Cold Store and Chiller Insulation in Ireland with Closed-Cell Spray Foam

Why cold store insulation fails

Water vapour moves from warm, humid air towards colder, drier air. Around a cold store or chiller that drive is almost always inwards, from the warmer building or outdoors towards the cold room. The insulation's job is to slow the heat flow. The vapour control's job is to stop that moisture reaching a surface cold enough to condense or freeze.

When either fails, the signs are familiar:

• ice and frost along panel joints, at ceiling junctions and around door frames;
• water dripping or pooling when the store is defrosted;
• damp or crushed insulation behind linings;
• compressors running longer and energy bills rising;
• mould, corrosion and hygiene problems at the junctions.

The weak points are nearly always the same: joints between panels, fixings through them, junctions between walls, roof and floor, pipe and cable penetrations, and door openings. Once moisture gets into a joint and freezes, it opens the gap a little more each cycle.

Why closed-cell spray foam suits cold stores

Closed-cell spray foam is sprayed as a liquid, expands and bonds to the substrate, then cures into a rigid, continuous layer. In a cold store that gives three things panels struggle to match:

• No joints. The layer is continuous across walls, ceilings and junctions.
• Bonded, not fixed. There are no mechanical fixings through the insulation.
• Any shape. It follows steelwork, corrugated sheets, pipes, corners and awkward retrofit geometry.

Source: Enverge Nexseal LE product data. Values are typical and the specification uses the current technical data sheet.

Open-cell foam is the wrong product for a cold store. It is vapour-open by design. Read open-cell vs closed-cell spray foam for the difference.

To be balanced: for a brand-new, simple rectangular cold room, factory-made insulated panels are often the obvious choice. Closed-cell spray foam earns its place in retrofits, in buildings converted to cold storage, around awkward structure, and in sealing the junctions and penetrations where panel systems leak.

Thickness and the design temperature

The colder the store, the bigger the temperature difference across the insulation, and the more insulation it needs. A chill store and a freezer in the same building will not have the same specification.

Thickness should come from a calculation, not a rule of thumb. The designer or installer needs:

1. the operating temperature of each room, chill or frozen;
2. the conditions on the other side of each surface: outdoors, a heated warehouse, a roof void, another cold room;
3. the existing construction, including any old insulation staying in place;
4. the target U-value for each element;
5. a condensation risk analysis for the build-up;
6. how often doors open, and what door protection is fitted.

The answer is a thickness for each element, with the U-value it reaches. Your designer confirms which Building Regulations requirements apply to the work: TGD L and TGD B in the Republic, or Technical Booklets F2 and E in Northern Ireland.

Retrofitting a live food site

Most cold store insulation work in Ireland is on sites that cannot simply close: meat and dairy processors, food distribution, fruit and vegetable stores, pharmaceuticals. A retrofit is planned around the operation:

• Zones. The building is split into areas that can be emptied one at a time.
• Stock and equipment. Product is moved out of the zone, and equipment that stays is sheeted and protected.
• Substrate conditions. Foam goes onto a clean, dry surface within the conditions set by the manufacturer. The installer agrees with you whether a zone needs to come up to temperature before spraying.
• Re-entry. The work area stays closed until the installer's method statement and the product safety data say people and food can return.
• Cleaning. The area is cleaned before stock goes back in.
• Timing. Night, weekend and shutdown working are all common.

Every zone is recorded with thickness readings and photographs, so the handover file shows what was applied where. Our cold store spray foam article and spray foam for food processing go into more detail.

Hygiene finishes and fire protection

Food areas need surfaces that can be kept clean, and every building needs a fire strategy. Settle both before the specification is fixed, not after the foam is on.

Hygiene

Ask your food safety auditor what finish they expect on walls and ceilings in each area. In some rooms exposed foam is acceptable. In others a lining or cleanable finish goes over it. The answer changes the specification and the price, so it belongs in the survey.

Fire

Your designer confirms the fire performance required for the building under TGD B in the Republic or Technical Booklet E in Northern Ireland. Where a protective coating over the foam is specified, DC315 intumescent coating is the product Duratite supplies for the job. The coating is applied to the specified thickness and recorded like the foam.

Floors, doors and thermal bridging

Walls and roofs get most of the attention, but cold stores also lose performance at the floor and at every junction.

• Floors. Floor insulation is designed with the slab. Freezer floors can need insulation and, in some designs, heating beneath to stop the ground freezing. Spray foam is not a substitute for that design.
• Wall-to-floor and wall-to-roof junctions. These are classic cold bridges. Foam can be carried around the junction to close the gap.
• Columns and steelwork. Steel passing from a warm area into the cold room conducts heat. Wrapping it with foam for a distance reduces the bridge.
• Penetrations. Refrigeration pipework, drains and cable routes are sealed as part of the job.
• Doors. Strip curtains, rapid-roll doors and good seals cut the warm, moist air that comes in every time a door opens.

Where the cold room sits inside a larger metal-roofed building, the main roof may also drip condensation onto the cold room roof. See metal roof condensation and warehouse insulation.