Noise is a common complaint about air conditioners. The average central air conditioner outdoor unit being installed today is around 70 decibels. Some of the noisiest are closer to 80 decibels. So how loud is that? It puts the average outdoor unit at about the same noise level as a normal conversation. If you happen to have a noisy air conditioner, it is more like running a vacuum cleaner or music playing in a small auditorium. Not exactly what you want to hear when you are trying to sleep at night.
4 Things that Impact Air Conditioner Noise Levels
There are several factors that can impact how much noise your air conditioner is making.
- Air Conditioner Service – If your A/C unit needs service, it may cause louder than normal operation
- The size of the air conditioner. Larger (more tons) units produce more noise
- The type of A/C unit you have installed. The most expensive units are not always the quietest – but there is some correlation.
- The noise level you hear in your house is impacted by your home’s insulation and window quality
Air Conditioning Noise That Can Be Quieted with Service
While all air conditioners make noise, if your outdoor unit seems louder than it used to be it could be because it needs service. Here are a few common things that cause loud operation.
- Noisy Fans – Debris in the case, dirty fan blades, bent or broken blades or just a loose fan can all increase fan noise. Debris in the case or broken fan blades may cause loud banging.
- Coil Fins – The coil fins are the radiator-like metal tabs on the outside of the A/C unit. Bent coil fins (from string trimmers, lawn mowers or other objects) can cause the A/C to run louder than normal. A technician can bend these fins back with the use of a fin comb to quiet the unit. Too much dirt in the fins can also cause a similar noisy problem.
- Loose Screws – Parts of the cover or even internal parts can get loose due to the vibration of the air conditioner. Sometimes a simple screw driver is all you need to reduce some rattling and vibration noises.
- Fan Motor – On some units, the fan motor needs lubrication each year to stay quiet. If you hear a loud screeching sound when you A/C unit runs, it is likely the bearings in the fan motor are bad and replacing the motor is the only solution.
- High Pitched hissing or screaming sound – This usually indicates a problem with the compressor pressure. You should shut of the A/C unit and call for service.
Many of these problems can be prevented with routine maintenance. If you are in the Charlotte metro area, we offer a planned maintenance program where we clean your A/C unit and check for many of these problems to help your air conditioner run smoothly and as quiet as possible.
Air Conditioner Size Impacts Noise
Large air conditioners have bigger fans and move more air, so they create more noise. You can’t do anything about this with your existing unit, but if you are replacing your unit, a load calculation can help determine if you can replace it with a smaller size that will create less noise.
The Quietist Types of Air Conditioners
Air conditioner noise can be controlled by the type of air conditioning equipment you use.
Geothermal Systems are Very Quiet
If you are looking for the quietest solution (and most energy efficient), then a geothermal heat pump system is the best option based on noise alone. Geothermal units do not exchange heat the same way as traditional systems. Instead of an outdoor unit with a fan, the heat is exchanged in an underground (or underwater) loop. So the geothermal unit can actually be placed indoors and it doesn’t have a noisy outdoor fan. The only noise you get is from the fan that blows the air through your ducts. It is simply the quietist solution for your house and your neighbors.
Traditional System Features that Help with Noise
- Compressor noise suppression – Mounts and insulation included in the unit can help muffle the noise made by the compressor
- Fan Technology – Improved design and sound muffling techniques can reduce noise from the outdoor fan
- Variable Speed blower fans – The indoor unit fan runs at different speeds to keep the house comfortable. When running at lower speeds indoor fan noise is reduced.
- Inverter Technology on Ductless Units – The variable speed technology used in many ductless mini-split units leads to a quieter outdoor unit than a full sized A/C. But these are generally for special heating and cooling needs, rather than entire homes.
The Quietist Air Conditioner We Install (besides geothermal)
Trane makes two variable speed models rated at 55 decibels, which are some of the quietest air conditioners you can have installed. The XV20i and the XV18 both have True Comfort Variable Speed technology. The XV20i is the top of the line model, with the highest SEER rating Trane makes at 22 SEER. At 55 decibels, they are less than half as loud as a 70 decibel unit and rated as quieter than background music (6o db). Among mid-priced Trane models, the XL16i is the quietist, at 69 decibels, which is still half as loud as an 80 db AC unit.
Ready to do something about your noisy air conditioner in the Charlotte/Rock Hill/Fort Mill area?