Technical Report #1 ASHRAE Standard 62: Ventilation Compliance Evaluation

Transcription

1 Mechanical Option Technical Report #1 Technical Report #1 ASHRAE Standard 62: Ventilation Compliance Evaluation Instructor: Dr. Srebric Building Sponsors: CCG Facilities Integration

2 Table of Contents Executive Summary 2 Existing Building Data 3-5 Proposed Building Plans 6-7 Assumptions 8 Analysis 9-15 Discussion 16 References 16 Appendix A Appendix B Appendix C Excel Spreadsheets Page 1

3 Executive Summary The purpose of this report is to determine whether this data center can be renovated into office space using the existing air handling units (AHU s). The American Society of Heating Refrigerating and Airconditioning Engineers Ventilation Compoliance Standard (ASHRAE Standard 62, Addendum N) does not apply to data centers because all supply air is unvitiated and data centers do not meet occupancy requirements. If the data center were converted into office space, it would need to comply with ASHRAE Standard Addendum N to meet the outdoor air requirements based on both occupancy and floor area. The overall size of this renovation is approximately 120,000 square feet. In order to evaluate the data center for a renovation into office space, this report will first explain the existing conditions and then determine whether a renovation into office space would comply with ASHRAE Standard , Addendum N. The report will also take a comprehensive look at the critical spaces are and how the OA supplied by existing AHU s compares and complies with requirements and criteria of Standard 62. By using the spreadsheets provided by ASHRAE, it was determined that the critical fraction of outdoor air for the air handling systems range greatly. These calculations are illustrated in detail in the analysis section of this report. This data suggests that given the wide range of outdoor air requirements, the building would benefit from reconfiguration. Currently there is very little outdoor air being supplied from the air handling units. Provisions would need to be made in order to compensate for this. Several areas of the renovated office space would not require as much air as the air handling units are providing. A possible reconfiguration of air handling units to rebalance the loads and/or removal of excess air conditioning units would be necessary, though not ideal. Since the current terminal boxes either have minimums of zero or are set for constant volume, variable air volume boxes would need to be installed for each zone. Page 2

4 Existing Building Data The Data center contains 3 levels covering approximately 175,000 square feet. This report will focus on the service level and computer rooms on the first and second floor. This space contains 11 types of spaces, which are listed below. Table 1: Building Space breakdown Space Name Area (sf) Untreated areas 11,815 Unlimited Power Supply (UPS) 5,720 Battery 3,846 Telecommunication 2,022 Offices 1,702 Conference 2,202 Transformer 1,807 Lunch 422 Data 66,040 Corridor 9,095 Storage 14,223 Totals 118,894 SF Graph 1: Building Space Break Down Square Footage Breakdown Storage 12% Corridor 8% Untreated areas 10% Unlimited Pow er Supply (UPS) 5% Battery 3% Telecommunication 2% Offices 1% Conference 2% Transformer 2% Data 55% Lunch 0% Page 3

5 The mechanical system for this data center is a combination of constant volume and variable volume with ten separate air handlers taking care of ventilation. Supplimental computer room air conditioning units (100% recirculated air) are added for additional cooling. Two of these air handlers supply the service floor. Four air handlers supply the electrical UPS rooms with transfer air to the battery rooms, this includes N + 1 redundancy. Two air handler units are dedicated to the ventilation of the first and second floor computer rooms and UNIX rooms, this also consists of one redundant unit. The following are a list of the air handling units and the components of their design. Units 4, 5: Serve the service level of the data center. These are variable volume units. The AHU s are set up in parallel with the same supplies of return air and outdoor air. Air is exhausted both out of the mixed air duct and through the exhaust fans (EF-1 and EF-2) located in the east corridor. The primary on/off is provided by the building automation system, with start/stop switches also located at the starter. Each AHU has a return air damper and discharge damper, they share a common outside air damper. The supply air fans of each are provided with inlet vanes and are controlled to maintain system static pressure. Return air fans are provided with inlet vanes and are controlled to maintain a set point differential airflow. The supply air temperature is set to 55 F (adjustable). A differential pressure switch is located across each AHU filter. A temperature sensor is located in each AHU mixed air plenum operates a 3-way cooling control valve to modulate temperature. System airflow is 25,850 cfm for each AHU. When halon discharge or purge mode is signaled by the Building Automation System (BAS) the system dampers and fans operate accordingly. A schematic of this system is shown in Figure 1 in Appendix A. Units 1, 2, 3, 10: Serve the service level UPS and battery rooms. These are constant volume units. The AHU s are set up in parallel and use 100% return air. This air is supplied into the UPS rooms with transfer air into the battery rooms. Air is exhausted through EF-1 and EF-2 in the east corridor. A small amount of outdoor air is supplied through Units 4 and 5. Units 1, 2, 3, and 10 run continuously to serve the UPS room. Primary on/off control of each UPS AHU is provided by the AHU hands off automation (HOA) switch or via the BAS. Each AHU has return and discharge air dampers. Space temperature is controlled by the BAS which modulates each of the AHU s 2-way cooling control valves in unison. The BAS selects system air handlers based on priority ranking. As the control valves close off, the quantity of operating AHU s stage off. A differential pressure switch is located across each AHU filter. Upon a loss of motor current the next available in-line AHU shall be energized. System airflow is 28,000 cfm for each AHU. When halon discharge or purge mode is signaled by the BAS the system dampers and fans operate accordingly. A schematic of this system is shown in Figure 2 in Appendix A. Units 8, 9: Serve as ventilation units for the first and second floor UNIX and computer rooms. These are variable volume units. Primary control is the BAS, but manual start/stop switches are located at the starters. Each AHU is equipped with a return and discharge air damper. Supply air fan inlet vanes maintain system static pressure set point. Temperature and humidity is monitored. Air is supplied at 50F and 50% RH for space conditions of 55 F and 53% RH. Humidification is served by humidifiers H-1, 2, 3, and Page 4

