Commercial HVAC Service & Repair


Commercial heating and air conditioning systems serve a vital role in facilitating normal business operations and maintaining a comfortable indoor environment. Over one-third of a company’s total monthly power consumption can be attributed to the operation of the HVAC system. Facilities administrators and business owners recognize the importance of choosing a contractor with a strong background in every phase of the commercial air conditioning and heating industry.


Light commercial systems usually range from 5-15 tons in total output capacity. Unlike residential applications, the heating and cooling load can fluctuate significantly depending on the nature of the business. Manufacturing and IT facilities usually generate a substantial amount of process heat. Retail and food service companies have varying occupancy rates and periodic disruptions in the external air barrier.

To ensure that the load requirements are satisfied during the most extreme conditions, it is vital that the HVAC contractor assembles a comprehensive set of load calculations for the entire building and each partitioned area.

At Gilman Heating, Cooling & Plumbing, our designers engineer every system according to ACCA Manual J standards. These complex calculations account for a variety of energy consumption factors including:

  • Projected occupancy rate
  • Insulation value of walls and ceiling
  • Process generated heat
  • Perimeter tightness
  • Windows and doors
  • Duct leakage
  • Local climate history

Once the total load has been established, our designers will match the capacity of the equipment to meet the most extreme anticipated demand. This will ensure that the system operates efficiently while providing an elevated level of indoor comfort.


In the business environment, every commercial air conditioning and heating malfunction is an urgent situation. When the indoor environment is uncomfortable, productivity can suffer and sales opportunities may be lost. For industries with rigid temperature and humidity specifications, an unexpected equipment failure can be catastrophic.

We understand the importance of answering every service inquiry promptly and dispatching a technician in a timely manner. We allocate significant resources to service, so we can address multiple jobs simultaneously.

On the jobsite, our technicians use advanced tools and equipment to locate the cause of the failure and rapidly restore the system to full functionality.

To help avoid the potential for an unexpected breakdown, we recommend a commercial heating and air conditioning maintenance agreement. Preventive maintenance can improve system efficiency and help identify small problems before they affect equipment performance.


In new construction or retrofit applications, a commercial heating and AC contractor must adhere to the construction schedule and coordinate directly with the general contractor. During the rough-in phase of the job, our field mechanics install the air distribution system according to ASHRAE 90.1 and UL 181 standards. After the equipment is set, the system is charged with refrigerant, and we run several tests to verify it is performing to the manufacturer’s specifications. Economizers and make-up air units are adjusted for optimal performance, and the diffusers are air balanced.

Complete Commercial HVAC Services

Gilman Heating, Cooling & Plumbing has served the business community in Virginia since 1917. We provide a wide selection of commercial HVAC services designed to improve indoor comfort, lower utility costs and extend the lifecycle of the equipment.


Customer Feedback

  • Stephanie H, Oct 19, 2023

    They not only replaced my faucet, but did an annual plumbing inspection which I’ve never had and was hugely helpful. I would highly recommend this company for the way they treat their customers and the good service.

  • Janelle H, Sept 23, 2023

    Wonderful first experience with Gilman Plumbing, It's so hard to find good people out here in the NNK. I called them with a non-emergency today and within 30 min they were at my house and repaired everything within 1 hour 40 min from first call to a finished product. Thank you so much Gilman, we are customers for a long time!

  • Michelle M, June 15, 2023

    I have used Gilman's for years and have never been disappointed. The men who come out are always polite, respectful, and careful to explain what is going on and what my options are. I cannot say enough how much I recommend them for whatever service you may need.

  • Leslie I, Oct 9, 2023

    I can not say enough good things about the team at Gilman in Kilmarnock. Whenever I have had an issue I get a very timely appointment due to great administrative management. Everyone from front desk to HVAC and plumbing are great to work with. They will not quit until the job is done. Kudos especially to "Noah" for two days of dead ends with a drain clog. He kept a pleasant attitude no matter how messy the job became! I highly recommend Gilman. Thanks for a great job every time.

  • Cristina T, May 18, 2023

    We had an area in the kitchen with damp drywall. Gilman sent a technician early the next morning who found the leak, verified where it was coming from, removed damaged pipe and installed new pipe. Our technician Chris was professional, knowledgeable, and completed the job timely. I would recommend Gilman to any of our neighbors.

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