Room Airflow Balancer

See where your system's air actually goes — and how damper adjustments move it to the room you care about. Tap a room, tell us more or less, and get suggested damper settings.

Total airflow

1200 CFM

held constant (ECM-like)

Supply static

0.19 in. w.c.

at the plenum

Total external static

0.47 in. w.c.

✓ healthy

Your room

tap a room to track it

Your duct system — live airflow at every register

Drag anywhere along a duct to work its damper: green is the open part, gray is how far the damper is closed.

SUPPLY PLENUMTrunk 1Trunk 2Trunk 3Trunk 4Trunk 5Hallway114CFMMaster bath58CFMMaster bedroom162CFMEntry147CFMKitchen202CFMLiving room304CFMBedroom 2112CFMBedroom 3101CFM

Balance a room

1. Tap the room you care about on the diagram above.

2. What do you want?

Dampers (0% = fully open)

Trunk dampers (at the plenum)

open
open
open
open
open

Branch dampers

open
open
open
open
open
System details (for the pros)
Blower model:
TrunkSegment / roomDiameterLengthFitting equiv.
Trunk 1Trunk 1 · Master suite8"8 ft35 ft
Trunk 1Hallway6"10 ft65 ft
Trunk 1suite run8"10 ft10 ft
Trunk 1Master bath5"12 ft80 ft
Trunk 1Master bedroom7"8 ft60 ft
Trunk 2Entry6"18 ft80 ft
Trunk 3Kitchen7"22 ft95 ft
Trunk 4Living room8"25 ft80 ft
Trunk 5Trunk 5 · Bedrooms7"15 ft35 ft
Trunk 5Bedroom 26"12 ft75 ft
Trunk 5Bedroom 36"18 ft90 ft

Duct friction from the round metal duct relation (0.109136·Q1.9/D5.02 per 100 ft) with Manual D-style equivalent lengths for takeoffs, elbows, and boots. Dampers modeled as butterfly-type loss coefficients. Return side + filter + coil allowance ≈ 0.28 in. w.c. at 1200 CFM. In fixed-airflow mode the blower holds total CFM like an ECM motor; in PSC mode total airflow falls as the system is choked down.

Want it measured, not estimated?

This tool shows how balancing works on a typical duct layout. Real systems vary with duct condition, flex compression, and register types. Vargas HVAC can measure your actual airflow with calibrated instruments and balance it properly.