Insulation done! Shop heater questions. Electrical gurus.

I just finished insulating my 24x24x9 detached shop Monday. It was in the 18 F to about 35 F. I'm using a 1500 watt quartz space heater that has a small fan in it. It heated the shop to 48-50 F and didn't run all the time. The temperature was fine for what I was doing with a long sleeve shirt and occasional jacket. It does seem to have a few cold dead spots. I have propane available at the shop but, I’m just not comfortable having an open flame and the moisture they produce. Also, I'll be creating a lot of dust from grinding, cutting, sanding, painting etc. this winter. Yes, venting air while doing such.

If I stay with electric, watts are watts, whether I'm using 120 or 240 volt it isn't going to matter on the bill. I'm thinking about comfort and possible cost savings from run time or some other factor I haven't considered. I was wondering about the fan forced electric heaters sold at Northern Tool. Most have a higher BTU and wattage, so I'm thinking more air movement equates to quicker heat-up, more comfort. I do have a few shop fans I could run to get possible same effect. Thoughts please!

Am I thinking about this correctly?

Also, what about a heat-pump...I know a HVAC guy and can probably get a unit cheap from a disconnect or remodel.


Craig