Indoor Air Quality in Schools

Florida Elementary School #2

At the second Florida elementary school, issues identified from the conditions audit included low classroom temperatures, high relative humidity levels and operations and maintenance problems. Room temperatures as low as 64oF were measured during the audit visit, with the average temperature of 13 rooms measured at 68.4oF. Monitored temperature and relative humidity data from 7 classrooms during the week after the audit also showed a number of rooms with low temperatures and high RH levels. Dew point temperatures in Florida are commonly well above 70oF, so maintaining rooms at these low temperatures can provide surfaces on which water can condense. Recommended retrofits included:

  • a dedicated outdoor air ventilation system
  • tightening of building envelope/evaluate fan coil leak openings.

The scope and estimated cost of this project made it difficult for the school system to fund the recommendations. However, one of the most pressing issues at this school was the continuing occurrence of mold in two classrooms. In order to resolve this situation, school personnel installed a ceiling mounted dehumidifier for the two classrooms. Pre and post dehumidifier installation conditions were monitored in the classrooms. Post retrofit relative humidity levels were found to be running between 40% and 50% most hours in the two classrooms, which is a significant drop from before the installation. While this retrofit strategy did not provide the school-wide conditions and energy benefits that the more comprehensive retrofit recommendations were designed to provide, the results do indicate that the dehumidifier is effectively controlling humidity in this area of the school. A school board engineer later reported that the dehumidifier was working well and the previous mold problems in the two classrooms have not continued post retrofit.