Commercial AC Unit Installation Guide
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Commercial AC Unit Installation Guide

An easy installation guide to reference for your next AC install

Is your business looking for a Commercial HVAC professional in the Billings and surrounding area? With most HVAC systems lasting well up to 15 years, a commercial unit can be some of the best money spent. However, hiring the wrong contractor can leave your business with an ineffective and costly expense.

It is better, in the long run, to do diligent research and hire the best HVAC specialist in your area. A licensed professional you trust will help you to understand the unit you are purchasing and how to maximize its efficiency. This service guide by Brink Inc. will go through our process for helping customers in Montana, Wyoming, and South Dakota get the best commercial AC service possible.

Commercial AC Unit Installation Guide

Types of AC Systems

HVAC systems are one of the most important components of a commercial building. They are responsible for regulating the temperature and air quality and ensuring the comfort of occupants. There are a variety of HVAC systems available, each with its advantages and disadvantages. When selecting an HVAC system for a commercial building, office, or restaurant, it is important to consider the size of the space, climate, and the installation costs associated with the system.

Split systems

Utilizing a 'split' between indoor and outdoor components is what makes the Split System the most popular type of central air system in the US. A Split System is normally connected to a building's ductwork. A metal cabinet containing the compressor and condenser coil (the refrigeration system) sits alongside or on the rooftop of the building. The Air Handler, which holds the blower and evaporator coil is inside helping to move cold air throughout the building. Great for small buildings and offices, the split system allows for greater individual control of air temperature. The greater control does come at a cost. More units are needed to create individual management resulting in a cluttered rooftop.

Heat Pump

Heat pumps are another type of split system that supplies cool air in the summer and heat in the winter. A heat pump uses mechanical energy to extract heat from the air and transfer it either outside or inside, depending on whether your location requires heat or air conditioning. As with other split systems, the air handler is inside while the heat pump cabinet sits outside.

Packaged Air Conditioners

A Packaged air conditioner can be a RTU (rooftop unit) and is considered an all-in-one central air system consisting of the compressor, condenser, evaporator, and fan coil all compact into a weather resistant housing cabinet. For commercial use, these units sit on the rooftop and have a higher capacity that is typically enough to cool an entire commercial building. The integrated thermostat is great for easy control and regulation of air temperature. A Packaged HVAC System uses both inside and outside air to keep CO2 levels safe. This also helps avoid overworking the unit during days with extreme temperatures to help save energy. They are often preferred for commercial use due to their modest footprint, space-conscious layout, and versatile installation.

Ductless Mini-split

A ductless mini-split system is one of the simplest and most versatile HVAC systems to install. Basic installation requires a hole in the wall for electrical wiring and a refrigerant line. The system requires two components, an indoor and outdoor unit, connected by copper refrigerant tubing and electrical wiring to deliver heated or cooled air without ductwork. The indoor unit consists of an evaporator coil and a blower fan while the outdoor unit holds the compressor, condenser coil, and fan. Ductless air condition systems use a similar process for cooling as a standard central air conditioning system. While central air conditioning systems use a single centrally located indoor unit to distribute cool air throughout an entire building through a series of ducts and vents, ductless indoor units deliver cool air directly to one area. A ductless HVAC system is highly efficient for commercial use in older buildings or smaller offices that don't require a massive output. It offers users greater control of personal airflow, minimal installation, and quiet operation. Here are two types of zones for a ductless air conditioning unit:

— Single Zone

A single-zone unit is a set-up planned for one area. The connected units carry refrigerant and power via copper tubing and wiring to direct airflow from the outside unit directly inside.

— Multi-Zone

A single outdoor compressor can distribute airflow to multiple indoor units, each controlled separately by a wireless remote, providing users with personal comfort control.

The Most Common HVAC Issues

HVAC systems are essential for maintaining a comfortable indoor environment in commercial buildings. However, HVAC systems can be prone to a number of issues, including air leaks, clogged filters, and dirty coils, to name a few. Here are the most common HVAC system issues that we find and fix.

Leaking Refrigerant

The most common issue found in HVAC systems is refrigerant leaks. If not fixed early enough, refrigerant leaks could harm your HVAC system and cause much larger issues down the road. Indications of a refrigerant leak include oil around valves, service ports, AC connections, or if your system simply fails to blow cool air. Short cycling is a normal audible queue in that your system has a refrigerant leak.

Short Cycling

Typically, an air conditioner runs the compressor until the thermostat tells it to stop. Damage to the thermostat, clogged or dirty filters, and refrigerant leaks can cause your compressor to short cycle. The audible queue previously mentioned is the sound of the compressor in a continuous restart state until the cooling cycle finishes.

