Frequently
Asked Questions
FAQ- How much does it cost to replace an AC unit?
- Why is my electric bill so high?
- Is it cheaper to repair or replace my HVAC system?
- How long does an AC unit last?
- How often should I have my HVAC serviced?
- What maintenance can I do myself vs. calling a pro?
- How often should I change my air filter?
- Duct cleaning vs. replacement?
- What size AC do I need for my house?
- What brand of HVAC system do you recommend?
- How long does it take to install a new system?
- What’s the difference between a heat pump and an AC?
- What is a SEER rating?
- Is a smart thermostat worth it?
- What temperature should I set my thermostat to at night?
- Can I control my HVAC from my phone?
- How do I improve the air quality in my home?
- What causes dust buildup even after cleaning?
- Do I need a whole-home air purifier or humidifier?
Costs & Pricing
How much does it cost to replace an AC unit?
Most HVAC replacements range depending on the size of your home, the efficiency (SEER rating) of the new unit, and the complexity of installation (ductwork changes, electrical upgrades, etc.). During your free in-home estimate, our Comfort Specialist will give you an exact, itemized quote. We’ll walk you through every line item so you know exactly what you’re paying for and why.
Why is my electric bill so high?
A spike in your electric bill is usually a sign your system is working harder than it should. Common causes include a dirty air filter restricting airflow, low refrigerant, aging or inefficient equipment, leaky ductwork, or a thermostat that isn’t set efficiently. Extreme weather also makes your system run longer cycles just to keep up. A quick tune-up can often identify the culprit. Our Energy Savings Membership includes seasonal maintenance designed to keep your system running at peak efficiency year-round.
Is it cheaper to repair or replace my HVAC system?
It depends on the age of your system, the cost of the repair, and how often it’s been breaking down. As a general rule of thumb: if your unit is under 10 years old and the repair costs less than 30% of a full replacement, repair usually makes sense. If it’s older, needs frequent repairs, or uses discontinued refrigerant, replacement often saves you money long-term through lower energy bills and fewer service calls. Our technicians will always give you an honest recommendation based on the numbers.
How long does an AC unit last?
A well-maintained HVAC system typically lasts 10–15 years. Skipping regular maintenance, running the system in poor condition, or living in a hot, humid climate like the Midlands can shorten that lifespan. Routine tune-ups are the single best way to maximize the life of your system.
Troubleshooting
Why is my AC running but not cooling the house?
This is one of the most common summer service calls. Possible causes include low refrigerant (a sign of a leak), a dirty or frozen evaporator coil, a failing compressor, a clogged air filter, or a thermostat that isn’t communicating properly with the system. If your AC is running constantly but the house isn’t cooling down, turn it off and give us a call. Running it in this condition can cause further damage.
Why does my house feel humid even with the AC on?
Your AC is designed to remove humidity as it cools, but if it’s oversized for your home, it may cool the air too quickly without running long enough to pull out moisture. Other causes include a dirty air filter, low refrigerant, or a system that’s aging and losing efficiency. If humidity is a persistent issue, a whole-home dehumidifier paired with your AC can solve the problem.
Why is my AC making a loud noise?
The type of noise usually points to the issue. Banging or clanking can indicate a loose or broken part inside the compressor. Squealing often means a belt or motor bearing needs attention. Clicking may be electrical. Hissing can signal a refrigerant leak. Any new or unusual noise is worth having checked out promptly; noises are often an early warning sign before a bigger breakdown.
Why does my house have hot and cold spots?
Uneven temperatures are usually caused by leaky or poorly designed ductwork, a system that’s undersized or oversized for your home, blocked vents or registers, or poor insulation in certain rooms. In two-story homes, it’s also common for upstairs rooms to run warmer. A duct inspection can usually pinpoint the exact cause and whether balancing dampers, sealing, or a zoning system would help.
Why does my AC smell musty/burning when I turn it on?
A musty smell usually points to mold or mildew growth in the ductwork or on the evaporator coil, often from excess moisture. A burning smell is more serious and can indicate dust burning off after a period of inactivity (common and harmless if it clears quickly) or an electrical/motor issue (which is not something to ignore). If a burning smell persists for more than a few minutes, shut off your system and call us right away.
My AC is freezing up — what does that mean?
Ice on your AC unit or refrigerant lines usually means airflow is restricted (often a dirty filter) or refrigerant levels are low. Running a frozen system can damage the compressor, which is an expensive repair. Turn off your AC and let it thaw completely, check your air filter, and give us a call if the problem returns once it’s back up and running.
My indoor fan is always running. Is that a problem?
Sometimes homeowners turn the fan switch to “On” versus “Auto” which causes the indoor fan to run continuously. Turn the switch to “Auto” and the fan should stop running continuously. For any reason if this does not resolve the issue, give us a call.
Maintenance
How often should I have my HVAC serviced?
Every air conditioning system should be serviced at least twice a year. We recommend servicing it once for the AC season and once for the Heating season.
What maintenance can I do myself vs. calling a pro?
