Smallest Oil Fired Boiler

Combination

• Combination units are the smallest types of oil-fired boilers available on the market at the time of publication. The primary reason combination oil-fired boilers are smaller than conventional oil-fired boilers is the absence of a water storage tank. Combination oil-fired boilers rely on heating coils to warm running water, rather than incorporating a tank to store 20 to 80 gallons of water. The boiler's oil-fired burners warm the water as it passes through the coils, providing homeowners with instantaneous hot water.

Advantages and Disadvantages

• Because of its small size, a combination oil-fired boiler is easier and less expensive to install than conventional boilers. The small size of a combination oil-fired boiler makes it suitable for houses of any size, whereas conventional boilers need more space. However, combination boilers have a slower rate of water flow than conventional boilers. The water flow rate is further slowed if two water taps run simultaneously.

Sizing

• The size of an oil-fired boiler is determined by the number of British thermal units (BTUs) it emits per hour. A British thermal unit is the amount of heat energy required to raise one pound of water one degree Fahrenheit. Boilers heat a house by replacing cool air with warm air, or BTUs. A smaller boiler does not provide as much heat as larger boilers. However, the U.S. Department of Energy claims many oil-fired boilers are oversized and should be reduced to make the unit more energy efficient. One way to reduce a oil-fired boiler's size is to replace the unit's burner, which saves up to 20 percent on fuel costs.

Installation

• Although they are smaller than conventional units, combination oil-fired boilers are limited on where they can be installed because they run on fossil fuels. Oil-fired boilers emit gases that are harmful if inhaled, and they should not be installed in closets or rooms with flammable items such as paint thinners, aerosol spray cans or propane tanks. Garages and basements are two suitable locations for installing oil-fired boilers. Also, the boilers must be on level flooring and close to the house's duct system.