AC Angel Home Management

A Modern Solution For Private Landlords To Maintain Their Rental Homes' AC's

AC Angel is an HVAC filter subscription service for private landlords to service all of their properties. I have been working on this web app for several years and through many iterations. I am currently working on a launchable version, and attracting beta users and customers.

The Problem

Private landlords face a unique problem: Repairing and replacing HVAC units can be extremely costly for property owners, and while mitigating these costs is as simple as replacing the home’s air filters regularly, relying on tenants to do so can be unreliable.

The Solution

My idea is to provide private landlords a central account from which set up unique air filter subscriptions for each of their homes. The app will send text message reminders to tenants to change their air filters. And transparent purchase history and cost analysis will allow private landlords to easily understand their expenses.


Some family members who are invested in real estate made me aware of the problem that tenants are not changing their air filters, and it’s costing them (the owners) a lot of time and money. I first tried to build this web app as a hackathon project; however, because of my lack of knowledge in web development back then, the project did not get far. We called the project, AC Angel.

The second iteration that I worked on this was with a team as part of a semester long group project in my Junior year of college. I convinced my team to pursue this idea, and that we could potentially work on bringing it to market after the semester. We named the project “Okapi” arbitrarily. We built the project with Ruby on Rails, and hosted our demo site on Heroku. While the website was visually pretty, the database was unstable, and the functionality was limited.

The third iteration that I worked on this was for my Senior capstone course in college. Again, I coerced my team to work on an AC filter subscription service for private landlords – this time named “Hammes” after the brothers who invented the original AC filter. We decided to build the website with more modern technologies. We used Python Flask for the backend and React JS for the front end. I served as the product lead, and backend lead. As we got closer to the deadline, I implemented much of the functionality in the front end. We used Stripe to handle payments, and we hosted the site on Heroku. Due to some teamwork issues, and self-built password security, our final product for the course, while functional, was insecure and bug-filled. During the course, we did a lot of good market research, and honed in on how the product should be designed.


I am currently working alone on a fourth iteration that combines everything I have learned from my previous experiences, that will hopefully be market ready. I am using plain HTML CSS and Javascript with a Firebase backend, and Typescript cloud functions. I am using Stripe to handle payments. I am also doing market research by asking leaders in the investment real estate industry for advice and opinions on my product.


My hope for this project is that it will successfully increase the lifespan of private landlords’ HVAC units in each of their homes. I would like to expand this into providing an interface for tenants to report HVAC issues, and for landlords to answer work orders. The website could help landlords automate calling AC contractors to specific homes, and data reported could then be used to help private landlords choose the best AC filters for their homes.

Link to Website →