Research on Optimization Design Strategies for Natural Ventilation in Living Units of Institutional Elderly Care Facilities Based on Computational Fluid Dynamics Simulation
Abstract
:1. Introduction
1.1. Natural Ventilation Research
1.2. CFD Simulation Studies Based on Architecture
1.3. Research on Elderly Care Living Facilities
1.4. Research Objectives
2. Analysis of Natural Ventilation Requirements and Extraction of Typical Floor Plans
2.1. Analysis of Natural Ventilation Requirements
- (1)
- Regarding preference for natural ventilation, 100% of the elderly believe that opening windows effectively promotes air circulation, and 97.3% prefer natural ventilation over mechanical ventilation systems. Reasons include discomfort from the cool air of mechanical systems, a personal preference for opening windows, and unfamiliarity with operating mechanical ventilation systems.
- (2)
- Usage of Mechanical Ventilation Systems: Although all elderly residents use mechanical ventilation systems for half an hour daily, this process is managed by staff and the systems are turned off before the residents return to their rooms. In summer, 26% of the elderly extend the use of mechanical ventilation systems to one hour, especially during rainy or humid conditions when natural ventilation is insufficient.
- (3)
- Window- and Door-Opening Habits: In summer, most elderly residents keep balcony doors open all day, even with curtains drawn, as it feels comfortable and does not hinder rest and communication. Some elderly residents close windows and doors at night, and a very small number keep them open for less than six hours due to physical discomfort, mental illness, or mobility issues, relying on staff to manage window operations. In winter, almost all elderly residents open windows for 0–6 h daily, mainly in the morning and after naps, to refresh the air.
2.2. Typical Layout Construction of Elderly Care Living Facilities
- (1)
- Key Influencing Factors in Overall Building Layout:
- (a)
- Traffic Flow Organization: A rational layout ensures comfortable movement for residents and prevents corridors and public areas from becoming barriers to air circulation.
- Functional Zone Division: Scientifically separating living areas from rest areas can manage and guide airflow, enhancing natural ventilation.
- (b)
- Balcony Configuration: Balconies provide additional resting space and are crucial for promoting air circulation. Their design should consider orientation, size, and shading to enhance ventilation.
- (c)
- Room Organization and Air Convection: Room and public space layouts should promote natural air circulation and avoid dead zones. This involves considering aerodynamic characteristics when designing room positions and the orientation of doors and windows.
- (2)
- Main Influencing Factors in Individual Room Layouts:
- (a)
- Room Size and Layout: Proper room dimensions and layouts significantly enhance air convection and temperature control, improving ventilation efficiency.
- (b)
- Door and Window Design: The size, type, and placement of windows and doors directly affect air entry and circulation patterns. Cross-placed windows, for example, can greatly promote cross-ventilation.
- (c)
- Bathroom Ventilation: Proper ventilation design in bathrooms is crucial for overall air quality. Effective exhaust facilities and their placement can prevent humidity and odors from spreading to other areas.
- (3)
- Study Methodology
- (4)
- Findings and Typical Floor Plans
- (a)
- Living rooms on the south side with double rooms on both sides.
- (b)
- Living rooms on the north side with double rooms on both sides.
3. Numerical Model of Indoor Wind Environment under Natural Ventilation
3.1. Measurement Environment and Methods
- (1)
- COS-03 extension-type temperature and humidity sensor (Figure 6) for indoor measurements at a height of 1.1 m, recording every minute;
- (2)
- SWEMA micro anemometer (Figure 7) for measuring ventilation inlet wind speed, recording every 30 s;
- (3)
- Agilent analyzer (main unit 34970A, modules 34901A, T-type copper–copper nickel thermocouples) for measuring the temperature of the building envelope and lighting surfaces (Figure 8), recording every minute;
- (4)
- Handheld weather station (Figure 9) for measuring outdoor wind speed as a supplement.
3.2. Measurement Results and Selection of Operating Conditions
3.3. Validation of Simulation Effectiveness
3.3.1. Room Model Construction and Simplification
3.3.2. Mesh Generation
3.3.3. Governing Equations
3.3.4. Boundary Conditions
3.3.5. Comparison of Simulation Results with Measured Data
3.4. Preset and Validation of Typical Floor Plans
3.4.1. Typical Plan Simulation Preset
3.4.2. Grid Independence Test
3.4.3. Validation of Bathroom Space Exclusion
4. Simulation Analysis of Natural Ventilation in Living Space Units
4.1. Overall Building Layout Simulation Analysis
4.2. Simulation Analysis of Three Key Elements
4.2.1. Floor Plan Organization
- (1)
- Location of Public Living Rooms
- (2)
- Openness of Public Living Rooms
4.2.2. Room Dimensions
4.2.3. External Openings
- (1)
- Symmetrical Window Configuration in Living Rooms
- (2)
- External Opening Area
4.2.4. Ventilation Methods within Living Spaces
4.3. Impact Factors and Improvement Proposals
5. Optimization and Improvement Strategies
5.1. Design Optimization Strategies
5.2. Renovation Optimization Strategies
6. Conclusions
- (1)
- South-facing living rooms improve indoor air quality while enhancing lighting.
