Methodology
The goal is to make it obvious which numbers come from official sources and which are our own estimation choices.
AC capacity
The starting point is the empirical Saudi TVTC training rule: room volume in m³ × 300 ≈ BTU/h. We then apply modest site heuristics for city/climate, sun, insulation, windows, occupancy, top floor and kitchen/high internal heat.
| Factor | Multiplier / adjustment |
|---|---|
| City | Riyadh 1.05; Jeddah 1.03; Dammam/Khobar 1.04; Makkah 1.06; Madinah 1.05; Taif 0.88; Abha 0.78; other 1.00 |
| Sun | Mostly shaded 0.95; average 1.00; strong direct sun 1.08 |
| Insulation | Good 0.90; average 1.00; weak/unknown 1.12 |
| Windows | Small 0.97; average 1.00; large/many 1.08 |
| Top floor / sun-exposed roof | × 1.08 |
| Kitchen / high internal heat | × 1.12 |
| Occupants above two | +600 BTU/h per person |
Standard-size rounding
After estimating load, we round upward to the first practical size in our list: 9,000; 12,000; 18,000; 24,000; 30,000; 36,000; 42,000; 48,000; 54,000; 60,000 BTU/h.
Electricity cost
We apply the published Saudi residential tiers piecewise: SAR 0.18/kWh up to 6,000 kWh/month and SAR 0.30/kWh above that. Incremental AC cost is the difference between the household energy charge before and after adding the AC consumption.
VAT and efficiency comparison
The optional VAT switch adds 15% as the current standard Saudi VAT rate where applicable. Efficiency comparison uses annual kWh entered from product label data; we do not assume a fixed “inverter savings percentage.”
Limits
- Not an engineering design or compliance certificate.
- No brand recommendation or product price is implied.
- Calculator inputs run locally in the browser.
- Official sources and assumptions are reviewed when requirements change.