Temporary makeup air heaters facilitate perfect finish
March 1, 2008
To handle increasing enrollment, Lincoln-Way Community High School District, just 40 miles southwest of Chicago, approved the construction of two new 2,500-student high schools. The 414,000-sq-ft Lincoln-Way North High School, situated on a 98-acre site, will be the first to open to freshman, sophomores, and juniors in the fall of 2008.
The plans include construction of 70 classrooms, 17 labs, an auditorium, a field house, a professional-size football field, competition gym, Olympic swimming pool with moveable partition, library and information center, a three-bay shop that will provide automotive service to the public, and daycare for student parents.
All About The FinishTo meet their rigid schedule, Henry Brothers Construction Company (Hickory Hills, IL) needed a temporary air management solution that would allow them to apply finishes without having to fire up the permanent HVAC system. In order to place tile flooring, the concrete had to have moisture content below 5 lb of water per 1,000 sq ft. Based on a referral, they called Steve Lupella and Valerie Taylor of TEMP-AIR, a provider of temporary, portable heating, cooling, dehumidifying, and air filtration services.
According to the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA), use of the permanent HVAC system in an attempt to dry wet surfaces, such as drying recently poured concrete floors or expediting the installation of carpet or wooden floors should not be permitted. Permanent HVAC systems typically are not designed or constructed to perform in such a manner. Such activities may result in subsequent IAQ problems associated with mold and other related airborne contaminants.
Construction heaters are generally not intended to heat the space for worker comfort. The first priority is to control the moisture resulting from construction processes such as concrete curing and fireproofing. Drying will require that the moisture be exhausted, either by infiltration or mechanical ventilation. That’s why, when opening this project for bid, Henry Bros. specifically requested makeup air heaters.
Makeup air is air from the outdoors that is heated and then evenly distributed indoors in a controlled manner to replace the air that is being exhausted. This drier, tempered fresh air has the ability to absorb moisture, and ventilate the toxic fumes from the construction process. It provides lower relative humidity levels and dewpoint temperatures inside the building to prevent condensation and minimize the potential for mold.
TEMP-AIR designed the IAQ proposal for this project for outdoor conditions of 10
Dropping The Pounds“The units were all – located – at the exterior of the building, which allowed us to install the floor finishes on the interior of vestibules and doorways without removing or relocating the units,” said John Tondelli, project manager for Henry Bros.
According to Tondelli, prior to installation of the portable heating equipment, initial readings of the space were between 6 to7 lb of moisture/1,000 sq ft, well above their 5 lb requirement. Within a few weeks of running the TEMP-AIR equipment, readings dropped down to between 3 and 4 lbs, with temperatures averaging 60°.
“By utilizing makeup air heating units, the humidity levels helped establish permanent conditions for various finishes to be installed, such as – cabinetry, painting, vinyl composition tile, and wood flooring.” The units performed well enough that the same process will be repeated for Lincoln-Way West High School, opening the fall of 2009. ES