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HVAC Frequently Asked Questions 

Answering Your Common HVAC Questions 

HVAC systems, the unsung heroes of our homes and offices, silently maintain the comfort and quality of our indoor environments. From battling hot summer days with a cool breeze to providing a warm refuge during freezing winters, these systems are indispensable parts of our daily lives. 

This page is designed to be your go-to resource for understanding and troubleshooting common HVAC issues. We cover a range of topics, from the basics of how HVAC systems work to more complex concerns like maintenance schedules, energy efficiency, and system upgrades. You will also find answers to everyday queries about thermostat settings, strange noises, or unexpected system behaviors. 

Have More Questions? Reach Out to Us Today!

If you still have heating and cooling questions, you should check out our blog. We offer regular advice and answer other common questions. 

Russell & Abbott also offers customers high-quality HVAC services. Should you need maintenance, repair, or installation work on your AC or heating unit, our team offers residential and commercial HVAC services. 

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    • What types of HVAC systems do you specialize in servicing?
      Our team specializes in servicing a wide range of HVAC systems, including central air conditioning, heat pumps, furnaces, and ductless systems.
    • Do you provide maintenance plans for HVAC systems in Maryville, TN?
      Yes, we offer comprehensive maintenance plans for HVAC systems in Maryville, TN. Regular maintenance helps extend the lifespan of your HVAC system and ensures optimal performance.
    • What brands of HVAC equipment do you repair?
      Our team is experienced in repairing all major brands of HVAC equipment.
  • HVAC

    • What Typically Makes Up an HVAC System?

      Your HVAC system has multiple parts, which can include:

      • Air purifier. Air purifiers, or air cleaners, remove pollutants and allergens from the air, improving indoor air quality. They are especially beneficial for individuals with allergies or asthma.
      • Ductless air conditioning. Ductless air conditioning, similar to mini-splits, offers a solution for cooling spaces where traditional ductwork is not feasible. These systems are comprised of an outdoor unit and one or more indoor units that distribute air directly into the living space, eliminating the need for ductwork.
      • Exhaust outlet. To prevent overheating, your HVAC system may have an exhaust that allows heat to be released through a duct or vent.
      • Filters. At the end of your ductwork, there should be one or more filters that keep the air free of dust, dander, and debris.
      • Furnaces. A furnace is a vital component of an HVAC system that generates heat by burning fuel (natural gas, propane, or oil) or by using electricity. The heat generated is then distributed throughout the building via ductwork.
      • Heat pump. Heat pumps are a versatile component of an HVAC system, serving both heating and cooling purposes. During colder months, heat pumps extract heat from the outdoors and channel it indoors. Conversely, in warmer months, they remove heat from indoors and release it outside. This is achieved through a cycle of evaporation and condensation facilitated by a refrigerant fluid.
      • Humidifier/dehumidifier. Humidifiers add moisture to the air in dry climates or during winter when the heating system can make the indoor air too dry. On the other hand, dehumidifiers reduce humidity levels in damp climates or specific areas of the home, like basements, preventing mold growth and other moisture-related problems.
      • Thermostats. Thermostats are the control units of an HVAC system. They maintain the desired temperature by regulating the operation of the heating or cooling system based on the ambient temperature. Modern thermostats can be programmable or smart, allowing for energy-efficient use and remote control.
    • What Makes Heat Pumps So Energy Efficient?

      Heat pumps have been widely recognized for their energy efficiency, serving as an innovative solution for heating and cooling homes. They operate by transferring heat from one location to another instead of generating heat directly. As they do not burn fuel, heat pumps are more energy-efficient than traditional systems.

    • What Size HVAC Unit Do I Need?

      Choosing the right size for an HVAC unit is crucial to ensure efficient operation, maximum comfort, and reduced energy consumption. The size of the building is a fundamental factor affecting the size of the HVAC unit, but there are other key elements to consider, which we discuss below.

