Codes / Standards
ASHRAE opens revised residential energy standard for input (90.2-2007R)
November 17, 2016 - Recognizing the amount of energy used by the residential building sector, ASHRAE and IES (Illuminating Engineering Society) say they are revising their residential energy standard with a goal of making it 50% more efficient than the 2006 International Energy Conservation Code.
By Renée Francoeur
As such, ASHRAE/IES Standard 90.2-2007R, Energy Efficient Design of Low-Rise Residential Buildings, is open for public comment from November 4 until December 19, 2016.
Theresa Weston, chair of the Standard 90.2 committee, said the revision of the standard, last published in 2007, offers an “accurate, flexible performance-based tool to enable user creativity in meeting the performance objectives”. She adds, “The new standard contains detailed rules governing the energy modeling and analyses needed to determine compliance with the performance objectives.”
The rule set is based on ANSI/ICC/ RESNET 301 with specific exceptions and adjustments for building size.
Additional key components include:
• The standard now covers manufactured housing, which was not included in the 2007 version. It also addresses renewable and non-renewable forms of energy.
• The standard recognizes that long-lived building envelope decisions play a critical role in achieving the targeted building performance. Certified performance of insulation, fenestration and envelope air sealing are prioritized. Testing and verifying the envelope air leakage is mandatory.
• The standard recognizes the importance of HVAC and water heating system performance as essential to achieving the overall building performance targets. Proper sizing and verification of duct system performance, as well as having all ductwork within conditioned space are fundamental to these objectives. Similarly, plumbing system design, insulation levels and controls are prioritized and are fundamentally new.
• The standard includes revised modelling rules for quantifying residential lighting energy, credits for the use of vacancy sensors, dimmers and other control devices and revised lighting allowances for interior, exterior, garage and other residential lighting.
• The standard emphasizes load minimization and HVAC performance strategies first so that any onsite power systems used can have maximum impact toward the overall building performance goals.