- (2)
- Reducing the depth of windward-facing rooms facilitates the entry of fresh air.
- (3)
- Increasing the external opening area, especially horizontally, enhances natural ventilation in breathing zones.
- (4)
- Longer ventilation durations correlate with better air quality.
- (5)
- The relative positions of doors and windows strengthen natural air circulation.
- (1)
- Expanding the study of ventilation factors at different levels: Previous discussions have highlighted the significant impact of various factors on individual buildings. This includes evaluating building siting, surrounding building density, and greenery to select sites with good natural ventilation resources for elderly care facilities. Building form and layout also influence natural ventilation. Designing wind deflectors and thermal chimney ventilation can greatly aid summer ventilation.
- (2)
- Detailed study of window-opening behavior and needs in different seasons and climates: Future research should explore how opening and closing some doors and windows meet ventilation needs in seasons with lower ventilation requirements or under different climate conditions. If natural ventilation is insufficient, the possibility of supplementing with mechanical ventilation should be considered. Managing natural and mechanical ventilation to meet ventilation needs during special climate conditions, such as rain and temperature drops, is also a crucial topic for future research.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Category | Element | Quantity (%) | Typical Form | |
---|---|---|---|---|
Floor Plan Combinations | Traffic Flow Organization | Indoor Corridor | 42 (84%) | |
Outdoor Corridor | 8 (16%) | |||
Functional Layout | North-side Bedrooms | 36 (72%) | ||
North-side Non-Bedrooms | 14 (28%) | |||
Non-Balcony | 32 (64%) | |||
Balcony | 18 (36%) | |||
Room Organization | Direct Entry | 42 (84%) | ||
Staggered Entry | 8 (16%) | |||
Room Layout | Room Type | Double Room | 50 (100%) | |
Common Living Room (Activity Room) | 50 (100%) | |||
Suite | 6 (12%) | |||
External Openings | Single Window | 43 (86%) | ||
Double Window | 7 (14%) | |||
Bathroom Location | Inside | 42 (84%) | ||
Middle Side | 1 (2%) | |||
Outside | 7 (14%) |
Item | Regulation | Typical Floor Plan Dimensions |
---|---|---|
Inner Corridor Width | At least 1800 mm | 2450 mm |
Bedroom Entrance | At least 1200 mm | 1200 mm |
Living Space Area | At least 14 m2/bed | 20.7 m2/bed |
Room Ceiling Height | At least 2600 mm | 2700 mm |
Activity Area per Person | At least 1.2 m2 | 2.1 m2 |
Window-to-Floor Area Ratio | 1:6 | 1:6 |
Category | Variable Element | Details |
---|---|---|
Common Living Room (Activity Room) | Openness, Opening Configuration | Open/Semi-Open/Closed |
Plan Convection Form | Entrance | Directly Facing/Staggered |
Bathroom | Location | Outside |
Room Dimensions | Depth, Room Type | Double Room/Single Room, |
External Openings | Size, Arrangement | Area, Height, Combination |
Additional Features | High Windows, Louvered Windows | Windows above interior doors |
Instrument Name | Measurement Range | Measurement Accuracy |
---|---|---|
COS-03 | −40~80 °C, 0~100%RH | ±0.1 °C (25 °C) ±1.5%RH(60%RH, 25 °C) |
SWEMA Micro Anemometer | 0~10 m/s | 0.05–2.0 m/s: ±(0.05 m/s ± 2% of reading) >2.0 m/s: ±(0.1 m/s ± 2% of reading) |
T-type Thermocouple | −100 °C~400 °C | ±1 °C, Temperature Coefficient 0.03 °C |
Time | Average Entrance Wind Speed/m·s−1 | Average Surface Temperature of Enclosure Structures/K |
---|---|---|
8:45–9:00 | 0.010 | 297.3 |
10:15–10:30 | 0.017 | 298.1 |
12:35–12:50 | 0.015 | 298.5 |
15:50–16:05 | 0.023 | 299.4 |
16:45–17:00 | 0.022 | 298.6 |
Time | Temperature | Wind Speed |
---|---|---|
8:45–9:00 | ||
10:15–10:30 | ||
12:35–12:50 | ||
15:50–16:05 | ||
16:45–17:00 |
Time | Average Euclidean Distance | Average Similarity | Processed Euclidean Distance | Processed Similarity |
---|---|---|---|---|
8:45–9:00 | 0.26 | 0.733 | 0.27 | 0.790 |
10:15–10:30 | 0.48 | 0.633 | 0.22 | 0.821 |
12:35–12:50 | 0.42 | 0.658 | 0.31 | 0.761 |
15:50–16:05 | 0.46 | 0.643 | 0.37 | 0.729 |
16:45–17:00 | 0.51 | 0.621 | 0.25 | 0.799 |
Grid Size | Wind Speed | Air Age |
---|---|---|
0.08 m | ||
0.1 m | ||
0.125 m | ||
