I have a Metris van and installed the Mark 2 inside the van but use the roof vent as a external port for the air exchange. I have 250 amp hour lithium that is hooked to the alternator with a 12/12 30 amp limiter (Vitron). Cool air all night from the batteries. Metris also has 16 gallons of electrically heated thermostatically controlled H2O, shower, commode, refrigerator, microwave, 2K pure sine inverter, hot and cold H2O on demand, $600 foam mattress, charger for Mac Pro, sink, LED ceiling disable lights, total iso insulation behind Cali Vynil. Nothing like it on earth....so nice to have the alternator charging the batteries on my daily driver and keeping them at 13.3 volts all the time. Have had solar on another RV since 2004; never again. The industry will figure it out one of these days that the gas or hybrid's alternator is man's best friend next to his dog "Goldie".