      • Square footage. While a small home or office may only need a two-ton unit, larger properties (around 3,000 sq. ft.) may need a four to five-ton unit.
      • Ceiling height. Higher ceilings mean more air to heat or cool, which can impact the size of the HVAC unit needed. A building with high ceilings may require a larger system than one with standard 8-foot ceilings.
      • Insulation. Well-insulated buildings retain heat or cold air better, reducing the workload on the HVAC system. If your building is well insulated, you might get away with a smaller HVAC unit.
      • Number of windows. Windows can be a significant source of heat gain or loss. More windows, or poorly insulated windows, might require a larger HVAC unit to compensate for the energy loss.

      Professional HVAC contractors typically use a complex calculation called a Manual J Load Calculation to determine the exact size of the HVAC unit required. This calculation takes into account all the factors mentioned above and more, including the building's orientation, number of occupants, and even the type of lighting used.

    • How Can I Make My HVAC System More Efficient?

      If you are wondering how efficient your HVAC system is, the first thing you should do is check what rating your system has. Some of the most common scientific ratings include:

      • SEER (Seasonal Energy Efficiency Ratio). This rating measures the cooling efficiency of your HVAC system. The higher the SEER rating, the more efficient the system is.
      • EER (Energy Efficiency Ratio). EER is similar to SEER, but it measures efficiency over a steady state rather than a season.
      • AFUE (Annual Fuel Utilization Efficiency). This rating is used for furnaces and boilers. It indicates how efficiently the appliance converts fuel into heat over a year.
      • HSPF (Heating Seasonal Performance Factor). This rating measures the heating efficiency of heat pumps. The higher the HSPF rating, the more efficient the heat pump is.
      • COP (Coefficient of Performance). This rating is used for heat pumps and refrigeration units. It measures the ratio of useful heat movement per work input.
      • MERV (Minimum Efficiency Reporting Value). This rating can range from one to 16 and indicates how effective an air filter is. The higher the MERV rating, the more effective the filter is at trapping dust and other particles.

      Aside from being mindful of the system’s rating when you obtain your heating and cooling systems, you can also take the following steps to increase your unit’s efficiency:

      • Be mindful of your thermostat settings. You can help your HVAC unit be more efficient by simply adjusting your thermostat by a few degrees up in the summer and down in the winter. For instance, in the hotter summer months, during the day, setting the temperature five degrees higher can put less strain on your system. If you have a smart thermostat, you can set your system to automatically adjust throughout the day, even when you are away from home.
      • Be mindful of when your curtains and blinds are open. Sunlight can warm your home or certain rooms. By closing your blinds or curtains on sunnier days and during the summer, you can help keep the temperature in your home regulated.
      • Clean your condensate drain line. If this line is clogged, your AC unit can have problems that affect efficiency. To be more specific, a clogged condensate drain line can trap water in your AC, which can lead to a frozen evaporator coil, an overflowing drain pan, or other serious damage.
      • Insulate your home. Proper insulation and strategic closing off certain areas in your home can greatly enhance the efficiency of your HVAC system. Insulation acts as a barrier to heat flow, keeping your home warmer in winter and cooler in summer. This means less work for your HVAC system as it doesn't have to compensate for heat loss or gain due to poor insulation. Efficient insulation can help maintain a more consistent indoor temperature, reducing the need for your HVAC system to constantly kick on and off, thus saving energy and extending its lifespan. Similarly, closing off areas that aren't in use or don't have heating or air conditioning can also help. By doing so, you're essentially reducing the total area that your HVAC system needs to heat or cool. This means your system can focus on maintaining the temperature in smaller, frequently used areas, working more efficiently and using less energy.
      • Schedule routine maintenance. Having professional maintenance completed at least once a year can help you improve HVAC efficiency and prevent costly issues from arising. During a maintenance appointment, a technician can clean your unit and address smaller issues immediately.
      • Keep indoor vents clear. It is best to avoid having any furniture or items blocking your vents, as this can affect airflow and push your system to work unnecessarily harder.
    • How Often Should I Replace My Air Filters?