6 or 4. When humidifiers are on, the corresponding electric duct coils 1, 2, 3, 4 operate to maintain a minimum discharge air temperature of 72 F. A differential pressure switch is located across each AHU filter. A temperature sensor is also located in each AHU mixed air plenum. When halon discharge or purge mode is signaled by the BAS the system dampers and fans operate accordingly. A schematic of this system is shown in Figure 3 In appendix A. Units 6,7. These variable volume direct expansion units serve office space in a separate section of the building and will not be discussed in this report. Page 5

7 Proposed Building Plans Modifications will be made to all 3 levels including the service level, first and second floor computer room space. The space types will change as follows. (Table 2, Graph 2) Table 2: Modified Building Space Break Down Space Name Area (sf) Proposed Space Area (sf) Untreated areas 11,815 Unrated areas 11,815 Conference 2,202 Conference 2,202 Lunch 422 Lunch 422 Corridor 9,095 Corridor 9,095 Storage 14,223 Storage 14,223 Unlimited Power Supply (UPS) 5,720 Office Battery 3,846 Office Telecommunication 2,022 Office Offices 1,702 Office Transformer 1,807 Office Data 66,040 Office 83,339 Totals 118,894 SF 118,894 SF Graph 2: Modified Building Space Break Down Modified Square Footage Breakdown Corridor 8% Storage 12% Untreated areas 10% Lunch 0% Offices 70% Page 6

8 The modified mechanical system will include eight of the ten air handlers taking care of ventilation. Supplimental computer room air handlers may not be necessary in the event of a renovation into an office building but calculations were bade both to include the recirculated air and also without them in the event of demolition. Two of these air handlers will still supply the service floor, but will need more outdoor air for new occupants in renovated office space. The Four air handlers supplying the UPS rooms with transfer air to the battery rooms, will now serve office space and require outdoor air intake. The two air handler units dedicated to the ventilation of the first and second floor computer rooms and UNIX rooms, will now serve office spaces. The following list the AHU s modified behavior taken into account for ASHRAE Standard 62 Addendum N compliance calculations. Units 4, 5: Will serve the service level office, storage and corridor spaces. The AHU s are set up in parallel with the same supplies, return air and outdoor air ducts and exhaust routs. Outdoor air will no longer be provided to the zones served by AHU 1,2,3,10. Calculations have been made to account for extra computer room air conditioning (CRAC) units in the automated print room. They have also been made pending demolition of the CRAC units. The rest of the components of the system will remain in tact. Occupancy is also based on floor area following the ASHRAE Standard 62 Addendum N. System airflow will remain 25,850 cfm for each AHU. A schematic of this system is shown in Figure 1 in Appendix B. Units 1, 2, 3, 10: Serving the service level UPS and battery rooms converted into office space. The AHU s set up in parallel using 100% return air will now be set up to receive outside air. This air is supplied into the former UPS rooms with transfer air into the former battery rooms. Air is still exhausted through EF-1 and EF-2 in the east corridor. Outdoor air will no longer be supplied from AHU s 4, 5. Occupancy is also based on floor area following ASHRAE Standard 62 Addendum N. Since redundancy is not necessary in office buildings, it will not be accounted for in the calculations. The calculations will be made with the use of all of the units on. System airflow is 28,000 cfm for each AHU. A schematic of this system is shown in Figure 2 in Appendix B. Units 8, 9: Serving as ventilation units for the first and second floor UNIX and computer rooms will now serve open plan offices on both floors. Numerous computer room air conditioning units are located on these floors for extra sensible cooling of computers and racks. Calculations have been taken into account for both the use of CRAC units, and with their demolition. No VAV or CAV boxes are currently installed in this system, but the spreadsheets divide up the ventilation based on floor area. Occupancy is also based on floor area following ASHRAE Standard 62 Addendum N. A schematic of this system is shown in Figure 3 in appendix B. Units 6,7. These variable volume direct expansion units serve office space in a separate section of the building and will not be discussed in this report. Page 7

9 Assumptions ASHRAE Standard 62 Addendum N has been followed in order to analyze the amount of outdoor air necessary to satisfy ventilation requirements. Since most of the space in the current data center is unoccupied, occupancy numbers must be assumed. The 2003 International Building Code allows 100 sf per person in offices. This report, however has based occupancy on Addendum N. These requirements allow 5 persons per thousand square feet in office areas. Currently there are no corridors on the first or second floors. These would be added by the architect for means of egress, (2 exits for up to 200 occupants, 3 for up to 1000, and 4 for over 1000 occupants) as specified by the 2003 International Building Code. Lavatories and water closets are not located on the first and second floors, but shall be designed to meet the 2000 International Plumbing code. In general there shall be 1 water closet (WC) per 50 occupants in a business. From ASHRAE Standard 62, 2001, 50 cfm/wc is required. To stay conservative, no space was taken away from the building to account for lavatory space, the 50 cfm per WC was added as transfer air to the existing system. Variable air volume (VAV) boxes are not currently installed for the AHU 8, 9 system. Further, VAV boxes on AHU 4, 5, and AHU 1, 2, 3, 10 have box minimums of zero. In the event of change into an office building, box minimums will be assumed to be 30% the maximum as stated by the Environmental Protection Agency (EPA). In the event this space is renovated into office space, new AHU configuration may be necessary, the following calculations will explain why. Page 8

