water heater...so Im not sure if can do what you say, or else the hot water heater will not turn on if the boiler is not hot. THis never happens but the redundancy is desired..anyway im going to continue to "chew" on your idea.

barkeater

 

[in hot water]

tekmar of Canada is a leader in mixing and reset controls for hydronics. The "customer" tab has some good general info or drill down on products and concepts at the "pro' tab.

www.tekmarcontrols.com/index.php