Setra Blog

How much can you save if you get rid of a hot-wire anemometer?

Written by Meghan Kelley | March 19, 2020

Although hot-wire anemometers are widely used throughout hospitals, such technology is deceptively costly. Anemometers must be frequently cleaned to remain accurate, and if not maintained, they waste massive amounts of energy.


Below are guidelines to calculate how much you can save if you replace your hot-wire anemometer with capacitive technology like Setra's Hot-Wire to Setra FLEX™ Conversion Kit.

Cost Savings to Remove Hot-Wire

For a free downloadable version of the savings calculator, click here.

Monthly Cleaning of Wires (Debris)

1 hour per room X $40/hr labor = $40 per month, per room

Note: Add in cost to bring down Operating or Patient Recovery room for 1 hour $__________

Cost of Air Mover Leaking CFM Through Hole in the Wall

@2800 CFM required for ACH

Vel thru hole = 60 fpm

Hole = 0.259 ft³

0.259 X 60 = 15.5 cfm per room

$0.17 per CFM per month = $2.64 per room per month (electricity) AND (room additions not available due to fan curve)

Cost of Alarm Thresholds Running Higher than Necessary (Debris on Wires)

Typical hot-wires run at 0.03" WC alarm threshold. Setra's Hot-Wire to Setra FLEX™ Conversion Kit allows running at 0.005" WC alarm threshold.

Based on typical fan curve: 0.03 - 0.005 = 0.025" WC improvement

0.025" WC improvement on fan curve = 9 CFM reduction available

@ $0.17 per cfm per month = $1.53 savings per room, per month

Monthly Savings for 30 Rooms

($22 + $2.64 + $1.53) X 30 = $785.00 per month

Add revenue for keeping Operating or Patient Room open $_______

Add Revenue for Room Additions Available on Fan Curve $_______