Ten Minutes With Conservation Goals Continue to Push HVAC Designers
OAs LEED has developed into the norm, some of the sustainable elements employed have become so common as to be pedestrian and expected, such as alternate refrigerants, better filtration, and low-flow fixtures.
The team-based ‘design charette’ process within LEED often leads to some very creative solutions. The most interesting sustainable element we have installed is an ice thermal storage system where ice made at night is used the following day to cool the building. Our design went one step farther, using the heat rejected from the making of ice to heat another building in the off-hours. The process came to be known as ‘freeze-heat pumping.’
Another example of sustainable design is a mixed use project with each use having different cooling and heating load profiles. The system uses the heat rejected from a large grocery store refrigeration system to heat residential units, resulting in savings for both.
How do solutions like BIM help?
For years we have taken advantage of 3D drafting software at the detailing and coordination phase of the project. This reduces conflicts with other trades and saves on installation costs. The 3D drafting software also downloads directly to our automated sheet metal manufacturing equipment. AutoCAD Revit MEP (2010 release) is our BIM software of choice, and we expect it to continue to evolve.
Now more equipment suppliers are adding BIM objects, which reduces the design time for us. However, the cooling and heating load module in Revit MEP still requires the designer to input glass and wall thermal performance (U-factors), even if the architect has input the wall assemblies in their Revit Architecture model.
BIM contributes greatly to the success of a project, according to participating companies, by having all parties immersed in the same communication medium. BIM has another positive consequence in that in order to be successful the team must be formed early in a project, providing opportunities for superior collaboration.
With the stress on conservation, how is your business changing?
Every new set of codes is more stringent than the last, forcing architects and developers to consider conservation from initial conception of a project. This has brought the design of mechanical systems to the fore along with a tighter building envelope. With our design/build expertise honed over the past 30 years, we are on the team often before the general contractor has been selected. Accurate cost estimates of the various options in the conceptual stages permit better decision-making up front, with fewer changes as the design and engineering get more detailed. The team can focus on designs that will not only meet the code, but provide the payback needed to make the project a success.
What do you think will be the biggest change in five years?
Continued pressure from government and utilities to reduce consumption of our natural resources will mean that every building will be upgraded or replaced in the next five to ten years.
Because we are on the cutting edge of sustainable design of mechanical systems, we will be working hand-in-hand with the architect and owner to take advantage of every rebate, tax credit, and innovation in design to make these buildings energy-smart.