10 Analysis Schedule information for the AHUs for each section is provided to determine amount of supply air provided to the space. (Table 3) Table 3 Information for all AHU obtained from schedules AHU Max Min Service Level 4 25,850 14, ,850 14,750 Total: 51,700 29,500 Service level Electrical 1 28,000 28, ,000 28, ,000 28, ,000 28,000 Total: 112, ,000 First and Second Floors 8 17,090 1, ,090 1,600 Total: 34,180 3,200 The building is evaluated on the zone level. This section includes definitions, equations and summaries for each zone. The information for each zone is listed on the ASHRAE spreadsheets listed in Appendix C. The zone floor area (A z ) [ft^2] is calculated. This is the net occupiable floor of the zone. (ft^2) o This was calculated using the area command in autocad drawings. Zone population (P z ) [people] is also calculated. Default values were calculated due to lack of information regarding a renovation into an office building. o ASHRAE Standard 62 Addendum identifies this as the largest number of people expected to occupy the zone during typical use. Default values for occupancy are found in table 6.1. o For Office space, typical occupancy is 5 persons/ 1000 sf. Outdoor airflow rate (R p ) [cfm] required per person is determined in Table 6.1. o These values are also set into the spreadsheet provided by ASHRAE as lookup values. o Since water closets were not taken into account, ASHRAE Standard 62, 2001 was referenced. 50 cfm/ Water Closet is recommended. Outdoor airflow rate (R a ) [cfm] required per square foot is determined in Table 6.1. o Along with R p, R a is also listed by ASHRAE as a lookup value in the spreadsheet. o ASHRAE Standard 62 does not specify any outdoor air flow for water closets based on area. Page 9

11 Breathing Zone Outdoor Airflow (V bz ) [cfm] is the design airflow required in the breathing zone of the occupiable space or spaces in the zone. This is determined by Equation 6-1. o V bz = R p P z + R a A z (6-1) o The spreadsheet calculates R p R z and R a A z separately. o Vbz is helpful in finding the outdoor airflow to the zone which will be described on the following page. Zone Air Distribution Effectiveness (E z ) [unitless] is determined in table 6.2 as follows: o Zones served by AHU 4,5 and AHU 1,2,3,10 use ceiling supply of cool air with E z = 1.0. o Zones served by AHU 8,9 have under-floor air distribution with floor supply of cool air and ceiling return provided that the 150 fpm supply jet reaches at least 4.5 ft above the floor, E z = 1.0. Zone Outdoor Airflow (V oz ) [cfm] is the outdoor airflow required in the zone at design and is computed using breathing zone outdoor airflow and zone distribution effectiveness as listed previously. o V oz = V bz /E z (6-2) Zone primary airflow (V pz ) [cfm] is the primary airflow supplied to the zone from the air handling unit. o The minimum value of the primary airflow to the zone from the air handler is signified by V pzm [cfm]. This is set by the box minimum to each zone. For variable air volume boxes this is one third the total box volume. o This includes outdoor air and recirculated air from the air handling unit, but not from other zones or infiltration/exfiltration. The maximum zone primary air fraction (Z p ) [unitless] is needed when looking for the system ventilation efficiency in Table 6.3. o Z p = V oz /V pz (6-5) Any time 100% Transfer air is used to ventilate a room, Z p approaches infinity. Page 10

12 The building is then evaluated on the system level. The system population (P s ) [people] is the maximum number of occupants in the system served by the air handlers. o This is found by summing the P z s. o Since occupants may move from zone to zone, only the number of people likely to be in the system at design is needed. AHU 4, 5 Ps = 92 people AHU 1, 2, 3, 10 Ps = 48 people AHU 8, 9 Ps = 415 people Occupant diversity (D) [unitless] accounts for variation in Ps due to occupant movement within the system. o D = P s / (Σ all zones (P z )) (6-7) o Occupants in Lavatories, conference rooms, lunch rooms, training rooms, or copy rooms for instance, are not accounted for in the system population, but are accounted for if you sum the occupants for each zone. AHU 4, 5 D = 0.94 AHU 1, 2, 3, 10 D = 0.96 AHU 8, 9 D = 0.96 Uncorrected outdoor air intake (V ou ) [cfm] is defined and summarized as follows. o V ou = D (Σ all zones R p P z + Σ all zones R a A z ) (6-6) AHU 4, 5 V ou = 1,959 cfm AHU 1, 2, 3, 10 V ou = 899 cfm AHU 8, 9 V ou = 7,589 cfm System primary airflow (Vps) [cfm] is the total primary airflow supplied to every zone in the system. o V ps = Σ V pz AHU 4,5 V ps = 19,650 cfm AHU 1, 2, 3, 10 V ps = 112,000 cfm AHU 8, 9 V ps = 34,180 cfm Average outdoor air fraction (X s ) [unitless] is the fraction of outdoor air intake flow in the system primary flow. This ratio is taken at the air handler. o X s = V ou /V ps AHU 4, 5 X s = 0.10 AHU 1, 2, 3, 10 X s = 0.01 AHU 8, 9 X s = 0.22 Page 11

