Adjusting Water Flow Using ΔT (Delta-T)

The Delta-T is the temperature difference between the water temperatures entering and leaving the heat pump.

The equipment can be fine-tuned for maximum performance by balancing water flow rates to maintain an ideal ∆T.

The adjustment procedure must be completed with the unit in heating mode.

  • Installed temperature ports are required to perform the following procedures.
  • These ports are typically located on the pool in and pool out water lines approximately six inches away from the heat pump.

Please Note -

  • The installation of temperature ports is required for all commercial applications.
  • The installation of temperature ports is strongly recommended for residential installations.

 

Temperature Port

(Shown with Probe)

 

  1. Adjust the thermostat to its lowest setting with the unit in heating mode.
  2. Deactivate the water filtration pump.
  3. Confirm that the filters leading to the heat pump are clean.
  4. Adjust the valves controlling water headed towards the heat pump to the half-open position.
  5. Adjust the valves controlling water leading away from the heat pump to a fully open position.
  6. Activate the pool water filtration pump.
  7. Slowly raise the thermostat temperature until the heat pump activates.
    • After a three-minute delay, the heat pump's compressor will start.
  8. With the heat pump running, confirm the filtration pump is operating properly with adequate flow and no short cycling.
  9. Wait for water temperatures to stabilize (approximately 5 minutes).
  1. Adjust valves in the following order using the temperature chart provided.
    1. Adjust the valve that controls water exiting the heat pump until the correct temperature differential is achieved. Match the temperature measured with a temperature probe to the chart.
    2. Wait for water temperatures to stabilize. Then check the temperature again. Re-adjust the valve as needed.
  2. Mark valves at these positions for future reference.

 

Table 3 - Temperature Chart
HEAT EXCHANGER TYPE MODEL TEMPERATURE
Titanium ThermoLink® SQ120R

3° to 7° F

(1.7° C to 3.9° C)
Titanium ThermoLink® SQ125

3° to 7° F

(1.7° C to 3.9° C)
Titanium ThermoLink® SQ145

3° to 7° F

(1.7° C to 3.9° C)
Titanium ThermoLink® SQ150VS

3° to 7° F

(1.7° C to 3.9° C)
Titanium ThermoLink® SQ166R

3° to 8° F

(1.7° C to 4.4° C)
Titanium ThermoLink® SQ225

4° to 9° F

(2.2° C to 5° C)
Tube-in-Tube T035

1° to 4° F

(.5° C to 2.2° C)
Tube-in-Tube T055

2° to 5° F

(1.1° C to 2.8° C)
Tube-in-Tube T075

3° to 7° F

(1.7° C to 3.9° C)
Titanium ThermoLink® T090

3° to 6° F

(1.7° C to 3.3° C)
Titanium ThermoLink® T115

3° to 7° F

(1.7° C to 3.9° C)
Titanium ThermoLink® T135

4° to 8° F

(2.2° C to 4.4° C)
Titanium Tube-in-Tube T170

3° to 7° F

(1.7° C to 3.9° C)
Titanium Tube-in-Tube TC500

2° to 5° F

(1.1° C to 2.8° C)
Titanium ThermoLink® TC1000

2° to 5° F

(1.1° C to 2.8° C)
Titanium ThermoLink® TC1500

3° to 7° F

(1.7° C to 3.9° C)

Please note -

  • Temperature differences are based on pool water temperatures of 69° to 75° F. (20.5° to 23.8° C)
  • For water temperatures outside this range, contact AquaCal®.