SR18T Empire 18K Radiant Heater | Foster Fuels Home Products SR18T Empire 18K Radiant Heater SR18T Empire 18K Radiant Heater Brand: Weight: lbs Product Number: Price: $439.00 Add to cart Product Description: No matter what type of space you need to heat, Empire’s American-made zone heaters will suit your needs perfectly. Empire Vent-Free Heaters are 99.9% fuel efficient. Because they don’t require outside venting, no heat is lost. And best of all, Empire Vent-Free units do not require electricity to operate. All parts carry a 5-year limited warranty with a 5-year limited labor warranty.