The required internal summer ventilation rate should be at least 10 times
greater than the minimum continuous rate. This is the prescriptive approach
of the American Society of Heating, Refrigerating and Air-Conditioning
Engineers (ASHRAE); current ventilation standards are America National
Standards Institute (ANSI) and are ANSI/ASHRAE Standard 62–2001
(ASHRAE, 1999) plus ASHRAE BOD approved for publication Addenda
and ASHRAE Standard 62.2-2003 (ASHRAE, 2003). In fact, these documents
provide techniques to establish minimum ventilation requirements
(liter/sec) per person or per surface unit (liter/sec per m2), but the minimum
values must be specifi cally estimated according to specifi c conditions, such
as internal and external temperature, relative humidity, and recommended
CO2 (or a specifi c targeted pollutant) concentration. Anyhow, just to give
an order of magnitude, the continuous rate may be 10 liter/sec per person,
at 22°C and 40% relative humidity. ASRHRAE standards may be a useful
start-up approach for each food industry internal environment, if the gasproblem
concentrations within the building must be kept at a known level
during the summer in a properly designed facility. It worth reminding that
the creation of ASHRAE standards and guidelines are recommendations,
determined solely by their usefulness, hence, the conformance to them so
far is completely voluntary.