6.6 Internal Loads/Occupancy

6.6.1 Residential

Occupant Quantity

See Section 6.3.1.

Number of Bedrooms

Based on the total number of bedrooms in the building.

Humidity Sources

Internal sources due to respiration or evaporation. Default value of 0.0041 [lb/(ft2hr)].

Per ASHRAE standard 160, clause 4.3.2.1.1, if there is a jetted [whirlpool] tub installed in a room without an automatically controlled (e.g. humidistat) exhaust fan, it would be appropriate to add 1.3 liters/day or 0.12 lb/h to the moisture generation rate.

6.6.1.1 Calculation Methods

The energy use for most appliances is proportionate to the number of occupants. This holds true for dishwashers, clothes washers, dryers, and cooktops.

• Generally, do not adjust the quantity of these appliances. 
• Default: If only 1 zone in the project, select “PH Case Occupants” as the “Reference Quantity”. 
• If multiple zones in the project, select “Zone Occupants” as the “Reference Quantity”.

For refrigerators and freezers, consumption is not dependent on occupancy, it is proportional to the number of devices. 

• Default: Select “PH Case Units” as the “Reference Quantity”. 
• The quantity may be adjusted as needed.

6.6.1.2 Devices/Appliances

Pre-defined devices are built into the software. Choose ‘Set Standard Dataset’ to insert one of each typical appliance.

Below is a list of typical devices. Median Energy Star (ES) values as of 2018 are listed for each device. This may be used for projects early in design, or in some cases for pre-certification until the appliance is selected.

Dishwasher 

• ‘Energy demand (norm) reference’ = ‘Year’ 
  • Year: Use Energy annual kWh rating. 
    • Median value (ES, 2018): 260 kWh/yr 
• Dishwasher Capacity: In place settings, from manufacturer or ES. 
  • Standard (12), Compact (8), or User Defined. 
• Calculated per ANSI/RESNET/ICC 301-2014

Kitchen fridge/freeze combo 

• Select ‘Energy demand (norm) reference’ as ‘Day’ or ‘Year’. 
  • Day: Use annual kWh divided by 365 days. 
  • Year: Use annual kWh rating. 
• Median Values (ES, 2018):

Label	Volume	kWh/day	kWh/yr
Compact	<10 ft3	0.69	253
Average	15-20 ft3	1.23	449
Large	>25 ft3	1.96	715

Kitchen freezer 

• Select ‘Energy demand (norm) reference’ as ‘Day’ or ‘Year’. 
  • Day: Use annual kWh divided by 365 days. 
    • Median Value (ES, 2018): 1.08 kWh/day 
  • Year: Use annual kWh rating. 
    • Median Value (ES, 2018): 394 kWh/yr

Laundry – washer 

• ‘Energy demand (norm) reference’ = ‘Year’. 
  • Year: Use annual kWh rating
    • Median Value (ES, 2018): 116 kWh/yr 
• Capacity of clothes washer: Tub volume, provided by Energy Star. 
  • Default value of 2.87 ft3 . 
• MEF (or IMEF) – (Integrated) Modified Energy Factor: From Energy Star. Considers the amount of dryer energy used to remove the remaining moisture content in washed items, in addition to the unit’s energy use and water heating energy. 
  • Median value (ES, 2018): 2.38 
  • Higher the I/MEF, more efficient the clothes washer. 
• Calculated per ANSI/RESNET/ICC 301-2014, whereas, Annual Gas Cost (AGC) = Labeled Energy Rating*0.0593 + 3.7066

