hvac_extended Flashcards
(20 cards)
Why are duct sizes important in air-based systems?
Large duct sizes, especially trunk lines, can significantly impact ceiling heights and design layout.
Why do designers often place supply ducts at the building perimeter?
To address heat gain/loss at windows, where conditioning needs are greatest.
What is the risk of placing return diffusers too close to supply diffusers?
It can cause short-circuiting of airflow, reducing effective air circulation in the room.
What is a plenum in HVAC systems?
A ceiling space used as a return air path in place of ducted returns.
What are pros and cons of using a plenum system?
Pros: cost savings, fewer ducts, reduced ceiling crossings. Cons: acoustic issues, balancing difficulties.
Why are flexible ducts used in HVAC systems?
They allow easier repositioning of diffusers for future office layout changes.
What is the visual symbol difference between supply and return ducts in section?
Supply ducts have an ‘X’; return ducts have a single slash.
Why do drop ceilings benefit HVAC systems?
They support plenums, improve acoustics, allow maintenance access, and accommodate flexible layouts.
What is the advantage of spiral ducts in exposed systems?
Spiral ducts hold shape well and look more aesthetically pleasing.
How does ceiling height affect HVAC design?
It must accommodate ductwork, sprinkler systems, lighting, and access, especially in commercial settings.
What does a trunk line imply for office layout?
It can guide spatial organization, like defining circulation zones or lower ceiling areas.
How are vertical ducts typically routed between floors?
Via dedicated chases or shafts, often as large as elevator cores.
Why is fire safety a concern for vertical duct chases?
Duct shafts can act as chimneys and must be properly fire-separated.
What structural systems make ductwork coordination easier?
Flat slab concrete allows more flexible routing than steel wide flange systems.
Why are residential HVAC systems typically simpler?
Smaller space volumes, less need for layout flexibility, and shorter duct runs.
How does HVAC coordination affect floor-to-floor heights?
Larger systems require more space for ducts, increasing total building height.
What system characteristics make HVAC integration more complex in offices?
Higher air volumes, flexibility demands, and large trunk lines.
Why might some rooms be ducted even in a plenum system?
To preserve acoustic privacy in sensitive areas like HR or executive offices.
How do acoustics influence ceiling design in open offices?
Drop ceilings diffuse and absorb sound, preventing intelligibility of conversations.
What are key considerations when integrating HVAC and structural systems?
Duct routing must align with structural framing to avoid clashes and maintain efficient layouts.
