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Johnson Air-Rotation HVAC system solutions for large, open spaces.

HVAC Systems use high volume, low velocity, air-circulation to distribute conditioned air to a large open space. We say “conditioned air” because the air in the space may be heated, cooled, humidified, dehumidified or supplemented with outside, fresh air as defined by the requirements of the space. Air Rotation HVAC is a total conditioning system, including general ventilation that results in no stratification, vertical temperature control, low energy and maintenance costs. The general concept of Air-Rotation HVAC (sometimes referred to as air turnover) is to return all the air in the space to an Air-Rotation unit a sufficient number of times per hour to ensure an even distribution of the conditioned air. This concept provides for an even temperature distribution of the conditioned air product. Throughout the building, the temperature will not vary by more than (+) or (-) 2 degrees Fahrenheit from a set point and more frequently will only vary by 1 degree Fahrenheit.

Additionally, the measured temperature variation throughout the building height will typically indicate a maximum 2 degree temperature rise for every 10 feet of elevation increase. Our Air-Rotation HVAC System is designed to pull the return air in at floor level by means of a continuously circulating fan system. The return air section has a thermostat that measures air temperature. When the thermostat detects the requirement to add building heat, for example, the heat module directly above the Air Mover Module will function to heat the air. The discharge air is passed on to an air outlet where it is directed into the space, typically near the ceiling. The heated air is a low temperature product, generally only 20 degrees Fahrenheit above the thermostat set point. This low temperature air, when delivered to the space, will mix better with the existing ambient air and will not stratify as easily as if it were delivered at a high temperature.

Save Big With Johnson Air-Rotation Systems

Lower Horsepower

Johnson Air-Rotation HVAC Systems require lower fan motor horsepower than conventional rooftop units to heat and/or cool, thus saving you on electrical utility costs. When you start comparing 10, 20, 30 rooftop units to a few Air-Rotation HVAC Systems total fan motor horsepower really adds up!

Utility Savings

It takes only 1 Johnson Air-Rotation HVAC System to condition 150,000 sq.ft. Air-Rotation customers will see higher energy savings versus traditional HVAC options- approx 30%-70% utility savings versus traditional HVAC options. This costs savings adds up significantly year after year facilitating quicker ROI.


Another major benefit of a Johnson Air-Rotation HVAC System is the ease of portability. A significant number of our customers, especially tenants who are leasing a building on a short-term basis, prefer Johnson Air-Rotation HVAC Systems because of their portability. Other types of HVAC systems are practically impossible to move to another location, especially after the large upfront cost of installation.

Reduced Maintenance

Customers save money on repairs because ground level servicing means no need to climb on the roof to tackle potential weather elements like wind and rain. By making proper routine maintenance easy and at ground level maintenance costs are cut & product life is extended. Also, because Johnson uses readily available repair parts, there’s no need for timely waiting or expensive component repairs.

Bespoke Engineering

Each Johnson Air-Rotation HVAC System is custom designed by our engineering team, we do not sell a one-size fits all model, as a result, each Johnson System is as energy efficient as possible and will heat and/or cool to the exact facility specifications.

Installation Cost Savings

With no need for ductwork, no additional rooftop support, fewer utility hook-ups, no rooftop penetrations and quicker installation, customers save a tremendous amount of money right away by installing a Johnson Air-Rotation HVAC System.

What Can It Do?

Johnson Air-Rotation HVAC Systems are designed to project air up to 400 feet from the heat source and 350 feet from the cooling source. One Johnson Air-Rotation System can effectively heat approximately 150,000 square feet and cool up to 125,000 square feet. We provide our systems with a custom-designed air outlet for each space that can directionally project the conditioned air out over the tops of storage racks, etc., where it gently drops down into rack aisles and these aisles then become our invisible return air ducts. For this reason it is necessary to have a certain minimum height for the Air-Rotation / air turnover principle to work properly. If the building is less than 12 feet in height or has a poor height to width and length ratio, the Air-Rotation system cannot physically be built high enough to project the air away from the unit and it will “short cycle” and not condition the building properly. The Johnson Air-Rotation HVAC System is the best choice for high ceiling, large cubic content buildings, generally anything above 50,000 square feet. Johnson Air-Rotation HVAC Systems can be fully customized to meet any building’s unique requirements. Whether a system requires a chilled water coil, steam heat, dehumidification, or stainless steel, Johnson Air-Rotation Systems can be configured to meet your custom requirements.

Unique Advantages

  • Lower Horsepower
  • Electricity Savings
  • Highly Portable
  • Low Maintenance
  • Bespoke Engineering
  • Low Installation Savings

Frequently Asked Questions

Where Is Air-Rotation Applicable?

Any single zone space of at least 20,000 ft², with 15-20 ft.+ ceilings, is a potential Air-Rotation HVAC candidate.

Where Can I Locate My Systems?

Inside or outside – anywhere you want! There’s a lot of flexibility; your call!

How Much Area Can One System Cover?

A lot! It’s extremely common for a single Air-Rotation system to serve 100,000+ft2.

Where Are These Systems Made?

Manufactured in the USA!

What Are My Control Options?

Anything you want – Standalone controls or DDC.

Can You Handle Outside Air – Ventilation, Makeupair & Economizers?

Absolutely! Give us a call – +91 9900247421

Can I Use Them In An Existing Building?

Absolutely – retrofit or new construction are a great fit for Air-Rotation!

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