13 Further, System Efficiencies are Calculated. System ventilation efficiency (E v ) [unitless] is defined in Table 6.3 for maximum zone primary air fractions (Max Z p ) for any Max Z p less than or equal to AHU 4, 5 Max Z p = 0.99 (Approaches infinity with WC) AHU 1, 2, 3, 10 Max Z p = Approaches infinity AHU 8, 9 Max Z p = 0.71 (Approaches infinity with WC) o For values greater than 0.55, Appendix G is used. The use of Appendix G is necessary for every system in the building. In order to use Appendix G, evaluations must be made on both the zone and system levels. Page 12

14 Appendix G Appendix G uses several values calculated above, but it also takes into account several new values. Values in the Appendix G spreadsheet repeated from previous calculations are listed as follows and can to be referred to above. o A z, P z, R p, R a, V bz, V oz, V pz, V pzm, P s, D, V ou, X s, E v The following are calculated in Addendum N but not necessary in Appendix G. o V pz, V pzm, Z p Appendix G on Zone Level Zone discharge Airflow (V dz ) [cfm] is the expected discharge to the zone including air from the air handler and air locally recirculated or transferred in from other zones. o Zones with computer room air conditioning units and with transfer air are going to have a larger V dz than Vpz. Minimum zone discharge airflow (V dzm ) [cfm] is the minimum V dz. o This was calculated by taking the V pzm and adding the V dz. The outdoor air fraction based on minimum zone discharge (Z d ) [unitless] is similar to the primary outdoor air fraction (Z p ), however it includes recirculated and transfer air. o Z d = V oz /V dzm Primary air fraction to the zone (E p ) [unitless] is calculated based on the number of zones in the system. o Multiple zone systems: E p = V pz /V dz o Since all of the systems have more than one zone, E P can be assessed accordingly. In Zones with secondary recirculation of return air, the fraction of secondary recirculated air to the zone that is representative of average system return air (E r ) is o E r <=1.0 for every zone because of plenum return o 1.0 has been chosen for this value. The fraction of supply air to the zone from sources outside the zone (F a ) can now be calculated. o F a = E p + (1-E p )*E r The fraction of supply air to the zone from fully mixed primary air (F b ) is the same as the primary air fraction to the zone (E p ). The fraction of outdoor air to the zone from sources outside the zone (F c ) is calculated in the following equation. o F c = 1-(1-E z )*(1-E r )*(1-E p ) Page 13

15 The system level can now be looked at for Zones with recirculated air. System primary airflow (V ps ) [cfm] is the total primary airflow supplied to all the zones served by the system from the air handling unit. o V ps = Σ V pz o For systems with computer room air conditioning units remaining: AHU 4, 5 V p s = 19,650 AHU 1, 2, 3, 10 V ps = 112,000 AHU 8, 9 V ps = 34,180 o For systems with computer room air conditioning units demolished: AHU 4, 5 V ps = 19,650 AHU 1, 2, 3, 10 V ps = 112,000 AHU 8, 9 V ps = 34,180 The zone ventilation efficiency (E vz or E vs ) is the efficiency with which the system distributes outdoor air from the intake to an individual breating zone. It can be calculated for systems with single or multiple zones. o Multiple zone systems: E vz = (F a + X s *F b Z d *F c )/F a (G-2) o For systems with computer room air conditioning units remaining: AHU 4, 5 E vz = 0.99 AHU 8, 9 E vz = 1.00 o For systems with computer room air conditioning units demolished: AHU 4, 5 E vz = 0.71 AHU 1, 2, 3, 10 E vz = 1.00 AHU 8, 9 E vz = 0.51 Design outdoor air intake flow (V ot ) [cfm] compares uncorrected outdoor air intake, as stated in Addendum N, with the system ventilation efficiency. o V ot = V ou /E v o For systems with computer room air conditioning units remaining: AHU 4, 5 V ot = 17,233 cfm AHU 1, 2, 3, 10 V ot = 806 cfm AHU 8, 9 V ot = 14,925 cfm o For systems with computer room air conditioning units demolished: AHU 4, 5 V ot = 17,233 cfm AHU 1, 2, 3, 10 V ot = 806 cfm AHU 8, 9 V ot = 14,925 cfm Page 14

16 Now that these quantities have been satisfied the Percent Outdoor air intake may be evaluated as the ratio of minimum outdoor air intake over total system primary flow to all zones. o (V ou /E v )/( Σ V pz ) o For systems with computer room air conditioning units remaining: AHU 4, 5 OA = 88 % AHU 8, 9 OA = 44 % o For systems with computer room air conditioning units demolished: AHU 4, 5 OA = 88 % AHU 1, 2, 3, 10 OA = 1 % AHU 8, 9 OA = 44 % o The similarity in these results shows that recirculation within the zone does not effect the outdoor air requirement to the zone or system. Page 15

