Waterchiller.
Testing stand-alone? (Pump,tubing/fitting,measuring equip)
Closed loop or water to heaven?
Inlet and Outlet Temps. Additionally Flow-Rate would be interesting.
Varying TEC Voltage? ( Possibly the most "User Important" investigation - Peltier Efficieny, as defined by COP, increases with decreasing Voltage
http://www.jr001b4751.pwp.blueyonder.co.uk/COPa.jpg )
Could compare with a Kryotherm produced Family of curves.Family cos Kryotherm does not compute for 220W Peltiers.
Any numbers, with which to play, would be appreciated.