The Hubbell F Model is a compact, highly efficient, packaged instantaneous steam fired water heater perfect for new or replacement water heating requirements. This highly efficient Hubbell heater requires no large storage tank, is easily installed and requires minimal floor space. Furthermore, the Hubbell F model utilizes a helical coil as its source for heat transfer and is up to 40% more efficient than traditional "U" tube heaters. When you specify and install a Hubbell steam fired water heater, you will have confidence in knowing the owner will be provided with a long lasting, trouble-free source for hot water.