[ Pobierz całość w formacie PDF ]
glazed with 1/8-inch clear glass glazings, and use an aluminum frame with thermal breaks. No internal
shades are used. Manufacturer s NFRC ratings indicate the window has a U-value of 0.649 BTU/(hr-
sqft-F) and a shading coefficient of 0.82. All windows have a 4-inch reveal depth. Window data is
shown in Figure 3.4 while external shading data is shown in Figure 3.8
Doors. Each vestibule contains a pair of stile and rail doors. Doors contain a single-glazing in an
aluminum frame. The frames use thermal breaks. Each door measures 7 feet in height by 4 feet in width.
Manufacturer s ratings indicate the door U-value is 1.13 BTU/(hr-sqft-F) and the shade coefficient is
0.94. Door data is shown in Figure 3.6.
Lighting. Recessed, unvented fluorescent lighting fixtures are used for all rooms in this portion of the
school building. A lighting density of 3.00 W/sqft is used. The fixture ballast multiplier is 1.08.
For classrooms, offices, storage rooms and practice rooms we will use design day lighting levels of 100%
from 0700 through 1700, the standard occupancy period for the school, and 5% from 1800 through 2100
when lighting is reduced or operated intermittently for custodial work. This lighting profile applies for
the days the school is in session. For weekends and holidays lighting levels of 0% are used. The holiday
period includes a summer shutdown period from late June to early August. Therefore the
Weekend/Holiday lighting profile will be used for July for design calculations. Lighting schedule data is
shown in Figure 3.5.
For the corridors and vestibules we will use design day lighting levels of 100% for 0700 through 2100.
Security lighting levels of 5% will be used for all other hours. This lighting profile applies for days the
school is in session. For weekends and holidays lighting remains at 5% security levels for all hours.
Lighting schedule data is shown in Figure 3.5
Occupants. The maximum number of occupants varies by space and will be discussed later in this
section. For all rooms except the music room, a seated at rest activity level will be used (230
BTU/hr/person sensible, 120 BTU/hr/person latent). For the music room the office work activity level
will be used due to the higher level of activity in this room (245 BTU/hr/person sensible, 205
BTU/hr/person latent).
For all rooms we will use design day occupancy levels of 100% for 0700 through 1700, the normal hours
of operation for the school. Occupancy during the period 1800 through 2100 is very infrequent and will
be ignored. Thus, occupancy levels of 0% will be used for all other hours of the day. This occupancy
profile applies for days the school is in session. For weekends and holidays 0% occupancy is used for all
HAP Quick Reference Guide 3-3
Chapter 3 System Design Example Problem
hours. For the summer shutdown period from late June to early August these 0% occupancy values will
be used. The occupant schedule is shown in Figure 3.5.
Spaces. A total of 12 spaces will be defined. Data for these spaces appears in Figures 3.9 through 3.20.
Details:
" Floor areas are shown in Table 3.1.
" The average ceiling height is 8 feet for all spaces.
" The building weight is 70 lb/sqft (medium category).
" Ventilation airflow rates will be defaulted by choosing the appropriate ASHRAE Standard 62-2001
space usage type.
" One type of lighting fixture is used in all spaces. Lighting fixture characteristics and schedules were
discussed earlier in this subsection.
" Occupants per space are listed in Table 3.1. Occupant heat gains and schedules were discussed
earlier in this subsection.
" One set of common wall, door, window and external shading constructions are used for the building.
Wall orientations, wall areas, and window and door quantities for each space are summarized in
Table 3.1.
" One common roof construction is used for the building. Roof areas are shown in Table 3.1.
" Infiltration is only modeled for the vestibules at the end of each corridor. Infiltration has been
estimated at 18 CFM for design cooling conditions and 27 CFM for design heating conditions.
Infiltration is assumed to be present for all hours of the day.
" This wing of the school building uses slab on grade floor construction. The floor slab is constructed
of 6-inch of heavy weight concrete with an overall U-value of 1.2 BTU/(hr-sqft-F). R-7 edge
insulation is used for the slab. Slab floor areas and exposed perimeters are shown in Table 3.1. Note
that slab floors are not modeled for the corridor spaces since neither has an exposed slab perimeter.
Table 3.1 Summary of Space Characteristics (continued)
Floor People Wall, Window, Door Roof Data Slab Slab
Area Data Floor Exposed
(sqft) Area Perimeter
(sqft) (ft)
D101 - Typical Classroom 907.5 25 E: 275 sqft, 3 windows H: 907.5 sqft 907.5 27.5
D104 - Classroom 907.5 25 E: 275 sqft, 3 windows H: 907.5 sqft 907.5 60.5
S: 330 sqft, 0 windows
D106 - Classroom 907.5 25 W: 275 sqft, 3 windows H: 907.5 sqft 907.5 71.5
S: 330 sqft, 0 windows
E: 110 sqft, 0 windows
D107 - Classroom 907.5 25 W: 275 sqft, 3 windows H: 907.5 sqft 907.5 27.5
D108 - Music Room 1781.0 50 S: 242 sqft, 2 windows H: 1781.0 sqft 1781.0 24.2
D109 - Practice Room 65.0 1 W: 66 sqft, 0 windows H: 65.0 sqft 65.0 16.5
S: 99 sqft, 0 windows
D110 - Storage Room 120.0 0 W: 121 sqft, 0 windows H: 120.0 sqft 120.0 12.1
D111 - Office 174.0 1 W: 132 sqft, 1 window H: 174.0 sqft 174.0 13.2
D113 - West Corridor 1054.0 0 None H: 1054.0 sqft 0.0 0.0
D114 - South Corridor 920.0 0 None H: 920.0 sqft 0.0 0.0
D105 - South Vestibule 73.0 0 S: 110 sqft, 2 doors H: 73.0 sqft 73.0 11.0
D112 - West Vestibule 68.0 0 W: 88 sqft, 2 doors H: 68.0 sqft 68.0 8.8
3-4 HAP Quick Reference Guide
System Design Example Problem Chapter 3
3.3.3 Gathering Air System Data
One air handling system will provide cooling and heating to the rooms in this wing of the school
building. Therefore, we will define one HAP air system to represent this equipment. Data for this air
system is shown in Figure 3.21. Details:
" Equipment Type. A VAV packaged rooftop unit will be used.
[ Pobierz całość w formacie PDF ]