When I mount my 4 bulb vho retro to the top of my canopy should I leave some space between the top of the canopy and the reflector or can I just screw it in to the top of the canopy? I don't want a fire...
You can mount the reflector right to the top if you want. If your using uri bulbs you really don't need a reflector. Me personally, I would leave space up there in case you want to add a fan or something. JMO
Get plastic pipe just large enough for the screw to go through and use that as the spacer between the reflector and the canopy, cut to desired length, this allows you to raise or lower the overall height of the reflector.