User Inputs for Water Heater Analysis

In the detail screens of the Home Energy Saver, users can modify the water heater characteristics to more closely simulate their equipment and it’s usage. Table 13 shows the range of values for the inputs previously mentioned and lists other characteristics (and their range of values) that users can modify.


Table 13. User Inputs for Water Heaters (Detailed Inputs Level)

Variable Name

Range of Possible Values

Default Value

Modeling Treatment

      Fuel

Electric

Natural Gas

Liquid Propane Gas (LPG)

Fuel Oil

Varies by climate zone

 

      Type

Separate from heating system

Separate

Water heater energy calculated using process described in this section

Combined boiler, tankless

 

Water heating energy calculated by DOE-2

Combined boiler, storage tank

 

Adult at Home during weekdays

Yes

No

Varies by climate zone

 

Energy Factor

0 – 1.0

See Table 12

 

Recovery Efficiency

0 – 1.0

See Table 11

 

Rated Input

0 – 99,000 (kWh, Btu/hr)

See Table 11

 

Tank Size (gallons)

0 – 500

See Table 11

 

Thermostat setting

Low (110 °F)

Medium-Low (120 °F)

Medium (130 °F)

Medium-High (140 °F)

High (150 °F)

Medium-Low

(120 °F)

 

      Location

Basement or Crawlspace



Garage

Tamb=(Tindoors+Toutdoors)/2

Garage

Tamb= Toutdoors

Indoors

Tamb= Tindoors; standby losses sent to DOE2 as internal gains

Outdoors

Tamb= Toutdoors

Note:       Tamb = annual average air temperature around water heater (°F)

Tindoors = 67.5 ˚F

Toutdoors = average outdoor air temperature from weather tape data

 

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