Dirty Filters

The filter is vital in protecting your air conditioner and evaporator coil from dirt and debris. When it gets clogged, the system and coils cannot adequately allow air to flow creating negative pressure and causing the system to work twice as hard. Changing the filters of your system quarterly or monthly can help your HVAC system's power and lifespan.

Dirty Condenser Coils

A key component of HVAC systems is the condenser coil. These coils help release heat generated by the unit to the outside. An accumulation of dust, dirt, debris, leaves, and grass, among other things, can reduce the unit's ability to release the heat generated. In fact, an EPA study showed a 21% drop in cooling efficiency as a result of as little as 0.042” of dirt on condensing coils. Clearly, it is important to keep condenser coils clean in order to maintain optimal HVAC performance. There are a few different ways to clean coils, but the most effective way is to use a coil cleaning brush. These brushes are designed to reach into tight spaces and remove even the most stubborn dirt and debris.


Noises emanating from your HVAC system are great auditory signs of issues with your HVAC unit. A few that we typically run into are as simple as:

  • Squeaking - could be a lack of lubricant in the motor
  • Vibration - unbalanced fan
  • Thud - obstructed fan
  • Rattling - from the blower of loose ducts
  • Buzzing or Hissing - typically a leak
  • Boom - the furnace fails to ignite
  • Whistling - from a boiler meaning there is trapped air or a blockage

Malfunctioning Economizer

With nearly two-thirds of RTUs experiencing a malfunctioning economizer, this is a common problem we find and fix. An economizer helps reduce energy consumption for cooling. A damper opens up to collect outside air for circulation if the outside air is cool enough and low in humidity. If the economize isn't function as intended, its air temperature sensors might fail or the dampers become stuck.

Clogged Drain

A clogged drain can cause a drop in air quality and create a buildup of stale and moldy water that can damage and rust components. This moisture and condensation, collected on the coil, is the result of refrigerant converting from liquid to gas in the evaporator coils. We recommend checking the drain pipe every time your or your maintenance provider performs an inspection.

Loose Evaporator Belt 

If you have a loose evaporator belt, it can be hard on the pulley, reduce the fan's speed, and inevitably freeze the coil. The belt should be inspected and replaced quarterly or bi-yearly depending on its wear.

The Ultimate Central Air Conditioner Installation Checklist

The actual steps may vary depending on the specifics of the job. However, this checklist for commercial ac installation can provide an overlook of the steps most likely to be taken. When working with Brink Inc.'s HVAC service team, we are a source for the customer at every step of the process. 

  1. Confirm all shipments and delivery times with all parties.
  2. Set a date to start prepping the installation site. For an RTU, a time early in the morning is better.
  3. Confirm with third parties on the date, and the use of hoisting equipment if the unit is to be installed on the rooftop. 
  4. Take apart and remove the existing air conditioner/ductwork.
  5. Install new duct systems or perform duct repairs.
  6. Prepare the installation site. Depending on the unit or system installed, rooftop supports or concrete pads will be positioned to secure the unit in place. 
  7. Connect the indoor and outdoor units. As previously calculated on the job inspection, the appropriate size for drain piping, electrical lines, and refrigerant will be connected.
  8. Connect the new or existing thermostat to the central air conditioner.
  9. The vacuum will remove contaminants from the refrigerant lines 
  10. Charge the new central air conditioner with refrigerant.
  11. The new cooling system will start and run.
  12. Perform a final installation inspection to ensure the system functions properly.

HVAC Maintenance Benefits

HVAC systems are essential to maintaining a comfortable and safe environment in commercial buildings. And like all complex machinery, HVAC systems require regular maintenance to function. Neglecting HVAC maintenance can lead to several problems, including decreased efficiency, premature failure of components, and breakdowns. In extreme cases, poor maintenance can even pose a health and safety hazard. Fortunately, commercial air conditioner maintenance is relatively straightforward and definitely worth it. Brink Inc. offers comprehensive maintenance contracts that cover all the necessary inspections, repairs, and parts. And like all preventive maintenance, investing in HVAC maintenance can save you a lot of money in the long run.

Better Air Quality

HVAC systems play a role in customer experience, and it is important to keep them well-maintained in order to ensure the comfort of your customers and employees. Regularly performing maintenance can help to identify dirty coils, filters, or blower parts which can all lead to poor indoor air quality. By keeping your HVAC system clean and running smoothly, you can improve air quality within your business and create a more positive in-store experience for your customers. In turn, this can help to increase sales and prosper your business. Therefore, it is clear that a simple maintenance check can have numerous benefits for commercial businesses.

Reduce Expenses

Preventative commercial HVAC maintenance is a must for any business owner. By keeping up with the maintenance on your air conditioner, you can reduce repair costs, prevent further damage to the unit, and prolong its lifespan. In addition, proper maintenance can lower your energy bills by up to 40 percent. Regularly checking and cleaning your unit will ensure that it is running efficiently and not overworking itself. Don't wait until your air conditioner breaks down to call a technician - schedule preventative maintenance today and rest easy knowing your business is in good hands.