Clothes Dryer 

• Clothesline
  • May only be used if no future hookup/space for dryer. 
• Drying Closet (cold), Drying Closet (cold) at exhaust 
  • Input any auxiliary or fan energy. 
• Condensation Dryer 
  • Select ‘Energy demand (norm) reference’ as ‘CEF – Combined Energy Factor’ 
    • CEF – From Energy Star 
    • Median CEF Value (ES, 2018): 3.93 
  • Calculated per ANSI/RESNET/ICC 301-2014 
• Electric Exhaust Air Dryer 
  • ‘Energy demand (norm) reference’ as ‘CEF – Combined Energy Factor’ 
    • CEF – From Energy Star, if applicable. 
    • Default CEF Value if no Energy Star Rating: 3.14 
  • Select ‘Field utilization factor’ – Timer controls or Moisture sensing 
  • Calculated per ANSI/RESNET/ICC 301-2014 
• Gas Exhaust Air Dryer
  • ‘Energy demand (norm) reference’ as ‘CEF – Combined Energy Factor’ 
    • CEF – Gas: From Energy Star, if applicable. Default 2.67 (lbs/kWh) 
    • Gas Consumption: Match the electrical kWh/use of the washer and assign the rest to Gas consumption. 
      • For example, if using the default 3.5 kWh/use for the dryer, and the washer is rated at 0.5 kWh/use, input for the gas consumption: 
        • 3.5-0.5 = 3.0 kWh * 3412 Btu/kWh = 10236 Btu. 
  • Select ‘Field utilization factor’ – Timer controls or Moisture sensing 
  • Calculated per ANSI/RESNET/ICC 301-2014

Kitchen Cooking 

• Cooking with gas: 0.25 kWh/use. 
• Cooking with electricity/induction cooktop: 0.20 kWh/use. 
• This input accounts for cooking energy from ovens, microwave, etc., not just the cooktop. It is assumed that 500 single serving size meals are cooked annually, per occupant.

6.6.1.3 Lighting and Miscellaneous Loads

The list of devices covering lighting and plug loads are listed below. The annual energy use is calculated internally per Section 6.6.1.1.

PHIUS+ Interior Lighting 

• Should be used for all single family PHIUS+ projects. 
• If only 1 zone in the project, select “PH Case Floor Area” as the “Reference Quantity”. If multiple zones in the project, select “Zone Floor Area” as the “Reference Quantity”. 
• Input a fraction of high efficiency lighting.

PHIUS+ Exterior Lighting 

• Should be used for all single family PHIUS+ projects. 
• If only 1 zone in the project, select “PH Case Floor Area” as the “Reference Quantity”. If multiple zones in the project, select “Zone Floor Area” as the “Reference Quantity”. 
• Input a fraction of high efficiency lighting.

PHIUS+ Garage Lighting 

• Should be used for all single family PHIUS+ projects with a garage. 
• No “Reference Quantity” required. 
• Input a fraction of high efficiency lighting.

PHIUS+ MELS 

• Includes all miscellaneous electric loads, including televisions and plug loads.
• Should be used for all single family PHIUS+ projects. 
• Select “PH Case Floor Area” as the “Reference Quantity”. 
• If multiple zones in the project, only add the PHIUS+ MELS device to one zone.

User Defined – Misc electric loads (MELS) 

• Enter value from external MELS calculation for multi-unit projects (see below) 
• This will separate MEL energy use in your reports 
• Do not enter commas - this will be interpreted as a decimal point!

User Defined – Lighting 

• Enter value from external lighting calculation for multi-unit projects (see below) 
• This will separate lighting energy use in your reports 
• Enter interior and exterior lighting as separate line items 
  • For exterior lighting, un-check the box for ‘In conditioned space’. 
• Do not enter commas - this will be interpreted as a decimal point!

User Defined 

• Input any additional device not covered in the common device list 
• Units are in kWh/yr.
• User Defined devices will be used for multi-unit projects, see details below in Section 6.6.1. 
• Do not enter commas - this will be interpreted as a decimal point!

