Literature Review on Building Envelope, Heating and ... - Beeshive.org

3. Heating, Ventilation, and Energy Technologies
Heating and Ventilating
HVAC Design Considerations
Meckler (1991) and Armstrong (1993) discussed design challenges of HVAC in the arctic
regions of Alaska and Canada. Armstrong noted that the climate presents environmental
challenges that must be recognized and addressed in every HVAC system design. The
challenges result from extremes of cold, wind, snow, dry air, solar gain, and extended
darkness.
Climate Challenges: Alaska
• Heating degree days range from 6697 heating degree days (base 65°F) in Ketchikan
(at 55º 21 N´ latitude) to 20 341 heating degree days (base 65°F) in Barrow (at 71º 18
N´ latitude).
• Snowfall varies greatly in Alaska.
• Temperate coastal communities (e.g., Ketchikan) have an average annual snowfall of
94 cm (37 in.) and little accumulation over a few days.
• South central and northern communities (e.g., Valdez) receive large quantities of
snow; an average annual snowfall is 625 cm (246 in.) with a record snowfall in excess
of 1524 cm (600 in.). Snow accumulates for most of the winter, and compacts to a
depth of about 4 m (12 ft.).
• Low temperatures can range from -57ºC (-70ºF) for weeks in interior areas to
-34ºC (-30ºF) in south central and western areas and last for extended periods.
Temperatures can reach 35ºC (95ºF) in summer. There is very little temperature
swing from night to day during the winter months when there is little or no sun.
• Wind speeds in excess of 200 km/h (125 mph) are common. The coastal areas are
subjected to storms with hurricane force winds.
• Summer days are long, particularly north of the Arctic Circle where the sun rises in
the early summer and stays until fall. Continuous sunshine poses special challenges in
dealing with solar gain that does not subside during the night.
HVAC Design Considerations
Meckler (1991) noted that design considerations for the arctic region differ from
temperate climates and require greater attention to condensation on building envelope
surfaces and glazing. In some areas, the moisture content of the outdoor air is almost zero
for several months of the year, and heating without adequate humidification can result in
an unacceptable indoor humidity level. Design of HVAC systems in such regions
requires modifications to the common design methods used in temperate climates
PERD-079: Task 2 - <strong>Literature</strong> <strong>Review</strong> 79