Abstract
The adoption of energy-efficient standards significantly cut the energy consumption in buildings by reducing envelope heat transfer and internal heat gain. These energy efficiency measures reduce not only the electrical load, but also the cooling load as well as the supply airflow rate. On the other hand, a minimum airflow rate is always required for all building types. As a result, additional reheat is typically required to maintain the minimum airflow set point under partial spacecooling loads for conventional air-handling units (AHUs) and may degrade the effectiveness of energy efficiency measures. The AHUs with return-air bypass (RAB) provides an alternative to reduce additional reheating and overcooling at the minimum airflow rate with good space humidity control. However, because of insufficient performance data, the AHUs with RAB are still notwidely applied. The purpose of this study is to investigate the energy and control performance of the AHUs with RAB under differen to perating conditions through simulations. First, the AHU thermodynamic models and simulation approaches are developed, and then the system performance, including reheating and cooling loads and space humidity, is simulatedon apseudo-AHU. Thesimulation results reveal that the studied AHU with RAB can wellmaintain the desired space humidity without the additional reheating and overcooling as the space cooling load varies from 100% to 15% and space sensible heat ratio varies from 0.9 to 0.7.
| Original language | English (US) |
|---|---|
| Title of host publication | ASHRAE Transactions - 2017 ASHRAE Annual Conference |
| Publisher | Amer. Soc. Heating, Ref. Air-Conditoning Eng. Inc. |
| Pages | 229-239 |
| Number of pages | 11 |
| Volume | 123 |
| ISBN (Electronic) | 9781939200778 |
| State | Published - Jan 1 2017 |
| Event | 2017 ASHRAE Annual Conference - Long Beach, United States Duration: Jun 24 2017 → Jun 28 2017 |
Other
| Other | 2017 ASHRAE Annual Conference |
|---|---|
| Country | United States |
| City | Long Beach |
| Period | 6/24/17 → 6/28/17 |
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ASJC Scopus subject areas
- Building and Construction
- Mechanical Engineering
Cite this
Energy and control performance investigation of air-handling units with return-air bypass. / Wang, Gang; Zheng, Xuejing; Song, Li; Andiroglu, Esber.
ASHRAE Transactions - 2017 ASHRAE Annual Conference. Vol. 123 Amer. Soc. Heating, Ref. Air-Conditoning Eng. Inc., 2017. p. 229-239.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Energy and control performance investigation of air-handling units with return-air bypass
AU - Wang, Gang
AU - Zheng, Xuejing
AU - Song, Li
AU - Andiroglu, Esber
PY - 2017/1/1
Y1 - 2017/1/1
N2 - The adoption of energy-efficient standards significantly cut the energy consumption in buildings by reducing envelope heat transfer and internal heat gain. These energy efficiency measures reduce not only the electrical load, but also the cooling load as well as the supply airflow rate. On the other hand, a minimum airflow rate is always required for all building types. As a result, additional reheat is typically required to maintain the minimum airflow set point under partial spacecooling loads for conventional air-handling units (AHUs) and may degrade the effectiveness of energy efficiency measures. The AHUs with return-air bypass (RAB) provides an alternative to reduce additional reheating and overcooling at the minimum airflow rate with good space humidity control. However, because of insufficient performance data, the AHUs with RAB are still notwidely applied. The purpose of this study is to investigate the energy and control performance of the AHUs with RAB under differen to perating conditions through simulations. First, the AHU thermodynamic models and simulation approaches are developed, and then the system performance, including reheating and cooling loads and space humidity, is simulatedon apseudo-AHU. Thesimulation results reveal that the studied AHU with RAB can wellmaintain the desired space humidity without the additional reheating and overcooling as the space cooling load varies from 100% to 15% and space sensible heat ratio varies from 0.9 to 0.7.
AB - The adoption of energy-efficient standards significantly cut the energy consumption in buildings by reducing envelope heat transfer and internal heat gain. These energy efficiency measures reduce not only the electrical load, but also the cooling load as well as the supply airflow rate. On the other hand, a minimum airflow rate is always required for all building types. As a result, additional reheat is typically required to maintain the minimum airflow set point under partial spacecooling loads for conventional air-handling units (AHUs) and may degrade the effectiveness of energy efficiency measures. The AHUs with return-air bypass (RAB) provides an alternative to reduce additional reheating and overcooling at the minimum airflow rate with good space humidity control. However, because of insufficient performance data, the AHUs with RAB are still notwidely applied. The purpose of this study is to investigate the energy and control performance of the AHUs with RAB under differen to perating conditions through simulations. First, the AHU thermodynamic models and simulation approaches are developed, and then the system performance, including reheating and cooling loads and space humidity, is simulatedon apseudo-AHU. Thesimulation results reveal that the studied AHU with RAB can wellmaintain the desired space humidity without the additional reheating and overcooling as the space cooling load varies from 100% to 15% and space sensible heat ratio varies from 0.9 to 0.7.
UR - http://www.scopus.com/inward/record.url?scp=85041458233&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85041458233&partnerID=8YFLogxK
M3 - Conference contribution
VL - 123
SP - 229
EP - 239
BT - ASHRAE Transactions - 2017 ASHRAE Annual Conference
PB - Amer. Soc. Heating, Ref. Air-Conditoning Eng. Inc.
ER -