Part 3 Technicians Guide Workbook for Duct Diagnostics

Part 3 Technician’s Guide & Workbook for Duct Diagnostics and Repair

Section 1. 3 Duct Basics: System Efficiency Losses

Std 52. 2 MERV 1 -4 Average Particle ASHRAE Size Dust Spot Arrestance Efficiency Ranges Std 52. 1 Filtration <20% 60 to 80% <20 to 35% >80 to 95% 3. 0 10. 0 µm 9 -12 40 to 75% >95 to 98% 1. 0 - 3. 0 µm 13 -16 80 to 95% 0. 30 >98 to 99% + 1. 0 µm 17 -201 N/A Typical Filter Type Permanent / Self Charging (passive) Residential / Minimum Light > 10. 0 Washable / Metal, / Commercial Minimum / µm Foam / Synthetics Equipment Protection Disposable Panels Fiberglass / Synthetics 5 -8 99. 972 99. 9992 Typical Applications Industrial Workplaces Pleated Filters Commercial Better / Extended Surface Residential/ Paint Booth / Filters Media Panel Finishing Filters Superior / Residential Better Non-Supported / Bag / Industrial Workplaces Rigid Box Rigid Cell / Better / Commercial Cartridge Buildings Smoke Removal General Rigid Cell / Cartridge Surgery Hospitals & Health Rigid Box Non. Care Superior / Commercial Supported / Bag Buildings ≤ 0. 30 Clean Rooms High Risk µm Surgery Hazardous Materials HEPA ULPA

Telltale Signs of Problem Ducts • Uninsulated Ducts Heat Leaving Duct Surface During Heating Season

Telltale Signs of Problem Ducts • Uninsulated Ducts Heat Entering Duct Surface During Cooling Season

Common Return

Telltale Signs of Problem Ducts • Disconnected, Torn, or Damaged Ducts Squashed Disconnected Holes/Tears

Telltale Signs of Problem Ducts • Abandoned Ducts Branch To Nowhere

Duct Sizing Duct Design Basics http: //www. acca. org/certification/qtech

Telltale Signs of Problem Ducts • Inadequate Return Duct Supply Duct Return Duct

Telltale Signs of Problem Ducts • Inadequate Supply Duct Return Duct

Telltale Signs of Problem Ducts • Evidence of Supply and/or Return Duct Leakage Supply Duct Leakage Return Duct

General Air Leaks

Equipment Efficiency Furnace Losses 43 Total Fuel Energy 197 Leakage 100 ÷ 197 X 100 = 50. 76% 54 Conduction System Interactions Heat to Building 100

Building Spaces Used As Ducts

Opportunities in New Buildings ANSI/ACCA 5 QI-2015 HVAC Quality Installation Specification

Lessons Learned You should now be able to explain items to include on a duct sketch. You should now be able to explain how bad ducting can influence HVAC system efficiency. You should now be able to explain why some locations are better efficiency-wise for installing duct work.