Indoor Air Quality and Ventilation Standards Flashcards

In the ASHRAE 62.1 Ventilation Rate Procedure, how is breathing zone outdoor airflow (Vbz) calculated?

Answer: Vbz = Rp·Pz + Ra·Az

Vbz sums a people component (Rp × zone population) and an area component (Ra × zone floor area).

Per ASHRAE 62.1, what are the default people and area outdoor air rates for a typical office space?

Answer: 5 cfm/person and 0.06 cfm/ft²

Table 6-1 of 62.1 lists office space at Rp = 5 cfm/person and Ra = 0.06 cfm/ft².

What zone air distribution effectiveness (Ez) does ASHRAE 62.1 assign to ceiling supply of warm air at least 15°F above space temperature with ceiling return?

Answer: 0.8

Warm air supplied and returned at the ceiling tends to stratify, so 62.1 assigns Ez = 0.8.

In a multiple-zone recirculating system under ASHRAE 62.1, how is occupant diversity (D) defined?

Answer: System population divided by the sum of peak zone populations

D = Ps / ΣPz, reflecting that not all zones peak at the same time.

Which ASHRAE 62.1 compliance path lets a designer reduce outdoor air by using air cleaning, based on contaminant mass balance and target concentrations?

Answer: Indoor Air Quality Procedure

The IAQ Procedure is performance-based and credits air cleaning toward meeting contaminant limits.

Under ASHRAE 62.1, what minimum separation distance is required between an outdoor air intake and a Class 4 air exhaust outlet?

Answer: 30 ft

Table 5-1 requires 30 ft separation from Class 4 (highly objectionable) exhaust.

ASHRAE 62.1 requires mechanically cooled systems to limit space relative humidity to what maximum at the peak outdoor dew point design condition?

Answer: 65%

Section 5.9 sets a 65% RH limit to reduce microbial growth risk.