Presentation by Galen Staengl for the workshop Balancing Moisture, Ventilation, and Energy Efficiency, held in Arlington, VA on December 11, 2013

1. High Performance Ventilation for
Multi-Family Buildings
- Case Studies Galen Staengl, PE
LEED BD&C
Certified Passive House Consultant
Principal
Staengl Engineering

2. Ventilation System Design for
Multi-Family Buildings
Design Objectives
1. Maintain Healthy Indoor Environments
•
•
Provide Fresh Air – Dilute Air Contaminants
Control Humidity in Ventilation Air and Building
2. Minimize Building Energy Consumption
3. Minimize Cost of System and Cost of
Ownership
The Best Strategies Vary Based on Factors Such as
Building Height and Unit Size.

3. Governing Codes
ASHRAE 62.1
• Applies to Multi-Family 4 Stories and Greater
• Does Allow Natural Ventilation
ASHRAE 62.2
• Applies to Single Family and Multi-Family Up to 3
Stories
• Does Not Allow Natural Ventilation in Most Climates
GOOD PRACTICE: Don’t Rely on Natural Ventilation!

4. Centralized vs. Unit Level
Ventilation
Unit Level Ventilation
• Less Maintenance for Building Owner
• Can Be Cheaper
• Can Help to Avoid Stack Effect Issues
Centralized Ventilation
• Multi-Family Economy-of-Scale Allows for
Better Heat Recovery / Dehumidification
Equipment
• Can Provide Better Energy Performance and
Building Humidity Control
• Increased First Cost

5. Integrated vs. Dedicated
Ventilation
Integrated Ventilation
• Ventilation System Integrated with Unit HVAC
• Requires System Fan to Operate to Ventilate
• Dehumidification is Done by HVAC Unit

6. Integrated vs. Dedicated
Ventilation
Dedicated Ventilation
• Independent System for Ventilation
• Does Not Depend on Unit HVAC
• Dehumidification Can be Done at the Outdoor Unit

7. Benefits of Energy Recovery
Ventilation
• Reduces Heating and
Cooling Loads by 1530%
• Reduces Heating
Energy by 20 – 35%
• Helps to Control
Building Humidity

8. The Crossings at
th
4
and Preston
BRW Architects

9. The Crossings at
th
4
and Preston
• Low Income Housing
• 60 Unit Single Room Occupancy
• 3 Stories + Basement
• Mixed Use: R-2, B & A-2
• Earthcraft Award
• Best Multi-Family 2012

10. The Crossings at 4th and Preston
Challenges / Opportunities
1. Small Unit Size
•
•
2.
Right Sizing Equipment
Encourages Centralized System
Developer Owned
•
Allows Recoup of Up Front
Investment
3. Low Income Population
•
•
Smoking in Units
Occupied Much of The Time

11. The Crossings at 4th and Preston
Ventilation Strategy
Building:
• Dedicated Outside Air Unit
• Pressurized Corridors / Building
Units:
• Intermittent Exhaust Driven

12. The Crossings at 4th and Preston
Ventilation Strategy
Pros:
• DOA Unit Controls Building Humidity
• Reduced Ductwork Cost
• Fresh, Neutral Air Available on Demand
Cons:
• No Energy Recovery
• Good IAQ Relies on Occupant Behavior
• Corridor Pressurization Does Not
Effectively Prevent Cigarette Smoke
Migration

13. Crescent Square
VIA Design Architects, PC

14. Crescent Square
• Low Income Housing
• 80 Unit Single Room Occupancy
• 4 Stories
• Mixed Use: R-2, B & A-2
• Earthcraft (Pending)

15. Crescent Square
Ventilation Strategy
Building:
• Dedicated Outside Air Unit
• Energy Recovery
Units:
• Continuous, Balanced Ventilation &
Exhaust Ducted to Each Unit
• Intermittent Range Hood Exhaust

16. Crescent Square
Ventilation Strategy
Pros:
• ERV + Dehumidification Unit Control
Building Humidity
• Energy Recovery Saves Energy
• Continuous Ventilation to Building
Cons:
• Increased Cost of Ductwork

17. Crescent Square
Built-Up DOA Unit
Built-up Outdoor Air System with an ERV + Split
A/C Unit.
• Cost Effective Outdoor Air Humidity Control

18. System Testing and
Commissioning
• Build it Tight and Ventilate
Right!
• Building Air Leakage Testing
• Duct Leakage Testing

19. Summary
• Built it Tight and Ventilate Right
• Best Ventilation Strategy Varies Based on
Building and Unit Size
• Continuous Ventilation Preferred
• Dedicated Ventilation Has Many
Advantages
• Air and Duct Sealing Important