Multi-Unit Projects 

• Energy use calculated for most appliances (dishwasher, washer, dryer, cooktop) are driven by occupancy. The “Reference quantity” that should be selected for these appliances is “PH case occupants” if the whole building is in one zone, or “Zone occupants” if the model has multiple zones. 
• Fridge/freezer inputs are driven by the number of units input under the “PH Case” branch. The “Reference Quantity” in WUFI Passive for the fridge/freezer should be “PH Case Units”. 
• Calculating the lighting and plug loads should be done on a “per unit” basis using the PHIUS+ Multifamily Calculator. 
• User Defined inputs are not applied to any internal patterns, and inputs are simply in kWh/yr. Therefore, when inputting lighting and plug loads as User Defined inputs, this should be for the whole building. (Or, if there are identical units, input per unit and adjust the quantity as needed).

Download the PHIUS+ Multifamily Calculator from the Calculators and Protocols page, which has all of the protocol below embedded.

The basic protocol for lighting and miscellaneous electric loads is that they are calculated at 80% of RESNET (2013) levels for the “Rated Home”.  RESNET’s formulas are intended to apply to living/dwelling units, whether detached or attached, and strictly speaking to buildings of three stories or less. RESNET does not yet have protocol for multifamily common spaces. For PHIUS certification, the scope of the RESNET formulas is expanded to include multifamily buildings four stories or more in height, but applies only to the dwelling units. Supplemental protocol for multifamily common spaces and certain outdoor loads follows Building America House Simulation Protocols (2014). [30]In the formulas, iCFA is used in place of RESNET’s CFA and Building America’s FFA. The RESNET lighting formulas have been expressed more compactly here but are algebraically equivalent to the published versions. There are additional options for calculating the energy use of pools and elevators.

Miscellaneous Electric Loads (MELs)

For whole-building certification:

MEL = MELDWELL + MELCOMM + MELYARD (kWh/yr)

MELDWELL accounts for the living units.

MELCOMM accounts for the common spaces (if the design includes any).

MELYARD accounts for Large / Uncommon Electric and Gas loads (if the design includes any).

To facilitate verification, the MELDWELL calculation must be itemized. This may be done by unit type or floor-by-floor.

For itemization by unit type k:

MELDWELL = ∑𝑘 𝑢𝑛𝑖𝑡𝑠𝑘 ∗ (413 + 69 ∗ 𝑁𝑏𝑟𝑘 + 0.91 ∗ 𝑖𝐶𝐹𝐴𝑘 ) ∗ 0.8

k are the unit types.

𝑢𝑛𝑖𝑡𝑠𝑘 is the number of units of type k in the building.

𝑁𝑏𝑟𝑘 is the number of bedrooms in a unit of type k.

𝑖𝐶𝐹𝐴𝑘 is the interior conditioned floor area of a unit of type k. 

For purposes of this calculation, 𝑖𝐶𝐹𝐴𝑘 may include or exclude the projected floor area of interior partition walls within or between units, whichever approach is simpler to document.

For itemization by floor n:

MELDWELL = ∑𝑛(𝑢𝑛𝑖𝑡𝑠𝑛 ∗ 413 + 69 ∗ 𝑁𝑏𝑟𝑛 + 0.91 ∗ 𝑖𝐶𝐹𝐴𝐷𝑊𝐸𝐿𝐿,𝑛) ∗ 0.8

n are the floors.

𝑢𝑛𝑖𝑡𝑠𝑛 is the number of units on floor n.

𝑁𝑏𝑟𝑛 is the number of bedrooms on floor n.

𝑖𝐶𝐹𝐴𝐷𝑊𝐸𝐿𝐿,𝑛 is the interior conditioned floor area of all the dwelling units on floor n, including the partition walls within and between units, but not including the floor area of the common spaces.

For purposes of this calculation, 𝑖𝐶𝐹𝐴𝐷𝑊𝐸𝐿𝐿,𝑛 may include or exclude the projected floor area of interior partition walls to common spaces, whichever approach is simpler to document.

For MELCOMM add the following, or submit a more detailed accounting.

