Will air conditioning noise make you hot and bothered, or is a small increase in sound levels worth the cooling breeze?

'How much air conditioning noise can I expect' is arguably one of the most common questions asked by anyone considering adding it to their homes. But, is it realistic to expect it to be whisper quiet?

With fixed air conditioning units comprising interior and exterior units, and portable air conditioners venting externally through windows, it's safe to assume you will experience some level of volume, but how much?

We explore air conditioning noise and whether one solution is quieter than another so you know what to expect when choosing a system or cooling solution.

Fixed air conditioning noise: How noisy is it?

If you're investing in the air conditioning costs for a fixed system, you'll want to be sure that it's money well spent. While the cooling breeze it will bring is guaranteed to bring relief from rising temperatures, if you can't bear to turn it on because it's simply too noisy, you will have wasted money, time and effort.

“One of the most common concerns people have about air con is noise," agrees Adam Knight, a lead engineer at heating and cooling experts, BOXT. "But modern systems are surprisingly quiet," he assures us.

"The indoor units BOXT installs, such as high-efficiency Bosch models, are designed to be whisper-quiet. They typically produce around 50 - 55 decibels of sound, which is comparable to low background music or a modern fridge running," he explains.

"Some Bosch units even come with a 'silent mode' feature which reduces the indoor sound even further to 21 decibels," he adds.

"Overall, air conditioning is certainly quieter than an oscillating fan whirring away in the corner of the room," says Adam.

It's a statement backed up by Hamid Salimi, residential product manager at Daikin UK.

"While it’s normal for air conditioning (otherwise known as air-to-air heat pumps) to make some noise, they are much quieter than most people think," says Hamid.

"Indoor units make a gentle whirring noise which measures around 30 decibels. For context, that’s quieter than a refrigerator and as soft as a whisper, meaning it’s very unlikely that an air conditioning unit will cause a noise disturbance to you or your neighbours," he explains.

Is the noise level from the outdoor unit more than the indoor one?

While on the subject of neighbours, you'll also need to remember that as well as indoor noise, fixed air conditioning installation will include an external unit that will be placed outside.

So is this as quiet as the indoor unit, or will it generate more noise?

"The outdoor unit does make more noise," confirms Adam Knight, "around 60 to 65 decibels – but again, it's important to remember this is similar to the level of background noise on a street. Because it’s installed outside, you’re also unlikely to hear much from indoors."

"A typical Daikin air-to-air outdoor unit is usually no louder than 60 decibels, just like an electric toothbrush or a normal conversation," agrees Hamid Salimi, noting how there are also industry regulations to protect you and your neighbours against the air conditioning noise produced by your system.

"Heat pumps are not permitted to produce more than 65-70 decibels, depending on their power," explains Hamid. " That’s the same noise level as a dishwasher."

Worried a nieghbour may question the noise level of your air con external unit? "For extra peace of mind, all heat pumps must have a CE label stating their sound level," says Hamid, meaning you can clearly show them what noise it's producing.

If however noise of any kind is a top concern, there are ways to help reduce it further.

"Choosing a premium brand with quieter technology, ensuring the unit is properly installed and serviced, and placing the external unit in a sensible location can all help," says Adam.

"Expert installers should always be trained to advise on the quietest, most efficient set-up for your space too," he adds.

Adam Knight

Adam Knight is a lead engineer at heating and cooling experts, BOXT. He brings over 17 years of industry experience and now leads BOXT’s Tech Survey Team, with specialist training in air conditioning and heat pump systems.

Hamid Salimi

Hamid Salimi has a BSc and MSc in mechanical engineering and has worked with Daikin for over 13 years in various roles such as product applications and HVAC design. He is currently a residential product manager leading a team of product specialists covering all aspects of residential renewable heating.

Portable air conditioning noise levels

Not able to retrofit air con and instead find yourself looking at the best portable air conditioning units? Noise should again inform your buying decisions, so before you press buy, what should you expect once you've set it up?

“Portable air conditioners are not silent appliances as they compress air, circulate it, and expel heat," says Katie Lilywhite, air treatment expert at AO.com.

"You should certainly expect a bit of humming," she confirms, but how loud is this humming?

"Typically speaking, this is usually between 50-65 decibels depending on the model of your air conditioner and the setting you’re running," says Katie. "By comparison, this is about the same as a dishwasher, light traffic or even a normal conversation."

But, while kitchen appliances such as dishwashers and fridges are often integrated, which helps to partially reducing the noise produced, portable air con units need to be left in the open in order to work properly. Add to this any additional external noise from having a window open for the external vent, and there's no doubt that a portable model will be noisier than fixed air con.

But is it noisier than a fan which circulates air, even if it doesn't cool it? Again it depends on the model you buy and exactly what it is you need. Having tested the MeacoFan Sefte 10" Pedestal Fan, it certainly felt as if it was as whisper quiet as promised, whereas cheaper pedestal fans I've used are often equally as noisy as a portable air con unit.

To expect something that works so hard to be silent isn't realistic, but you can make sure you choose the quietest model by checking the decibel ratings on the product description before you buy, or looking for units that are Quiet Mark rated.

Katie Lilywhite

Katie is one of the many experts at AO.com, covering a multitude of appliances including air quality products for homes and gardens.

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FAQs

Why is my portable air con unit so noisy?

“If your air conditioner is running at a much louder volume than expected, this could be the sign of problems," warns Katie Lilywhite. "It could indicate there is an obstruction in the filter or hose, or it might be struggling on an extra hot day.

"To keep things as quiet as possible, keep your filters clean and be sure to keep all windows and doors closed," she suggests, "which will stop your air conditioner from overworking and being any noisier than it needs to be."

Where you position your air con unit will form part of the advice given during installation, but make sure you also know what best advice is by reading our guide to the 7 places never to put air conditioning. And, if a portable air con unit is your only option, weigh up the differences first between air con vs air coolers to check you are buying the right product.