If you are using the 13" late 2017 model of the MacBoo Pro without Touch Bar I have a great tip for you. It may be possible to drastically increase the RPMs of your MacBook Pro's fan without installing third party software. Depending on your browsing habits, Apple's Safari browser will do the trick nicely.
I have had my MacBook Pro for about three weeks now. In that time I have actually heard the fan on only three occasions: once while encoding a video, once while fully indexing gigabytes of text based data, and once while browsing the Interwebs using Safari. While the first two instances were not surprising, the latter was more than unexpected.
Obviously this is anecdotal, and every user's experience will be different to some degree. In addition, there is nothing inherently wrong with your fan spinning up. The fan speeds up to keep things cool because electronics do not like heat. Still, it seems problematic for browsing the Internet to put enough of a load on the CPU to lead to an audible fan situation (from this point forward known as an AFS). I was trying Safari because despite its lack of love from Apple for the last several years, I though it would be nice to use the same browser on my iPhone and Mac since they are connected at the hip in typical Apple fashion (which is not always a bad thing). I am also not a fan of Google collecting all my data.
It is important to note that running the same tabs in Google Chrome uses more RAM, but does not put nearly as much strain on the CPU or the battery. As a matter of fact, I have not yet reached a point at which Chrome has caused an AFS. I have had fifteen tabs open including YouTube, Gmail, and Twitter with no discernible difference in fan speed, and by that I mean the computer is dead silent. In the end, I decided to give in to Google and start using their mobile browser on my iPhone. Heck, they already know enough about me to figure out when I will die, what will cause my death, and where I will be buried.
I find the entire thing to be fairly pathetic. As with a lot of Apple's problems, it is difficult for me to understand why it exists. It seems that a company with a market cap of one trillion dollars (with a "t") would be able to create and sustain a web browser that was at the very least on par with Google, if not better. It also seems that doing so might be a waste of resources, although that is not entirely clear given their emphasis on privacy. Finally, it seems like given these facts, the best thing they could do is quit shipping second rate software and either dump the entire project in the trash, or bite the bullet and forge the one browser to rule them all. Prediction: they will not do that. In the mean time, I am personally not willing to listen to my computer's fan, and more importantly, decrease the life expectancy of my CPU simply to browse the web.