Rooftop units in winter

This winter, facilities’ departments may increase the amount of outside air (OA) beyond what’s considered “standard” to help dilute COVID-19 particles from potentially circulating through the airstream. From a healthcare perspective this sounds great but from an operations perspective, not so much.

The increased amount of OA could potentially cost facilities thousands of dollars due to two factors:

  1. Lower outside air temperatures require more energy to condition air to the ideal temperature.
  2. Without the proper equipment, freezing outside air can cause damage to existing systems within the building.

Luckily fall is a great time to prepare your facility for winter. Keep reading our facilities’ winter prep checklist below to ensure your HVAC system is ready to take on winter!

Airflow Measurement – Do you have measurement systems or equipment?

Air Monitor Corp. VOLU-probe/FY

Appropriate airflow is important for both the health and comfort of the building’s occupants and the health and long-term performance of a building. Ensuring your facility has the proper airflow measurement equipment will provide the building with proper airflow control. This is especially important in the winter when increased outdoor air is often circulated through a building.

Flow Tech represents Air Monitor Corporation and will gladly provide a consultation regarding your facility’s airflow measurement needs. You can’t manage and improve what isn’t measured.

AIR MIXERS – Have you considered adding them to your facility?

Blender Products Channel Blender
Blender Products’ Channel Blender

Air mixing blenders are proprietary equipment that evenly mix outdoor air with air returning to an air-handling unit from inside a building (return air) for the purpose of maintaining breathable air at a comfortable temperature. In a smaller footprint than traditional mixing boxes, Blender Products air mixing blenders save facility owners time and money by eliminating the risk of freeze stat trips and frozen coils and allow full utilization of economizer systems.

If your facility does not utilize air mixing technology, allow us to further discuss with you and provide a free quote.

COILS – What’s stopping them from freezing?

Cooney Coils
Cooney Technologies’ Cooney FreezeBlock Coils

Heating, ventilation and air conditioning (HVAC) coils are thin tube heat exchangers used to transfer heat between fluid and air. Even with safeguards in place on a standard coil, mechanical failure, human error, and extreme weather conditions can allow freezing air to reach vulnerable coils causing them to freeze, bulge and split. To prevent your preheat coil from failure check the following potential issues:

If your AHU utilizes a steam preheat coil:

  • Steam PRV or control valve failure
  • ATC failure
  • Blockage inside the steam or condensate piping
  • Loss of steam pressure from source (i.e. boiler, campus energy, etc.)

If your AHU utilizes a hot water preheat coil:

  • Hot water supply temperature should be between 120°F-180°F, designed leaving water temperature should be well over freezing temps
  • Check that the preheat hot water system has the proper GPM flow rate and pressure
  • Ensure the preheat coil is not air-bound – air vent if necessary

Failure of Freeze Stat – customer installed freeze stats sometimes fail to shut down the fan above the freezing point.

  • Check the set point of the freeze stat
  • Investigate freeze stat control circuit to make sure it is powered and functioning properly

Failure of Outside Air Dampers – when using blended air, OA dampers stuck wide open can trigger a freeze.

  • Check outside air damper linkages and power connections to ensure proper function

Rooftop AHUs – if outside air enters a side panel on a rooftop AHU, frigid outside air can bypass the preheat coil and cause coils to freeze.

  • Make sure all side panel doors are closed
  • Check that no insulation has been removed from side panels

Until now better technology for freeze protection was unavailable. For superior HVAC coil freeze protection consider replacing critical coils with Cooney Freeze Block Coils. Flow Tech is available for a free, no-hassle quote.

DAMPERS – Are the linkage components worn or broken?

TAMCO dampers.

Dampers help control the flow of air in and out of a building, duct or room and they can even prevent air from entering specified areas. It is important to check the functionality of your dampers to ensure they will work properly over the winter months. Linkage components that connect to a damper’s blades can easily be worn or break. When this occurs, the damper could potentially malfunction and bring too much outdoor air inside the space, increasing energy costs.

Flow Tech is happy to visit your facility and offer a free damper inspection. If we find that your dampers are in need of replacement, we’ll provide a free quote for replacement dampers. We proudly represent TAMCO dampers that feature slip-proof linkage components and a self-sealing, auto-lubricating dual bearing system that results in a complete maintenance-free performance.

ENERGY RECOVERY SYSTEMS – Are they clean and blockage-free?

Heat Pipe Technology systems

Whether your energy recovery system is in the form of a heat wheel or glycol-based system, they are remarkable energy and cost savers. Energy conservation and cost reduction are enormous concerns in all industries but they are especially crucial in facilities with requirements for a large percentage of outside air in air handling and conditioning.

When a heat wheel ages it can lose performance as the properties that transfer latent and sensible heat break down or the mechanical properties are compromised. This can mean the coating on the media (desiccant) has worn away, is clogged with particulates or the mechanical components such as the drive, motor or wheel itself are damaged. For glycol systems this could mean dirty coils or air in the glycol loop.

For these reasons it is important to check that your energy recovery system is free from clogs and filth and is working properly. If you’re not comfortable doing so, Flow Tech is happy to help and can offer you a free inspection of your energy recovery system. If it needs replacement, Flow Tech is your source for the best replacement Thermotech wheels or Heat Pipe Technology systems.

Mike Davis pointing out the features of TAMCO dampers to Evan Benoit in 2015 at Travelers, Hartford, CT.

Flow Tech will help ensure your HVAC systems are ready to take on winter. We will work with your maintenance personnel or mechanical contractor and our factory teams to design replacement systems that will be easy to install, at the best price, with top performance. Contact us today to learn more about our free inspections. For more information about our products and services call us, 860.291.8886 or visit us on the web. You can always stay up-to-date on the latest Flow Tech happenings by following us on social media: Facebook, LinkedIn, Twitter and YouTube.

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