Propoer Load Calculations for High Efficiency Buildings

In most commercial buildings mechanical systems account for nearly fifty percent of the buildings energy use. Being that the mechanical system is responsible for almost half of the total energy consumption of the building, manufacturers have been forced to address different means of achieving a more sustainable product. But first some questions must be answered. These questions include, what are the most demanding loads for the building, what is the criteria for the mechanical system, how does newer more efficient HVAC equipment compare to convention HVAC equipment, what ways can manufacturer use new unconventional designs to accommodate the needs of the building while addressing sustainability.

 

                One of leading factors in unsustainable and inefficient mechanical systems is improper load calculations. This results in under loading or overloading the mechanical equipment. By overloading the equipment, the undersized units have to work harder and need more energy to push the internal motors. By installing equipment that is too large for the application, the unit will cycle on and off more, causing the same amount of energy use as under sizing the unit. To cut down on load consumption, designers must design buildings with the smallest but most efficient unit for the application as well as calculate when peak loads may occur. Traditional methods of calculating heat loads include use general rules or "rules of thumb". With today's technology, designers are depending more on software, especially when designing buildings for sustainability and maximum efficiency. Traditionally system loads were sized by the amount of cooling required per square foot of floor area, which is diffucult and senseless in high performance buildings which require maximum efficiency with minimum energy.  Once the load has been calculated designers must choose what equipment will meet the design intent of the building.