Pics - ICTE NASEB HVAC Trip Report 020325.pdf

Engineering Evaluation for the ICT NASEB HVAC System

Wichita Dwight D. Eisenhower National Airport

Wichita, Kansas

JCN# 1007172

Conducted on April 4th, 2023

FAA

Infrastructure Engineering Center B

AJW-2C18D

Fort Worth, Texas

Engineering Report Prepared by Brandon Gabro

I. Engineering Evaluation for the NASEB HVAC system on site at the Wichita Dwight D. Eisenhower National Airport

(ICT)

II. Executive Summary:

A site visit was made to Dwight D. Eisenhower National Airport on April 4th, 2023 to assess the HVAC (Heating/Ventilation/Air Conditioning) system supporting the short-range ASR (Airport Surveillance Radar) on airport grounds, located in building NASEB. This trip is associated with JCN 1007172.

This investigation was conducted by:

Mr. Brandon Gabro, AJW-2C18D

Escorted by:

Mr. Rickey Johnson, WCR16-ICT

III. Table of Contents

I. Engineering Evaluation……………………………………..……2 II. Executive Summary ………………………………………..……2

III. Table of Contents…………………………………………..….…3 IV. Background information…………………………………..……..4 V. Issues………………………………………………….….…..…. 4

VI. Activities/Findings……………………………………………….5 VII. Solutions/Recommendations……………………………..……

VIII. Costs………………………………………………………...……6 IX. Conclusions…………………………………………………… X. Attachments………………………………………………………7

A. Pictures…………………………………………………...7 B. Contacts………………………………………………….14

IV. Background Information The ICT NASEB Facility is owned and operated by the FAA. The geographical coordinates are 37°38'36.3"N 97°26'08.5"W and it is at 1,333’ of elevation. The current HVAC system supporting the ASR is composed of two Carrier 15-ton split units for cooling and four Emerson heaters ranging from 3.7-5 kW for heating. The two Carrier units are intended to run in a lead-lag-standby configuration, meaning that one unit (the lead) will be the sole source of cooling until it can no longer sustain the building heat load and only then will the backup (the lag) unit turn on to supplement additional cooling in tandem with the lead unit. However, both units are currently running in tandem full time.

The system is controlled by two Emerson thermostats and lead/lag switches. Both units are currently setup in the “lead” position. The system appears to have no automatic control of the lead/lag configuration of the units but are adjusted manually by technicians via lead/lag switches.

The current system is approximately 15 years old and is the 3rd HVAC system to serve the building. The building has existing ductwork in the ceiling from the original HVAC system and new fabricated ductwork suspended from the ceiling from its replacement. The building contains an old HVAC control panel, but it no longer is part of the current HVAC system. It contains a few circuits to the EG but the functionality of these circuits and purpose is not entirely known.

V. Issues

• Current HVAC units are at end of useful lifetime. ~ 15 years old

• Leaking refrigerant and suboptimal cooling

• Unbalanced cooling in the ASR shelter

• Mixture of existing ductwork in ceiling and suspended fabricated ductwork is being used

VI. Activities/Findings The HVAC system at the ICT NASEB has gone through a few different iterations. In the past it was designed to have packaged units, which was later changed to a split system. The SSC is currently requesting that the HVAC revert to packaged units and remove the air handlers from inside of the NASEB. The current system uses a combination of ductwork from the original building design, which is above the raised ceiling and displaced through the original diffusers. In addition, fabricated ductwork is suspended from the ceiling and air is distributed through this as well in a more directed manner towards the radar equipment. Part of the suspended ductwork is blocking air from the original ceiling diffusers. There is also a vent that is unused on the west side of the building that has visible openings for air to leak out of the building.

The interior of the NASEB contains two air handlers. AHU1 is suspended from the ceiling and AHU2 is mounted on the floor against the south wall of the building. It is a peculiar setup and I have not encountered a similar HVAC configuration in the past. In addition, the safety switch for AHU1 is mounted to the air handler against the ceiling making maintenance a hassle.

There is no automatic switching of lead/lag between units 1 and 2. There are manual toggle switches that display lead/lag for each unit. Both units were toggled in the “lead” position. This is not an ideal configuration because it does not provide the redundancy needed. It is unknown if 1 of the current units can provide adequate cooling for the facility but suspected that it cannot, considering this survey was done during April and both units were running. The middle of summer will increase the heat load on the HVAC system.

VII. Solutions/Recommendations (20 - 25 Ton Packaged Units)

I recommend removing the current HVAC system and replacing with 2 packaged units rated 20 - 25-tons, reusing the existing concrete pad if able. All suspended fabricated ductwork shall be removed and either new ductwork be fabricated or reuse the existing ductwork that is above the ceiling. All old safety switches, controls, and thermostats shall be removed and replaced with individual thermostats that can be manually adjusted by the SSC Technicians in a primary/standby configuration. I do not recommend using any automated HVAC controls. I recommend removing the unused vent located on the west side of the building and sealing the opening.

VIII. Costs

TBD

IX. Conclusion

TBD

X. A. Pictures

Existing condensers and concrete pad

Existing Thermostats/Controls

Existing duct and diffusers mixed with suspended fabricated duct

Obsolete Vent

Existing AHU 1

Existing AHU 2

Obsolete HVAC Control Panel

B. Contacts

Brandon Gabro (AJW-2C18D) Mechanical Engineer 682-978-1727 brandon.gabro@faa.gov

Fekadu Waktola (AJW-2C18D) Engineering Supervisor 817-291-0679 fekadu.waktola@faa.gov