Fume Hood Control Constant Air Volume Fume Hood

Fume Hood Control Constant Air Volume Fume Hood 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 11

Fume Hood Control Variable Air Volume Fume Hood 12

Fume Hood Airflow Control Via Siemens Venturi Air Valve Control Process: VAV Fume Hood Controller 400 4 cfm Ft 2 1. Controller Determines Sash Position Siemens Venturi Air Valve 2. Controller Calculates Total Open Area Airflow Sensor = Sash Height x Width + Fixed Open Area 3. Controller Calculates Req’d. Exhaust = Area Ft 2 x Face Velocity (4 Ft 2 x 100 Ft/Min = 400 Ft 3/Min (400 CFM) 4. Measure Airflow & Compare Sash Sensor 5. Position Cone Update Display Panel FPM 14

Laboratory Ventilation Air Consumption vs. Type of Hood Constant Volume Bypass LARGE BYPASS SASH AREA FULL EXHAUST AT ALL TIMES AIRFLOW RELATIVELY CONSTANT AT ALL TIMES CAV bypass hood exhaust to remain “essentially unchanged” (less than 5% change)…. Z 9. 5 VERY COSTLY TO OPERATE 6’ FUME HOOD @ 1250 CFM ANNUAL COST*…. $3750 to $6250 FULLY 100% 50% CLOSED OPEN *Annual average cost of $3 to $5 per CFM 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 15

Laboratory Ventilation Air Consumption vs. Type of Hood Constant Volume Bypass - 2 Position EXHAUST REDUCTION DURING UNOCCUPANCY DAMPER W / 2 POSITION CONTROL LARGE BYPASS AREA SASH ROOM CONTROLLER SASH CLOSED § SAME AS REGULAR CAV DURING OCCUPANCY. § AIRFLOW REDUCED TO 20% DURING UNOCCUPANCY. FULLY 100% 50% CLOSED OPEN § WORKS IN CONJUNCTION NNWITH SUPPLY AIR REDUCTION. 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 16

Fume Hood Shutdown Requirements 1. Maintain Required Room Ventilation Rate. 2. Maintain Room Negative Pressurization if ……. . Hazardous Substances Are Present in Room. 3. Remove All Chemicals From Fume Hood. 4. Post Sign: Warning Fume Hood is Not Operational. Do Not Use ! + 100. 5 Warning Fume Hood is Not Operational. Do Not Use ! 17

CAV 2 - Position Laboratory Ventilation Control EXHAUST AIRFLOW SUPPLY AIRFLOW ROOM SUPPLY AIR TERMINAL CAV 2 - POSITION CONTROLLER ROOM CONTROLLER UNOCCUPIED INFLOW FROM ADJACENT AREAS Laboratory Room 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ CAV FUME HOOD 18

Laboratory Ventilation Air Consumption vs. Type of Hood Variable Air Volume EXHAUST MODULATION FOR CONSTANT FACE VELOCITY RESTRICTED BYPASS SASH VAV FUME HOOD FACE VELOCITY CONTROL BY SASH SENSING SASH POSITION FULLY 100% 50% CLOSED OPEN § AIRFLOW CONTROLLED TO ENSURE CONSTANT FACE VELOCITY. § AIRFLOW REDUCED TO 20% WHEN SASH IS FULLY CLOSED. § COST OF OPERATION TYPICALLY 40% OF CAV BYPASS FUME HOOD § ALSO REQUIRES VAV ROOM 19 VENTILATION CONTROL.

VAV Laboratory Ventilation Control SUPPLY AIRFLOW EXHAUST AIRFLOW ROOM SUPPLY AIR TERMINAL VAV FUME HOOD CONTROLLERS EXHAUST ROOM CONTROLLER INFLOW FROM ADJACENT AREAS Laboratory Room VAV FUME HOODS 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 20

Laboratory Room Ventilation Negative Room Pressurization = EXHAUST Diff. Pressure Sensing Airflow Tracking SUPPLY Inward Airflow 21

Dynamic Graphics FUME HOOD 046 SASH HEIGHT 0 Inches 18 28 Inches EXHAUST 525 250 CFM 800 FACE VELOCITY 103 Ft. /Min. 64 NORMAL Ft. /Min. 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 22

Average Face Velocity Recommendations n. ACGIH n 80 to 100 fpm n. NIOSH n 100 to 150 fpm n. ANSI (Standard Z 9. 5 -1992) n 80 to 120 fpm n. NFPA n 80 to 120 fpm n. OSHA n 60 to 100 fpm n. NIH n 100 fpm n. SEFA n 100 fpm 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 23

Fume Hood Testing – ASHRAE* 110 Standard 1. 2. 3. Measurements of Face Velocity Air Flow Visualization Test (Smoke Test) Tracer Gas Containment Test * American Society of Heating, Refrigerating and Air-Conditioning Engineers 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 25

Measurements of Face Velocity 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 26

Airflow Visualization Test (Smoke Test) 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 27

Tracer Gas Containment Test 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 28

Tracer Gas Test - Video Simulation 1390 ﺯﻣﺴﺘﺎﻥ - ﻣﻬﻨﺪﺱ ﻫﻤﺖ ﺟﻮ 29