Thursday, August 13, 2020

AIRAH has released the latest addition to its suite of DA manuals, DA07 Moisture Control Design Analysis in Buildings. 

“Although the majority of new buildings are safe, comfortable, and designed to provide effective protection against moisture-related problems, a certain number of buildings constructed each year do in fact experience moisture or mould problems,” says AIRAH CEO Tony Gleeson, M.AIRAH.

“Whether or not this number is now increasing – and whether or not the increase is due to the greater emphasis on energy-efficiency measures today – are widely debated questions. The purpose of DA07 Criteria for Moisture Control Design Analysis in Buildings is not to answer either of these questions but rather to provide guidance on how best to design buildings to have adequate moisture-control features. Considerable effort has gone into preparing it for publication.”

Based on ASHRAE’s revised Standard 160, DA07 specifies performance-based design criteria for predicting, mitigating, or reducing moisture damage to all building components, depending on climate, construction type and HVAC system operation.

These include criteria for selecting analytic procedures, for inputs, and for evaluation and use of outputs.

DA07 incorporates a number of important updates in the latest version of ASHRAE Standard 160. 

These are focused on: 

  • Simplifying the conditions necessary to minimise mould growth
  • Limiting indoor relative humidity to 70 per cent or less in the design analysis and revising the residential design moisture-generation rates
  • Simplifying the calculation procedure for wind-driven rain without significantly impacting the accuracy of results
  • Updating references.
“DA07 also replaces the simplified mould growth criterion with a mould index that predicts risk, which is more consistent with assembly performance observed in the field,” says AIRAH Education and Technical Services Manager Brendan Pejkovic.

“This manual has been designed for use by engineers, architects and contractors, as well as equipment owners, operators and specifiers.”

AIRAH members can access a complimentary digital version of DA07 as part of their membership. 

Hard copies are available via the AIRAH store. AIRAH is hosting a webinar later this month about DA07.