Buildings in arctic and subarctic climates face not only challenges related to cold, but remoteness, limited utilities, permafrost, and extreme temperature shifts. Designers must meet these challenges while keeping occupants comfortable and minimizing impacts on the environment.
The newly published “Cold-Climate Buildings Design Guide” from ASHRAE provides information on issues commonly faced by designers not only in these climates, but any climate that has a heating season.
“We do cover the extreme-cold climates very well, but we also have very useful information for any buildings which have heating for part of the year,” Frank Mills, who helped write the guide, said. “This covers a lot of climate regions, including Europe, where I am.”
A cold climate is defined by a combination of factors that create a unique set of building design challenges. These factors include temperature, frozen precipitation, wind, humidity, thermal comfort, thermal envelope/enclosure, maintainability, permafrost and frozen ground, and remote building locations.
Following are tips from several committee members for designing, operating, and maintaining buildings and systems in cold climates:
- What happens when building air exfiltrates a building envelope in cold weather is similar to what happens in cooling coils in hot humid weather—understanding psychrometrics is essential to understanding building-envelope performance in cold climates.
- The colder the climate, the more important it is for critical equipment to be sheltered—one cannot expect service personnel to properly repair HVAC equipment in a winter blizzard.
- In extreme climates, windblown snow takes on a consistency similar to sand and requires special design techniques to keep it from getting into HVAC intakes.
- Be mindful of design impacts of non-mechanical components. For instance, snow and ice sliding down a metal roof can shear off mechanical roof penetrations as well as hoods on the exterior wall below.
- A building envelope must address all modes of heat loss to be truly efficient; ignoring any mode of loss may lead to excessive thermal transfer.
- Frost can be devastating to HVAC equipment, blocking intake hoods, filters, coils, etc.
- Design out cold bridges in both building fabric and engineering penetrations.
- Avoid or minimize any external-service pipe runs.
- Locate air inlets and exhausts in locations that avoid snow drift and blockage.
- Ensure condensing pipes never freeze and block.
- Provide safe access to roof mechanical plants in all weather—frozen roof surfaces can be a hazard.
In addition to HVAC calculations and system design, the book covers sustainability, controls, building design, and commissioning. The book includes an appendix with seven case studies of buildings located in cold and extreme-cold climates.
The cost of “Cold-Climate Buildings Design Guide” is $77 for ASHRAE members and $90 for non-members. Copies can be ordered by phone at 800-527-4723 (United States and Canada) or 404-636-8400, by fax at 678-539-2129, or online at www.ashrae.org/bookstore.