Tuesday, January 23, 2018, 3:15 PM - 4:45 PM
SEMINAR 50: Low Energy Design Impacts on Peak Heating and Cooling Load Calculations
Track: Fundamentals and Applications
Sponsors: 04.01 Load Calculation Data and Procedures
Chair: Glenn Friedman, PE, Fellow ASHRAE, Taylor Engineering, Alameda, CA
Energy codes like Standard 90.1 and technological change have reduced peak loads significantly. This trend continues in RP 1742, Update to Measurements of Office Heat Gain Data, used in the latest ASHRAE Handbook, Fundamentals volume. This significantly impacts design of HVAC and other building systems and can create a new set of pitfalls. Engineers should recognize these trends and the impact they have on old "rules of thumb." Likewise these trends can have a significant impact on energy modeling and built environment energy use. Tuning existing buildings and systems to take advantage of these trends is a major industry opportunity.
1. Heating and Cooling Load Trends: Down, Down, Down
Steven Bruning, P.E., Fellow ASHRAE, Newcomb & Boyd, Atlanta, GA
As energy codes have evolved over the years since ASHRAE 90-75, their requirements have steadily improved building envelopes and reduced allowable lighting loads. While technology exploded with the advent of personal computers in the early 80's, plug loads resulting from that technology at first significantly increased cooling loads. More recently that trend has reversed with improved technology, thin clients and cloud technology. What impact have these trends had on HVAC design, the old one cfm/sf rule of thumb is literally out the window.
2. Decreasing Internal Loads: Could This Lead to Problems?
Christopher K. Wilkins, P.E., Member, CBR USA, Cambridge, MA.
This presentation reviews the downward trend for internal loads over time, with an emphasis on lighting loads and plug loads. The presentation also discusses the most recent research by TC 4.1 on low energy lighting (LED) and plug load measurements. The presentation also introduces the question of determining the point where lower loads can present system or indoor air quality issues.
3. Low Loads: Reap the Benefits but Read the Fine Print
Manalee Nabar, P.E., Associate Member, Bright Power Inc., New York, NY.
Low loads, both overall and internal plug/lighting are pivotal factors when achieving energy efficient (Passive House, Net Zero, etc.) building design. This presentation first delves into the basic components of heating and cooling loads and examines how different load calculation methods handle the interdependency and time lag between them. Next, strategies to minimize internal loads is discussed. Lastly, common pitfalls in HVAC system sizing due to low loads is discussed and what factors should be kept in mind when specifying equipment.
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ALL ASHRAE committee meetings, including this TC’s meetings at the Winter and Annual Society conferences, are open to the public at no cost nor is conference registration required. Interested visitors, local chapter members, and potential new TC members are always welcome. However to attend technical program sessions sponsored by the TC will require registration and payment of any applicable fee.
Participation in an ASHRAE TC provides the opportunity to grow professionally and to contribute to the advancement of HVAC&R within an international organization recognized for shaping the future of the built environment through research, standards writing, publishing, and education.