Customized Checklist

When it comes to preparing a maintenance plan, a one-size-fits-all approach simply won't cut it. In order to keep your building comfortable all year round, you need a comprehensive, customized plan for maintaining your HVAC equipment. That's where an experienced HVAC service provider can be a valuable asset. They'll take factors like your climate, budget, and type of equipment into account to create a checklist to help you improve efficiency and reduce operating costs.

Frequent Service

Depending on the climate you live in, the frequency of your maintenance tasks will vary. Those in temperate climates can be more lenient with their maintenance schedule, while those in harsher climates might need to perform monthly checks. However, all commercial maintenance programs should include at least four annual services. These services should include; checking and cleaning the air conditioner, as well as other routine tasks. By performing regular maintenance, you can help extend the life of your commercial air conditioner and prevent expensive repairs down the road.

Other Considerations

As running a commercial HVAC system is a heavy operation expense, your HVAC contractor should lend assistance in the eventual purchasing decision. As a heating and cooling contractor in Montana and Wyoming, where temperatures can reach extremes, we know how to maximize the potential of your unit. Here are some quick considerations when starting your search.

  • AC Unit Size: Consider the size of the unit needed to maximize efficiency. Buying and installing a unit that is either too small or too large can lead to inadequate or constricted airflow. HVAC contractors use different formulas to help calculate the approximate airflow needed to adequately cool a specific room.
  • Building Layout: The layout and design of your building can play a large role in the type of system you plan to install. Different systems may better suit your building's layout, saving on installation cost, and improving airflow. You should take into consideration the amount and size of the rooms in your building.
  • SEER Rating: Having a unit with a higher SEER Rating will ultimately reduce utility expenses. Try to find a balance between size and efficiency to get the most out of your unit. 
  • AC Durability: Brink Inc. provides customers HVAC maintenance agreements that offer perfectly-timed service visits. Most units can last up to 15 years, and having a trusted maintenance schedule is vital to ensuring this lifespan. RTUs (Rooftop Units) are vulnerable to hail damage and extreme weather conditions. Consider a unit with extra protection if you're likely to experience extreme seasonal conditions.

Commercial HVAC Contractors

Having a properly functioning HVAC system is crucial for maintaining a comfortable and healthy indoor environment. Regular maintenance and timely repairs can not only prolong the lifespan of your HVAC system but also save you from costly replacements and energy bills. By implementing the tips and tricks mentioned in this blog post, you can ensure that your HVAC system is running at its optimal level. Remember, a small investment in maintenance can go a long way in preserving your HVAC system's efficiency and keeping your indoor air quality at its best. So, don't wait any longer and schedule a maintenance appointment with your HVAC technician today to keep your system in top-notch condition.

Frequently asked questions

Frequently asked questions
Can I Install A Commercial AC Unit Myself?

Installing a commercial AC unit yourself is not recommended. It can be dangerous and lead to further damages and expenses. It is better, in the long run, to have a licensed professional install your AC unit. Research local companies to find a professional HVAC installer with experience from start to finish.

How Do Commercial AC Units Work?

Basic RTU units consist of an Air Hood that draws in outside ambient air that will circulate into the building. The fresh air then flows through a rotating collection of sheet metal called Dampers that open to allow air into the unit or close to prevent air from entering or leaving. The controlled air then flows through a Filter that protects the electrical and mechanical components from dirt and dust that can reduce the effectiveness and efficiency of the machine. From here, the air is met by Coils that cool or heat the air by adding or removing thermal energy. A refrigeration system is typically used to cool the air. Comprising of a compressor, condenser, fan, and electrical controls. Typically a belt-driven fan will be pulling and pushing the air from the outside, through the system, and eventually throughout the building.

How Do You Size A Commercial AC System?

Firstly, you will need to calculate the heating and cooling loads for each room. Convert these loads into Mass Flow Rates (ṁ=Q+(cp x ΔT) before converting into Volume Flow Rates (V̇=ṁ x v). This ultimately provides you with approximately the air needed to meet the cooling load for a given room. Take into consideration the shape, material, and construction of the ductwork to optimize efficiency and reduce friction. Create your layout with listing and labels for design and efficiency. Use a Duct Pressure Loss Chart to identify the duct size needed for various pieces to optimize the flow rate and pressure drop. Use Dampers to help balance your system.

Why Is AC Installation So Expensive?

Commercial HVAC installation is expensive due to its significance to business owners and the specialization of contractors. Getting the right system installed can save business owners thousands of dollars every year. Likewise, contractors are quite specialized in understanding refrigerant dynamics, airflow, electrical, plumbing, thermodynamics, and undergo continual training.

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