You can use this as a non-hot fan. Simply move the hot/cold lever to the cold side, then pull the knob to turn the fan on.

The temperature lever should turn off the flow of coolant from the engine, so only stagnant coolant is sitting in the core. Theoretically the core cools down in a minute, and cool air from outside blows into the car.

In practice it works OK. Just make sure the valve on the heater hose closes all the way. For true no-heat, disconnect both hoses under the hood. You could also connect them together with a length of copper pipe to bypass the heater core.