FIG 61 SCHEMATIC SKETCH OF BYPASS CONTROL WITH BYPASS OF RETURN AIR ONLY
NOTES FOR TABLE 66:
1. The required apparatus dewpoint for the high elevation is determined from the sea level chart or Table 65 by use of the equivalent effective sensible heat factor. The relative humidity and dry-bulb temperature must be used to define the room condition when using this table because the above
equation was derived on this basis. The room wet-bulb temperature must not be used because the wet-bulb temperature corresponding to any particular condition, for example, 75 F db, 40% rh, at a high elevation is lower (except for saturation) than that corresponding to the same condition (75 F db, 40% rh) at sea level. For the same value of room relative humidity and dry-bulb temperature, and the same apparatus dew-point, there is a greater difference in moisture content between the two conditions at high elevation than at sea level. Therefore, a higher apparatus dewpoint is required at high elevation for a given effective sensible heat factor. 2. Air conditioning load estimate (See Fig. 44). The factors 1.08
and .68 on the air conditioning load estimate should be multiplied by the direct ratio of the barometric pressures . Using this method, it is assumed that the air quantity (cfm) is measured at actual conditions rather than at standard air conditions. The outdoor and room moisture contents, grains per pound, must also be corrected for high elevations. 3. Reheat-Where the equivalent effective sensible heat factor is
lower than the shaded values in Table 65, reheat is required.
(p1) (po) (p1) (1 – ESHF) (po) (ESHF) + 1 1
Absorbent dehumidifier, see
sorbent dehumidifiers
Adiabatic saturation, see spray
processes
Adsorbent dehumidifier, see.
sorbent dehumidifiers
Air
By passed around conditioning equipment heat gain from outdoor
Air conditioning
adiabatic saturation cooling and dehumidification
cooling and humidification evaporate cooling
heating and
dehumidification, see sorbent dehumidifiers heating and humidification sensible cooling
sensible heating sorbent dehumidifiers
Air conditioning apparatus
coil characteristics sorbent dehumidifiers sprays characteristics
Air conditioning load estimate,
form internal load outdoor load
Air constants, derivation Air density difference effect on
infiltration
Air quantity
from air conditioning load estimate form
psychrometric calculations
Altitude angles, solar
table 66
psychrometric principle table
Appliances, heat gain from all
types, see heat gain, internal
Azimuth angles, solar
table 18
B
Bibliography Building survey
heat load sources location of equipment location of services space characteristics
Bypass control, for partial load Bypass factor
coils table 61
C
Centrifugal fan capacities
table 46
Coil characteristics, bypass
factor table 61
Coil processes
cooling and dehumidification with all outdoor air with high latent load cooling with humidification sensible cooling
sensible heating
Computers, electronic, heat
maximum room rh without con-densation
chart 2
maximum moisture added to supply
air without causing condensation on supply ducts
table 64
Cooling and dehumidification
with coils, see coil processes
with sprays, see spray processes
Cooling and humidification
with coils, see coil processes
with sprays, see spray processes
Cooling loads, diversity of
table 14
Cooling processes
with coils, see coil processes
with sprays, see spray processes
Crack method
summer infiltration thru doors
and windows table 44
winter infiltration thru doors and
windows table 44
D
Dehumidifier pump, heat gain to
system, see heat gain, system
Dehumidifier, sorbent, see
sorbent dehumidifiers
Design conditions
industrial processes table 5
inside factory comfort, winter and summer table 4
inside summer comfort table 4
inside winter comfort table 4
maximum outdoor design, summer
table 1
normal outdoor design, summer
table 1
normal outdoor design, winter, table 1
outdoor design corrections for time of day
table 2
outdoor design corrections for time of year
table 3
Diversity, of cooling loads
table 14
Door infiltration, see infiltration
Duct
heat gain to return duct, see heat gain, system
heat gain to supply duct, see heat gain, system leakage loss, supply and return duct, see heat gain, system
E
Effective sensible heat factor Effective surface temperature Electric appliances, heat gain
From all types, see heat gain,internal
Electric motors, heat gain from,
see heat gain, internal
Electronic computers, heat gain
from, see heat gain, internal
Equipment selection Equivalent temperature difference
roofs, sunlit and shaded table 20
walls, sunlit and shaded table 19
Evaporative cooling, see spray
processes
F
Factory, inside comfort design