Multifamily Common Space MELs

Alternate for elevators: More detailed calculations may be made using the following resources.

https://www.thyssenkruppelevator.com/Tools/energy-calculator

http://www.schindler3300na.com/cgi-bin/calc/calc.pl

Although BAHSP has protocol for some “Multipurpose Room MELs”, in a whole-building model any television, dishwasher, range, or microwave in a multipurpose room may be neglected – usage of these in the multipurpose room is assumed to displace usage in the units. However, any refrigerators or freezers in a multipurpose room should be added as additional appliances at their rated kWh/day.

For MELYARD use the table below or perform a more detailed calculation.

Large Uncommon Electric and Gas Loads

Appliance	Electricity (kWh/yr)	Natural Gas (therms/yr)
Pool heater (gas)	-	3/0.014 × Fscale
Pool heater (electric)	10.1/0.0044 x Fscale	-
Pool pump	158.5/0.07 x Fscale	-
Hot tub/spa heater (gas)	-	0.87/0.011 x Fscale
Hot tub/spa heater (electric)	49/0.048 x Fscale	-
Hot tub/spa pump	59.5/0.059 x Fscale	-
Well pump	50.8/0.127 x Fscale	-
Gas fireplace	-	1.95/0.032 x Fscale
Gas grill	0.87/9.029 x Fscale	-
Gas lighting	0.22/0.012 x Fscale	-

Where the scaling factor, Fscale = (0.5 + 0.25 Nbr/3 + 0.25 iCFA/1920).

1 therm = 100 kBTU / [3.412 kBTU/kWh] = 29.3 kWh

IndoorPoolCalc, an online spreadsheet from the Washington State University Extension Energy Program, estimates the savings of several energy conservation measures for pools. Download the calculator and background information on the Calculators and Protocols page.

Lighting

The lighting formulas below refer to “qualifying” light fixtures or locations, which means highefficacy lighting. For residential projects fluorescent hard-wired (i.e. pin-based) lamps with ballast, screw-in compact fluorescent bulb(s), LEDs,

LIGHTSINT,DWELL accounts for the living units. or light fixtures controlled by a photocell and motion sensor, are all considered high-efficacy.

Interior Lighting

For whole-building certification:

LIGHTSINT = LIGHTSINT,DWELL + LIGHTSINT,COMM (kWh/yr)

LIGHTSINT,COMM accounts for the common spaces (if the design includes any).

As with MELs, the LIGHTSINT,DWELL calculation must be itemized. This may be done by unit type or floor-by-floor.

For itemization by unit type k:

LIGHTSINT,DWELL = ∑𝑘 𝑢𝑛𝑖𝑡𝑠𝑘 ∗ (0.2 + 0.8 ∗ (4 − 3 ∗ 𝑞𝐹𝐹𝐼𝐿)/3.7) ∗ (455 + 0.8 ∗ 𝑖𝐶𝐹𝐴𝑘 ) ∗ 0.8

qFFIL is the ratio of the qualifying interior light fixtures to all interior light fixtures in qualifying interior light fixture locations.

For itemization by floor n:

LIGHTSINT,DWELL =∑𝑛 (0.2 + 0.8 ∗ (4 − 3 ∗ 𝑞𝐹𝐹𝐼𝐿)/3.7) ∗ (𝑢𝑛𝑖𝑡𝑠𝑛 ∗ 455 + 0.8 ∗ 𝑖𝐶𝐹𝐴𝐷𝑊𝐸𝐿𝐿,𝑛) ∗ 0.8

For LIGHTSINT,COMM use the table below for any of the listed Room Types that are included in the design, or submit a more detailed calculation.

Multifamily Common Space Lighting

LIGHTSINT,COMM = (𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 ℎ𝑜𝑢𝑟𝑠 ∗ 𝑜𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 𝑑𝑎𝑦𝑠 ∗ 𝐿𝑃𝐷 ∗ 𝑖𝐶𝐹𝐴𝐶𝑂𝑀𝑀)/1000

𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 ℎ𝑜𝑢𝑟𝑠 are per day.

𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 𝑑𝑎𝑦𝑠 are per year.

