01455 203 205
sales@thermo-floor.co.uk
Cold Store Anti-Heave Systems:
Anti-heave systems are essential for any cold store or freezer built at ground level. Glycol-filled underfloor heating circulates warmed fluid through pipework under the floor, keeping the ground beneath above freezing and protecting the slab from frost heave.
Why Anti-Heave Protection Is Essential
A cold store operating at -20 °C or below gradually draws heat out of the ground beneath it. Over time, moisture in the soil freezes, and as water turns to ice it expands, forming ice lenses that push up on the floor slab. The result is a floor that heaves and cracks, leading to uneven surfaces and, in severe cases, serious structural damage to the facility.
How It Works
A heating system is installed under or within the cold store floor, beneath the insulation layer. A heated glycol and water mixture circulates through the pipework, replacing the heat drawn out by the store and holding the sub-base at a safe temperature.
Only 10–12 W/m² of heat is needed to keep the ground beneath the floor from freezing, so the system runs at low output and low cost.
Efficient Heating with Waste Heat
For even greater efficiency, waste heat from the refrigeration plant can be used to warm the water in the anti-heave system. Heat that would otherwise be rejected to atmosphere is put to work under the floor, delivering significantly lower running costs than electric heating.
| Factor | Glycol-filled system | Electric heater mat system |
|---|---|---|
| Heat source | Waste heat from refrigeration plant, heat pump, boiler or other fluid heat source | Mains electricity |
| Running cost | Typically lower, especially with waste heat recovery | Typically higher, direct electric resistance |
| Heat pump and low-carbon compatibility | Excellent, suits low flow temperatures | Not applicable |
| Heat distribution | Even, fluid carries heat across the full loop | Even, but a fault can affect a single mat or zone |
| Repair and maintenance | Fluid and pumps can be serviced without touching the slab, pipework is long-life | Cable or mat faults are hard to locate and repair once buried |
| Best suited to | Larger freezers and cold stores, and sites with a spare heat source | Smaller freezers, retrofits and sites with limited plant space |
Design Principles
Every anti-heave system we install is engineered for the specific cold store, so that ground freeze cannot occur. We calculate pipe spacing, flow rates and circuit lengths for each project, and the glycol mix protects the system down to -33 °C. The result is an even, reliable heat output across the whole floor.
Manifold Selection
Thermo-Floor supplies both blending and low-temperature distribution manifolds. The choice depends on the temperature of the water supplied to the manifold.
| Supply water temperature | Manifold type | Purpose |
|---|---|---|
| Above 30 °C | Blending manifold | Reduces the water temperature at the manifold before it enters the floor circuits |
| Below 30 °C | Low-temperature distribution manifold | Distributes the water directly to the floor circuits |
Typical System Components
- Heating pipework laid under or within the floor, beneath the insulation layer
- Heat source: waste heat recovery from refrigeration, heat pump or boiler
- Circulation pump set and blending or low-temperature distribution manifold
- Glycol and water mixture with corrosion inhibitor, protected to -33 °C
- Expansion vessel and pressure relief
- Control panel with temperature monitoring
- Slab temperature sensors installed in the sub-base
Design Considerations
- Cold store operating temperature and the insulation thickness above the system
- Ground conditions, water table and soil type
- Slab size, loading and construction build-up
- Available heat source and supply water temperature
- Glycol concentration and viscosity
- Redundancy, such as duplicate pumps and dual circuits
- Monitoring and alarm strategy for the sub-base temperature
Why Thermo-Floor
The UK’s longest established underfloor heating company, with nationwide coverage from our base in Leicestershire. We design and install anti-heave systems for warehouses, cold stores and industrial freezers.
Every cold store is different. For project-specific design data, system sizing and a tailored proposal, contact our technical team.