Miscellaneous Equipment Energy Consumption

The miscellaneous appliance category contains a varied assortment of small and/or unusual devices that could occur in a house, both electricity and gas. They are divided into several main categories; Entertainment, Home Office, Miscellaneous Kitchen Appliances, Hot Tubs and Spas, and Other Appliances. Energy for a particular piece of equipment is calculated according to the following equation and summed across all miscellaneous equipment to get total miscellaneous equipment energy consumption.

            Equation 25

          where

             UEC = annual energy consumed by the equipment (kWh)

             ActivePower = ((P1 * P1Usage) + (P2 * P2Usage) +... + (Pn * PnUsage))

                Pn = the energy consumed at various power levels (e.g. active use, on but idle etc.)

                PnUsage = hours per year the equipment spends at this power rate.

             StandbyPower = (8760 – Sum(all active Usages)) * StandbyRate

             StandbyRate = energy consumed in standby mode

             1000 converts WattHours to kWh.

             NumberMachines = the quantity of this type of equipment in the house.

Typical energy consumption rates (both Active and Standby rates) for each piece of equipment as well as standard patterns of usage are documented in the MEL table. We selected the default set of miscellaneous equipment types present in a house by examining the national saturation for each type. Those devices for which Sanchez (1998) estimated a national saturation greater than 80% were selected as part of the default set for all houses.

At the detailed inputs level, users can add and remove specific miscellaneous equipment types from the default set, and specify the usage for each item. The MEL table lists the equipment types present in the Home Energy Saver, showing the number of instances of this type of equipment included in the default set for all houses, the energy consumption for various modes of activity, both per unit time and annual totals, and the default usage assumption. 

Scoring Tool

The estimate of the energy use of most miscellaneous appliances in the Scoring Tool is calculated using home floor area and energy intensity. The exception is televisions where the electrical use is calculated using the number of bedrooms, with bedrooms, as elsewhere in the Scoring Tool, being a proxy for number of occupants. Both calculations are based on Parker, D., P. Fairey, and R. Hendron (2010).

Electrical consumption by miscellaneous end-uses (MELS) is calculated using equation 1:

                    MUse = 0.91 * (conditioned floor area)                                                                - Equation 1

                    Where:

                        MUse = electrical use by miscellaneous end-uses (kWh/year)

Electrical consumption by Televisions is calculated using equation 2:

                    TUse = -3 * (Number bedrooms)^2 + 89 * (Number of bedrooms) + 390               - Equation 2

                    Where:

                        TUse =  electrical use by televisions (kWh/year)