PTC Fan Heater, 120 VAC, 250W, screw mount
Here is a great electronics enclosure heater. A UL tested, low watt heater meant for confined spaces. The heater uses straight AC power so you can use a SSR to control the heater with your own thermistor in either firmware or using one of the many plugins on OctoPi. This should be considered a more advance modification for your environment as you can reach temperatures hot enough to melt plastic parts, cause heat creep, distort bearings and stretch belts.
The 250w very combined with your 150w bed heater can help you maintain above 70c in an enclosure of about 5 cubic feet.
|Voltage||120 VAC, 50/60 Hz|
|Max. Current||9 A (inrush)|
|Heating Element||PTC resistor, temperature limiting|
|Housing||Plastic UL 94V-0, black|
|Surface Temperature at Housing||122 ºF (50 ºC)|
|Surface Temperature at Top Grill||212 ºF (100 ºC)|
|Axial Fan, Ball Bearing||40,000 h at 104 ºF (40 ºC)|
|Air Flow, Free Blowing||8 cfm (13.8 m³/h)|
|Connection||2-pole terminal, AWG 14 max (2.5 mm²)|
|Weight||17.6 oz (500 g)|
|Operating/Storage Temperature||-49 to 158 ºF (-45 to 70 ºC)|
|Protection Class||II (double insulated)|