      Generally, you should change your air filters at least once per season. However, you may need to change your filter more frequently, especially if you notice visible signs of clogging or dirt. The frequency of replacing air filters in your HVAC system is largely dependent on several factors, including:

      • The type/size of the filters used. While a standard one-inch pleated filter only needs a replacement every two months or so, a two-inch filter can be replaced every three or four months, and a three-inch pleated air filter has an even longer lifespan.
      • The air quality in your area. If you live in a location with high pollution levels or a lot of dust, your air filter will likely become dirty and clogged more quickly. This is because the filter's job is to trap these particles to prevent them from circulating in your home, and a higher quantity of pollutants means the filter has more work to do. Similarly, if you live in an area prone to wildfires, the smoke and ash in the air can also contribute to a faster build-up on the filter. On the other hand, if you live in a relatively clean, rural area, your filter might not need to be replaced as frequently.
      • The usage of the system. If your home's heating and cooling system only runs a few times a year, you might need to replace the air filters every six to 12 months. However, more frequent use requires more frequent filter replacements.

      The consequences of not replacing your air filter timely can range from reduced airflow and higher energy consumption to damage to the HVAC system itself. A clogged filter can restrict the airflow, which forces the system to work harder to maintain the set temperature and leads to higher energy bills. Failing to change your air filters can also compromise your indoor air quality (IAQ).

    • What Can I Do to Lower My Energy Bills? | Reduce HVAC Energy Bills

      In today's fast-paced, high-tech world, energy consumption has become an inevitable part of our daily lives. From the moment we wake up, switch on our lights, and crank up our AC or heating unit to the time we go to bed after a late-night Netflix binge, our energy usage is constant and often excessive.

      The result? Skyrocketing energy bills that can cause a significant dent in our monthly budgets. But there are effective ways to lower these bills without compromising on our comforts. Here are some practical ways you can lower your energy bills:

      • Change your HVAC filters regularly.
      • Clean your HVAC ducts.
      • Complete an audit on your home energy usage.
      • Seal and gaps and cracks in/around doors and windows.
      • Replace old windows.
      • Improve your home’s insulation.
      • Work with seasonal temperatures instead of against them when setting your thermostat.
      • Invest in a smart thermostat.
      • Consider cooking outdoors when possible, as cooking indoors can affect your property’s temperature and indoor air quality.
      • Plant trees or invest in blackout curtains or reflective blinds.
      • Utilize your ceiling fans for better circulation and cooling.
    • At What Temperature Should I Set My Thermostat?

      The summer months in Tennessee are typically hot and humid, with temperatures often reaching the 90s. Conversely, winters can be quite cold, with temperatures frequently dropping into the 30s. These extreme variations in outdoor temperature significantly impact the indoor environment, making a well-regulated thermostat essential for comfort and energy efficiency.

      With energy efficiency in mind, the U.S. Department of Energy suggests setting your thermostat at 78 degrees Fahrenheit when you're at home and awake during the summer months. This temperature strikes a balance between comfort, energy efficiency, and cost-effectiveness. At night or when you're away from home, it's recommended to increase the temperature by several degrees to save energy.

      In the colder winter months, the U.S. Department of Energy recommends setting your thermostat to 68 degrees Fahrenheit while you are awake and lowering it while you're asleep or away from home. This allows for comfort while minimizing energy usage.

      It's important to remember that temperature greatly affects our well-being. A too-hot or too-cold environment can disrupt sleep, decrease productivity, and even affect mood. Therefore, while energy savings are important, it's crucial to prioritize comfort and health.

      For optimal energy savings, consider adjusting your thermostat settings based on your daily routines. For instance, when sleeping, our bodies tend to stay warm; hence, a cooler environment is more conducive to sleep. Similarly, if your home is empty during the workday, there's no need to maintain a comfortable temperature until shortly before you return home.

