Document LTM0883 rev 2e
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.
- 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.
- The adjustment procedure must be completed with the unit in heating mode.
Please Note -
- The installation of temperature ports are required for all commercial applications.
- The installation of temperature ports are strongly recommended for residential installations.
Temperature Port
(Shown with Probe)
- Adjust thermostat to its lowest setting with unit in heating mode.
- Deactivate the water filtration pump.
- Confirm that the filters leading to the heat pump are clean.
- Adjust the valves controlling water headed towards the heat pump to the half open position.
- Adjust the valves controlling water leading away from the heat pump to a fully open position.
- Activate the pool water filtration pump.
- Slowly raise the thermostat temperature until the heat pump activates.
- After a four-minute delay, the heat pump's compressor will start.
- With the heat pump running, confirm water filtration pump is operating properly with adequate flow and no short cycling.
- Wait for water temperatures to stabilize (approximately 5 minutes).
- Adjust valves in the following order using the temperature chart provided:
- Adjust the valve that controls water exiting the heat pump. Match the temperature measured with a temperature probe to the chart.
- Wait for water temperatures to stabilize. Then check temperature again. Re-adjust the valve as needed.
- Mark valves at these positions for future reference.
Please note -
- Temperature differences are based on pool water temperatures of 69° to 75° F.
- For water temperatures outside this range, contact AquaCal®. See "Contacting AquaCal AutoPilot, Inc."