LPD is the lighting power density of the space in W/ft2 .

𝑖𝐶𝐹𝐴𝐶𝑂𝑀𝑀 is the interior conditioned floor area of each unique common space, not including interior partition walls.

Occupancy Sensors: A 10% reduction in LPD is allowed for common spaces where occupancy sensors are documented in project submission (as in ASHRAE 90.1 Appendix G). Projects may also complete a custom calculation for reduction in LPD in corridors based on occupancy sensors, using PHIUS MF Interior Corridor Lighting Occupancy Sensor Calculator, downloadable on the Calculators and Protocols page.

Exterior Lighting

LIGHTSEXT = LIGHTSEXT,DWELL + LIGHTSEXT,COMM + LIGHTSGAR (kWh/yr)

LIGHTSEXT,DWELL pertains to exterior lighting for the dwelling units (balcony/porch or general building lights). 

LIGHTSEXT,COMM pertains to exterior lighting for the common spaces (exterior courtyards, exterior corridors/stairs, outdoor walkways, etc.)

LIGHTSGAR pertains only if the project includes a garage.*

For itemization by unit type k:

LIGHTSEXT,DWELL = ∑𝑘 𝑢𝑛𝑖𝑡𝑠𝑘 ∗ (1 − 0.75 ∗ 𝐹𝐹𝐸𝐿) ∗ (100 + 0.05 ∗ 𝑖𝐶𝐹𝐴𝑘 ) ∗ 0.8

FFEL is the fraction of exterior fixtures that are qualifying light fixtures.

For itemization by floor n:

LIGHTSEXT,DWELL = ∑𝑛 (1 − 0.75 ∗ 𝐹𝐹𝐸𝐿) ∗ (𝑢𝑛𝑖𝑡𝑠𝑛 ∗ 100 + 0.05 ∗ 𝑖𝐶𝐹𝐴𝑛) ∗ 0.8

For LIGHTSEXT,COMM use the table below for any of the listed Room Types that are included in the design, or submit a more detailed calculation.

Exterior Lighting

LIGHTSEXT,COMM = (𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 ℎ𝑜𝑢𝑟𝑠 ∗ 𝑜𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 𝑑𝑎𝑦𝑠 ∗ 𝐿𝑃𝐷 ∗ 𝑖𝐶𝐹𝐴𝐶𝑂𝑀𝑀)/1000

𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 ℎ𝑜𝑢𝑟𝑠 are per day.

𝑂𝑝𝑒𝑟𝑎𝑡𝑖𝑛𝑔 𝑑𝑎𝑦𝑠 are per year.

LPD is the lighting power density of the space in W/ft2 .

𝑖𝐶𝐹𝐴𝐶𝑂𝑀𝑀 is the interior conditioned floor area of each unique common space, not including interior partition walls.

Garage lighting may be calculated by the “80% RESNET” formula, BA default, or a more detailed calculation.

LIGHTSGAR = Units * 100*(1-0.75*FFGL) * 0.8

Units is the total number of dwelling units in the building

FFGL is the fraction of garage fixtures that are Qualifying Light Fixtures.

Garage Lighting*

Note: PHIUS does not require projects to include lighting energy for an open parking lot / parking garage, block heaters, or vehicle charging in the energy model for certification. For now, these are considered to be part of the “transportation sector” as opposed to the “building sector”.

6.6.2 Non-Residential

Utilization Pattern

The internal loads and occupancy calculation for non-residential projects begins with the definition of utilization patterns. These patterns are used for two purposes: lighting energy calculation and internal gains due to people and the equipment they use.

A utilization pattern consists of a set of several parameters: 

• Beginning hour 
• Ending hour 
• Days/year 
• Illumination level 
• Height of utilization (0 or 2.62 ft) 
• Relative absence 
  • 1 = Occupants always absent 
  • 0 = Occupants never absent 
• Part use factor of building period for lighting 
  • 1 = No reduction in lighting energy 
  • 0 = Full reduction in lighting energy

A set of standard default patterns (per DIN V 18599-10:2007-02, Table 4) is shown in the table in Section 6.6.2.1 below. 

