@old man emu ---- Do you realize that the beds are generally heated between 60°C to 110°C? You will have one million four hundred forty thousand square millimeters heating? For we running on the old system that is ~15.5 square feet at 140°F to 230°F degrees. That is one BIG HEATER drawing A LOT OF POWER and putting our A LOT OF HEAT. A Suggestion ---- Print with PLA and no heat. Or Nylon. Otherwise you are going to need to call you electric company for more connections and a contractor for more insulation around the machine and the HVAC guys for more A/C for anyone in the area..... ;-D

More math --- on one of my machines heating up draws 190W for a small hot end and a 4" X 4" (102mm X 102mm) heated bed. For our calcs and the inefficiencies for a massive head bed we will assume my tiny hot end consumption is negligible. So, 190W to heat 16 square inches (10,486 sq mm) of heated bed. Ignoring rounding errors for discussions Your bed is ~2,232 square inches (1,440,000 sq mm). 190W/16sq in = 11.9W/sqin. times this by your 2,232sqin = 26,505W or 27kW... I don't even want to know what the Btu would be..... Whew its hot over there......

(disclaimer: It is 2am here, I'm tired... I may have really screwed up the math somewhere.... But, it is to be one BIG HEATER!)

Brian.