Cooling knowledge,
in plain language.

How to size an AC unit correctly

The single most common mistake in AC buying is choosing capacity by room size alone. Floor area matters, but it's only one input. Ceiling height, sun exposure, the number of people usually in the room, heat-generating equipment, and even the colour of the roof directly above all shift the actual cooling load.

An undersized unit runs almost continuously, struggles to reach the set temperature on hot afternoons, and wears out faster from the constant strain. An oversized unit cools the room quickly but shuts off before it has properly removed humidity — leaving the space feeling cold but clammy, and short-cycling in a way that also shortens compressor life.

As a starting point, a general office or living room in Nairobi's climate needs roughly 130–170 BTU/hr per square metre, adjusted upward for west-facing glass, a busy kitchen, or a room full of computers, and downward for a shaded, low-occupancy space. Our sizing estimator on the services page gives a rough figure — but for anything beyond a single room, a proper site visit accounting for insulation and window area will get the number right.

A seasonal AC maintenance checklist

Most emergency call-outs trace back to something that would have been caught on a routine service. A basic maintenance visit, done every three to six months for a typical home or office unit, covers:

• Cleaning or replacing air filters, which restrict airflow and force the compressor to work harder when clogged
• Checking the indoor and outdoor coils for dust and debris buildup
• Inspecting the condensate drain line for blockages that can lead to water damage
• Checking refrigerant pressure for early signs of a slow leak
• Testing electrical connections and the compressor's start-up behaviour

Commercial units running longer hours, or units in dusty environments near construction or unpaved roads, benefit from quarterly visits rather than the standard interval. Cold rooms and chillers should be checked more frequently still, given the cost of a temperature excursion to whatever they're storing.

Keeping the cold chain unbroken

For food retailers, restaurants, pharmacies and logistics operators, a cold room or chiller failure isn't an inconvenience — it's stock loss, and in the case of pharmaceuticals or vaccines, a compliance issue. A few practices reduce that risk substantially:

• Fit independent temperature monitoring with an alert, not just the unit's built-in display, so a fault is flagged even outside working hours
• Keep a service contract with a defined response time, rather than relying on a one-off repair call when something breaks
• Avoid overloading a cold room beyond its rated capacity — every extra pallet makes the compressor work harder to hold temperature
• Check door seals regularly; a worn gasket lets warm, humid air in continuously and is one of the most common causes of a struggling cold room

We build in temperature monitoring and controls as standard on new cold room installs, and offer maintenance contracts specifically for businesses that can't tolerate downtime.

R32 vs R410A vs R134a — what's the difference?

Most residential and commercial split systems installed today run on R32 or R410A. R32 has become the more common choice in newer equipment — it has a lower global warming potential than R410A and is used in a single-component form, which makes servicing and any future recharge slightly simpler.

R410A remains widely installed in existing systems and continues to be supported for servicing. R134a is typically found in domestic refrigerators, some smaller chillers and automotive AC, while larger commercial refrigeration and cold rooms more often use R404A.

The practical takeaway for a client is less about the chemistry and more about matching: a system should always be recharged with the refrigerant it was designed for, never substituted, and any technician handling refrigerant should be doing so with proper recovery equipment rather than venting it to atmosphere.

Five signs your AC needs a service

A handful of warning signs usually show up well before a full breakdown:

• Weaker airflow than usual, even with the fan on full
• The room takes noticeably longer to reach set temperature
• A musty smell when the unit starts, often a sign of drainage or coil buildup
• Water pooling near the indoor unit, pointing to a blocked condensate drain
• Unusual noise on start-up, which can indicate a failing capacitor or compressor

Any one of these on its own is worth a service call before it becomes an emergency call — the difference in cost and disruption is usually significant.

Cutting your cooling electricity bill

Cooling is typically one of the largest electricity line items for offices, retail and hospitality in Kenya. A few adjustments make a measurable difference without touching comfort:

• Set the thermostat a few degrees higher — each degree closer to outdoor ambient meaningfully reduces compressor run time
• Keep filters and coils clean; a dirty system works harder to move the same amount of air
• Use blinds or window film on west-facing glass to cut the afternoon heat load before the AC has to fight it
• Consider zoning a ductable system so unoccupied rooms aren't cooled unnecessarily
• For older units, compare the running cost of a repair against replacing with a more efficient current-generation system

We can review an existing installation and advise honestly on whether it's worth repairing or replacing, based on age, refrigerant type, and repair frequency.