17 Discussion ASHRAE Standard 62 Addendum N was used to determine the fraction of outdoor air required for the data center in the event of turn over into an office building. Addendum N revised the Ventilation Rate Procedure specified in Standard 62, Spreadsheets provided by ASHRAE were used in order to organize information. The indoor air quality method of design deals with the contamination within the space, how much and how to get rid of it. It deals with sick building syndrome due to both CO 2 and other contaminants such as airborne chemicals and disease. Addendum N is a step forward from the original Standard 62, 2001 because it accounts for floor area on top of zone population. This means that in areas such as corridors with no set occupancy, there will be outdoor air supplied to get rid of contaminants due to off-gassing, asbestos, etc. The air handling units are capable of supplying enough outdoor air necessary for the system. AHU 1, 2, 3, 10, however, would require outdoor air intake. Also since there is such an imbalance between system outdoor air, the configuration of the systems may be rearranged, cost limiting. References: 1. ASHRAE Standard , Addendum N, Ventilation for Acceptable Indoor Air Quality. 2. International Building Code 2003, Table , Maximum Floor Area Allowances Per Occupant. 3. The Architect s Portable Handbook, First-Step Rules of Thumb for Building Design, Third Edition 2000, Pat Guthrie. 4. U.S. Environmental Protection Agency, 5. Penn State Architectural Engineering Department, Thesis Advisors Mechanical Department. 6. CCG Facilities, Construction Drawings and Specifications. Page 16

18 Appendix A Figure 1 Existing AHU 4,5 and AHU 1,2,3,10 Systems Page 17

19 Figure 2 Existing AHU 8, 9 System Page 18

20 Appendix B Figure 1 Modified AHU 4,5 and AHU 1,2,3,10 Systems. Page 19

21 Figure 2 Modified AHU 8, 9 System Page 20

22 Appendix C ZONE LEVEL Zones served by AHU 4,5 122 Automate d Print Tape Storage Corridor Mech Shop/ Corridor Office space Security Building/ Control Conference /Squad Office/ Security Lunch Receptio n Clerk Mail Motor Control Center Transformer Space type (select from pull-down list) Office spaceoffice spaccorridors Office spacoffice spacoffice spacoffice space Office space Cafeteria / Office spacoffice spacoffice spacoffice space Office spac Office space Az Floor area of zone, ft Pz Zone population, largest # of people expected to occupy zone Rp Area outdoor air rate from Table 6.1, cfm/person Ra People outdoor air rate from Table 6.1, cfm/ft^ Pz*Rp Az*Ra Ez Zone air distribution effectiveness, Table (1.0 for Ceiling supply of cool air.) Voz Outdoor airflow to the zone corrected for zone air distribution effectiveness, (Pz*Rp + Az*Ra)/Ez, cfm Vpz Primary airflow to zone from air handler. In VAV systems, use the design value. cfm Vpzm The minimum value of the primary airflow to zone from air handler. In CAV systems, Vpzm = Vpz. cfm Zp Primary outdoor air fraction, Voz/Vpzm ######### Transfor mer Telecom Water Closet SYSTEM LEVEL Ps System population, maximum simultaneious # of occupants of space served by system D Occupant diversity, ratio of system peak occupancy to sum of space peak occupancies, = Ps/ ΣPz Vou Uncorrected outdoor air intake, = D* ΣRp*Pz +ΣRa*Az, 1959 Vps System primary airflow Xs Mixing ratio at primary air handler of uncorrected outdoor air intake to system primary flow, = Vou/Vps 0.10 Not used in calculation SYSTEM EFFICIENCY Max Zp Max Zp ######### Ev System ventilation efficiency, Table 6.3 based on maxzp 0.50 Percent outdoor air intake Vot Minimum outdoor air intake, Vou/Ev, cfm % = Vot/Sum of Vpz

23 RESULTS Vot Minimum outdoor air intake, Vou/Ev, cfm Percent outdoor air intake, Vot/Vps 88% Ev System ventilation efficiency 0.11 ZONE LEVEL Zones served by AHU 4,5 122 Appendix G Automated With CRAC Units Print - Office Tape Storage - Office Corridor Mech Shop/ Corridor Office space Security Building/ Control Space type (select from pull-down list) Office space Office space Corridors Office space Office space Office space Office space Office space Cafeteria / fasoffice space Office space Office space Office space Office space Office space Az Floor area of zone, ft Pz Zone population, largest # of people expected to occupy zone Rp Area outdoor air rate from Table 6.1, cfm/person Ra People outdoor air rate from Table 6.1, cfm/ft^ Pz*Rp Az*Ra Conference /Squad Office/ Security Lunch Reception Clerk Mail Motor Control Center Transformer Transformer Telecom Water Closets Voz Vpz Vdz Vdzm Zd Outdoor airflow to the zone corrected for zone air distribution effectiveness, (Pz*Rp + Az*Ra)/Ez, cfm Primary airflow to zone from air handler (intake plus recirculated air, but not local recirculation such as at mixing boxes), cfm. In VAV systems, use the design value. Supply/discharge to zone including primary air Vpz and locally recirculated air, cfm. In VAV systems, use the design value. Minimum supply/discharge to zone used to calculate Ev, cfm. In CAV systems, Vdzm = Vdz. In VAV systems, Vdzm is the minimum expected value of Vdz. Outdoor air fraction required in air discharged to zone, = Voz/Vdzm Ep Primary air fraction to zone, = Vpz/Vdz (=1 for single duct and single zone systems) Er Fraction of secondary recirc to zone representative of system average, only applies if Ep<1. For plenum return =1. For duct return with local secondary recirc =0. Ez Zone air distribution effectiveness, Table Fa Fraction of supply air to zone from sources outside zone, = Ep + (1-Ep)*Er Fb Fraction of supply air to zone from full mixed primary air, = Ep = Vpz/Vdz Fc Fraction of outdoor air to zone from sources outside zone, = 1 - (1-Ez) * (1-Er) * (1-Ep) SYSTEM LEVEL Ps System population, maximum simultaneous # of occupants of space served by system D Occupant diversity, ratio of system peak occupancy to sum of space peak occupancies, = Ps/ΣPz Vou Uncorrected outdoor air intake, = D*ΣRp*Pz +ΣRa*Az, cfm 1961 Vps Total system primary flow to all zones, Σ Vpz, cfm Note: In VAV systems, Vps is equal to the fan airflow, and the formula in cell c40 needs to be replaced by this value. Xs Mixing ratio at primary air handler of uncorrected outdoor air intake to system primary flow, = Vou/Vps 0.10 SYSTEM EFFICIENCY Evz Zone ventilation efficiency, (Fa +Xs*Fb - Z*Fc)/Fa Ev System ventilation efficiency, min(evz) 0.11 Percent outdoor air intake Vot Minimum outdoor air intake, Vou/Ev, cfm % = Vot/Vps

