Comment by Tade0
I'm in the market for an oven right now and 230V/16A is the voltage/current the one I'll probably be getting operates under.
At 90°C you can do sous vide, so basically use that waste heat entirely.
For such temperatures you'd need a CO2 heat pump, which is still expensive. I don't know about gas, as I don't even have a line to my place.
90C for sous vide??? You're going to kill any meal at 90.