      Investing in a programmable or smart thermostat can greatly facilitate energy optimization. These devices allow you to set a schedule for temperature changes so you won't forget to adjust the temperature when you leave or go to bed. Furthermore, some smart thermostats can even learn your routine and make adjustments automatically.

      Adjusting your thermostat when leaving the house can also lead to significant energy savings. Even a few degrees can make a noticeable difference to your energy bill over time.

    • How Often Should I Have My HVAC System Serviced?

      Generally, it's recommended to have your HVAC system serviced at least once or twice a year, typically during the transition periods between heating and cooling seasons. However, the frequency of HVAC system servicing can vary based on three key factors:

      • Your local climate. If you live in a region with extreme temperatures or high humidity levels, more frequent servicing may be necessary to ensure the system's efficiency and longevity. For instance, an HVAC system in a tropical climate might need to be serviced more often due to the constant high humidity and heat, which can lead to faster wear and tear.
      • The usage frequency of the system. If you frequently use your HVAC system constantly (i.e. running it continuously throughout the summer or winter), it would require more regular maintenance compared to a system that's used sparingly.
      • The age of the HVAC unit. Older systems, typically those over 10 years old, often require more attention and frequent servicing to keep them running smoothly and efficiently.
      • The state of the system. If your system has not had regular maintenance completed, the system may have more wear and tear or potential issues. Neglecting proper maintenance can lead to numerous potential dangers. For one, a poorly maintained HVAC system can become a breeding ground for mold and bacteria, affecting the indoor air quality and potentially leading to health issues for the occupants. It can also result in higher energy consumption, leading to increased utility bills.

      Regular servicing of your HVAC system offers a host of benefits, including:

      • Increasing energy efficiency
      • Reducing your carbon footprint
      • Saving on energy costs
      • Ensuring a healthier indoor environment by improving air quality
      • Preventing the build-up of harmful pollutants
      • Identifying potential issues and saving you from costly repairs or system replacements
    • How Do I Find a Trustworthy HVAC Company?

      Choosing the right HVAC company is crucial for maintaining a comfortable and healthy living environment. Here are eight actionable tips to guide you through the process and help you make an informed decision:

      1. Ask for recommendations. Word of mouth is a powerful tool when it comes to finding reliable services. Ask friends, family, or neighbors if they've had any positive experiences with HVAC specialists.
      2. Read online reviews. Look at online reviews on platforms like Google, Yelp, or Angie's List. They can provide insight into the company’s professionalism, quality of work, and customer service.
      3. Check qualifications and certifications. If you are interested in an HVAC company, see if they have any certifications, awards, or other qualifications, such as NATE (North American Technician Excellence), EPA (Environmental Protection Agency), and HVAC Excellence recognition.
      4. Consider their experience. An experienced HVAC company is more likely to offer high-quality services. Look for a company that has been in the business for several years and has experience dealing with your specific type of HVAC system.
      5. Ask about their service prices. When you contact a potential HVAC company, they should be transparent about their pricing so you can determine if their services are in your price range.
      6. Inquire about guarantees or warranties. A good HVAC company will stand by their work and offer warranties or guarantees on their services. This provides assurance that if anything goes wrong after the work is done, you won’t be left high and dry.
      7. Verify whether they have insurance. The HVAC company should have liability insurance to protect you in case of any accidents during the job. Don't shy away from asking for proof of insurance.
      8. Assess their professionalism. From the first contact, assess the company's professionalism. They should be punctual, respectful, and willing to answer all your questions.
    • Why Is My HVAC Rumbling? | Explaining Common HVAC Noises

      A well-functioning HVAC system produces a steady, low hum that is barely noticeable. When the system turns on or off, you may hear a brief, gentle whoosh of air. The outdoor unit's fan might also produce a faint buzzing sound. If you hear these sounds, your HVAC system is likely in good working order.

