ASHRAE STANDARD 62-2001 PDF
ANSI/ASHRAE Standard (Including ANSI/ASHRAE Addenda listed in Appendix H). Ventilation for Acceptable. Indoor Air Quality. Ventilation standards and mechanical codes have evolved to address ASHRAE Standard (2). Ventilation for .. ASHRAE Standard The Ventilation Rate Procedure found in ASHRAE Standard Addendum N was applied to Monmouth University’s Multipurpose Athletic.
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The statement below merely indicates that human body odor will most likely be acceptable if the conditions above are true. Using the steady-state model described in Appendix C of the Standard, 15 CFM per person would be the resulting quantity of outside air introduced into a space if a.
In addition, the section should strongly encourage the use of airflow measuring devices in critical zones of VAV systems for the continuous calculation and reset of the multi-space equation defined in section 6.
Providing permanently mounted airflow measuring stations would also support the requirements set forth in 7. It is unlikely that all contaminants of concern will be evaluated or reduced to acceptable levels. The allowable contaminant concentration in the occupied zone can be used with various system models in Appendix [D] to compute the required outdoor air flow rate. It incorporates both quantitative and subjective evaluation. The critical space is that space with the greatest required fraction of outdoor air in the supply to this space.
At the writing of this document, addendum x was still under public review.
Ventilation code enforcement has proven to be difficult because it is often misunderstood by the code enforcement agency in the local jurisdiction. Conversely, “When contaminants are generated in the space or conditioning system independent of occupants or their activities, supply of outdoor stsndard should lead occupancy so that acceptable conditions will exist at the start of occupancy.
Interpretations for Standard 62-2001
Other potential contaminants for which definite limits have not been set are discussed in Appendix B. HVAC system control strategies that ignore this relationship have inherent pressurization problems. However, there are numerous risks associated with both the quantitative and subjective evaluations provided within the procedure that every designer should be aware of.
The Ventilation Rate Procedure is a rate based standard. Anything that changes the pressurization flow will result in fluctuations in building pressure. Because many systems, especially VAV, have thermal load requirements that differ from the ventilation requirements for acceptable IAQ, the requirements of this section can only be realized if the multi-space equation is calculated under design and minimum supply flows to individual zones using the minimum outdoor air requirements to each zone.
Standard 62 has been incorporated into many building codes. Outside airflow rates can also be reduced if the critical zones have variable occupancy. The Ventilation Rate Procedure “prescribes the rate at which ventilation air must be delivered to a space and various means to condition that air. The calculation requires that the total supply airflow rate measured, QSA, usually with an airflow measuring station in the total supply air circuit and the airflow rate of the critical zones is measured with an airflow measuring station capable of accurate measurement.
Once more the Standard attempts to clear up the misunderstandings about CO2. The assumptions made to conclude that a 15 CFM per person rate is actually maintained when the ppm rise is detected are considerable.
ASHRAE Standard | Midwest Air Filter
Section 6, Procedures, is the heart of the standard. Recirculation criteria are defined in 6.
Present motivation to design to the standard has been driven mostly by liability and risk management concerns and in some cases the desire of the design professionals to meet their obligation by designing to national, professional standards. In such cases, twice the amount of outside air as indicated in Table 2 would be required for acceptable indoor air quality.
Interpretations for Standard
VAV systems with fixed outdoor air damper positions may not meet this requirement. The alternate Indoor Air Quality Procedure “uses one or more guidelines for the specification of acceptable concentrations of certain contaminants in indoor air but does not prescribe ventilation rates or air treatment methods.
Not requiring airflow measurement is analogous to ignoring the requirement for temperature measuring devices to maintain automatic temperature control.
Rates can be determined either directly using airflow measuring devices or indirectly by other means i. Great care should be given to the selection between these procedures.
In reality, this latter scenario describes most facilities and suggests that outside airflow rates are directly set by the HVAC system based on standzrd parameters, prior to occupancy.
Ashgae, maintenance of minimum outdoor airflow defined in section 6 essentially requires the use of permanent devices capable of maintaining outdoor airflow rates for compliance. Airflow sensors provided with VAV boxes should not be used for this calculation. Moisture is a prerequisite for mold and fungal growth and the condition should be avoided.
Also, caution should be exercised when reducing outside airflow rates since outside air is required to maintain proper building pressure.
Whether or not it explicitly requires airflow measuring devices or not is irrelevant. The system outdoor air quantity shall then be determined using Equation see References 23 and The scope of Standard 62 “applies to all indoor or enclosed spaces that people may occupy, except where other applicable standards and requirements dictate larger amounts of ventilation than this standard.
Addendum u was approved for incorporation into the parent document at the ASHRAE winter meeting in January and adds a new section, 5. If approved, it will replace the entire Ventilation Rate Procedure in the parent document. According to this section, “Under the ventilation rate procedure, for other than intermittent variable occupancy as defined in 6. It is important to recognize that if the building is altered or its use is changed, the ventilation system must be reevaluated.
Recirculation with air-cleaning systems is also an effective means for controlling contaminants when using the Indoor Air Quality Procedure.