The prince George’s sports & learning complex is a large facility with an approximate area of 300,000 square feet which encompasses a variety of areas such as track & field area, gymnasiums, swimming pools, fitness areas, classrooms, offices, snack bar, kitchen, locker rooms and other common areas. Due to the age and physical condition of the rooftop air conditioning units, our scope of work consisted of preparation of construction documents for the replacement of existing roof top air conditioning units, modifications of the HVAC system and replacement of the existing Building Energy Management System.

• Review of existing mechanical and electrical drawings in conjunction  with the information obtained during our site visits and conversation with the maintenance personnel and users assisted us to determine the proper comfort zones in multi zone areas served by a single rooftop unit.

• The drawings show replacement of existing twenty-four (24) constant air volume gas fired rooftop air conditioning units with twenty-four (24) new constant and Variable Air Volume (VAV) gas fired rooftop units. The  constant volume gas fired rooftop units were selected for the open space areas such as track & field area, gymnasiums fitness areas and other common spaces. The variable air volume gas fired roof top units were selected for areas which included various heating/cooling zones served by a single rooftop unit. The existing air distribution system served by the  new VAV rooftop units were modified and VAV boxes with electric reheat coils were added to serve their dedicated zones.

• The dimensions and weights of the new rooftop units were compared with the dimensions of existing rooftop units (including roof curbs and  supports) and their weight. Existing roof supports were reutilized where suited and curb adapters were specified to be used where the dimensions of new rooftop units differed from the dimension of the existing rooftop units.

• Cost estimate for the replacement of the gas fired rooftop units was prepared.