There are currently no known retrofit options available on the market to increase the
efficiency of combination ovens.
When purchasing a new combination oven or replacing an existing one, look for
models that are connectionless and that use no more than 15 gallons of water per
or 3.5 gallons per pan per hour.
Combination ovens come in varying sizes, depending upon the amount and types
of food cooked. Consult the manufacturer to choose a combination oven that is the
appropriate size for the cooking needs of the facility. A larger-than-necessary combi-
nation oven can waste water and energy to heat unused compartment space.
Boiler-based combination ovens can use as much as 30 to 40 gallons of water per
Switching to a connectionless combination oven can reduce that water use to
gallons of water per hour or less.
The Food Service Technology Center has a life cycle and energy cost calculator, which
can be used to calculate the savings potential from replacing many types of commer-
cial kitchen equipment, including combination ovens.
To estimate facility-specific water savings and payback, the facility can also use the
Current Water Use
To estimate the current water use of an existing combination oven, identify the fol-
lowing information and use Equation 4-3:
Hourly water use rate in gallons per hour. A typical boiler-based combination
oven may use as much as 30 to 40 gallons per hour.
Average daily use time. This will vary by facility.
Days of facility operation per year.
East Bay Municipal Utility District (EBMUD). 2008.
WaterSmart Guidebook—A Water-Use Efficiency Plan Review Guide for New Businesses
Food Service Technology Center (FSTC). Combination Ovens.
U.S. Environmental Protection Agency (EPA) and U.S. Energy Department’s (DOE’s) ENERGY STAR. Best Practices—How to Achieve the Most Efficient Use of Water
in Commercial Food Service Facilities.
FSTC. Commercial Foodservice Equipment Lifecycle Cost Calculators.