How It Works

A rotary compressor uses an eccentric rotating cylinder to compress refrigerant — the rotor rolls around the inside of the cylinder bore, sweeping and compressing gas as it rotates. Single-stage rotary compressors dominate Kenya’s residential split AC market. Twin rotary compressors (two rotary stages on the same shaft) provide quieter operation and are used in premium LG and Samsung residential models.

Kenya Applications

All residential split AC in Kenya — 0.75T to 2.5T — uses rotary compressors. Brands: LG, GMCC (inside Midea, Gree, Haier, Hisense), Invotech, Samsung. The vast majority of Kenyan HVAC technician compressor replacements are rotary compressor jobs. Best T3 rotary choices for Kenya: LG (premium), GMCC (OEM Chinese brands), Invotech (price-sensitive).

Kenya Service Notes

Always test run capacitor before condemning a rotary compressor — a degraded capacitor causes hard starts that mimic compressor failure. Always replace the Danfoss filter drier alongside any rotary compressor replacement. Always test the condenser fan motor and its capacitor before commissioning the new rotary compressor.

How It Works

A scroll compressor uses two interleaved spiral scrolls — one fixed, one orbiting — to progressively compress refrigerant from the outer periphery to the centre. Scroll compressors have fewer moving parts than reciprocating compressors, run with less vibration, and handle liquid slugging better than rotary compressors. They are the standard choice for commercial AC capacities above 2.5 tons.

Kenya Applications

Nairobi commercial AC — VRF outdoor units from Daikin, Mitsubishi, LG, and Samsung, large ducted split systems in Nairobi office towers, and Carrier and Trane packaged AC in Kenya’s institutional sector. Mombasa five-star hotel central AC plants. Scroll compressor failures in Kenya are high-urgency commercial events requiring air freight from Dubai. Always send the system model number immediately — scroll compressor identification requires the outdoor unit model.

Rotary vs Scroll — Kenya

Rotary and scroll compressors are not interchangeable — they have different form factors, refrigerant connections, and oil types. Never substitute a rotary compressor for a scroll unit or vice versa regardless of capacity. If a building was fitted with a scroll compressor, only a scroll replacement of the correct specification can be used. The compressor type is visible from its physical shape and is confirmed in the outdoor unit service manual.

How It Works

An inverter AC compressor is a standard rotary or scroll compressor driven by a variable-frequency inverter board (IPM — Intelligent Power Module) that controls the compressor motor speed rather than switching it on and off. Instead of cycling fully on and off like a fixed-speed compressor, an inverter compressor ramps its speed up and down to match the cooling load — reducing electricity consumption and maintaining more stable room temperature.

Kenya Applications

LG Dual Inverter — Nairobi premium apartments and offices. Daikin Inverter — Kenya’s premium hotel and commercial sector. Mitsubishi Electric MSZ-EF R32 — Nairobi corporate and hospitality. Inverter AC penetration in Kenya is growing rapidly in the premium segment but remains lower than fixed-speed in the mass residential market — making inverter compressor service a specialist high-value skill for Kenyan HVAC technicians.

Kenya Service Notes

Inverter compressors require exact model matching — never substitute by capacity alone. The inverter board (IPM) must be tested before condemning the compressor — IPM board failure produces the same fault symptoms as compressor failure. IPM boards are significantly cheaper than inverter compressors. Always check the IPM board first. Inverter compressor replacement in Kenya typically requires air freight from Dubai due to the high business impact of inverter AC failures.