Zone Valves
Zone valves are used to control the flow to a individual plumbing circuit (i.e. zone). In geothermal heat pump systems, they are used to control flow to the heat pump in either closed-loop or open-loop systems. Geo-Flo supplies Taco Zone Sentry and Belimo zone valves for close-loop systems. The Taco Geo-Sentry may be used for closed-loop systems or open-loop systems.
| PART NUMBER | DESCRIPTION |
|---|---|
| VMT2F-CL | Taco geo closed loop vlv, brass 1/2" FPT, 24V w/end switch, Cv = 4.9**** |
| VMT3F-CL | Taco geo closed loop vlv, brass 3/4" FPT, 24V w/end switch, Cv = 10.3**** |
| VMT3P-CL | Taco geo closed loop vlv, brass 3/4" Press, 24V w/end switch, Cv = 10.3**** |
| VMT3C-CL | Taco geo closed loop vlv, brass 3/4" Copper Sweat, 24V w/end switch, Cv = 10.3**** |
| VMT4P-CL | Taco geo closed loop vlv, brass 1" Press, 24V w/end switch, Cv = 8.9**** |
| VMT4F-CL | Taco geo closed loop vlv, brass 1" FPT, 24V w/end switch, Cv = 8.9**** |
| VMT4C-CL | Taco geo closed loop vlv, brass 1" Copper Sweat, 24V w/end switch, Cv = 8.9**** |
| VMT4F-CL-3W | Taco geo closed loop vlv, brass 1" FPT, 24V w/end switch, 3-Way, Cv = 8.9**** |
| VMT3F-OP | Taco geo open loop vlv, brass 3/4" FPT, 24V w/end switch, Cv = 10.3**** |
| VMT4F-OP | Taco geo open loop vlv, brass 1" FPT, 24V w/end switch, Cv = 8.9**** |
| VMSPR | Powerhead for older (orange) VMSBZ Valves |
| VMBBN4F-SR | Belimo B225+LFR24-S+NC/FO motorized ball vlv, nickle plated brass 1” FPT, spring rtrn, 24V w/end sw, Cv=30**** |
| VMBBN5F-SR | Belimo B232+AFR24-S+NC/FO motorized ball vlv, nickle plated brass 1-1/4” FPT, spring rtrn, 24V w/end sw, Cv=37**** |
| ****Choose valve based upon Cv (Flow Coefficient) for flow rate (see Table 1). Higher Cv = lower pressure drop. | |
Flow Regulators and Balancing Valves
Flow regulators are used to control the volumetric flow rate of a fluid through a device such as a geothermal heat pump. Some flow regulators, such as fixed orifice valves, operate at a specific flow rate. Balancing valves are flow regulation devices that typically allow a range of flow rates so that the installer can vary the flow through the valve to match the requirement of the system during commissioning. These types of valves are also known as circuit setters. Another type of balancing valve is the pressure independent automatic balancing valve that operate at a specific flow rate independent of the available pressure.
The Caleffi Quicksetter (QS) balancing valve is a perfect complement to geothermal heat pump installations with multiple units and a central variable speed pump. The balancing valves allow you to quickly commission a job by setting the flow rate on each heat pump individually rather than measuring the pressure drop across the unit’s heat exchanger, looking up the flow rate in the manual, and attempting to balance the flow with a standard ball valve. Check out this video from Caleffi to see how easy it is to set the flow rate on each circuit. Unlike automatic balancing valves with a cartridge for a specific flow rate, each QS balancing valve will cover a range of heat pump sizes.
In open loop systems, a single part number can replace an entire range of fixed orifice flow limiting devices. This allows you to stock a single part number (VQS4F) for nearly all open loop geothermal heat pump installations.
Here is our recommendation:
| Part Number | Connection Size1 | Flow Rate Range2 | Heat Pump Nominal Tons3, Closed Loop | Heat Pump Nominal Tons4, Open loop | Valve Cv (Fully Open) | Pressure Drop5 | Photo |
| VQS4F | 1″ | 3.0 – 10 | 1 to 3 | 2 to 6 | 8.3 | 2.7 ft-hd @ 9 GPM |  |
| VQS5F | 1¼” | 5.0 – 19 | 2 to 6 | 4 to 12 | 15.2 | 3.2 ft-hd @ 18 GPM |  |
| VQS6F | 1½” | 8.0 – 32 | 3 to 10 | 5 to 21 | 32.3 | 2.9 ft-hd @ 36 GPM |  |
- Valves should be selected based on the required flow rate, not connection size. For example, if you have a 5-ton heat pump with 1” connections, you should select the VQS5F and use a reducing fitting to go from 1-1/4” to 1”.
- The flow rate range for each valve overlaps the next size up; chose the valve that is closest to the pipe size you are using. In some cases you may chose to use all the same size valve on a job even when a smaller one will work for simplicity. For example, you may use the 1-1/4″ VQS5F for 2 ton units when you also have 4 ton and 5 ton units installed so that you can use one valve size for every unit on the job.
- This recommendation is for closed loop systems with a nominal flow rate of 3 GPM per ton. Check the heat pump manufacturer’s literature for actual recommended flow rate.
- This recommendation is for open loop systems with a nominal flow rate of 1.5 GPM per ton. Check the heat pump manufacturer’s literature for actual recommended flow rate.
- Pressure drop assumes water and is provided at the flow rate for the maximum Geo-Flo recommended nominal tonnage. When using an antifreeze solution either use Cv to calculate pressure drop or apply the appropriate antifreeze correction factor.
- For flow rates or sizes not listed, contact Geo-Flo.
Fixed orifice flow regulators are typically used in open-loop geothermal systems since they are relatively low cost, and the high pressure drop through the valve is not a large concern since the open-loop well pump provides plenty of head capacity. Fixed orifice flow control valves should be used with caution or avoided in closed-loop systems since the high pressure drop through these valves may require a much larger circulation pump to achieve the required flow rate.
| PART NUMBER | DESCRIPTION |
|---|---|
| VFR33F-2 | 2 GPM 3/4" FPT x 3/4" FPT |
| VFR33F-3 | 3 GPM 3/4" FPT x 3/4" FPT |
| VFR33F-4 | 4 GPM 3/4" FPT x 3/4" FPT |
| VFR33F-5 | 5 GPM 3/4" FPT x 3/4" FPT |
| VFR33F-6 | 6 GPM 3/4" FPT x 3/4" FPT |
| VFR33F-7 | 7 GPM 3/4" FPT x 3/4" FPT |
| VFR33F-8 | 8 GPM 3/4" FPT x 3/4" FPT |
| VFR33F-9 | 9 GPM 3/4" FPT x 3/4" FPT |