How is the build chamber in your 3D-printer heated? Is there any thermal insulation and if how thick is it?
My two cents:
** thermal insulation**
That's the math for a small 300x300mm printer heated to 70°C (for 130°C tripple this number).
With a 6030 aluminium extrusion a 60mm insulation would fit within the walls and bring down the heatloss to approx. 45W. In other words: Once it is heated up the thermal losses are small enough for it to hold the temperature on its own. Reducing the overall power consumption.
heating/temperature control
For cooling and heating: oil<-> air heat exchanger/radiator might be a good solution:
- place one inside the printer
- the other on the outside
- insert a heater in the loop (only when heating is required, for cooling keep it off)
- possible to push past the 100°C liquid temperature.
Add a fan that circulates the air within the chamber to equalize the temperature.
This way the chamber can be heated and cooled without venting any air into the room.
I do resin printing (SLA) and warmer is always better (within reason). On cooler days I wrap the UV shield with a brewer's belt (AKA a fermentation belt). Then I cover the whole thing with the cardboard box the printer came in. Works like a charm. The belt keeps it nice and warm without getting scary hot (75-80F or 24-27C). It pulls low wattage, less than most light bulbs.
For filament printing, something similar might work, but I have zero experience with FDM.