Maria’s Restaurant Lesson 22 Appendix C Zone 2 Duct Design

Maria’s Restaurant Design (Staff: Maria & 7 Employees each shift. Glass Store Front and front door) C1 R1 F1 Woman’s Restroom 1 handicap 1 standard Men’s Restroom 1 handicap 1 urinal S3 Shelv.. R3 DW Bar 12 X 10 Seating 12 Counter C6 Bar S2 B2 Ice R4 Shelving/Storage 25 ft. Shelv. B1 C7 C2 Fry S1 Restaurant 33 X 15 11 X 4 & 11 X 6 Seating 58 CT/O C3 SP SK H1 R2 F2 WH S1 66 ft. B = Beverage Area R = Refrigerator (blue walk in C = Counter S = Sink; S1 Hand; S2 3 Pot; S3 Bar CT = 4 burner plus flat top over ovens SK= Steam Kettle DW = Dishwasher SP = Salad/cold Prep table F = Freezer (blue walk in) H1 = Hot Prep Table with Heat Lamp Shelf

Zone 2 Kitchen Exhaust & OA Sketch AIR In 1,150 CFM AIR In 600 CFM Zone 1: Restaurant Area Fresh Air Required 589 CFM EX. AIR AIR In Setting 1: 1,900 CFM Setting 2: 100 CFM AIR In 500 CFM Package Heat Pump ERV 2 Bathrooms Airflow ½ each EX. AIR EX 2 Zone 1 EX AIR OUT 500 CFM Supply Air 3,200 CFM Return Air Setting 1: 1,300 CFM Setting 2: 3,100 CFM EX 1 EX 2 AIR Out 600 CFM EX AIR Out Speed/Setting 1: 3,450 CFM Speed/Setting 2: 1,650 CFM

Maria’s Restaurant Duct Design (one grid square = one ft2) Zone 2 G Supply Diffuser 550 CFM H F H A 6 Supply Diffusers 400 CFM B 25 ft. Zone 1A Duct F D Zone 1 B EX. Hood E G E C A C D 5 Supply Diffusers 530 CFM 66 ft. Zone 1 Constant Volume 2,400 CFM Return: 1,711 CFM Zone 2 Constant Volume 3,200 CFM Stage 1 Return: 1,300 CFM Stage 2 Return: 3,100 CFM

Fan Cabinet Return Connections for 7 Fan Cabinet Return Connections for 7.5 & 10 Ton Rooftop Package Unit Supply Duct 27”× 24” = OEM Opening 24” 27” 26” Round 24” 27” Friction Rate (FR) Calculation Zone 1 Unit Return Trunk: 2,400 CFM ÷ 4.5 ft2 = 534 FPM FR = 0.016 (Will use 0.020 as per Manual Q Minimum value) Zone 2 Unit Return Trunk: 3,200 CFM ÷ 4.5 ft2 = 711 FPM FR = 0.030 Note: Sketch not to scale

Zone 2 Friction Rate Not a significant Pressure Drop: For longer runs or smaller ducting the return total needs to be added to the supply to obtain the system’s total loss. Friction Rate 0.030

Not a significant Pressure Drop: For longer runs or smaller ducting Fan Cabinet Supply Connections for 7.5 & 10 Ton Rooftop Package Unit Supply Duct 28”× 20” = OEM Opening 20” 28” 26” Round Not a significant Pressure Drop: For longer runs or smaller ducting the return total needs to be added to the supply to obtain the system’s total loss. 20” 28” Friction Rate (FR) Calculation Zone 1 Unit Return Trunk: 2,400 CFM ÷ 3.89 ft2 = 617 FPM FR = 0.026 Zone 2 Unit Return Trunk: 3,200 CFM ÷ 3.89 ft2 = 823 FPM FR = 0.045 Note: Sketch not to scale

Zone 2 Kitchen Duct Design A to B 10’ 4’ 3’ 3’ 3’ 4’ 2’ Diffuser 90O Rectangular Elbow Wye 90 Return Register

