Empire Heating Systems Residential Zone Heaters allow you to turn down the central furnace and heat just the rooms you use most. These systems also save your energy dollars by not suffering the heat-loss common in a long vent run from the central furnace. Unlike a conventional furnace, most Empire heaters provide heat even when electric power fails. Empire offers a variety of gas-fired heaters with four different technologies – Vent-Free, Power Vent, Direct Vent, and B-Vent. Nearly all are available in propane and natural gas models.