Product Guide

TANKLESS MODELS
GROUND WATER TEMPERATURE
FACTOR
The temperature of incoming ground water
(cold water inlet temperature) varies greatly
throughout the U.S. and also fluctuates
with the changing of the seasons. The
temperature of water as it enters the
water heater will determine the amount of
“temperature rise” required to achieve the
desired hot water outlet temperature (120°F
is recommended).
The best way to measure incoming ground
water temperature is to use a thermometer
to measure cold water temperature during
the coldest season of the year. To simplify
the process, use this map to determine
whether your installation location is in the
Southern Zone, Central Zone or Northern
Zone.
PEAK HOT WATER DEMAND
The next step is to determine how many
gallons per minute of hot water will be
required during the busiest usage period
(peak demand). Consider all appliances
and fixtures that use hot water, including
lavatory faucets, kitchen faucets, washing
machines, dishwashers, showers and
bathtubs. Be sure to determine how many
appliances and fixtures will be used at the
same time (peak demand).
Average Ground Water
Temperature: 62°F to 77°F
Average Ground Water
Temperature: 52°F to 61°F
Average Ground Water
Temperature: 37°F to 51°F
NORTHERN ZONESOUTHERN ZONE CENTRAL ZONE
Remember, these are general recommendations. Your Takagi Water Heater Specialist can review your family’s
needs in even greater detail to make sure the model you choose will always provide enough hot water to meet
the demand.
Average Ground Water Temperature
SIMPLE TANKLESS SIZING
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