Friction Rate 0.2 Galvanized Metal Corresponding Airflows in CFM Friction Rate 0.2 Duct Board

A to B

Typical Straight Duct Calculation CE = f/100 × ft. ÷ 100 CE = 0.045 × 4 ÷ 100 = 0.0018

Typical Wye Calculation

Zone 2 Kitchen Duct Design A to B 10’ 4’ 3’ 3’ 3’ 4’ 2’ Diffuser 90O Rectangular Elbow Wye 90 Return Register

Zone 2 Wye C Rectangular (Pv) Using the Manual Q Table A6-5 to Calculate for main Coefficient C at point C on the duct drawing: Ab ÷ Ac = 154 ÷ 560 = 0.275 Ab ÷ As = 154 ÷ 408 = 0.377 Qb ÷ Qc = 530 ÷ 3,200 = 0.166   Where: Ab = 7 × 22 = 154 in2 Ac = 28 × 20 = 560 in2 As = 28 × 17 = 408 in2

Main Branch Wye D Rectangular (Pv) Ab/As Ab/Ac Wye Main Branch Coefficient C Qb/Qc 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 0.25 -0.01 -0.03 0.05 0.13 0.21 0.29 0.38 0.46 0.33 0.08 -0.02 0.02 0.16 0.24 0.34 -0.06 -0.05 0.06 0.12 0.19 0.27 0.35 0.67 0.04 -.02 -0.04 0.23 0.37 1.0 0.72 0.48 0.28 0.09 0.18 0.30 0.22 1.33 0.10 0.01 0.03 0.20 2.0 0.62 Close Enough to 0 Ab ÷ Ac = 154 ÷ 560 = 0.275 Ab ÷ As = 154 ÷ 408 = 0.377 Qb ÷ Qc = 530 ÷ 3,200 = 0.166

WYE 90O Pt = C × Pv Pt = 0 × 0.638 = 0

Zone 2 Smooth Radius 3 Vane 90 H/W = 7 ÷ 22 = 0.31 R/W = 11 ÷ 22 = 0.5 No need to interpolate C = 0.01 R/W Coefficient C H/W 0.25 0.5 1.0 1.5 2.0 3.0 4.0 5.0 6.0 7.0 8.0 0.05 0.11 0.10 0.12 0.13 0.14 0.16 0.18 0.19 0.21 0.22 0.23 0.07 0.06 0.08 0.09 0.15 0.04 0.20 0.03 0.02 0.30 0.01 0.35 0.40 0.45 0.50 0.31

Rounded up to 0.0001 to fit sheet Pt = C × Pv Smooth Radius 3 Vane 90 Calculations Pt = 0.008 × 0.01 = 0.00008 Rounded up to 0.0001 to fit sheet Pt = C × Pv

Zone 2 Total Loss = 0.503

10’ 22×7 3’ 22×15 3’ 28×17 4’ 28×20 4’ 22×7 3’ 22×11 2’ 28×15

Zone 2 Kitchen Duct Design A to B 10’ 4’ 3’ 3’ 3’ 4’ 2’ Diffuser 90O Rectangular Elbow Wye 90 Return Register

Zone 2 Kitchen Duct Design A to B Diffuser 90O Rectangular Elbow Wye 90 Return Register

24” 27” 26” Round 24” 27” Friction Rate (FR) Calculation Zone 1 Unit Return Trunk: 2,400 CFM ÷ 4.5 ft2 = 534 FPM FR = 0.016 (Will use 0.020 as per Manual Q Minimum value) Zone 2 Unit Return Trunk: 3,200 CFM ÷ 4.5 ft2 = 711 FPM FR = 0.030 Note: Sketch not to scale

Field Notes To do field diagnostics technicians need a differential pressure meter and the ability to read and use a duct slide rule. For further training on the duct slide rule see the Qtech on line course Duct Design Basics. For further training see Technician’s Guide & Workbook for Quality Installations and/or the related Qtech course.