Car air conditioning: maintenance and recharge

Air conditioning improves comfort and safety (visibility, alertness) in summer. To keep it effective, a minimum of maintenance is needed. Here is what to check and when to consider a recharge.

How it works (in brief)

The system compresses a refrigerant (gas) that circulates in a loop. As it expands, it absorbs heat inside the cabin and rejects it outside via the condenser (in front of the radiator). A cabin filter (often combined pollen/charcoal) filters incoming air. Over time, gas can leak (system not perfectly sealed) and the filter gets dirty, reducing flow and causing odours.

When to recharge

A recharge is useful when the blower stays lukewarm with the A/C on full and it is hot outside. The most common cause is low refrigerant pressure (small leak or natural loss). Recharging means restoring the correct gas quantity and pressure. It must be done by an equipped professional (gas recovery, environmental rules). DIY “quick recharge” kits are not allowed if you are not qualified.

Cabin filter maintenance

The cabin filter is usually behind the glovebox or under the bonnet. Replace every 1–2 years or 15,000–30,000 km as recommended. A dirty filter reduces airflow, causes odours and can reduce evaporator efficiency. Replacement is often simple and cheap.

Order of magnitude for costs

A/C recharge (pressure check + gas recharge): €80–150 at a garage. Cabin filter: €15–50 (part), fitting often quick. Leak detection and repair (dye, repair): variable (€100–400 and more). My Auto Check-up helps you prepare your visit by gathering useful information for an initial cost estimate.