24 RESULTS Vot Minimum outdoor air intake, Vou/Ev, cfm Percent outdoor air intake, Vot/Vps 88% Ev System ventilation efficiency 0.11 ZONE LEVEL Zones served by AHU 4,5 122 Appendix G Automated Removed CRAC Units Print Tape Storage Corridor Mech Shop/ Corridor Office space Security Building/ Control Space type (select from pull-down list) Office space Office space Corridors Office space Office space Office space Office space Office space Cafeteria / fasoffice space Office space Office space Office space Office space Office space Az Floor area of zone, ft Pz Zone population, largest # of people expected to occupy zone Rp Area outdoor air rate from Table 6.1, cfm/person Ra People outdoor air rate from Table 6.1, cfm/ft^ Pz*Rp Az*Ra Conference /Squad Office/ Security Lunch Reception Clerk Mail Motor Control Center Transformer Transformer Telecom Water Closets Voz Vpz Vdz Vdzm Zd Outdoor airflow to the zone corrected for zone air distribution effectiveness, (Pz*Rp + Az*Ra)/Ez, cfm Primary airflow to zone from air handler (intake plus recirculated air, but not local recirculation such as at mixing boxes), cfm. In VAV systems, use the design value. Supply/discharge to zone including primary air Vpz and locally recirculated air, cfm. In VAV systems, use the design value. Minimum supply/discharge to zone used to calculate Ev, cfm. In CAV systems, Vdzm = Vdz. In VAV systems, Vdzm is the minimum expected value of Vdz. Outdoor air fraction required in air discharged to zone, = Voz/Vdzm Ep Primary air fraction to zone, = Vpz/Vdz (=1 for single duct and single zone systems) Er Fraction of secondary recirc to zone representative of system average, only applies if Ep<1. For plenum return =1. For duct return with local secondary recirc =0. Ez Zone air distribution effectiveness, Table Fa Fraction of supply air to zone from sources outside zone, = Ep + (1-Ep)*Er Fb Fraction of supply air to zone from full mixed primary air, = Ep = Vpz/Vdz Fc Fraction of outdoor air to zone from sources outside zone, = 1 - (1-Ez) * (1-Er) * (1-Ep) SYSTEM LEVEL Ps System population, maximum simultaneous # of occupants of space served by system D Occupant diversity, ratio of system peak occupancy to sum of space peak occupancies, = Ps/ΣPz Vou Uncorrected outdoor air intake, = D*ΣRp*Pz +ΣRa*Az, cfm 1961 Vps Total system primary flow to all zones, Σ Vpz, cfm Note: In VAV systems, Vps is equal to the fan airflow, and the formula in cell c40 needs to be replaced by this value. Xs Mixing ratio at primary air handler of uncorrected outdoor air intake to system primary flow, = Vou/Vps 0.10 SYSTEM EFFICIENCY Evz Zone ventilation efficiency, (Fa +Xs*Fb - Z*Fc)/Fa Ev System ventilation efficiency, min(evz) 0.11 Percent outdoor air intake Vot Minimum outdoor air intake, Vou/Ev, cfm % = Vot/Vps

25 ZONE LEVEL Zones served AHU's 1,2,3,10 UPS/Batter y UPS/Batter y Water Closets Space type (select from pull-down list) Office space Office space Az Floor area of zone, ft Pz Zone population, largest # of people expected to occupy zone Rp Area outdoor air rate from Table 6.1, cfm/person Ra People outdoor air rate from Table 6.1, cfm/ft^ Pz*Rp Az*Ra Ez Zone air distribution effectiveness, Table (1.0 for Ceiling supply of cool air.) Voz Outdoor airflow to the zone corrected for zone air distribution effectiveness, (Pz*Rp + Az*Ra)/Ez, cfm Vpz Primary airflow to zone from air handler. In VAV systems, use the design value. cfm Vpzm The minimum value of the primary airflow to zone from air handler. In CAV systems, Vpzm = Vpz. cfm Zp Primary outdoor air fraction, Voz/Vpzm 0.00 ########## ######## SYSTEM LEVEL Ps System population, maximum simultaneious # of occupants of space served by system D Occupant diversity, ratio of system peak occupancy to sum of space peak occupancies, = PsΣPz Vou Uncorrected outdoor air intake, = DΣRp*Pz +ΣRa*Az, cfm 899 Vps System primary airflow Xs Mixing ratio at primary air handler of uncorrected outdoor air intake to system primary flow, = Vou/Vps 0.01 Not used in calculation SYSTEM EFFICIENCY Max Zp Max Zp ########## (Approaches infinity) Ev System ventilation efficiency, Table 6.3 based on maxzp 0.50 Percent outdoor air intake Vot Minimum outdoor air intake, Vou/Ev, cfm % = Vot/Sum of Vpz

