- Western Isles, Scotland
The Webasto / Chinese knock-offs need to exhaust outside - usually a relatively small hole is required for the exhaust. Air for combustion could come from inside, though outside would be better. There are 12V and 24V DC models. Peak current draw tends to be at startup, when typically 5A off 12V might be drawn. Once the glow plug gets hot enough, it does taper off after that, plus about 1A for the fan. The pump is usually an solenoid impulse type, that draws brief pulses of current. A typical current draw whilst running is about 1A.
Agree they need to exhaust outside but it is a c. 25mm hole so no real issues there. My one and only issue was relating to the power supply, they really need something that can supply clean power - I initially had it hooked up to a battery charger which could supply 40A but it didn't like the waveform. Ideally needs to run from a battery, current draw was closer to 15A for me (12v model) on startup. Don't assume a cheap PSU will cope with it. Pumps out enough heat for a uninsulated metal single garage although it's noisy. Great value for money.