Auxillary controller to drive modulating valve for open loop water to water heat pump

bnjmn

I am installing a Climate Master 10 Ton water to water heat pump on a project I am working on, this is an open loop system. This unit has two compressors so it operates as a two stage unit.

I am trying to put together a control and modulating valve that I can use to vary the source side water flow through this unit based off of delta T. I have used two valves in the past to accomplish flow control but on this one I really want to try and reduce needless well pump operation.

Does anyone have any past experiece or products they can steer me to?

hot_rod

Wonder if a solar controller would work. They can switch on a valve or pump based on two temperature sensors. Either in off or variable speed via a PWM signal

Pump and dump? Can you vary the speed of the well pump based on temperature?

bnjmn

Hot Rod,

The supply well is also servicing the domestic water system so varying the well pump wouldn't work.

I have seen some systems that have used a Honeywell T775 control to do this. I am just having a tough time finding anyone who is knowledgeable or has done it before.

I will check out some solar controls.

pecmsg

Penn Water regulating valve. Operates off of the head pressure.

For heat mode a motorized ball valve bypassing the regulating valve!

hot_rod

sounds like this valve @pecmsg mentioned
https://cgproducts.johnsoncontrols.com/MET_PDF/125687.PDF

pecmsg

> @hot_rod said:
> sounds like this valve @pecmsg mentioned
> https://cgproducts.johnsoncontrols.com/MET_PDF/125687.PDF

That’s it.

bnjmn

Thanks for input I will keep it in mind and take a closer look at those valves. I really want something automatic with no ball valves or seasonal settings to change.

pecmsg

It’s all automatic.

bnjmn

I took a look at the valves you mentioned.

I ended up ordering a Belimo energy valve. It has everything I'm looking for all in one unit. It also has the capabilities of recording BTU's so that will be fun.

Technical service at Belimo was very helpful. The gentleman I spoke with seamed almost excited about this application.

Rhuber

I am doing a district geothermal job that is servicing three buildings with a total of 8 heat pumps on a ranch here in Montana.
Challenge was that we are using two separate wells that produce 50 GPM each. Each well system has a heat exchanger that separates the well side from the load side, load side is antifreezed. I am using a Belimo modulating valve that takes a 2-10V signal, two Honeywell T775's are monitoring the Delta T at the supply and return from each heat exchanger and modulate the valve, two flow switches on the load side set for different flow rates are
powering up the T775 controls based on flow rate. I like the idea of the energy valve as it is hard to control open well systems with several heat pumps in the same building without getting more flow than is needed.
Let us know how that works out as I would love to go back to past systems and do this as an upgrade.
I have not been on the wall for over ten years, I think I have missed it.

EBEBRATT-Ed

I never like the T775s JMHO

I have better luck with Johnson 350s but they only use 1 sensor I think. Had good luck using the little DIN process controllers. You can make them do just about anything