Optimizing Control of Dedicated Outdoor Air Systems with Energy Recovery in Commercial Buildings

Energy consumption for ventilation purposes in buildings makes up a considerable portion of HVAC energy consumption. Energy recovery ventilators (ERVs) can reduce the required energy to pre-condition outdoor air in winter and summer seasons. Due to the high ratio of heat transfer area to volume, Fixed-Bed Regenerators (FBRs) can reach high effectiveness up to 90%. However, limited research studies are available for FBRs in HVAC applications. In this paper, a small-scale test facility is used to determine the sensible effectiveness of a FBR. Furthermore, a numerical model is proposed and validated against the experimental results from the small-scale test facility. The numerical results for latent effectiveness have been compared with available data in the literature and the comparison shows a satisfactory agreement between numerical and results from the literature.

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On Decentralized Air-conditioning for Hot and Humid Climates: Performance Characterization of a Small Capacity Dedicated Outdoor Air System with Built-in Sensible and Latent Energy Recovery Wheels

Energy Procedia ◽

10.1016/j.egypro.2015.12.332 ◽

2015 ◽

Vol 78 ◽

pp. 3471-3476 ◽

Cited By ~ 7

Author(s):

Portia Murray ◽

Adam M. Rysanek ◽

Jovan Pantelic ◽

Matthias Mast ◽

Arno Schlueter

Keyword(s):

Air Conditioning ◽

Energy Recovery ◽

Outdoor Air ◽

Performance Characterization ◽

Latent Energy ◽

Air System ◽

Hot And Humid Climates ◽

Small Capacity

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Analysis of the temperature, humidity, and total efficiency of the air handling unit with a periodic counterflow heat exchanger

Thermal Science ◽

10.2298/tsci19s4175j ◽

2019 ◽

Vol 23 (Suppl. 4) ◽

pp. 1175-1185 ◽

Cited By ~ 3

Author(s):

Marek Jaszczur ◽

Marek Borowski ◽

Daniel Satola ◽

Slawosz Kleszcz ◽

Michal Karch

Keyword(s):

Heat Exchanger ◽

Energy Recovery ◽

Energy Use ◽

High Efficiency ◽

Winter Period ◽

Total Efficiency ◽

Outdoor Air ◽

Air Handling Unit ◽

Energy Consuming ◽

Real Value

In this work, thermal, humidity and enthalpy recover efficiency of innovative energy recovery exchanger is presented. The system under analysis allows adjustment of the humidity recovery especially useful in the winter period and forefend energy use for an anti-froze system of energy exchanger. It is shown that the presented method can achieve the real value for humidity and thermal efficiency above 80% and 90%, respectively. Such high efficiency was possible to obtain because the proposed system does not require energy consuming anti-freeze systems. The presented system is able to work even in extremely adverse outdoor air conditions (-20?C and humidity 100%).

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Impact of outdoor air quality on the natural ventilation usage of commercial buildings in the US

Applied Energy ◽

10.1016/j.apenergy.2018.11.020 ◽

2019 ◽

Vol 235 ◽

pp. 673-684 ◽

Cited By ~ 20

Author(s):

Jianli Chen ◽

Gail S. Brager ◽

Godfried Augenbroe ◽

Xinyi Song

Keyword(s):

Air Quality ◽

Natural Ventilation ◽

Commercial Buildings ◽

Outdoor Air ◽

Outdoor Air Quality ◽

The Us

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Comparison of Heat Recovery Ventilator Frost Control Techniques in the Canadian Arctic: Preheat and Recirculation

E3S Web of Conferences ◽

10.1051/e3sconf/202124611010 ◽

2021 ◽

Vol 246 ◽

pp. 11010

Author(s):

Justin Berquist ◽

Carsen Banister ◽

Mathieu Pellissier

Keyword(s):

Energy Recovery ◽

Heat Recovery ◽

Ventilation System ◽

Heat Energy ◽

The Arctic ◽

Control Technique ◽

Outdoor Air ◽

Control Techniques ◽

Advantages And Disadvantages ◽

Heat Energy Recovery

Air-to-air heat/energy recovery ventilators can effectively reduce the cost associated with ventilating a home. However, high indoor moisture levels, in conjunction with extreme temperature differences between the outdoor and indoor air can cause frost accumulation in the mechanical equipment, leading to performance degradation or failure. In this research, a demonstration house using a heat recovery ventilation system in Iqaluit, Nunavut, Canada was used to compare the performance of two frost control techniques: recirculation and electrical preheat. The advantages and disadvantages of each method are outlined to highlight the need to adapt southern strategies to ensure system functionality in the Arctic. The system was equipped with a heat recovery ventilator (HRV) with built-in recirculation technology to defrost the HRV, as well as two electric preheaters that can be used instead of recirculation and prevent frost formation. Between December 2018 and April 2019 the ventilation system’s performance was monitored for seven weeks while using either recirculation or electrical preheat. The experiments showed the ventilation system equipment consumed more absolute energy with electrical preheat than with recirculation as the frost control technique. However, when using recirculation, the ventilation system experienced more losses throughout the ventilation system, causing the whole building to consume more energy due to an increase in energy consumption by the home’s heating system. Moreover, the quantity of outdoor air that was restricted while using recirculation made electrical preheat the superior option for this ventilation system design. The energy use of the ventilation system with electric preheat enabled was 35% lower on a per volume of outdoor air basis. Contrary to some belief that preheating is a poor approach for frost control in heat/energy recovery ventilators, this research finds that preheating can be a more energy efficient method to provide ventilation if controlled well.

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Simulation of energy impact of an energy recovery ventilator in Northern housing

E3S Web of Conferences ◽

10.1051/e3sconf/202124610005 ◽

2021 ◽

Vol 246 ◽

pp. 10005

Author(s):

Jing Li ◽

Radu Zmeureanu ◽

Hua Ge

Keyword(s):

Air Temperature ◽

Indoor Air ◽

Energy Recovery ◽

Energy Use ◽

Energy Savings ◽

Airflow Rate ◽

Outdoor Air ◽

Energy Impact ◽

Core Energy ◽

Air Intake

The single core Energy Recovery Ventilator (ERV) used in this study is equipped with defrost control that recirculates the exhaust indoor air, while keeps the outdoor air intake damper closed. This defrost strategy has the disadvantage of reducing the outdoor air supplied to the house, which may affect the indoor air quality. First, this paper presents new correlation-based models of supply air temperature T2 after the energy recovery core during normal and defrost operation modes based on laboratory experimental data. A pre-heating coil heats the supply air from T2 to indoor air temperature. Second, a house in Montreal (4356 HDD) is simulated as a reference using TRNSYS program. Since the program cannot simulate the operation under defrost mode, the new models are connected in TRNSYS using equation boxes. The energy use of houses at three locations in northern Canada with HDD of 8798 (Inuvik), 8888 (Kuujjuaq) and 12208 (Resolute), are also simulated, without and with ERV unit. The seasonal energy used for heating the house and pre-heating the supply air is compared with results from Montreal. Compared to the case without heat recovery, the ERV unit leads to energy savings: 24% (Montreal), 26% (Inuvik), 27% (Kuujjuaq), and 27% (Resolute). Compared to the minimum standard requirements, the outdoor airflow rate due to defrost is reduced by 4.7% (223 hours) in Montreal, 19% (1043 hours) in Inuvik, 13% (701 hours) in Kuujjuaq, and 24% (1379 hours) in Resolute.

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