Glossary

The terms you hear from the technician or read in studies, explained simply.

Indoor unit components — Filters retain some airborne particles.
The coil transfers heat; during cooling it can collect condensate.
The blower moves air.
The pan collects condensate for drainage.

How air moves through a split unit — Room air enters the unit.
Air passes through the filter and coil.
The fan returns it to the room.
A typical split recirculates air; it does not replace outdoor-air ventilation.

Collection cover / bag Husă / sac de colectare: Double-layer waterproof sheet sealed around the indoor unit that collects the wash water and sends it through a hose into a bucket; allows pressure washing on the wall without dismantling.
Evaporator (indoor coil) Vaporizator (baterie interioară): The aluminium-fin heat exchanger in the indoor unit on which air cools and condenses; wet for hours after shutdown, it is the main place where mould grows.
Cross-flow blower Turbină tangențială: The long finely bladed cylinder that pushes air into the room; it loads with moisture-bound dust and turns black; a blower with 1 mm of build-up loses 20–30% of airflow.
Drain pan and condensate hose Tavă și furtun de condens: Collect and drain condensed water; clogged with biological slime they cause smell and dripping; flushed at every sanitising.
Biofilm Biofilm: The thin, sticky layer of bacteria and mould that forms on the unit's wet surfaces; it resists drying and sprays and is removed only mechanically, by washing.
MVOC (microbial volatile organic compounds) MVOC (compuși organici volatili microbieni): The gases produced by the bacteria and mould in the biofilm; they are the 'cellar' smell you notice when the unit starts.
Spores Spori: The mould's 'seeds', a few microns in size, leaving the unit especially at start-up; even dead spores remain allergenic.
CFU (colony-forming units) UFC (unități formatoare de colonii): The unit in which laboratories measure how contaminated a surface is; above 500 CFU/cm² is considered dirty, and drain pans reach over 10,000.
Alkaline cleaning solution Soluție de curățare alcalină: The first solution: dissolves grease and bound dust on fins and blower; left to work and fully rinsed under pressure.
Sanitising solution Soluție de igienizare: The second solution, applied to already clean surfaces; reduces remaining bacteria and fungi; does not replace washing.
Service check Revizie: The annual check of the unit: filters, coil, blower, pan, drain, temperature split, noise, outdoor unit, photo report; does not include refrigerant circuit work.
Temperature split (delta T) Diferența de temperatură (delta T): The difference between return and supply air; normally 8–12 °C in cooling; a dirty unit shows a small split and weak airflow.
Relative humidity Umiditate relativă: The percentage of water vapour in the air; comfort and health between 40 and 60%; above 60% dust mites thrive, above 80% on surfaces mould grows.
Dust mites Acarieni: Dust-dwelling micro-organisms producing strong allergens; they multiply at humidity above 50–60%.
Poplar fluff Puf de plop: The fluffy May–June seeds that clog the outdoor unit coil in Bucharest; the reason we also wash the outdoor unit.
Outdoor unit Unitate exterioară: The balcony or façade unit with compressor and coil; when the coil is clogged, consumption rises and the unit shuts down on protection in heatwaves.
Ceiling cassette Casetă de tavan: Indoor unit mounted in the false ceiling with 4-way discharge and a condensate pump; sanitised with a square cover.
Ducted unit Unitate de duct: Concealed ceiling unit distributing air through ductwork; cleaned through the access hatch.
Multi-split Multi-split: One outdoor unit serving 2–5 indoor units; each indoor unit is sanitised separately, the outdoor one once.
BTU BTU: The commercial capacity unit: 9,000 BTU ≈ 2.6 kW (15–20 m² room), 12,000 ≈ 3.5 kW (25–30 m²), 18,000 ≈ 5.2 kW, 24,000 ≈ 7 kW.
Fan mode (unit drying) Mod ventilație (uscare aparat): Running the unit with the fan only, 30–60 minutes after cooling stops or before winter, so the evaporator dries and mould does not grow.
Job sheet Fișă de intervenție: The document with before/after photos, what was done, the unit's state and the recommendation for the next visit; you receive it on WhatsApp or by email.