Tuesday, January 31, 2017: 8:00 AM-9:30 AM
HVAC&R Systems and Equipment
Chair:
Frank Shadpour, P.E., SC Engineers, Inc.
This session examines multiple issues related to residential energy efficiency using laboratory results and modeling studies. Air conditioners are typically evaluated using SEER ratings based on performance measurements made across a very limited range of conditions. Measurements made across a much wider range of conditions are presented to help understand how variable capacity systems perform. Another paper discusses the impact of different mechanical ventilation systems used in multi-family buildings on building aesthetics, capital cost, annual energy cost, systems and equipment maintenance, and green construction rating impact. A method using singular value decomposition is introduced to reduce the computation time needed to carry out comprehensive energy optimization studies for residential buildings is introduced and used to perform case studies on a building in six different U.S. locations. Another study looks at the impact of various retrofits and air conditioner upgrades in Saudi Arabia. The final presentation finds differences of as much as +/- 50% in the annual electricity and gas use for the same house calculated by four widely used energy modeling programs and explores reasons for these differences.
1 Building Impacts of Code Compliant Ventilation in Multi-Family Dwellings (LV-17-C051)
Recently the majority of multi-family residential buildings have satisfied the ventilation requirements of the dwelling units via natural ventilation and have not provided an additional means of mechanical ventilation. Changes to ASHRAE Standard 62.1 and the adoption of those changes into local codes require multi-family dwelling units to be mechanically ventilated. This paper evaluates systems and equipment available to meet the code mandated mechanical ventilation requirements and discusses the impacts of the selection on the building. Areas of impact evaluated are building aesthetics, capital cost, annual energy cost, utility billing structure, building space requirements, systems and equipment maintenance and green construction rating impact.
2 Life Cycle Cost Optimization of Residential Buildings (LV-17-C052)
The optimization of energy efficient housing is a highly complex problem involving hundreds of parameters due to the many options that exist at the time that a building is being designed. To perform the optimization in an acceptable time frame, singular value decomposition is used to reduce the number of design variables by identifying those that contribute most strongly to the optimization problem. A case study of residential buildings in six separate locations across the U.S. is performed and the results are discussed.
3 Investigation of Potential Energy Savings in Retrofitting a Residential Building at Riyadh's Weather Conditions (LV-17-C053)
Recent official statistics have shown that Saudi Arabia electricity consumption growth rate at 7%. Buildings primary energy consumption and electricity consumption are 23% and 80%, respectively. This trend of high energy consumption is expected to rise in the upcoming few years. According to governmental statistics, 70% of the buildings in Saudi are not insulated. Furthermore, most of the air-conditioners in existing buildings were installed before enforcing minimum performance standards on air-conditioners. In this paper, an uninsulated existing residential building model was developed and validated against utility data.
4 Real-World Assessment of Three Residential Variable Capacity Air Conditioners of Varying SEER (LV-17-C054)
Variable capacity technology is a core feature in high efficiency air conditioners available in the residential, ducted market. Residential variable capacity air conditioners are available in a range of Seasonal Energy Efficiency Ratios (SEER), exceeding the federal minimum levels. Energy efficiency program implementers seek to understand the efficiency impact of variable capacity systems for their climates and applications. Program implementers seek guidance on structuring their programs based on available industry ratings. This report examines the performance of three variable capacity systems of varying SEER over a range of real-world operating conditions, away from the current standard testing conditions for SEER.
5 Comparison of Building Energy Simulation Models for Residential Homes (LV-17-C055)
Annual energy consumption of a 1200 square foot residential home was modeled using four energy modeling programs: CBECC-Res, BEopt, EnergyPro, and REM/Rate. A baseline house was developed that met California Title 24 Standards, and both slab and crawlspace foundations were considered. The baseline house was additionally modified to have non-compliant (lower-efficiency) inputs, as well as advanced-efficiency inputs, for parameters including insulation, window properties, HVAC system efficiencies and air infiltration. For given set of inputs, the four models produced significant variations in calculated annual electricity and natural gas consumption with differences as high as +/- 50%.