      However, the following types of noises can be indicative of issues your HVAC is having:

      • Banging or knocking. Banging or knocking sounds are usually a sign that something is loose or out of balance. This could be a connecting rod, piston pin, or crankshaft inside the air handler or compressor. These issues can cause significant damage if not addressed promptly. Turn off your system at once and contact an HVAC professional.
      • Booming. If you notice booming noises, your furnace may be having trouble lighting or lighting. This issue can be caused by a buildup of carbon particles or dirt.
      • Clicking. A repetitive clicking noise when your HVAC system starts up or shuts down is normal. However, if the clicking continues while the system is running, it could indicate a failing thermostat or a defective control relay. Both of these issues require professional attention.
      • Hissing. This sound may come from your AC compressor or furnace. If it seems to be coming from the furnace, an air duct may be leaking, or the furnace itself may have a leak. If the issue is with your AC compressor, there may be an internal refrigerant leak. Cut off the AC unit until a professional can inspect the unit if you think that’s the source of the hissing.
      • Humming. A humming sound from your HVAC system typically indicates that something is vibrating. It could be as simple as a loose screw or as severe as a malfunctioning motor. If tightening everything doesn't solve the issue, it might be time to call a professional to check the motor or the electrical components.
      • Popping. You may notice a popping sound coming from your ductwork—this is normal. If you suddenly run warm air and the ducts are cold metal, the popping noise is simply the ductwork expanding. However, if the popping noise persists or seems to be coming from a different part of your HVAC system, you should contact your HVAC technician.
      • Rattling. Rattling noises can indicate that your HVAC system is starting to deteriorate and parts are loosening. It could also mean that debris like leaves or twigs has gotten into your system. If it's debris, turn off your system and remove it. If no debris is present, consider calling an HVAC professional to check for loose screws, bolts, or other internal parts.
      • Squealing or screeching. Squealing or screeching noises often suggest that the belts or motors on your fans aren't functioning correctly. Belts can become worn over time and may need replacement. Motors can also fail, especially if they're not regularly lubricated. This is another situation where a professional should be contacted.
      • Thwacking or thumping sound. This sound may indicate that the blower fan blades have something stuck in them. Check and see if there is an object or debris stuck in the fan. If there is, the object should be removed to avoid wear and tear and get rid of the noise.
      • Whistling. This sound may come from your AC compressor. As soon as you notice a whistle or similar noise, you should cut the unit off and contact an HVAC technician, as your refrigerant pressure is likely high or the compressor is failing.
    • Why Is R-22 Being Phased Out?

      R-22, more commonly known as Freon, has been the refrigerant of choice in residential and commercial air conditioning (AC) units for several decades. However, research revealed that R-22 is a significant contributor to the depletion of the Earth's ozone layer.

      Recognizing the environmental implications of continued R-22 use, the United States, along with 196 other countries, signed the Montreal Protocol in 1987, an international treaty designed to phase out the production and consumption of ozone-depleting substances. As part of this agreement, the production of R-22 was officially banned in the U.S. in 2020.

      The phase-out of R-22 is not only an essential step towards protecting our environment but also presents opportunities for efficiency upgrades. In place of R-22, many are turning to R410A, a more environmentally friendly refrigerant. R410A, also known as Puron, doesn't contribute to ozone depletion and can offer better energy efficiency, potentially leading to lower electricity costs.

      However, switching from R-22 to R410A isn't as simple as replacing the refrigerant in your existing system. The two refrigerants require different operating pressures, meaning that R410A can't be used in an AC system designed for R-22 without potentially causing damage.

      A full system upgrade would be necessary to make the switch, which could be a significant investment. Still, given the increasing scarcity and cost of R-22, along with the potential energy savings of newer systems, many homeowners and businesses may find that upgrading is both an environmentally and economically sound decision.