AirRevive  vs. Manufactured Slip-in

 Case Study Overview

This study compares the operation of two adjacent hotel guest room vertical fan coil units.


In guest room 932 AirRevive re-commissioned the fan coil unit that was manufactured and installed in 1985. The re-commissioning included rejuvenating the fan coil, refurbishing the blower assembly and pan, and retrofitting the fan motor with an EC motor.


In guest room 933 a new off-the-shelf “slip-in” fan coil unit that was manufactured in 2013 was installed. The slip-in includes a factory installed EC motor.


The property is located in Washington, DC. The study was conducted between October 22nd and December 5th, 2014.

Fan coil unit details:


Make: Trane/Hi Rise Uni-Trane

Model: TVRB-0405

Year: 1985

Configuration: Vertical

Architecture and Design Impact


AirRevive Re-commissioned Unit


The fan coil re-commissioning neither altered nor changed the original fan coil unit cabinet, the guest room walls, or the design of the guest room. AirRevive refurbished the existing unit through the return register and supply grille. Valves and motors were retrofit using the return register access area to work inside the cabinet.

Slip-in Unit


To installed the slip-in fan coil unit required that the wall to be cut. The slip-in unit has a metal face that is larger than the size of the return register. The slip-in unit contains the fan coil, the blower assembly, the fan motor, and the valves. The large cut and size of the slip-in unit significantly alters the design and architecture of the guest room.

Performance Comparison

In addition to observing the design and architectural impacts of a refurbished unit and a slip-in unit, the purpose of the study was also to compare the key operational performance metrics of each.

Project Details

The following data was monitored to compare the operational performance of the units


air-revive-faviconEnergy consumption
Guestroom temperatureair-revive-favicon

Motor Details

Room 932

Room 933

EC Motor Upgrade

AirRevive re-commissioned unit with EC motor

Manufactured slip-in unit with EC motor


1/8 hp

1/2 hp

EC motors are variable speed.  The horsepower signifies maximum horsepower capabilities of the motor but not what is used to generate the manufacturer’s specified airflow.



The re-commissioned unit consumes the equivalent of $84 less energy annually,  approximately $58,800 in total!


In the graph below, the AirRevive re-commissioned unit in room 932 is represented in blue.


The AirRevive re-commissioned unit’s averaged fan amps, when the unit was operating fan amps, was 1.5 amps.


The slip-in unit in room 933 is represented in red.


The slip in unit’s averaged fan amps, when the unit was operating fan amps, was  4 amps.


Click on graph to enlarge.

If both units run continuously for the year, the re-commissioned unit in room 932 consumes 675 watts less than the unit in 933.


At the Washington, DC electric rate of $13 cents/kwh, room 932 costs $84 less annually to run.  Re-commissioning 700 guest room units will save approximately $58,800 in electricity annually.


Savings assume an energy rate of $0.125/kWh, 8760 possible hours/year of operation.


The graph below illustrates the room (return) temperature.


The AirRevive re-commissioned unit in room 932 is represented in blue.

The manufactured slip-in in room 933 is represented in red.


Return Air Temperature Graph

Click on graph to enlarge.


The manufactured unit represented in red produced guest room temperature demonstrates a wide band fluctuating between 60 and 74 degrees. It can be concluded the low temperature points on the bands represent a ramp up of very cold air before settling to the intended temperature set.


The AirRevive re-commissioned unit represented in blue produced guest room temperatures that fluctuated narrowly between 65 and 73 degrees. It can be concluded the accurate temperature set is reached quickly maintaining a comfortable guest room environment and using less energy.


The data demonstrates the re-commissioned unit maintained guest room temperature with a 6 degree variance while the slip-in unit produced guest room temperature with a 14 degree variance.



The slip-in consumes more electricity, is about 3x+ more expensive to install, and impacts the original guest room design aesthetic.