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HVAC Maintenance Checklist For Commercial Grow Rooms

Harvest Integrated


Preventive commercial grow room maintenance is not something you choose to have. It’s a must. That is unless you’re not concerned about your crop quality, lowering costs, and frankly, the success of your entire operation. 

But some aspects of preventative grow op maintenance are more important than others. HVAC maintenance comes at the top of the list — it’s crucial. 

Combined with lighting, HVAC systems account for most of the energy consumption in commercial grow rooms. While there are many ways to reduce this energy consumption, HVAC maintenance is one of the most effective and economical ways to optimize system performance, lower utility costs, and ultimately, maximize the system’s lifespan. 

We’ve already covered the 5 ways to extend the life of your grow room HVAC in this short guide, but here’s a broken down and actionable HVAC maintenance checklist to keep your system in top shape. 

Every HVAC maintenance checklist starts with a plan

Wondering how an HVAC maintenance plan is different from an HVAC maintenance checklist? 

Here’s the thing, the checklist is part of the plan.

Think of it this way. The plan details the work your team needs to do regularly to maintain your HVAC, why you need to do the work, how you will do the work, and who will do it. On the other hand, the checklist is where you break down all the different bits of work your team needs to do. 

So, the plan gives a comprehensive view of everything involved in HVAC maintenance, while the HVAC maintenance checklist is one part of the plan.  

For more info on grow room HVAC maintenance plans, check out “Grow room HVAC maintenance plans: The what, why and how of HVAC maintenance.”

Now that we’re clear on the distinction between an HVAC maintenance checklist and a maintenance plan, let’s have a look at some of the top things you should have on your checklist. 

HVAC maintenance for every 1-6 months

First on the checklist is the maintenance you have to undertake between every one to six months. 

System visual inspection

Carrying out a visual inspection of an HVAC system may seem simple enough, but it’s one task that’s often overlooked in commercial grow rooms. 

Since there are just so many other things to do to keep the operation running, growers will often only carry out checks after a costly system failure arises. 

Nonetheless, you can avoid problems by inspecting the HVAC system at least once every month. Performing a visual inspection involves simply checking all the components of your HVAC to see if there are any possible signs that something is wrong. For example, rust, leaks, and disconnected pipes may signal the need for further investigation and action. 

Filter replacement

Air filters are made to be replaced regularly. 

They capture dust, making them a good home for mold to thrive. Moreover, dirt and dust make them susceptible to clogging. As such, you have to inspect filters monthly and determine a feasible replacement frequency. Depending on the filters’ dirt load, you can expect to replace them every one to six months. 

Some top tips for filter maintenance:

  • Start with the best filter. The higher a filter’s MERV rating, the more efficient it is at removing small particles. You want to get a filter with a MERV rating of 11 or above.

Also, consider using high-efficiency pleated filters. Although they may cost a bit more, these filters have an electrostatic charge that grabs the smallest particles, even those that carry bacteria. 

Note: A good filter can improve indoor air quality. 

  • Opt for an HVAC system that has an easy-to-open panel to access the filters. You have to change filters regularly, so it’s important to have easy access to them. One way to ensure this is to get your commercial grow room HVAC design right. 

Refrigerant and drainage lines inspection

You must inspect the insulation on refrigerant lines leading into the grow room every month, and replace the insulation if it’s damaged or missing. 

Besides the refrigerant line insulation, you need to check and clean drainage lines as well. Heating and cooling equipment creates water vapor, which you must funnel out of the grow room efficiently to avoid structural damage. The vapor moves through drainage lines as condensate into an exterior collection tray before evaporating into the air naturally.  

However, the exterior tray can attract biological contaminants such as algae, mold and bacteria, all of which can lead to system blockage and other problems. Additionally, the tray can overflow and damage the grow room. Consequently, you should routinely check that the drainage lines are clear and working well (i.e., the condensate should be evaporating as required without overflowing).

Bi-annual HVAC maintenance

Next comes maintenance tasks you only have to undertake twice every year. 

Condenser and evaporator coil cleaning

Condenser coils are constantly exposed to unfiltered outdoor air and lots of dirt, leading to some energy inefficiency issues. 

Evaporator coils are constantly exposed to the warm, humid air that circulates through them during operation and they are always damp. The humid air and dampness mean there’s a high chance for fungi and mold to grow, and these two are the last things you want in your grow room. 

It’s for this reason that you should ensure that the coils get some cleaning at least twice every year. Built-up dirt and fungal growth are hard to clean from the coils, so frequent maintenance and cleaning will dramatically reduce the time required to complete the job. Plus, coil cleaning will cut energy waste and help lower your utility costs

After every cleaning, treat the coils.

