Read the unit first
Check whether a chart reports Btu energy, BTU/h capacity, kW thermal capacity, or refrigeration tons. HVAC equipment rows normally use BTU/h.
Common capacity rows
| BTU/h | kW | RT |
|---|---|---|
| 6,000 | 1.76 | 0.5 |
| 12,000 | 3.52 | 1 |
| 24,000 | 7.03 | 2 |
| 36,000 | 10.55 | 3 |
Know the limits
Room-size charts are screening aids. Heat gain, envelope performance, moisture, solar exposure, and occupancy can change the actual load.
FAQ
Can a BTU chart select equipment?
No. It converts or compares capacity; final selection requires a suitable load calculation and manufacturer performance data.