HVAC Refresher - Facilities Standard for the Building Services (Part 1)
A. Bhatia, B.E.
HVAC systems must be selected to routinely address multiple program goals, including: workplace performance, sustainability, energy efficiency, security, fire safety and operations/maintenance concerns, as well as other project expectations. Design solutions shall not sacrifice the basic needs of one program area to optimize another. Instead, designs must address a consistent design approach to the extent possible, assuring attainment of all critical performance goals.
This 4-hr course
sets out the criteria that describe a quality system along with key design and
The course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.
At the conclusion of this course, you will refresh:
This course is aimed at students, mechanical and HVAC engineers, architects, building designers, health & safety engineers, energy auditors, building service engineers, facility managers and general audience.
The HVAC system design is typically based on criteria, factors, and details recommended in the ASHRAE Handbook. The design should be conservative while providing acceptable operation with normal decreases in operating efficiency and average maintenance. Unnecessary complications to achieve ideal conditions under all operating extremes should be avoided. Heat loss and heat gain estimates are part of a design procedure that flows from system selection decisions, the actual load calculations, to equipment selection procedures, to placement and selection of air distribution hardware, to duct routing and airway sizing.
HVAC design in
general can either be described in the prescriptive method where the design
must meet specific criteria of equipment specifications or it can be based on
the system performance method which focuses on meeting the operational efficiencies
with minimum maintenance.
The course reviews the above items in detail and is followed by course summary and multiple - choice quiz at the end.
The course content is in a PDF file HVAC Refresher - Facilities Standard for the Building Services (Part 1). You need to open or download this document to study this course.Course Summary
a new building, designers and owners should take a high performance design approach.
A high performance HVAC design approach considers five steps:
1) Size the HVAC system correctly (right size). Oversized equipment costs more to operate and it will not run as efficiently as properly sized system. Do not specify larger HVAC equipment than needed in anticipation of a future building expansion. Instead, incorporate space to add HVAC capacity, if needed.
2) When selecting equipment, evaluate how it performs when operating at part load, not fully loaded. HVAC equipment is designed to operate at peak rated efficiency only when it is operating fully loaded. However, most HVAC equipment operates fully loaded only 1 percent to 2.5 percent of the time. In fact systems operate at 50% or less of their capacity.
3) Design distribution systems (ductwork or piping) that reduce pressure losses. This choice results in smaller pumps and fans and lower operating costs.
4) Use integrated control systems to operate the HVAC system. These control systems will help meet fluctuating HVAC loads efficiently by coordinating system operations. A direct digital control (DDC) system also offers more information feedback for control decisions and more precise control.
5) Commissioning the HVAC system: This step tests the system under all aspects of operation before the building opens for business. It identifies problems and ensures the system is operating as intended.
A building envelope's thermal performance determines HVAC equipment choices and sizing. If the elements of building's envelope and interiors such as lighting & equipment are selected with energy efficiency in mind, then the HVAC system can be smaller. Also when the HVAC system is sized properly, a building's owner will incur lower equipment costs up front as well as potentially lower operating costs over the equipment's lifetime.
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.