It usually doesn’t take long for mold to grow quickly on coils once they have been cleaned. Treat the coils with antimicrobial treatments after cleaning to inhibit the growth of mold. 

Inspect the area around the air intake

It’s common for water to pool around air handlers, particularly those mounted on roofs. But as with any place where water exists, mold can develop. It’s important to ensure that there’s no water around the air intake to reduce the likelihood of spores getting sucked into the grow room’s ventilation system. 

Inspect fans, belts and bearings 

Although fans, belts and bearings will have minimal impact on an indoor grow’s air quality, they will affect the grow room’s temperature control and ventilation. It only makes sense to include them on your HVAC maintenance checklist. 

Dirt on these three components can lower your HVAC system’s efficiency and airflow. Poor maintenance can also lead to component failure, which is often signified by excessive heat, noise, and vibration emanating from the bearings and belts.

When it comes to belts, proper adjustment is crucial. Improperly adjusted belts will misbehave, create noise, and require replacing way sooner than well-adjusted belts. 

You should also maintain proper tension. Belts that are too tight will put an excessive load on the motor and fan bearings, prompting early failure of the belts and/or bearings. On the other hand, loose belts will slip, causing rapid wear and tear, and torque loss.

Check system calibration

It’s prudent to recheck that your commercial grow room HVAC settings are still appropriate, especially right before summer and winter in anticipation of the temperature increases and decreases. Such checks can result in some major energy and financial savings. 

Annual maintenance tasks

Some maintenance tasks are for once every year.

Patch things up

Your annual checkups should include some patching up. Replace latches and crews, look for air leaks, and replace components such as gaskets. All these elements may seem small, but they can have a big impact on the grow room’s air supply. 

Clean air ducts

Although there’s no set frequency for cleaning supply and return air ducts, it’s still a good idea to inspect them once every year. 

Do keep in mind that the inspection frequency will come down to how regularly you maintain your HVAC. A well-maintained system will put a lower dirt load on the ducts, necessitating fewer inspections (e.g., once every two years).

If you discover duct contamination on inspection, cleaning is essential.  

Inspect and clean dampers

Improper damper operation is one of the most common problems that affect the performance of commercial HVAC equipment, contributing to poor indoor air quality and increasing energy consumption. 

During the annual checks, you should clean and lubricate dampers. When dirty and poorly lubricated, dampers will overload the cooling coil with hot outside air or rob an HVAC system of free cooling potential. 

Ongoing maintenance work

And last on the HVAC maintenance checklist is a task you’ll need to manage on an ongoing basis — quality assurance audits. 

Things to include in the ongoing audits include:

  • HVAC inspections. Simple inspections and swab tests can help you determine if pollutants are affecting your system. 
  • Evaluating indoor air quality for any indications of problems.
  • Proper documentation of readings. Maintaining a history of readings, plus inspection and evaluation findings will make it easier to track the efficiency of your HVAC and identify problems as they arise.

Getting the most out of your HVAC maintenance checklist

There are some aspects of your HVAC maintenance you can take care of on your own. 

For example, your team can do the following to keep your system in good working order until the professionals come in: 

  • Clearing the area around the outside unit(s) of any debris and removing dirt as it starts to gather around the unit(s).
  • Checking filters regularly. 
  • Ensuring that the various system components are kept clean

Your team can play a fundamental role in the efficient running and maintenance of your grow room HVAC, but remember that it’s still important to get some regular professional maintenance on your calendar. 

Professionals will carry out thorough diagnostics, system maintenance and necessary repairs. For example, they can:

  • Inspect your HVAC system and ductwork for air leaks
  • Examine electrical components and wiring
  • Check the system’s refrigerant levels
  • Identify and fix any blockages that disrupt air circulation
  • Inspect and clean components such as condenser and evaporator coils, belts and bearings, and refrigerant and drainage lines
  • Check your HVAC system’s calibration
  • Ensure that the system is achieving optimal performance and matching manufacturer specifications 

It’s a good idea to schedule professional maintenance at least twice every year. The best time to have professionals come in is before summer and winter. This will help ensure that your HVAC system is in great shape before you enter into the seasons that will demand the most work out of it. 

With regular professional HVAC maintenance, you will not only rest easy knowing that your system is in great condition, but you will also benefit from maximum system efficiency and a good ROI on your HVAC investment. 

And if you need help with finding a good HVAC consultant, we’ve got you covered with this quick guide on “How to choose the right grow room HVAC consultant.”

Further Reading: 3 Common Mistakes That Can Cost You HVAC Performance