Seems my propane furnace draws about 8amps while blowing. Doesn't seem like much but on/off throughout the night adds up. Are there any options regarding more efficient blower,mods,etc. Mines a single speed which is just high. Thanks
You could install a PWM in line with the blower fan. A PWM takes the positive voltage and pulses it on and off thousands of times per second. By adjusting the length of time it is on compared to off, the fan will run slower or faster with solid on the highest speed and solid off the fan is off. PWM's are used in 12 volt trolling motors so the operator can control the speed of the boat. You can buy a PWM off eBay. Here is a link to one; http://www.ebay.com/itm/12V-40V-10A-Pulse-Width-Modulator-PWM-DC-Motor-Speed-Control-Switch-Governor...
They are pretty cheap.
For a little more money, you can get one that is in a box;