0.15 m |
Simulation Status | Wind Speed | Air Age |
---|---|---|
Including | ||
Excluding |
Per Capita Living Area ) | Hourly Ventilation Rate |
---|---|
10 m2 | 0.7 |
10 20 m2 | 0.6 |
20 50 m2 | 0.5 |
50 m2 | 0.45 |
Room Type | Air Age (T) | Evaluation |
---|---|---|
Activity Room (20 People) | T 3600 s | Qualified |
3600 s < T | Not Qualified | |
Elderly Resident Room | T 1800 s | Excellent |
1800 s < T 7200 s | Qualified | |
7200 s T | Not Qualified |
Space Type | Data Type | 1.1 m Height | 1.5 m Height | A-A Cross-Section |
---|---|---|---|---|
South-Side Public Living Room | Wind Speed | |||
Air Age | ||||
North-Side Public Living Room | Wind Speed | |||
Air Age |
Space Type | Data Type | 1.1 m Height | 1.5 m Height | Not Meeting Standards (Grey) |
---|---|---|---|---|
South-Side Public Living Room | Wind Speed | |||
Air Age | ||||
North-Side Public Living Room | Wind Speed | |||
Air Age |
Space Type | Data Type | 1.1 m Height | 1.5 m Height | Not Meeting Standards (Grey) |
---|---|---|---|---|
South-Side Public Living Room | Wind Speed | |||
Air Age | ||||
North-Side Public Living Room | Wind Speed | |||
Air Age |
Space Type | Data Type | 1.1 m Height | 1.5 m Height | Not Meeting Standards (Grey) |
---|---|---|---|---|
South-Side Public Living Room | Wind Speed | |||
Air Age | ||||
North-Side Public Living Room | Wind Speed | |||
Air Age |
Space Type | Data Type | 1.1 m Height | 1.5 m Height | Not Meeting Standards (Grey) |
---|---|---|---|---|
South-Side Public Living Room | Wind Speed | |||
Air Age | ||||
North-Side Public Living Room | Wind Speed | |||
Air Age |
Space Type | Data Type | 1.1 m Height | 1.5 m Height | Not Meeting Standards (Grey) |
---|---|---|---|---|
South-Side Public Living Room | Wind Speed | |||
Air Age | ||||
North-Side Public Living Room | Wind Speed | |||
Air Age |
Space Type | Data Type | 1.1 m Height | 1.5 m Height | Not Meeting Standards (Grey) |
---|---|---|---|---|
South-Side Public Living Room | Wind Speed | |||
Air Age | ||||
North-Side Public Living Room | Wind Speed | |||
Air Age |
Data Type | Height | High Windows | Louvered Windows |
---|---|---|---|
Wind Speed | 1.1 m | ||
1.5 m | |||
Air Age | 1.1 m | ||
1.5 m |
Data Type | Height | High Windows | Louvered Windows |
---|---|---|---|
Wind Speed | 1.1 m | ||
1.5 m | |||
Air Age | 1.1 m | ||
1.5 m |
Factor | Adjustment | Impact on Ventilation |
---|---|---|
Living Activity Room | Enclosed | Slight decrease |
Semi-open | Improvement in central north-side room | |
Plan Convection Form | Staggered | Significant decrease on both sides |
Room Settings | Room Depth | Improvement in south-side rooms and corridors, decrease in north-side rooms |
External Opening Adjustments | Increase Area | Overall significant improvement |
Additional Measures | Internal Openings | High windows superior to louvered windows |
Space Type | Data Type | Design Scheme | Not Meeting Standards (Grey) |
---|---|---|---|
South-Side Public Living Room | Open | ||
Semi-Open | |||
North-Side Public Living Room | Open |
Space Type | Data Type | Design Scheme | Not Meeting Standards (Grey) |
---|---|---|---|
South-Side Public Living Room | Open | ||
Semi-Open | |||
North-Side Public Living Room | Open |
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Share and Cite
Liu, T.; Wang, J.; Zhou, D.; Meng, X.; Luo, X.; Wang, Y. Research on Optimization Design Strategies for Natural Ventilation in Living Units of Institutional Elderly Care Facilities Based on Computational Fluid Dynamics Simulation. Buildings 2024, 14, 1648. https://doi.org/10.3390/buildings14061648
Liu T, Wang J, Zhou D, Meng X, Luo X, Wang Y. Research on Optimization Design Strategies for Natural Ventilation in Living Units of Institutional Elderly Care Facilities Based on Computational Fluid Dynamics Simulation. Buildings. 2024; 14(6):1648. https://doi.org/10.3390/buildings14061648
Chicago/Turabian StyleLiu, Tianye, Jingxian Wang, Dian Zhou, Xiangzhao Meng, Xilian Luo, and Yupeng Wang. 2024. "Research on Optimization Design Strategies for Natural Ventilation in Living Units of Institutional Elderly Care Facilities Based on Computational Fluid Dynamics Simulation" Buildings 14, no. 6: 1648. https://doi.org/10.3390/buildings14061648