26 RESULTS Vot Minimum outdoor air intake, Vou/Ev, cfm 806 Percent outdoor air intake, Vot/Vps 1% Ev System ventilation efficiency 1.00 ZONE LEVEL Zones served by AHU 1,2,3,10 Appendix G Electrical (UPS) Battery Water Closet Space type (select from pull-down list) Office space Office space Az Floor area of zone, ft Pz Zone population, largest # of people expected to occupy zone Rp Area outdoor air rate from Table 6.1, cfm/person Ra People outdoor air rate from Table 6.1, cfm/ft^ Pz*Rp Az*Ra Voz Vpz Vdz Vdzm Zd Outdoor airflow to the zone corrected for zone air distribution effectiveness, (Pz*Rp + Az*Ra)/Ez, cfm Primary airflow to zone from air handler (intake plus recirculated air, but not local recirculation such as at mixing boxes), cfm. In VAV systems, use the design value. Supply/discharge to zone including primary air Vpz and locally recirculated air, cfm. In VAV systems, use the design value. Minimum supply/discharge to zone used to calculate Ev, cfm. In CAV systems, Vdzm = Vdz. In VAV systems, Vdzm is the minimum expected value of Vdz. Outdoor air fraction required in air discharged to zone, = Voz/Vdzm Ep Primary air fraction to zone, = Vpz/Vdz (=1 for single duct and single zone systems) Er Fraction of secondary recirc to zone representative of system average, only applies if Ep<1. For plenum return =1. For duct return with local secondary recirc =0. Ez Zone air distribution effectiveness, Table Fa Fraction of supply air to zone from sources outside zone, = Ep + (1-Ep)*Er Fb Fraction of supply air to zone from full mixed primary air, = Ep = Vpz/Vdz Fc Fraction of outdoor air to zone from sources outside zone, = 1 - (1-Ez) * (1-Er) * (1-Ep) SYSTEM LEVEL Ps System population, maximum simultaneous # of occupants of space served by system D Occupant diversity, ratio of system peak occupancy to sum of space peak occupancies, = Ps/ΣPz Vou Uncorrected outdoor air intake, = D*ΣRp*Pz +ΣRa*Az, cfm 804 Vps Total system primary flow to all zones, Σ Vpz, cfm Xs Mixing ratio at primary air handler of uncorrected outdoor air intake to system primary flow, = Vou/Vps SYSTEM EFFICIENCY Evz Zone ventilation efficiency, (Fa +Xs*Fb - Z*Fc)/Fa Ev System ventilation efficiency, min(evz) 1.00 Percent outdoor air intake Vot Minimum outdoor air intake, Vou/Ev, cfm 806 1% = Vot/Vps 0.01 Note: In VAV systems, Vps is equal to the fan airflow, and the formula in cell c40 needs to be replaced by this value.

27 ZONE LEVEL Zones served by AHU 8,9 Tape Storage Unix Computer Computer Corridor Help Desk Conference Conference Situation / Situation / Conference Conference Copy / Fax Training Presentation Situation/ Conference Space type (select from pull-down list) Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Az Floor area of zone, ft Pz Zone population, largest # of people expected to occupy zone Rp Area outdoor air rate from Table 6.1, cfm/person Ra People outdoor air rate from Table 6.1, cfm/ft^ Pz*Rp Az*Ra Ez Zone air distribution effectiveness, Table (1.0 for Ceiling supply of cool air.) Voz Outdoor airflow to the zone corrected for zone air distribution effectiveness, (Pz*Rp + Az*Ra)/Ez, cfm Vpz Primary airflow to zone from air handler. In VAV systems, use the design value cfm Vpzm The minimum value of the primary airflow to zone from air handler. In CAV systems, Vpzm = Vpz. cfm Zp Primary outdoor air fraction, Voz/Vpzm ######## Offices Computer Roms E&W Water Closets SYSTEM LEVEL Ps System population, maximum simultaneious # of occupants of space served by system D Occupant diversity, ratio of system peak occupancy to sum of space peak occupancies, = Ps/ΣPz Vou Uncorrected outdoor air intake, = D*ΣRp*Pz +ΣRa*Az, 7589 Vps System primary airflow Xs Mixing ratio at primary air handler of uncorrected outdoor air intake to system primary flow, = Vou/Vps 0.22 Not used in calculation SYSTEM EFFICIENCY Max Zp Max Zp ########## Ev System ventilation efficiency, Table 6.3 based on maxzp 0.50 Percent outdoor air intake Vot Minimum outdoor air intake, Vou/Ev, cfm % = Vot/Sum of Vpz

