Project Title: Scalable Thermal Buffer Tank System for Centralized Heating in Northern China
Location: Shijiazhuang, China
Industry Sector: Residential Building / District Heating
System Type: Rooftop-mounted Thermal Storage + Air Source Heat Pump Integration
Completion: November 2023
Project Background
In cold-climate regions, maintaining stable hot water output and efficient heating performance is a critical challenge for air source heat pump (ASHP) systems. Temperature drops below freezing can severely impact the compressor's performance, cause frequent cycling, and lead to higher energy consumption.
This project was commissioned by a real estate developer in Shijiazhuang, a northern Chinese city with winter temperatures as low as -10°C. The goal was to implement a modular thermal energy storage system that could:
Buffer the fluctuations in heating demand
Enhance the overall COP (Coefficient of Performance) of the heat pump
Ensure consistent hot water supply to residents during peak hours
Our Solution: Modular Thermal Storage Tank System
We designed and installed a rooftop thermal buffer tank solution consisting of 40 vertical insulated water tanks, each with a 200-liter capacity, providing a total of 8,000 liters of hot water storage. The system is fully integrated with an 80kW low-temperature air-to-water heat pump.
Key Components:
Thermal Storage Tanks:
40 × 200L stainless steel tanks
PU foam insulation for long-lasting heat retention
Vertical design optimized for rooftop space utilization
Piping System:
Anti-freeze insulated piping
Stainless steel and PPR connections
Fully weatherproofed for northern climate conditions
Heat Pump Integration:
Connected to an inverter-driven 80kW air source heat pump
Smart controller synchronizes tank charging during off-peak electricity periods
System Benefits
This thermal energy storage system provided several key operational and economic benefits to the client:
Improved Heat Pump Efficiency
By decoupling heat production from heat demand, the buffer tanks reduced short cycling of the compressor
This extended the lifespan of the heat pump and boosted overall COP by up to 15%
Load Shifting and Energy Cost Reduction
Heat was stored during off-peak hours when electricity was cheaper
The system then discharged hot water during peak demand periods, lowering total energy costs
Scalable, Lightweight Design
Each tank module was prefabricated and lifted to the rooftop for fast assembly
The modular design allows for future capacity expansion without system downtime
Climate Adaptability
All components were selected to operate reliably in sub-zero outdoor conditions
The entire system is designed for freeze protection, condensation control, and low-noise operation
Client Feedback
“This thermal buffer system stabilized our heat pump performance during the entire winter season. It helped us reduce our operating expenses and guaranteed hot water supply to all our residents, even on the coldest days.”
— Technical Director, Residential Property Development Company
Why Thermal Energy Storage Matters in Cold Climate Heat Pump Projects
Thermal buffer tanks are an essential part of any high-performance heat pump system operating in cold weather. They provide a cost-effective way to improve heating reliability, optimize energy usage, and reduce system wear and tear. For commercial or residential heating networks, thermal storage can also help manage peak load demand and qualify for grid-friendly, sustainable building certifications.
Ready to Build Smarter, More Reliable Heating Systems?
Whether you're working on a new development or retrofitting an existing building, we offer custom thermal energy storage solutions tailored to your region, building type, and climate challenges.
Contact us today to learn how we can support your next project with energy-efficient heat pump technology and smart thermal storage integration.
