HVAC Maintenance Tips: How to Keep Your System in Tip-Top Shape All Year Long

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Last updated: 
May 11, 2024

Everything You Need to Know About HVAC Systems


Imagine it's 90 plus degrees outside with high humidity. You've been working in your vegetable garden all day, and you're hot, sticky, and sweaty. The one thing you crave is hitting that wall of cold air when you walk into your house and relaxing with a tall glass of ice water. But when you open the door, you're greeted by hot, humid air instead. You have just experienced a failure of your HVAC system.

Do you check things out and handle it yourself or should you call a professional? Keep reading to discover everything you need to know about HVAC systems and how to maintain them.

What is an HVAC System?

HVAC stands for heating, ventilation, and air conditioning. It is your home's temperature control system that keeps your home cool in hot weather and warm in cold weather. According to the U.S. Department of Energy, HVAC systems account for about 48% of the energy use in a typical U.S. home, making it the largest energy expense for most homes1.

The History of HVAC

Ancient Times

The concept of heating and cooling has been around for centuries. Ancient Greeks and Romans created fire channels under marble flooring for radiant heat, similar to modern radiant flooring. The Romans also had the hypocaust, a central heating system using radiant heat2. The Egyptians used man-powered fans for cooling.


In the 1400s, Leonardo Da Vinci designed a water-powered fan for cooling. Chimneys were introduced in the 1500s to provide ventilation and remove smoke from homes. Fans were also used to remove toxic gas in mines, improving worker safety.


Major HVAC advancements occurred in the 1700s. Daniel Gabriel Fahrenheit invented the mercury thermometer in 17143. The first centrifugal fan ventilator was introduced. Benjamin Franklin invented the first steam heating system, and direct-fired heat exchangers were used in England. Boiler systems and hot water heating systems also emerged during this time.


In 1861, William Siemens invented the electric furnace with heated coils and fans. The first blast furnace was invented by Fayette Brown in 1885.


The 1900s saw a boom in HVAC advancements. Willis Carrier created air conditioning in 1902, and Stuart Cramer coined the term "air conditioning" in 19064. By the 1920s, air conditioning was available in homes but was still cost-prohibitive for many. Movie theaters began installing AC to attract patrons during the summer, leading to the creation of summer blockbusters.

Other notable 1900s milestones include:

  • AC first put in vehicles in 1939
  • Window air conditioners invented in the 1930s by J.Q. Sherman and H.H. Schultz
  • Heat pumps introduced as a more economical heating and cooling option
  • Puron refrigerant introduced by Carrier Corp in 1998 due to environmental regulations
  • Solar-powered HVAC units introduced in the late 1990s

2000s and Beyond

In the 2000s, renewable energy remains popular with the introduction of geothermal energy systems. Zoned HVAC systems allow temperature control in each area of the home. Many systems are now Wi-Fi enabled for remote control via smartphone.

HVAC Components and How They Work

While HVAC systems can be complex, they all have four main components:

  1. Source (furnace, boiler, heat pump, air conditioner)
  2. Delivery system (ductwork, vents, radiators)
  3. Ventilation
  4. Control (thermostat)

Here's a brief overview of how each component works:


Furnaces are forced-air systems that blow heated air through vents using a fan. Boilers provide radiant heating through a radiator delivery system. Heat pumps work with a furnace to heat or cool air from the ground, air, or water.

Air Conditioning

Air conditioners use a condenser and evaporator system to cool and remove moisture from the air, which is then delivered to the home. According to the U.S. Department of Energy, a home feels cooler with lower humidity levels, which is another way AC makes your home comfortable5.


Ventilation is usually built into the heating or cooling source to remove air from the home, remove byproducts of the heating and cooling process, and filter incoming air.


The control panel, usually a thermostat, allows you to set the desired temperature for heating and cooling. It may also provide fan control.

HVAC Maintenance

Regular HVAC maintenance is crucial for ensuring your system runs efficiently and safely. From our research, proper maintenance can help prevent up to 35% loss of heat6. Here are some key maintenance tasks:

Bi-Annual Professional Maintenance

Have your HVAC system professionally maintained twice a year, ideally in late winter and late summer. A technician will typically:

  • Tighten electrical connections
  • Inspect controls and safety devices
  • Clean coils, blower, burners
  • Lubricate moving parts
  • Replace worn parts and filters
  • Check refrigerant pressure
  • Inspect for leaks and damage

DIY Maintenance

Some HVAC maintenance tasks you can do yourself include:

  • Changing filters regularly (monthly or every three months)
  • Keeping the area around the unit clean
  • Listening for unusual sounds during operation
  • Visually inspecting for damage or wear
  • Staying alert for odd smells that may indicate issues

However, any tasks involving electrical components, refrigerants, or fuel lines should be left to licensed professionals to ensure safety and compliance with local regulations.

Repair vs. Replace

If your HVAC system is experiencing issues, you may wonder whether to repair or replace it. Consider replacement if:

  • The system is over 10 years old
  • Repair costs exceed 50% of replacement costs
  • The system uses outdated parts that are hard to find
  • You have rising energy bills, uneven heating/cooling, humidity issues, excessive noise, or frequent breakdowns

If you're selling your home soon, opt for repairs to ensure the system is safe and functional without investing in a full replacement.

HVAC Do's and Don'ts

To keep your HVAC system running safely and efficiently, follow these tips:


  • Keep flammable materials away from the furnace
  • Check thermostat settings often
  • Consider a programmable thermostat
  • Remove window AC units before winter
  • Cover outdoor units before winter
  • Get the chimney inspected for cracks and issues
  • Check carbon monoxide detectors
  • Insulate vents and pipes
  • Change ceiling fan direction each season
  • Seal leaky windows and doors
  • Use curtains and blinds to help manage temperatures


  • Reduce heat temperature too much when away
  • Use space heaters in large areas or when unattended
  • Constantly change thermostat temperatures when running the AC
  • Attempt DIY repairs when a professional is needed
  • Try to handle gas leaks yourself


A properly functioning HVAC system is essential for maintaining a comfortable, safe home environment. By understanding the basics of how HVAC systems work and following recommended maintenance practices, you can ensure your system operates efficiently for years to come. If you encounter issues beyond your DIY skills, don't hesitate to call a licensed professional for assistance.


  1. U.S. Department of Energy. (n.d.). Heating & Cooling. Retrieved from https://www.energy.gov/energysaver/heating-cooling
  2. Gannon, R. (2014, December 1). A Brief History of HVAC. Retrieved from https://www.achrnews.com/articles/129703-a-brief-history-of-hvac
  3. Bellis, M. (2019, January 23). The History of the Thermometer. Retrieved from https://www.thoughtco.com/the-history-of-the-thermometer-1992525
  4. Carrier. (n.d.). Willis Carrier. Retrieved from https://www.carrier.com/carrier/en/worldwide/about/willis-carrier/
  5. U.S. Department of Energy. (n.d.). Air Conditioning. Retrieved from https://www.energy.gov/energysaver/air-conditioning
  6. U.S. Department of Energy. (n.d.). Maintaining Your Air Conditioner. Retrieved from https://www.energy.gov/energysaver/maintaining-your-air-conditioner

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