Yes the lower the voltage the more amps it will draw and will eventually burn up the compressor. There are automatic devices that will shut the power off when it drops below a certain point to prevent damage. There is a Hughs Autoformer that boost voltage to a safe level as well, if voltage drops to a certain level it will shut down as well. I think 100 volts is to low. Normal voltage is around 120 mine under heavy load drops to 117 volts. A brush and air will not get the stuff inbetween the coils. You have to take the covers off and clean with water, power disconnected and fan motor wrapped in plastic so it does not get wet. There is another good thread open on the same subject explaining in more detail. Dirty coils can cause the unit to draw more amps as well.
Forgot to add the fins need to be straighten (carefully) if bent to get good airflow.
