978-0470444047 Chapter 9

Chapter 9

Facilities Systems

Answers to Problems at the End of Chapter 9 9-1

SECTION 9.2

9.1 The statement, “The grid structure should defer to the function of the facility” is true.

Some reasons why this is so are:

SECTION 9.3

9.2 The thermal performance of a facility can be improved by making better use of solar

SECTION 9.4

9.3 Allocate the mechanical equipment room space:

Total Gross Area = 120 ft x 180 ft = 21,600 ft2

9.4 QF = (120,000 ft2)[0.81 Btu/(hr)(ft2)(ºF)](72ºF – 12ºF)

9.5 QF = (120,000 ft2)[0.81 Btu/(hr)(ft2)(ºF)](72ºF – 12ºF)

QF = 5.83 x 106 Btu/hr

QR = (120,000 ft2)[0.20 Btu/(hr)(ft2)(oF)](72oF – 12oF)

QR = 1.44 x 106 Btu/hr

9.6 QF = (120,000 ft2)[0.81 Btu/(hr)(ft2)(ºF)](72ºF – 12ºF)

QF = 5.83 x 106 Btu/hr

9.7 QF = (120,000 ft2)[0.55 Btu/(hr)(ft2)(ºF)](72ºF – 12ºF)

QF = 3.96 x 106 Btu/hr

QR = (120,000 ft2)[0.20 Btu/(hr)(ft2)(oF)](72oF – 12oF)

9.8 QF = (120,000 ft2)[0.81 Btu/(hr)(ft2)(ºF)](98ºF – 78ºF)

QF = 19.4 x 105 Btu/hr

QR = (120,000 ft2)[0.20 Btu/(hr)(ft2)(oF)](98oF – 78oF)

Using Equation 9.3, the total cooling load may be calculated as follows:

Answers to Problems at the End of Chapter 9 9-4

QC = 32.32 x 105 Btu/hr

9.9 QF = (120,000 ft2)[0.81 Btu/(hr)(ft2)(ºF)](98ºF – 78ºF)

Using Equation 9.3, the total cooling load may be calculated as follows:

9.10 QF = (120,000 ft2)[0.81 Btu/(hr)(ft2)(ºF)](98ºF – 78ºF)

QF = 19.4 x 105 Btu/hr

Using Equation 9.3, the total cooling load may be calculated as follows:

If blinds are used, the cooling load required would be QC = 35.26 x 105 Btu/hr

SECTION 9.5

9.11 Step 1: Determine the Level of Illumination

From Table 9.5, for a regular office environment, the minimum level of illumination is

Answers to Problems at the End of Chapter 9 9-6

9.12 The changes in the facility would be that the minimum level of illumination would be

150 foot-candles. This would make the number of lamps and luminaries change as well,

9.13 From equation 9.8, the RCR changes from 0.373 to 0.64. This result changes the

coefficient of utilization in Table 9.8 slightly to 0.67. This changes the number of lamps,

9.14 The Ceiling Cavity Ratio (CCR) would have to be determined because the luminaries are

no longer mounted on recessed into the ceiling. From Equation 9.8:

9.15 If the walls and ceiling were painted a medium color, then the WR and ECR would

change to 50% instead of 80%. This changes the value of the CU to 0.62, using

Answers to Problems at the End of Chapter 9 9-7

9.16 If the fixtures were cleaned once every 36 months instead of once every six months, the

LLF value changes from 0.92 to 0.78. This changes the number of lamps to:

luminaries per banks will allow 750 luminaries to be placed within the facility.

SECTION 9.6

9.17 The required fire protection in a building, which is governed by the Uniform Building

Code (UBC). There are 20 classifications or groups of buildings governed by the UBC.

9.20 1. Safety of regular building occupants

2. Safety of firefighters

SECTION 9.7

9.22 The purpose of a trap in a sewage system is to prevent odor from passing back into the

facility.