Dear fellow Engineers,
I am working on an HVAC project and am looking for guidance on the governing standards and classifications for Air Handling Unit (AHU) casing construction.
My specific question relates to the type of casing construction and if any major standards (like ASHRAE, EN 1886, or regional codes) establish limitations or clear categorizations that dictate the use of one type over another.
- Is there a standard that mandates or recommends a specific casing type based on application, pressure, or hygienic requirements?
- Modular Casing: (Typically bolted sections, thermally broken frame).
- Sectional Casing: (Similar to modular, but perhaps implying smaller field-assembled segments).
- Frameless/Boneless Casing: (Often panel-on-panel construction, potentially with internal reinforcement).
I understand that performance metrics like Thermal Transmittance (T-Class), Thermal Bridging (TB-Class), Air Leakage (L-Class), and Mechanical Strength (D-Class) are defined by standards like EN 1886 and AHRI 1350/1351.
However, does the construction type itself (e.g., modular vs. frameless) have an explicit rating or limitation, or is the choice purely a manufacturer's preference as long as the final unit meets the required performance classes (e.g., D1, L1, T2, TB2)?
Any insights or references to specific clauses in relevant standards would be greatly appreciated.
Thank you in advance for your time and expertise!
AHU Standard
