Thermal Energy Storage (TES) is a technology that captures energy at one time and makes it available later. At home, the concept is simple: making ice in your freezer at night to chill drinks the next day. In large commercial buildings, the same principle applies—only on a much bigger scale—producing and storing ice at night to cool facilities during the day.
The main driver for adopting ice storage in buildings is cost reduction. By shifting energy consumption to off-peak hours, operators can lower peak electrical demand, benefit from cheaper nighttime rates, and cut cooling costs significantly. Ice tanks can also serve as reserve cooling capacity, ready for periods of unusually high demand or as backup for critical systems.
“Ice storage represents an efficient, environmentally friendly way to meet cooling needs while supporting grid stability,” says Nabil Shahin, Managing Director of AHRI – MENA.
Environmental and Energy Benefits
Ice storage taps into cleaner, more abundant nighttime electricity, which is increasingly sourced from renewables like wind—often generated overnight. By storing this energy for daytime use, ice storage addresses renewable intermittency and reduces reliance on less efficient peaking plants.
Compared with conventional on-demand cooling, ice storage can improve energy efficiency by enabling operators to decouple cooling production from consumption, drawing on cheaper and more efficiently generated power when demand is high.
Where Ice Storage Works Best
This technology is ideal for buildings with large daytime cooling loads—offices, hospitals, schools, airports, data centers, places of worship, and facilities pursuing LEED certification.
Applications include:
Reducing peak energy demand.
Supporting critical system backup.
Limiting the size of HVAC or electrical equipment.
Increasing operational flexibility and redundancy.
Systems can be adapted for new builds, retrofits, or expansions, and tanks come in various sizes for placement in basements, parking areas, rooftops, or underground.
How Systems Are Built
A typical system features:
Tank filled with water.
Tubular heat exchanger circulating a coolant (antifreeze).
Charging phase: Coolant at ~24°F (-4.4°C) freezes water on the coil’s exterior.
Discharge phase: Warm fluid melts the ice to provide cooling.
Design Variations
Ice-on-Coil (Internal Melt) – Ice forms on submerged tubes; melting starts closest to the coil using warmer fluid.
Ice-on-Coil (External Melt) – Ice also forms on tubes, but melting occurs outside via circulating unfrozen water.
Unitary Systems – Fully packaged with refrigeration and ice storage, performance-rated by the manufacturer.
Installation & Maintenance
Ice storage systems require strict installation per manufacturer guidelines. With no moving parts, maintenance is minimal—annual checks of water levels and glycol concentration are standard.
Standards & Certification
ASHRAE 189: Calls for a 10% demand reduction in new buildings, achievable through TES.
U.S. Army: Requires ASHRAE 189.1 compliance in all new or renovated facilities since 2015.
USGBC LEED v4: Offers up to 3 Demand Response points for load-shifting measures like ice storage.
AHRI Standards 900 & 901: Define performance ratings for cooling storage equipment.
AHRI Guideline T: Outlines minimum performance data for specifying cool storage equipment.
Bottom line: Ice-based thermal storage is a proven, adaptable, and environmentally responsible way to meet large-scale cooling needs. It cuts costs, supports renewable integration, reduces emissions, and offers building operators greater control over energy use—positioning it as a cornerstone in the future of sustainable cooling.
Source: mepmiddleeast.com