conditions table 4
Pan capacity
centrifugal, table 46 propeller, table 47
Fan motors, heat gain to See
heat gain, system
Formulas, see psychrometric
formulas
G
Gas appliances, heat gain from
All types, see heat gain, internal
Grand sensible heat factor Ground temperature, for
calculating heat loss thru basement floors and walls tables 16
H
Heat flow, thru building
structures
Heat gain, internal
appliances, electric and gas burning, miscellaneous appliances, hooded appliances, electric, restaurant,
table 50
appliances, gas burning, restaurant
table 51
appliances, steam heated, restaurant
table 51
electronic computer equipment
latent, credit to room sensible
heat lights table 49
moisture absorption motors, electric
table 53 people table 48, pipes, bare steel table 54
pipes, insulated table 55
pipes, insulated cold table 56
steam
storage factors for lights table 12
tanks, uninsulated table 57
water surface table 58
Heat gain, solar
direct and diffuse factors for glass block table 17
over-all factors or types of glass,
table 16
peak solar, thru ordinary glass
table 6
storage factors or glass, bare or
external shade
table 8,24-hour operation table 10, 16-hour operation table 11,12-bour operation storage factors for glass, intern shade
table 7, 24-hour operation table 9,16-hour operation table 11 12-hour operation, thru ordinary glass
table 15
Heat gain, system
air conditioning fan horsepower
horsepower table 60
percent addition to grand total heat
percent addition to room sensible and latent heat return air duct heat gain chart 3
return air duct leakage gain safety factor to room sensible and latent heat supply air duct heat gain chart 3
supply air duct leakage loss
Heating and dehumidification,
see sorbent dehumidifiers
Heating and humidification
with sprays, see spray processes
Heating load estimate
form
Heat loss
thru basement floors and walls in the ground tables 35 thru 37
Heating
with coils, see coil processes
with sorbent dehumidifiers, see sorbent dehumidifiers with sprays, see spray processes
Heat storage
factors for solar heat gain thru glass, bare or external shade
table 8, 24-hour operation table 10, 16-hour operation table 11 ,12-hour operation factors for solar heat gain thru glass, internal shade table 7, 24-hour operation table 9, 16-hour operation table 11, 12-hour operation factors -for space
temperature swing table 13 precooling as means of increasing storage stratification of heat
see transmission coefficient U
High altitude
apparatus dewpoints table 66
load calculation
Hooded appliances, see heat
gain, internal
I
Industrial process design conditions, inside design
table 5
Infiltration
air density difference offsetting with outdoor air, summer
table 42
stack effect, thru windows and doors summer table 41
summer, crack method table 44
winter table 43
winter, crack method table 44
wind velocity effect
Inside design conditions
factory comfort table 4
industrial process table 5
summer and winter comfort table 4
Insulated cold pipe
heat gain from, see heat gain, internal
transmission coefficient for, see transmission coefficient U
Insulated pipe
heat gain from, see heat gain, internal
transmission coefficient for, see transmission coefficient U
Internal heat gain, see heat
L
Lights, heat gain from, see heat
gain, internal
M
Moisture absorption, heat gain
from, see heat gain, internal
Motors, heat gain from, see heat
gain, internal, and heat gain, system
0
On-off control of air handling equipment, for partial load
Control
On-off control of refrigeration equipment, for partial load
control
Outdoor design conditions
corrections for time of day table 2
corrections for time of year table 3
maximum design, summer normal design, summer normal design, winter summer and winter table 1
P
Partial load control
bypass control
on-off control of air handling equipment
on-off control of refrigeration equipment
refrigeration capacity control
reheat control volume control
People, heat gain from, see heat
gain, internal
heat gain from, see heat gain internal
transmission coefficient for, see transmission coefficient U
Precooling, as means of
increasing storage, 1-3
Propeller fan, capacity
table 47 Psychrometric chart Psychrometric formulas air mixing bypass factor cooling load
derivation of air constants sensible heat factor temperature at cooling apparatus
temperature for supply air to space
Psychrometric terms
abbreviations
apparatus dewpoint, see effective surface
temperature table 65, standard conditions
table 66, high altitude bypass factor
table 61, coil equipment effective sensible heat factor effective surface temperature
grand sensible heat factor partial load control required air quantity room sensible heat factor