The illumination level, height of utilization, and part-use factor for lighting enter only into the lighting calculation.

The average occupancy (in ft2 /person) can be entered. It factors into the total occupancy associated with a utilization pattern if the mode of planning for occupancy is floor-area-based rather than direct entry. It influence the calculation of gains from people and the equipment they use if any equipment is assigned to that Utilization Pattern.

The other parameters enter into both the lighting and internal gains calculations.

Often, more utilization patterns will be needed for lighting purposes than for internal gains. For example in an office building with single-shift operation and everyone typically sitting at desks, a single pattern could suffice for internal gains due to people, but if there are space types that require a few different illumination levels, more patterns would be needed for lighting. That is, it may be necessary / appropriate to define utilization patterns that “overlap” in order to support the calculations for internal gains, lighting, and equipment electricity use.

In the table in Section 6.6.2.1, the patterns are grouped by required illumination level. The first step in the analysis is to identify the different space types that are present, from the floorplan. In the lighting calculation, the patterns can be applied room-by-room. Grouping of rooms may be appropriate if they share a pattern (or ones with similar required illumination) and have similar access to daylight.

6.6.2.1 Utilization Pattern

Standard Default Patterns (per DIN V 18599-10:2007-02, Table 4) for Internal Loads and Occupancy Calculations for Non-Residential Buildings

6.6.2.2 Occupancy 

• Occupant Quantity: The top-level occupancy entry should reflect the average day occupancy. This value influences total DHW consumption, daily tap openings for DHW distribution losses, and the ‘Supply air due to persons’ ventilation requirement shown under Ventilation/Rooms>Utilization Pattern. 
  • This entry does not influence the internal heat gains related to occupants. 
• Occupant Groups: Occupant groups should be entered in the lines below. 
  • Generally, each unique space type should have a new line entry.
  • Planned occupancy for the space should be entered. 
    • Keep in mind that the relative absence on the ‘Utilization Pattern’ tab is relative to this occupancy. 
  • Be careful not to double count occupants. 
    • For example, if there is an office with 20 desks, that should be input with the 20 occupants. If there are also two conference rooms that serve the same occupants that occupy the desks, do not also add the conference room with 20 occupants, or that will double count the occupants. The conference room can be a separate line item for lighting, but not for occupancy. 
  • Not all space types need designated occupants or entries on this tab. 
    • Transient spaces such as, stairwells, restrooms, storage spaces, etc. may have occupants at certain times, but those occupants should be included in the space types where they will reside the majority of the time they occupy the space. 
• Heat loss due to evaporation (per person): Default value of 51.2 BTU/hr
• Number of flush toilets: Enter the total number of toilets in the entire building. 
• Toilet Utilization Pattern: The utilization pattern with the most ‘Annual utilization days’ should be selected.

6.6.2.3 Office Equipment

Planned equipment for the building should be input here. 

• Pre-defined equipment types are built in. 
• Power Rating [W] must be input for all equipment.

See Appendix D – ASHRAE Fundamentals Non-Residential Equipment Tables below for guidance on office equipment power ratings.

PC, Monitor: 

• A utilization pattern must be assigned to each of these equipment types. 
• The amount of time in operational mode vs power saving mode is built in.

Copier, Printer: 

• A utilization pattern must be assigned to each of these equipment types
• The number of hours in energy savings mode will be calculated automatically. Or, you may define this number. The number of hours input here is out of the total hours in the Utilization Pattern – not out of all 8760 hours in a year.

Telephone system: 

• The quantity should be input, and the energy use is not dependent on the number of occupants.

