Positive Energy
Design Around People. A Good Building Follows.

Blog

Read more about a range of building science, engineering, and architecture topics on our company blog.

Posts tagged HVAC systems
The Case for Dedicated Dehumidification In Sealed Attics
The Case for Dedicated Dehumidification In Sealed Attics

Modern building design increasingly embraces sealed attic construction as a strategy to enhance energy efficiency and improve air leakage control, particularly beneficial for the performance of HVAC ductwork. This approach, where the attic space is brought within the building's thermal and air control envelope, fundamentally alters the moisture dynamics compared to traditional vented attics. While offering significant advantages, sealed attics introduce unique moisture challenges that demand precise and active management to prevent long-term durability issues and maintain superior indoor air quality.

Read More
Building Science, Architectural Design, Building Enclosure, Dehumidification, Healthy Home, Filtration, High Performance Homes, HVAC, Indoor Air Quality, Mechanical DesignPositive EnergySealed attics, dedicated dehumidification, moisture control, energy efficiency, indoor air quality, HVAC systems, air leakage, building durability, condensation risks, mold growth, air barrier, thermal barrier, insulation, roof deck temperature, building codes (IRC), ASHRAE standards, unconditioned attics, conditioned attics, psychrometrics, vapor control, duct performance, latent load, sensible load, building science principles, dew point, hygric buffering, controlled ventilation, air sealing, maintenance issues, cross-contamination, volatile organic compounds (VOCs), pests, allergens, duct leakage, system strain, pressure balancing, wood framing, sheathing, building envelope, resilience, sustainability, dehumidifier sizing, condensate management, building science experts, MEP engineering.
The Damp Deception: How a Well-Intentioned Code Change is Fostering Mold in New Homes
The Damp Deception: How a Well-Intentioned Code Change is Fostering Mold in New Homes

The promise of a new home often includes visions of a healthier, more energy-efficient living space. However, a subtle yet significant regulatory shift in U.S. building codes, particularly affecting hot-humid climate zones, may be inadvertently undermining this very promise. Before 2021, residential ventilation requirements were often loosely enforced; homes were typically required to have a ventilator, but the actual volume of air exchanged was not mandated to be measured. This frequently led to systems being ineffectively installed or even "sabotaged" by HVAC contractors, rendering them inoperable or improperly configured from the outset. Consequently, many homes, even in that period, did not achieve consistent fresh air exchange. Compounding this, most residential HVAC systems lacked any form of supplemental or dedicated dehumidification, a feature that building science experts have increasingly recognized as crucial, especially for high-performance homes in moisture-laden environments.

Read More
HVAC, CodePositive EnergyHVAC systems, ventilation requirements, indoor air quality, humidity control, mold growth, building codes, energy efficiency, public health, economic impact, environmental impact, building science, moisture management., Indoor Air Quality, Mold, Moisture Management, mechanical systems, Dehumidification, dedicated dehumidification