I live in NW, Brooklyn. I have in my apartment Thru-the-wall condensing units (AeroSys model # THDC-30T). I know that according to DOE (Department of Energy) has determined that the AeroSys air conditioners/condensers THDC-30T ( and many other units) consume more energy than allowed under federal law. I pay about $600/month in winter to heat my apartment. I am cinsidering repalacing this unit. I have an option either to put on the roof the carrier infinity heat pump (builder will help with the cost) or just add electric heater inside of the unit as it was recommended by one company. Please advise what is the difference and what is better option. Thank you.

Heat pump, much cheaper to operate, in most areas,till its around 30-35 degrees, then you must have backup to kick in