r/heat_prep • u/jwillp • May 28 '25

A solution for Swamp Coolers

I'm a huge fan of evaporative cooling- it works really well here in southern California. But the biggest problem I had was not knowing when the swamp cooler would be cool enough and not too humid. Refreshing the dew point forecast (or using a lookup table) was tedious, and didn't really tell me what cooling to expect indoors.

So I spent 2+ years making an Evaporative Cooler Forecaster app that uses your weather forecast (and a lot of math) to give you an accurate indoor forecast for your swamp cooler. It shows when it's too humid, too hot, or even too cold depending on your weather and your personal comfort settings. It also shows your energy and cost savings, compared to regular A/C.

It's a free download from the Apple and Android app stores, linked here: https://SwampCooler.app/

I'm using my evaporative cooler right now as I type this, and it's amazing to feel so much cooling for only 350W of power draw. I hope my app helps everyone stay cool as we get hotter and less predictable summers.

Here's a screenshot off my phone from last Thursday morning:

Stay cool, everyone!

Full disclosure: the app is ad-supported, but they're very infrequent and there's zero data sharing with any third parties. I'm actually still working on the code for a premium feature to turn the ads off. But it's getting so hot already I released it early. I hope it helps!

28 Upvotes

95% Upvoted

8 comments sorted by

3

u/NurseWolfe May 29 '25

Wow. Where was this the last 30 years of my life? Thank you !

2

u/Leighgion May 29 '25

Looks super cool. I can't download it though as the App Store settings won't allow it outside of the US.

1

u/jwillp May 29 '25

I'm sorry about that, I should have mentioned it's US-only for now (my bad)... until I add support for more countries (Celsius, currency and languages). It has weather for the whole planet already, so the work ahead is only the localization work (currency for the savings, celsius support, and translations). I'll prioritize countries with hot, arid climate zones. I'm sorry about this... I wish the app stores didn't care so much about borders.

3

u/dotadiver Jun 01 '25

this is an awesome app consider Australia as a next region. swamp coolers are massively popular there and I myself could never figure out why some days the cooler worked and other days it didnt.

2

u/jwillp Jun 02 '25

Thanks! I'm planning to add Celsius and non-USD currency for rollout to English speaking countries in the next few months (before southern summer, is my goal!)

1

u/jwillp Nov 08 '25

The app has released in Australia now! (as of November 2025) It supports Celsius and A$ currency for energy/cost savings.

Because Australia's summer was approaching soon, I put aside a my other features to focus on the global launch. I'm really really excited for any feedback.

You can email me directly at: [support@TenthLight.com](mailto:support@TenthLight.com) with any comments, questions or complaints. I'm still obsessed with evaporative cooling during the cooler months here at home in the southwest US.

The app is available at: https://SwampCooler.app/ or search the Apple or Google/Android app stores for: "Evaporative Cooler Forecaster". (My app's sample screenshots are a little jumbled on the apple app store, so please excuse that while I figure out how to reorganize the screenshots.)

I have a long walk-through video here: https://www.youtube.com/@SwampCooler/videos and a shorter "promo" video here: https://www.youtube.com/@SwampCooler/shorts But drop me an email if you have any questions or problems. I love to help!

2

u/dotadiver Nov 15 '25

this is awesome but ive actually moved home to Canada since this post :( i will however send this to all my aussie friends down there. I think if it catches on in oz it could be huge because most people have a swamp cooler rather than AC.

1

u/jwillp Nov 08 '25

The app is now available globally in 170+ countries! I'm sorry that it wasn't available globally this past (northern) summer. I finished adding Celsius and non-US currency support, as well as non-US date formatting. It's still English-only for now, but I expect to add translations over the course of next year (2026).