Winter heating is the second-largest energy expense for commercial complexes after cooling. This article documents a heating-season retrofit across four shopping malls under an East China retail group: from manual meter reading and temperature control by experience to sub-metering, hydraulic balancing, and weather-driven closed-loop control. In the first retrofit heating season, heating consumption per unit area fell by roughly 18 percent. All figures have been anonymized at the client's request.
An East China retail group operates eight shopping malls with a combined floor area of about 600,000 square meters, all heated by municipal district heating. In the 2024-2025 heating season, the group's heating bill reached about 28 million yuan, up 12 percent year over year. The harder problem was complaints: more than 200 tenant complaints about uneven heating arrived every winter month, with near-end mall top floors overheating while ice-rink areas at far-end malls stayed cold. The group's energy department concluded that the problem lay not with the municipal heat source but with its own secondary networks and terminal operations: no sub-metering, no hydraulic balancing, and no weather-adjusted supply-temperature strategy. In April 2025, the group commissioned a heating-system monitoring retrofit for the four worst-performing malls, requiring completion before the next heating season without any closure during construction.
The project faced three practical constraints. First, weak data foundations: each heat-exchange station still relied on manual meter reading, producing one reading per day, so instantaneous flow loss or over-temperature operation could not be detected. Second, large variation among malls: the four properties were built between 2012 and 2021 with different pipe-network topologies, terminal configurations, and operating hours, so the scheme had to be replicable yet parameterizable per mall. Third, limited construction windows: with dense daytime foot traffic, cabling and installation could only proceed in the roughly two hours after closing each night, forcing a lean point layout and lightweight installation methods.
The retrofit proceeded in three steps: metering first, balancing next, and a closed-loop strategy on top. Step one, metering: ZYH-542 ultrasonic heat meters at heat-exchange stations for heat metering and efficiency evaluation were installed on the supply and return mains of each mall's heat-exchange station, together with ZYH-342 water pressure transmitters for differential-pressure monitoring during heating-network hydraulic balancing on the supply and return pipes, building per-station ledgers of heat, flow, and differential pressure and raising data frequency from one reading per day to one every fifteen minutes. Step two, balancing: temperature and humidity transmitters placed by floor zone for zoned temperature control in malls focused coverage on overheated near-end zones and cold far-end zones; ZYH-WFS water flow switches were added to branch return pipes to help identify hydraulically imbalanced sections and guide balancing-valve adjustment. Step three, closed-loop control: the platform generates a supply-temperature curve from outdoor temperature and business hours; during low-load night periods, ZYH-100 anti-freeze switches interlocked for nighttime winter protection guard fresh-air units and circulating pumps, automatically interlocking startup when temperature drops below the setpoint. Data from all four malls is aggregated to the group's energy management platform through energy consumption gateways that centrally collect dispersed heating data across malls, where savings are verified against a baseline regression model.
The 2025-2026 heating season was the first full operating cycle. After degree-day correction to a typical meteorological year, the verified results are as follows.
| Metric | Before (2024-2025 heating season) | After (2025-2026 heating season) |
|---|---|---|
| Heating consumption per unit area (average of 4 malls) | About 186 kWh per square meter | About 152 kWh per square meter, down roughly 18 percent |
| Heating cost for the 4 malls | About 13 million yuan | About 10.7 million yuan, saving roughly 2.3 million yuan |
| Monthly uneven-heating complaints | Over 200 | Around 40, down about 80 percent |
| Top-floor supply temperature at overheated near-end mall | Chronically high | Lowered 3 to 5 degrees Celsius while room temperature stayed compliant |
| Station data frequency | One manual reading per day | Automatic capture every 15 minutes |
With a total retrofit investment of about 4.5 million yuan across the four malls, the static payback period is roughly two heating seasons. The group is now replicating the scheme to the remaining four malls and plans to extend metering to the summer cooling side, moving toward year-round energy management.
