1. Common Ventilation Methods for Residential Fresh Air Systems
1.1 Unidirectional Flow Fresh Air System
- Working Principle:
Only an supply fan is installed to deliver outdoor air into indoor spaces. This creates positive pressure, forcing stale air out through gaps in doors/windows via indoor-outdoor pressure differences.
1.2 Bidirectional Flow Fresh Air System
- Working Principle:
Equipped with both supply and exhaust fans. The supply fan introduces outdoor air, while the exhaust fan removes stale air. Pressure conditions (positive/negative) can be adjusted as needed.
2. Equipment for Residential Fresh Air Systems
- Types:
- Standalone Fresh Air Units:
- Wall-mounted (e.g., QL-160, QL-300)
- Cabinet-type (e.g., QL-520, QL-800, QL-300)
- Centralized Fresh Air Units:
- Ceiling-mounted
- Standalone Fresh Air Units:
3. Design and Selection Principles
3.1 Determine Fresh Air Volume
- Follow JGJ/T 440-2018 (Technical Standard for Residential Fresh Air Systems):
- Calculate minimum fresh air volume using air change rate method.
- For heated/cooled buildings, prioritize bidirectional flow systems with heat recovery.
3.2 Select Fresh Air Units
- 3.2.1 Air Purification Requirements:
Choose units with filters matching local outdoor air quality (e.g., ISO35Hz antibacterial filters). - 3.2.2 Unit Sizing:
- Standalone units: Based on fresh air volume.
- Centralized units: Based on fresh air volume and duct resistance.
- 3.2.3 Cold Climate Considerations:
For heat recovery systems in freezing regions:- Verify anti-frost and anti-condensation performance.
- Ensure built-in freeze protection.
- 3.2.4 Electrostatic Filters:
- Ozone emission ≤0.05 mg/m³/h.
- Include power cutoff protection during maintenance.
- 3.2.5 Sensitive Populations:
Use ozone-free physical filters for infants, elderly, or respiratory patients.
3.3 Unit Placement
- Standalone Units: Install near exterior walls/windows.
- Centralized Units: Place in bathrooms, kitchens, or balconies.
- Maintain distance from range hoods/exhaust vents.
- Locate indoor exhaust vents in bathrooms/kitchens.
3.4 Duct and Vent Layout
- Duct Design:
- Prioritize straight ducts with minimal bends to reduce resistance.
- Supply Vents:
- Install in every room, preferably opposite doors or at a distance from them.
- Return Vents:
- Concentrate in high-pollution areas (e.g., kitchens).
4. Standalone Fresh Air Purification Performance Parameters
| Category | Wall-mounted (QL-160) | Wall-mounted (QL-300) | Cabinet-type (QL-520) | Cabinet-type (QL-800) | Cabinet-type (QL-300) |
|---|---|---|---|---|---|
| Model | QL-160 | QL-300 | QL-520 | QL-800 | QL-300 |
| Dimensions (T×W×H, mm) | 168×350×460 | 290×360×1350 | 300×500×1750 | 460×570×1750 | 300×400×1200 |
| Filter Configuration | Nylon pre filter + HEPA/ISO35Hz antibacterial | Washable mesh + G4 pre-filter + P7 medium-efficiency + HEPA/ISO35H antibacterial | Same as left | Same as left | Same as left |
| PM2.5 Efficiency (%) | 99.9 | 99.9 | 99.9 | 99.9 | 99.9 |
| Airflow (m³/h) | 160 | 300 | 600 | 500 | 800 |
| Fan Type | Brushless DC inverter | Brushless DC inverter | Brushless DC inverter | Brushless DC inverter | Brushless DC inverter |
| Noise (dB) | <45 | <50 | <45 | <50 | <50 |
| Power Supply | 220V/50Hz | 220V/50Hz | 220V/50Hz | 220V/50Hz | 220V/50Hz |
| Power (W) | 25 | 90 | 180 | 170 | 260 |
| Weight (kg) | 12 | 35 | 43 | 64 | 120 |
| Heat Recovery | Yes | Yes | Yes | – | – |
| Control Method | Touchscreen + Smart App | Touchscreen + Smart App | Touchscreen + Smart App | Touchscreen + Smart App | Touchscreen + Smart App |
| Recommended Area (m²) | <30 | <100 (residential) | <160 (residential) | <150 (residential) | <200 (residential) |