Homeowners can safely check and replace air filters monthly, keep the outdoor unit clear of leaves, grass clippings, and debris, and make sure vents and registers aren’t blocked by furniture or rugs. Anything involving refrigerant, electrical components, the compressor, or internal parts should always be handled by a licensed technician. Our Energy Savings Membership covers the professional side of maintenance twice a year, so you don’t have to keep track of it.
How often should I change my air filter?
During the summertime, your air conditioning is running a lot more than in other months. Therefore, during this time, you should change your filter at least once a month to keep it running properly. This includes pleated filters that claim to be 3 month filters. For other months of the year, use your best judgment.
Duct cleaning vs. replacement?
If your ductwork has visible dust, mold, or debris buildup, or you’re noticing allergy symptoms tied to your home’s air, that’s usually a sign the ducts are damaged, leaking, or too far gone to simply clean and trust. Cleaning dirty ductwork doesn’t address the underlying problem causing the buildup in the first place, and contamination can return quickly. In these cases, replacement is the more reliable, long-term fix. A technician can inspect your ductwork and give you an honest recommendation on the best path forward.
Buying & Replacing
What size AC unit do I need for my home?
AC sizing depends on your home’s square footage, ceiling height, insulation, window placement, and even how many people live there; not just square footage alone. An oversized unit cools too fast without removing humidity, while an undersized one runs constantly and still can’t keep up. We perform a full load calculation during your free estimate to recommend the exact right size for your home.
What brand of HVAC system do you recommend?
While we are a Lennox Certified Dealer, we can install several trusted, high-efficiency manufacturers and help you choose based on your budget, home size, and efficiency goals. What matters most is proper installation and sizing, even the best-rated equipment underperforms if it’s not installed correctly. We’re happy to walk through your options during a free consultation.
How long does it take to install a new system?
A standard system replacement (same size, same location) usually takes about one day. More involved installations such as adding ductwork, upgrading electrical, or installing a new system type like a heat pump, may take one to three days. We’ll give you a clear timeline upfront so you know exactly what to expect.
What’s the difference between a heat pump and an AC?
A traditional AC only cools your home, you’ll still need a furnace for heat. A heat pump does both: it cools in the summer and, by reversing the refrigerant cycle, pulls heat from outside air to warm your home in the winter, even in cooler temperatures. Heat pumps are often more energy-efficient for year-round comfort, especially in a climate like ours where winters are mild.
What is a SEER rating?
SEER stands for Seasonal Energy Efficiency Ratio. The size of an air conditioner is rated in BTU or Tons. However, the efficiency is rated in SEER. This ratio is calculated as the cooling output divided by the power input for the average U.S. climate. It’s like MPG (miles per gallon) in a car – the higher the MPG (or SEER), the lower the gasoline (electricity) bill.
Smart Home & Thermostats
Is a smart thermostat worth it?
For most homeowners, yes. Smart thermostats learn your schedule, adjust automatically for energy savings, and let you control your system remotely so you’re never cooling (or heating) an empty house. Many homeowners see a noticeable reduction in energy costs after switching, and the ability to catch a malfunctioning system remotely can prevent bigger problems down the road.
What temperature should I set my thermostat at night?
For the best sleep and energy savings here in the Southeast, aim for 60°F–67°F in the winter and 72°F–75°F in the summer. Because our summers come with such high humidity, running your AC a bit cooler at night helps pull more moisture out of the air. Many Midlands homeowners land on 65°F–68°F as their sweet spot between comfort and lower energy bills.
Can I control my HVAC from my phone?
Yes, with a smart thermostat installed, you can adjust the temperature, view energy usage, and get maintenance alerts right from an app on your phone, whether you’re home, at work, or on vacation. We can help you choose and install a smart thermostat that fits your system and lifestyle.
Indoor Air Quality
How do I improve the air quality in my home?
Start with the basics: change your air filter regularly, keep humidity levels balanced, and have your ductwork inspected for leaks or buildup. Beyond that, whole-home air purifiers, UV lights, and upgraded filtration systems can actively remove allergens, dust, and pollutants that a standard filter alone won’t catch.
What causes dust buildup even after cleaning?
If you’re dusting frequently but it keeps coming back, the culprit is usually your HVAC system recirculating dust through leaky or dirty ductwork, a low-quality air filter that isn’t trapping fine particles, or inadequate air sealing in the home. Upgrading your filter, sealing ducts, and adding an air purifier can significantly cut down on dust between cleanings.
Do I need a whole-home air purifier or humidifier?
If you or your family deal with allergies, asthma, or frequent colds, or if you notice musty odors, excess moisture, or inconsistent humidity in your home, a whole-home solution is worth considering. Unlike portable units, whole-home systems treat every room through your existing ductwork. We can assess your home’s air quality needs during a routine visit and recommend whether a purifier, humidifier, or dehumidifier makes the most sense for you.
Learn More On Our HVAC Blog
Air Conditioning Why Your AC Feels Less Cool Even Though It’s Running Fine
Air Conditioning Does Your HVAC Unit Have a Surge Protector?
Air Quality 