For most Grade-A office buildings in Nairobi, cooling accounts for 35–50% of total electricity spend. With commercial tariffs continuing to climb, HVAC efficiency is no longer a sustainability talking point — it is a line item that decides operating margins. These are the five interventions we deploy most often, ranked by typical payback speed.
1. Fix the setpoints and schedules first
It costs nothing and routinely saves 8–12%. We regularly find buildings cooling to 21°C when 23–24°C satisfies occupants, and plants running full tilt on weekends for a handful of staff. Raising setpoints by one degree cuts cooling energy by roughly 3–5%, and properly programmed time schedules eliminate the silent waste of after-hours operation.
2. Variable speed drives on fans and pumps
Fan and pump power scales with the cube of speed — slow a motor to 80% speed and it draws roughly half the power. Retrofitting VSDs to AHU fans, cooling-tower fans and chilled-water pumps is usually the single biggest hardware saving available, with paybacks of 12–18 months in buildings running long hours.
3. Chemical coil cleaning and airflow restoration
A fouled condenser coil can add 20% to compressor energy. Restoring design airflow — clean coils, clean filters, corrected fan belts and unblocked grilles — returns the system to its commissioned efficiency at a fraction of the cost of new plant.
4. Zone what you actually use
Server rooms, meeting suites and trading floors have completely different load profiles from open-plan offices. Splitting single-zone systems, or migrating to VRF with individual indoor-unit control, stops the building cooling empty space to serve one hot room.
5. Heat rejection upgrades
At altitude, condensers are already working harder than sea-level ratings suggest. Upsizing condensers, adding adiabatic pre-cooling, or relocating heat rejection out of hot plant wells drops head pressure and compressor power — and dramatically extends compressor life.
Where to start
An energy walk-through by a mechanical engineer identifies which of these five applies to your building and in what order. Airmaster provides this survey free for commercial clients, complete with measured baseline data and a costed savings roadmap.