Cooling systems to be analyzed for proposed Saugus school – Wicked Local Saugus

Mike Gaffney saugus@wickedlocal.com @saugusnews

A subcommittee has tasked an engineering firm to evaluate the effectiveness of different cooling systems for the proposed high school/middle school project.

On March 13 Dominick Puniello of Garcia Galuska DeSousa Consulting Engineers, Inc. presented the Systems Subcommittee with a number of HVAC system options for a combination high school and middle school.

Lori Cowles, the project director for HMFH Architects, Inc., said the time has come to think about the mechanical systems in the proposed high school/middle school complex.

Puniello delved into the pros and cons for each cooling system to allow subcommittee members to decide which ones should be studied as part of a life cycle cost analysis.

Displacement ventilation is a cooling system that Garcia Galuska DeSousa is a proponent of, Puniello said. These systems use naturally occurring buoyant flow within a space to create the vertical rise of air, he explained.

Puniello said advantages of displacement ventilation include excellent pollution removal, low noise, low air velocity, low moisture levels, reduced initial cost and high ventilation effectiveness.

Disadvantages associated with displacement ventilation are the system requires perimeter radiation heating and perimeter radiation cooling to maintain full air conditioned set points during peak cooling, Puniello said.

Highland Avenue resident Ed LaSala expressed concern about exhaust from nearby Route 1 and whether a displacement system would filter out all of the carbon dioxide coming from vehicles.

Puniello also discussed induction systems that use chilled beam units to provide cooling. This type of system can be used in conjunction with displacement to bring room temperatures down a few degrees, he said.

With induction, room air is induced through heating and cooling coils.

Some of the pros for induction are that the process is energy efficient, the noise is low, flexibility of installation, a moderate initial cost, simplified controls and lower maintenance, Puniello said. Cons include the fact induction requires increased coordination with a ceiling system (such as additional piping), it needs additional ventilation air in some cases and increased energy consumption compared to a dehumidified system.

During his presentation Puniello brought up the possibility of a geothermal HVAC system, which involves drilling small holes into the ground and utilizing plastic tubes in the ground to heat and cool the building.

While geothermal plants are viewed as environmentally friendly options that are durable, subcommittee members questioned the expense of implementing such a system and whether it would be cost prohibitive.

Another cooling system the subcommittee focused on was variable flow refrigerant, or VRFs, which use refrigerant to heat and cool structures.

Puniello said pros for VRFs include the same unit can be used for heating and cooling, low piping installation costs and a reduced boiler plant size. Disadvantages can include higher noise levels, quarterly filter changes and maintenance of equipment in an occupied area, he noted.

The subcommittee directed Puniello to investigate four different cooling options as part of a life cycle cost analysis. They include partial air conditioning/displacement; full air conditioning through displacement ventilation; displacement for ventilation and adding chilled beams for full air conditioning; and doing everything by active chilled beams.

These options will be compared to a baseline system to estimate how much can be saved over a 40-year period, Puniello said.

When it comes to cooling systems people often want full air conditioning because they believe thats the way the school will be most comfortable, Cowles said. However, she pointed out full air conditioning has a cost implication to it.

Maybe we look at displacement and forms of air conditioning that can be spun off of that, Cowles said.

Saugus High School Principal Mike Hashem said the building auditorium will probably need to be air conditioned. He added that it would be nice to have a way to cool the gymnasium that can become stifling when crowded.

For a girls basketball game it was close to 100 degrees during the game, Hashem said.

Hashem said he would like to see a cooling system in place that allows classrooms to be comfortable if the temperature is 95 degrees and humid.

As long as its a comfortable learning environment throughout the year, thats what is important, Hashem said.

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Cooling systems to be analyzed for proposed Saugus school - Wicked Local Saugus