My brand new MacBook Air is making a loud fan noise.

Products purchased through physical Official Apple Store, including online Official Apple Store

usually have 14-day return grace from date of purchase for full refund; forgoing any damages.

Other sources of authorized Apple purchase, are usually 'independent business' with resale; and

some perhaps, may offer repair service too; and have their own in-house rules. They're not Apple.

So depending on where you bought the Apple product, your mileage may vary. Also limits on

product warranty could also differ. ~ Where did you buy this product? Details are important.

What are you doing with the device? If you are running several large applications (like Adobe After Effects, Premiere Pro, and Final Cut Pro) at the same time, your computer will make a moderately loud fanning noise, as it's cooling down. Otherwise, this could be an issue regarding your actual computer, and you should go to an Apple store to check it out. As mentioned in other posts, if you actually bought it from Apple, they can help you a lot more then if you bought it from a third party store.

In case you do not get a better response, please make sure you are not sitting the MacBook on top of any "soft" surface like a blanket or pile carpeting. It can block the ventilation system components that hug the sides of the unit. That can increase the internal heat and the fans might come on to keep your Mac hopefully as cool as the user. :-)

There are other options to reset the hardware if the fans come on too often without good reason, but since these are new, it is unlikely you need to do that for this issue.

There are options within this site link:

• Get Support - Apple

https://getsupport.apple.com/

To include where what how why, etc.

Good luck & happy trails!🌻🌤

You should get Apple to check it out. Click the Apple logo at the top left of your screen. Click About This Mac and then the Service tab.

Mine is doing the exact same thing! I just got mine last month, and from day 1 the fan is on.