new attic growroom, HVAC questions

[j2x]

Room is 12'x8' and approx. 3' tall at edges and approx. 5' tall ridge in middle. Approx. 500 cu ft. I wonder if (2) lines of 8" dia. duct running along both long sides of the room with (2) 210 cfm in-line duct-boosting fans mounted in-line with a supply vent at each corner of the room and an exhaust vent in the exterior wall would provide enough ventilation and, hopefully, cooling (if connected to a thermostat).

Also, would a portable electric oil-filled radiator-style heater that kicks out about 5100 btu produce enough proper heat for the space at night and in winter- since I want to grow year-round?

I live in the Willamette Valley in Oregon. We have weeks in the summer of 90+ days, with some days over 100, and weeks of 20-25 degree nights in the winter.

Also, other suggestions and concerns would be much appreciated. I'm going to be trying to grow 6-8 plants using the SCROG method.

 

[Mutt]

in the summer you may need to get a portable air conditioner. Your CFMs look ok for an 8" duct.
I tapped mine into the main house system insulated the grow cabs. intake in from the bathroom exaust through carbon scrubber then to return line. Stays house temp.

 

[Canso]

just remember, snow will melt off your roof weeks before any of your neighbours.
I agree with Mutt, you may need an ac unit for the summer,
your oil heater should work but if its not anough, you can point your intake fan at it, to heat the incoming air.