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ASHRAE 62.2 ventilation equation? 1

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carlosgw

Mechanical
Oct 3, 2004
167
Can someone give me the whole house ventilation equation from ASHRAE 62.2-2010? (IP version)
 
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You should get the whole standard. The equation is subject to many clauses, exemptions, reference to tables, clarification, interpretation and judgement by the designer and reviewer from the AHJ etc. It will also come in handy if you are arguing with other parties involved including your client, AHJ, architects, other engineers.
 
Or go to your local library for that reference. Any good size library will have ASHRAE but not necessarily for the year of interest, however, an equation does not get changed too often.
 
I just want to know if it is different than 2013.
 
Assuming you are designing it for someone... you should obtain a copy. How do you make sure you meet all codes? By asking on the internet for snippets and screenshots of the code?
 
Pressurize the building by about 5% (if total normally operating exhaust is 10,000 cfm, you should have a consistent minimum outdoor air of 10,500 under all conditions, regardless of CO2 or other factors), then figure out if the ventilation is acceptable by the current code required 0.06 cfm/ft2 PLUS 5 cfm per occupant standard. You'll usually find that you are okay. If not, increase outdoor air slightly until the 0.06 x 5 standard is met.
 
(l/s-person x total no. person)+) (l/s-m2)* total area in m2
 
Ventilation Rate Procedure
• Most commonly used method
• Lookup table (simple) or Appendix A (complex)
• Need zone air distribution effectiveness
• LEED requires this method

From ASHRAE 62.1 Table 6.1 and 6.2 you get the values:

Ventilation Air (OA) Calculation
Step 1
Vbz = RpPz + RaAz
• Vbz = Breathing Zone OA
• Rp= Outdoor Air Rate per person
• Pz = Zone Population
• Ra = Outdoor Air Rate per unit area
• Az = Zone Floor Area (Net occupiable)

Step 2
Voz =Vbz/Ez
• Voz = Ventilation Outdoor Airflow in the zone
• Vbz = Breathing Zone Outdoor Airflow
• Ez = Effectiveness of the air distribution
 
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