287-291 Lafayette Street - letter from engineer regarding HVAC Design 3.14.2017BLW ENGINEERS, INC.
BLW ENGINEERS, INC.
311 GREAT ROAD, LITTLETON, MA 01460
P.O. BOX 1551 LITTLETON, MA 01460
P. 978.486.4301 F.978.428.0067
MEMORANDUM
DATE: March 14, 2017
TO: John A. Seger, AIA, Seger Architects, Inc.
FROM:
Bill Scanlon - PE, BLW Engineers, Inc.
SUBJECT: Salem State University Temple Conversion– HVAC Systems
COPIES TO: File
The existing HVAC system at the former Temple was hot water boilers for heating and packaged roof top
unit and split air conditioning units for cooling. The existing systems before the renovation did not meet
code ventilation or energy requirements and did not provide cooling throughout the building.
Systems evaluated for the project was as follows:
1) Fan coils with chill water and hot water systems with roof mounted energy recovery ventilation
system – Fan coil system was evaluated for renovation at the Temple Conversion. Heating would
be provided through the existing hot water boiler and air cooled chiller would be added to provide
cooling. Chill water and hot water would be distributed throughout the building to fan coils. A
roof mounted dry cooler would be required to provide code required economizer. A roof
mounted energy recovery roof top unit with packaged cooling and gas heating would provide the
code required ventilation.
This system was not selected because of the amount of exterior equipment required, the size of
the exterior equipment, the acoustic output of the equipment. The limited roof area where the
systems could be installed and the limited area around the perimeter of the building and the
property lines and resident houses were also other factors why this system was not selected.
2) Variable refrigerant system (VRF) with roof mounted energy recovery ventilation system –The
VRF system was evaluated for renovation at the Temple Conversion. Heating and cooling would
be provided through the VRF heat pump system. A roof mounted energy recovery roof top unit
with packaged cooling and gas heating would provide the code required ventilation.
This system was not selected because of the large amount of exterior equipment required, the size
of the exterior equipment, the acoustic output of the equipment. The limited roof area where the
systems could be installed and the limited area around the perimeter of the building and limited
area to the property lines and resident houses were also other factors why this system was not
selected.
3) Packaged Roof Top Units – The packaged rooftop unit system was evaluated for the renovation at
the Temple Conversion. The existing roof top unit would be reused and a new packaged roof top
unit would be added to provide heating, cooling and ventilation throughout the spaces to meet
applicable code requirements. Economizer would also be provided through the rooftop controls.
BLW ENGINEERS, INC.
BLW ENGINEERS, INC.
311 GREAT ROAD, LITTLETON, MA 01460
P.O. BOX 1551 LITTLETON, MA 01460
P. 978.486.4301 F.978.428.0067
This system was selected by the owner because it met all the space requirements and met the
heating, cooling and ventilations requirements. Also the existing roof top system/hot water
boilers would also be reused.
During the design, multiple roof tops were evaluated which included flat rood area, equipment
size, equipment clearances, supply and return ductwork and OSHA safety requirements. BLW
found that (2) roof top units would fit within the existing space available.
The existing roof top unit, new roof top unit and supply and return ductwork were located on the
available roof area to meet OSHA safety requirements and equipment clearances. This system
was not installed at ground level because of the limited area around the perimeter of the building
and limited area to the property lot lines and resident houses.