The Effect of High Altitude on Heating and Air Conditioning Systems

Denver Colorado skylineDenver is famously known as the “Mile High City” due to its official elevation being exactly one mile above sea level. This rather infamously has consequences for both professional bakers and home cooks living and working in the city, who have to contend with the effects changes in atmospheric pressure have on the chemical processes involved.

The higher you go, the thinner the air becomes. Air pressure is lower, water boils at a lower temperature than the standard 212 degrees Fahrenheit, and all of this affects how your baked good turn out. As any new Denver resident quickly figures out, the same recipe that works in any other city won’t work as well a mile above sea level!

If baking is affected by increased elevation, then surely other things are as well—which leads to our question today: does Denver’s elevation affect heating and cooling systems as well as ovens?

In this blog, we’ll look at the effects of high altitude on heating and air conditioning and what can be done to ensure that a commercial HVAC system one mile above sea level functions just as well as an HVAC system at sea level.

Understanding High Altitude Heating and Air

As altitude increases, so does the density of air, along with other properties such as enthalpy and dewpoint temperature. At about a mile above sea level, this change in atmospheric pressure can affect the efficiency of various HVAC components, such as an air conditioner’s air-cooled condenser and air handler.

For example, due to the lower air density, HVAC systems have a reduced dehumidification capacity and air-cooled electric motors also have lower rated capacity. Because air is less dense, ventilation systems take a hit to their efficiency as well. A fan at sea level, for example, can move 90,000 pounds of air per hour, but the same van will move only 72,000 pounds per hour at 6,000 feet above sea level.

Other HVAC components such as filters, coils, diffusers, and ductwork also tend to experience efficiency hits due to high altitude. Pumps experience a greater risk of cavitation. It also becomes harder to cool motors, which can increase the risk of overheating.

Which HVAC components are altitude-dependent?

Some of the components of commercial HVAC systems that are particularly affected in their efficiency and operation by high altitudes include:

  • Fans and ductwork
  • Pumps
  • Evaporative coolers
  • Cooling towers
  • Condensers and chillers
  • Motors and electrical equipment
  • Combustion equipment, including boilers, furnaces, and generators

What are the consequences of the effects of high altitude on heating and air conditioning systems?

The effects of high-elevation on heating and cooling systems—namely reduced efficiency—change how engineers have to set up, calibrate, and maintain commercial HVAC systems across the Mile High City.

The altitude affects the accuracy of air pressure or refrigerant pressure measuring equipment—which means real pressure and measured pressure may be different by several degrees. Because of this, HVAC engineers need to use pressure-temperature charts to get accurate readings and properly calibrate high-altitude heating and air systems in commercial buildings.

As a result of efficiency losses, high-altitude heating and air conditioning equipment is likely to require more frequent cleaning, adjustments, and maintenance. As a result, high-altitude heating and air systems may have higher operational costs and reduced service lifespans.

The other consideration that has to go into designing and maintaining high-elevation heating and cooling is sizing. To make up for reduced air density, high-altitude HVAC systems often have to be built to a different scale. Undersized systems can end up struggling to maintain optimal temperatures across your building. On the other hand, oversized systems lead to less heating and cooling efficiency and higher operational costs.

However, that doesn’t mean high-altitude heating and air conditioning systems for commercial buildings are doomed to be high-maintenance, short-lived, and energy-inefficient. Quite the opposite, in fact—as long as HVAC systems are appropriately built for high-elevation environments, they can still be cost-efficient, energy-efficient, environmentally sustainable, and capable of ensuring the comfort, health, and productivity of your building’s occupants.

How to Build More Efficient high-elevation Heating and Cooling Systems

To avoid these issues with efficiency and dial in the appropriate scale for a high-altitude heating and air system, HVAC technicians need experience building and servicing commercial systems in places like Denver. Technicians with high-altitude heating and cooling experience know how to optimize HVAC designs and select components that are specifically rated or designed for optimal performance and longevity at high altitudes.

High-altitude heating and cooling systems, for example, can be built with larger or more efficient heat exchangers to maintain effective heat transfer even when dealing with reduced air density. The fans and pumps in air conditioning systems can use motors with variable speed drives (VSDs) to improve overall system efficiency and responsiveness. Ductwork can be optimized to minimize resistance and maximize airflow. Commercial HVAC systems can also integrate advanced smart controls and sensors for real-time adjustments according to high-altitude environmental conditions.

Ultimately, it takes Denver HVAC expertise to deliver cost-effective, energy-efficient, and reliable high-altitude heating and air conditioning to Denver businesses. With over 25 years of experience serving commercial and industrial customers across the Colorado Front Range, Chiller Systems Service boasts extensive experience working with both high-altitude and low-altitude HVAC systems, putting the right people, equipment, and service on the job to ensure best-value turnkey HVAC solutions built for your business.

From product selection and installation to maintenance and repair to energy efficiency analysis, we do it all. Reach out to us to get started on your building’s ideal HVAC solution.

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