User Defined:

• Enter the Power Rating [W] and the Utilization Hours per year. 
• May be used for any miscellaneous items that do not fit the built-in options. 
• External calculation for equipment energy use may be completed to determine kWh/yr. To input these external results: 
  • Enter the resulting kWh/yr as the Power Rating [W] 
  • Enter 1000 hrs/yr for the utilization 
  • The result will be [W] x 1 khr/yr = kWh/yr.

6.6.2.4 Kitchen Equipment

Planned kitchen equipment for the building should be input here. 

• Pre-defined equipment types are built in.

Cooktop: 

• Utilization pattern must be defined to define the utilization days per year. 
• Number of meals per utilization day refers to the total number of meals cooked in that zone, per day. 
  • By default, the model will assume 0.25 kWh/meal for cooking energy. 
• Quantity can also be input. Be sure not to double count the meals by adjusting the quantity. If quantity is adjusted, meals per individual cooktop should be input.

Dishwasher

• Utilization pattern must be defined to define the utilization days per year. 
• Number of meals per utilization day refers to the total number of meals cooked (place settings washed) in that zone, per day. 
  • By default, the model will assume 0.055 kWh/meal for dishwashing energy.

Refrigerator 

• Norm demand [kWh/day] must be input. 
• This data is available from Energy Star for residential fridges and some commercial fridges.
• To estimate energy use for walk-in fridges/freezers, an external calculator is available for download here.

User Defined 

• May be used for any miscellaneous items that do not fit the built-in options. 
• External calculation for equipment energy use may be completed to determine kWh/yr. To input these external results: 
  • Enter the kWh/yr calculated into the ‘kWh/day’ field 
  • Enter 1 day/yr 
  • The result will be kWh/day x 1 day/yr = kWh/yr

6.6.2.5 Lighting

Space types should be split out into individual line items here.

If multiple Utilization Patterns are used to define the full usage hours for a single space, that space must be entered multiple times on this sheet and assigned to the appropriate Utilization Patterns to cover all hours of usage.

Fraction of conditioned floor area:

• This should generally add up to 1 for any given Utilization Pattern.

Daylighting: WUFI Passive will estimate daylighting potential by requiring the following inputs: 

• Derivation from North: 0=North, 180=South 
• Glazing Visible Transmittance: Select a pre-defined option, or enter User Defined if known. This value is generally provided by window manufacturers. 
• Room Depth: Enter the room depth starting from a window on the wall defined in the Derivation from North. 
  • For example, if you input 180, select a ‘typical’ window on the south wall and measure to the north wall enclosing that space. 
• Room Width: Measure in the opposite direction of the Room Depth described above. 
• Room Height: Floor to ceiling height. 
• Façade has windows: Check this box if applicable. If not applicable, do not check the box and no daylighting potential will be assumed. 
• Lintel height: Height of the typical window head from the floor. 
• Window width: Sum of all the window widths on the wall specified above for ‘Derivation from North’.

Installed Lighting Power: Value should be input in W/ft2 . PHIUS requires lighting plans and documentation to verify these values. 

• Values entered here will override ‘illuminance [lux]’ entries from the Utilization Pattern.

Lighting full load hours: This entry will over-ride all entries utilized for the daylighting calculation built into the software. 

• The daylighting calculation utilizes the Derivation from North, Glazing Visible Transmittance, Room Width/Depth/Height, Façade with windows checkbox, lintel height, and window width.

6.6.2.6 Process Loads

As mentioned in Section 3.3.4, process load allowances may be defined for commercial projects. Each unique process load should be input as an individual line item. 

• Total energy in kWh/use may be input, or 
• Power Rating [W] and Annual use hours [hr] may be used with the built in […] calculator

Include in Source Energy Total: This checkbox allows the modeler to include/remove this process load in the calculated source energy total for the purposes of verifying compliance with the base source energy target before process loads and allowances are included.

Increase Source Energy Allowance: This checkbox allows the modeler to adjust the source energy target by including the process load allowance in the model. This will auto-adjust the Source Energy target in the results to include this allowance 

Note: Process load allowances must be reviewed and approved by PHIUS.

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