Air-Source Heat Pump Solutions for Large Shopping Malls
As high-energy-consumption, multi-format complexes, large shopping malls demand extreme stability, flexibility, and energy efficiency from their energy systems. Air-source heat pumps (ASHPs), with their high efficiency, multi-scenario adaptability, and low-carbon features, effectively meet these complex requirements. Below is a comprehensive solution covering application scenarios, equipment selection, and system design:
I. Typical ASHP Application Scenarios in Large Malls
1. Centralized HVAC Cooling/Heating Source
- Demand: Covers tens of thousands of square meters, handles holiday crowd-induced load fluctuations, and meets zoned temperature control needs (stores, cinemas, restaurants).
- Pain Points: High energy consumption from traditional chiller + gas boiler systems; weak zoned temperature control; insufficient winter heating (especially in southern China without centralized heating).
- Solution: ASHPs as primary cooling/heating sources + multi-split systems for localized loads.
2. 24/7 Domestic Hot Water Supply
- Demand: Continuous hot water for kitchen cleaning, restrooms, and staff showers (daily usage: 50–200 tons).
- Pain Points: Gas boilers vulnerable to fuel price volatility; solar systems require large space and perform poorly in cloudy/rainy weather.
- Solution: High-temperature ASHP units (output ≥80°C) + thermal storage tanks, prioritizing off-peak electricity for heating.
3. Waste Heat Recovery in Dining Areas
- Demand: Kitchen exhaust temperatures reach 200–300°C; waste heat from refrigerators/compressors can be recycled.
- Pain Points: Traditional exhaust systems waste energy by directly discharging heat.
- Solution: Heat recovery ASHPs convert waste heat to preheat fresh air or water.
4. Roof Snow Melting & Entrance Anti-Freezing
- Demand: Snow removal on northern mall roofs; ice prevention at entrance ramps.
- Pain Points: Electric heating consumes excessive energy (>500 W/m²); manual snow removal is inefficient.
- Solution: Low-temperature ASHPs (-25°C operation) drive radiant floor pipes for automated snow/ice management.
II. Equipment Selection & Key Technologies
Key Technical Enhancements
- Corrosion Resistance: Titanium/stainless steel evaporators for kitchen areas (resistant to oil fumes).
- Smart Defrosting: Humidity sensors + temperature gradient algorithms minimize unnecessary defrost cycles.
- Noise Reduction: Roof units with silencers + airfoil fans (noise ≤55 dB, compliant with GB 3096).
- Group Control: OPC protocol integration with BA systems for optimized load distribution and start-stop sequences.
III. Universal System Design (Example: 100,000 m² Mall)
System Architecture
[ASHP Host Units]
├─[Ultra-Low-Temp Modular Units] 4×200 kW (primary HVAC, COP≥2.2 at -25°C)
├─[Heat Recovery Multi-Splits] 20 units (restaurants/cinemas)
├─[High-Temp Cascade ASHPs] 2×150 kW (85°C kitchen water)
└─[Thermal Storage Units] 3×100 kW + 80-ton tank (domestic water)
↓
[Distribution System]
├─[Variable-Frequency Secondary Pumps] (HVAC water, with dynamic balancing valves)
├─[Plate Heat Exchangers] (isolate domestic water from HVAC loops)
└─[Waste Heat Pipeline Network] (connects kitchen exhaust/cold storage waste heat)
↓
[Terminal Systems]
├─[Air Handling Units] (main zones, with heat recovery)
├─[Radiant Floor + Air Curtains] (entrance anti-freezing)
└─[Constant-Temp Circulation Pumps] (instant hot water supply)
Operational Strategies
- Load Prediction: Adjust output 30 mins ahead using WiFi/camera-based crowd monitoring.
- Multi-Energy Coupling:
- Gas boiler backup at <-15°C;
- Solar PV prioritizes ASHP power during daytime.
- Waste Heat Cascade Utilization:
- Kitchen exhaust → preheats fresh air to 25°C → excess heat stored in tanks;
- Refrigeration waste → preheats domestic water from 15°C to 30°C.
IV. Cost-Benefit & Reliability
1. Cost Comparison
[Figure]
2. ROI Analysis
- Payback period: 3–5 years (with local clean energy subsidies).
- Carbon reduction: 800–1,000 tons/year per 100,000 m² mall (60% gas replacement).
V. Implementation Guidelines
- Design Phase:
- CFD simulations to optimize rooftop ASHP layout (prevent airflow short-circuiting).
- Dedicated subsystems for kitchens to avoid fouling.
- Installation:
- Roof units elevated ≥30 cm with drainage slopes.
- Refrigerant pipes sloped ≥1% + oil traps every 15 m.
- Maintenance:
- Monitor evaporator pressure drop (alert if >50 Pa).
- Quarterly refrigerant checks (leak detection if deviation >10%).
VI. Case Study
Guangzhou Mall (120,000 m², with supermarket/cinema/dining):
- 6 ultra-low-temp units (2,400 kW cooling / 2,600 kW heating).
- High-temp ASHPs + exhaust heat recovery meet 40% hot water demand.
- Rooftop PV + ASHP microgrid: 25% solar-powered daytime operation.
Results: Annual system COP 4.3, 47% energy savings vs. traditional systems; awarded China’s 3-Star Green Building Certification.
Conclusion
ASHP solutions for large malls focus on “zoned control, multi-energy synergy, waste heat utilization”:
- Ultra-low-temp units handle base HVAC loads; heat recovery multi-splits serve flexible zones.
- High-temp ASHPs + thermal storage resolve kitchen water demands.
- Waste heat from exhaust/refrigeration becomes free energy.
Integrated with smart controls and modular design, these systems maximize lifetime efficiency—ideal for scalable adoption by retail chains.