28 RESULTS Vot Minimum outdoor air intake, Vou/Ev, cfm Percent outdoor air intake, Vot/Vps 44% Ev System ventilation efficiency 0.51 ZONE LEVEL Zones served by AHU 8,9 Appendix G With CRAC Units Tape Storage Unix Computer Computer Corridor Help Desk Conference Conference Situation / Conference Situation / Conference Copy / Fax Training Presentatio Situation/ n Conference Space type (select from pull-down list) Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Az Floor area of zone, ft Pz Zone population, largest # of people expected to occupy zone Rp Area outdoor air rate from Table 6.1, cfm/person Ra People outdoor air rate from Table 6.1, cfm/ft^ Pz*Rp Az*Ra GMC Computer Roms E&W Water Closets Voz Vpz Vdz Vdzm Zd Outdoor airflow to the zone corrected for zone air distribution effectiveness, (Pz*Rp + Az*Ra)/Ez, cfm Primary airflow to zone from air handler (intake plus recirculated air, but not local recirculation such as at mixing boxes), cfm. In VAV systems, use the design value. Supply/discharge to zone including primary air Vpz and locally recirculated air, cfm. In VAV systems, use the design value. Minimum supply/discharge to zone used to calculate Ev, cfm. In CAV systems, Vdzm = Vdz. In VAV systems, Vdzm is the minimum expected value of Vdz. Outdoor air fraction required in air discharged to zone, = Voz/Vdzm Ep Primary air fraction to zone, = Vpz/Vdz (=1 for single duct and single zone systems) Er Fraction of secondary recirc to zone representative of system average, only applies if Ep<1. For plenum return =0. For duct return with local secondary recirc =1. Ez Zone air distribution effectiveness, Table Fa Fraction of supply air to zone from sources outside zone, = Ep + (1-Ep)*Er Fb Fraction of supply air to zone from full mixed primary air, = Ep = Vpz/Vdz Fc Fraction of outdoor air to zone from sources outside zone, = 1 - (1-Ez) * (1-Er) * (1-Ep) SYSTEM LEVEL Ps System population, maximum simultaneous # of occupants of space served by system D Occupant diversity, ratio of system peak occupancy to sum of space peak occupancies, = Ps/ΣPz Vou Uncorrected outdoor air intake, = D*ΣRp*Pz +ΣRa*Az, cfm 7654 Vps Total system primary flow to all zones, Σ Vpz, cfm Note: In VAV systems, Vps is equal to the fan airflow, and the formula in cell c40 needs to be replaced by this value. Xs Mixing ratio at primary air handler of uncorrected outdoor air intake to system primary flow, = Vou/Vps 0.22 SYSTEM EFFICIENCY Evz Zone ventilation efficiency, (Fa +Xs*Fb - Z*Fc)/Fa Ev System ventilation efficiency, min(evz) 0.51 Percent outdoor air intake Vot Minimum outdoor air intake, Vou/Ev, cfm % = Vot/Vps

29 RESULTS Vot Minimum outdoor air intake, Vou/Ev, cfm Percent outdoor air intake, Vot/Vps 44% Ev System ventilation efficiency 0.51 ZONE LEVEL Zones served by AHU 8,9 Appendix G Removed CRAC Units Tape Storage Unix Computer Computer Corridor Help Desk Conference Conference Situation / Conference Situation / Conference Copy / Fax Training Presentatio Situation/ n Conference Space type (select from pull-down list) Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Office space Az Floor area of zone, ft Pz Zone population, largest # of people expected to occupy zone Rp Area outdoor air rate from Table 6.1, cfm/person Ra People outdoor air rate from Table 6.1, cfm/ft^ Pz*Rp Az*Ra Offices Computer Roms E&W Number of Water Closets Voz Vpz Vdz Vdzm Zd Outdoor airflow to the zone corrected for zone air distribution effectiveness, (Pz*Rp + Az*Ra)/Ez, cfm Primary airflow to zone from air handler (intake plus recirculated air, but not local recirculation such as at mixing boxes), cfm. In VAV systems, use the design value. Supply/discharge to zone including primary air Vpz and locally recirculated air, cfm. In VAV systems, use the design value. Minimum supply/discharge to zone used to calculate Ev, cfm. In CAV systems, Vdzm = Vdz. In VAV systems, Vdzm is the minimum expected value of Vdz. Outdoor air fraction required in air discharged to zone, = Voz/Vdzm Ep Primary air fraction to zone, = Vpz/Vdz (=1 for single duct and single zone systems) Er Fraction of secondary recirc to zone representative of system average, only applies if Ep<1. For plenum return =1. For duct return with local secondary recirc =0. Ez Zone air distribution effectiveness, Table Fa Fraction of supply air to zone from sources outside zone, = Ep + (1-Ep)*Er Fb Fraction of supply air to zone from full mixed primary air, = Ep = Vpz/Vdz Fc Fraction of outdoor air to zone from sources outside zone, = 1 - (1-Ez) * (1-Er) * (1-Ep) SYSTEM LEVEL Ps System population, maximum simultaneous # of occupants of space served by system D Occupant diversity, ratio of system peak occupancy to sum of space peak occupancies, = Ps/ΣPz Vou Uncorrected outdoor air intake, = D*ΣRp*Pz +ΣRa*Az, cfm 7654 Vps Total system primary flow to all zones, Σ Vpz, cfm Note: In VAV systems, Vps is equal to the fan airflow, and the formula in cell c40 needs to be replaced by this value. Xs Mixing ratio at primary air handler of uncorrected outdoor air intake to system primary flow, = Vou/Vps 0.22 SYSTEM EFFICIENCY Evz Zone ventilation efficiency, (Fa +Xs*Fb - Z*Fc)/Fa Ev System ventilation efficiency, min(evz) 0.51 Percent outdoor air intake Vot Minimum outdoor air intake, Vou/Ev, cfm % = Vot/Vps