HVAC Load Calc: Manual J

Right-size any residential system in seconds. HVAC Load Calc runs a whole-house block load (the Manual J method) from a few envelope inputs — no spreadsheets, no guesswork. ENTER THE HOUSE - Floor area, ceiling height, and climate (built-in design temps for major US cities) - Insulation presets for walls, ceiling, and floor — or your own U-values - Window area and glazing type, air tightness, and occupants GET THE LOAD - Design HEATING load (BTU/h) - Design COOLING load, split into SENSIBLE and LATENT (BTU/h) - Recommended equipment TONNAGE, with a sanity check that flags oversizing BUILT ON REAL PHYSICS - Textbook ASHRAE heat transfer: envelope conduction, infiltration, solar and internal gains — the same basis as ACCA Manual J block load. - Transparent assumptions you can adjust, not a black box. Free to download and try. Pro unlocks unlimited calculations with a 7-day free trial, then renews yearly — cancel anytime in Settings. Engineering reference only — a whole-house block load, not a substitute for a certified room-by-room Manual J or professional engineering judgment. Terms: https://manualj.vovaluka.com/terms Privacy: https://manualj.vovaluka.com/privacy