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Classroom unit ventilators have been heating, cooling, and ventilating schoolrooms for over half a century. The memory is so deeply imbedded in our national psyche, Norman Rockwell could have painted the scene: snowsodden gloves drying on the units and a snowy hill outside that captures the attention of reluctant students.
Although their end uses sometimes vary from the manufacturers' original intentions (certainly no one would recommend that their airflow become blocked by wet clothing), it is very important that classroom unit ventilators operate as one would expect.
Having performance standards for this equip?ment gives HVAC contractors a basis from which to make equipment selections.
According to Mary Coleman, Marketing-Communications team leader, Trane, "It is important that designers of these systems have accurate information to make system decisions.
"That is why the industry has developed performance standards and certification programs, which ensure that the equipment information provided to the design community is correct and comparable across all the different manufacturers," she said.
Air-Conditioning and Refrigeration Institute (ARI) Standard 840 "ensures that performance data is the most useful to the customer," Coleman said. It offers a consistent method to rate the design performance of the equipment. Moreover, "ARI-840 certification sets a minimal acceptable level of economizer performance."
Certification ensures that the equipment performs up to today's classroom requirements - for comfort, economical operation, and good IAQ. Moreover, "Classroom unit ventilators can be a single-source unit for the multi-functioning school," Coleman said.
"Many schools choose classroom unit ventilators because of their single-source equipment design." ("Single source" in this case means one unit per classroom provides climate conditioning to students and staff.) "By installing one unit - a complete HVAC package - in the classroom, cross contamination between classrooms can be minimized, and with proper filtration, cross contamination can also be eliminated," Coleman said. Floor-mounted models deliver treated air into the classroom without ductwork.
Of primary importance is the health of students and staff at the...