Lin'an Central Urban Area New China Telecom Building and Office Building Project

Hangzhou Lin'an/Office Building

Ultra-Low Energy Consumption Building Design Stage Certification

Source｜Zhonghan Design Group Co., Ltd.

 

 

Project Overview

 

The Hangzhou Lin'an Central Urban Area zx-03-10 plot (New China Telecom Building and Office Building Project) has a total construction area of 12,535㎡, 11 floors above ground, and is expected to be completed in 2026.

 

Ultra-Low Energy Consumption Building Certification

 

Site Plan

 

Energy-Saving Design Goals

 

This project is located in a hot-summer and cold-winter climate zone. Through simulation calculations, the project actually achieves:

• Building Comprehensive Energy Saving Rate 51.75%
• Building Body Energy Saving Rate 39.47%
• Renewable Energy Utilization Rate 24.72%

 

 

Key Technology System Analysis

 

Architectural Design

 

The site layout makes full use of the site's natural resources. In summer and the transition seasons, the building wind field has good ventilation at pedestrian height, with no large-area wind shadow or stagnant areas, and the wind speed is appropriate, which is conducive to summer ventilation and winter wind prevention; by optimizing the area and type of exterior windows, the natural lighting and ventilation effects indoors are ensured.

 

Architectural Form Diagram

 

High-Performance Enclosure Structure Design

 

Exterior Wall System: Uses 100mm thick rock wool external insulation (heat transfer coefficient K=0.40 W/(㎡·K)), and is supplemented by 50mm inorganic lightweight aggregate insulation board, forming a double insulation layer structure.

 

Technical Points: The high fire-retardant performance (Class A non-combustible) of rock wool is combined with the crack resistance of inorganic insulation board, ensuring both safety and durability.

 

Exterior Window System: Uses triple-glazed double-cavity hollow glass (5+12A+5+12A+5), with double-silver Low-E coating and heat-insulating aluminum alloy profiles, with an overall heat transfer coefficient K=1.80 W/(㎡·K).

 

Technical Points: The double-silver Low-E coating selectively transmits solar radiation, blocking heat from entering in summer and reducing indoor heat loss in winter, achieving dynamic energy saving.

 

Roof Structure: Both planted roofs and ordinary roofs use XPS extruded polystyrene board (K=0.25 W/(㎡·K)), but planted roofs additionally add waterproof, drainage, and vegetation layers, which improves insulation performance and alleviates the urban heat island effect.

 

Dry-Hung Exterior Wall Node Detail

 

Fine-Grained Thermal Bridge-Free and Airtightness Control

 

Airtightness Measures: A continuous plastering layer is set on the inner side of the exterior wall as the main airtight layer. Waterproof and vapor-permeable membranes are used for double sealing at window and door openings, and sleeves are reserved at pipe wall penetration points and sealed with silicone sealant.

  

Technical Logic: Through a multi-layer sealing system, the building airtightness is controlled to N50≤0.6 h - (air changes per hour), reducing energy loss caused by unorganized ventilation.

 

Thermal Bridge-Free Design: Thermal bridge simulation (such as THERM software analysis) is performed on key parts such as parapets, curtain wall connections, and basement ceilings to ensure that the inner surface temperature is higher than the dew point temperature. For example, both the inner and outer sides of the parapet are covered with insulation, and fire-retardant rock wool is filled between the curtain wall and the structural layer.

 

Design Value: Avoids local condensation and mildew, while reducing overall heat loss by 5%~10%.

 

Standard Floor Airtight Zone Diagram

 

Vertical Airtight Zone Diagram

 

Parapet Node Detail

 

Curtain Wall Node Detail

 

High-Efficiency Energy System Integration

 

Air Conditioning System: Uses variable refrigerant flow multi-split units (VRF), independently controlled according to different functional zones such as office areas and equipment areas, with a comprehensive APF (annual performance factor) of over 4.5.

 

Technical Adaptability: VRF systems have high part-load efficiency, suitable for the intermittent use characteristics of office buildings, saving 15%~20% energy compared to central air conditioning systems.

 

Fresh Air System: Full heat exchanger (enthalpy efficiency ≥70%) and CO ₂ concentration monitoring linkage to achieve on-demand adjustment of fresh air volume. The filter has a single-pass efficiency of 60% for PM0.5, significantly improving indoor air quality (IAQ).

 

Innovation: Integration of heat recovery and air purification functions, reducing energy consumption while ensuring a healthy environment.

 

Perspective View

 

Renewable Energy Coupling Application

 

Photovoltaic System: Monocrystalline silicon components (408㎡) are laid on the roof. Through optimized tilt angle and azimuth design (recommended 25° tilt angle for the Hangzhou area), the annual power generation is 79,216 kWh, accounting for about 20% of the building's total electricity consumption.

 

Technical Details: String inverters are used to reduce the impact of shading, and the system efficiency is over 82%.

 

Air Source Heat Pump Hot Water System: Uses a high-efficiency unit with COP 4.64 to supply 55℃ domestic hot water to the canteen, and a 500L hot water storage tank is used to balance supply and demand fluctuations.

 

Economic Analysis: Compared with electric water heaters, it saves about 32,000 yuan in electricity costs per year, and the static payback period is about 4 years.

 

Photovoltaic Layout Diagram of the Structural Layer

 

Annual Solar Radiation Total Amount Diagram on the Roof

 

Smart Operation and Maintenance Platform   

 

Energy Consumption Monitoring System: Provides itemized metering for lighting, air conditioning, power outlets, etc., uploading data to a cloud platform to generate energy consumption benchmark reports and assist in management decision-making.

 

Building Automation System (BAS): Automatically starts and stops equipment based on preset strategies (such as adjusting air conditioning temperature settings at night), provides real-time alerts for abnormal operating conditions, and is expected to reduce operating energy consumption by 8%~12%.

 

Lighting Control: Uses a DALI dimming system, linked with illuminance sensors and occupancy sensors to maintain constant illuminance (300 lx) in office areas and automatically turn off lights when unoccupied.

 

 

Incremental Cost Analysis

 

The incremental cost of using ultra-low energy consumption technologies in this project is approximately RMB 3,426,800, with an incremental cost per unit area of approximately RMB 273.38/㎡. The main allocation is as follows:

• Passive Technologies: 88.51%
• Active Technologies: 2.35%
• Automation System: 9.14%