I am a fan of Perfect Temperature Control and will use their services for my HVAC maintenance. Here's why: I recently bought a remodel single family 3-floor Victorian workers cottage; if you've been to Chicago, you know the 1.5 story houses around the Bungalow Belt. I knew from the inspection that I needed a new AC unit, and on even mild spring days we were dying upstairs. But what I learned from my service technician at another company that the furnace was oversized for the house (explains the $800 gas bill from the mild winter) and not enough air intakes (which were also the wrong size). I got estimates from three different places that I trusted and used before, and the estimates to fix the HVAC problems were between 25K (low end) and 50K high end. Yikes! Not what I wanted to hear after going in a bidding war to get this house... But daddy needs to be cool in the summer or he's a grumpy fella! Perfect Temperature Control was recommended by my neighbor. They made an appointment the next day, and Sergio came out to inspect the units. His first stated goal was "to use the available ducts and space to maximize airflow and minimize cost." Awesome! Having come up with similar solutions in other bungalows, Sergio offered references of others who were able to use the Carrier products and get it comfortably cool upstairs without freezing the basement, or needing to install "mini-splits" upstairs. The "Infinity Series" that he recommended as the top of the line also came with a dehumidifier to help reduce electric costs, and its thermostat could be managed by Wifi and an iOs app (I assume there's an Android app). It honestly works better than the Nest since its humidity sensor is very accurate (don't ask me how I know this, but I have four humidity sensors in the house) and, rather than just cooling to a temperature, the Infinity series will dehumidify so that you "feel cooler" at higher temperatures because of lower humidity. This is perfect for the upstairs bungalow! Sergio was confident that we would be fine in the house with the system that he provided. And the costs were ranged from 10K (mid-range product) to 12K (top range product), which included the rebates (12-14K with up front before rebates get processed--and they do it for you!). To provide a review (because, let's face it, businesses need yelp reviews to make their business!), they offered the humidity control, too. But I'm an honest and ethical reviewer here, so do consider that. In short, his proposal was well-thought out and succeeded in making the upstairs comfortable in hot summer nights. Sergio was quick to schedule the work. We'll see how the heat goes in winter, though. Good warranty product, too, on both products. There was a small snafu where they needed the whole second day to complete the project (and with no AC during the heat wave, I was pretty understanding but noticeably hot!), but all-in-all, this was pretty uneventful and direct project. I really appreciated the level of professionalism and communication in the process. Perfect Temperature Control really did their work well, and Sergio really exceeded my expectations with his time, thoughtfulness to the project, and cost-saving interests knowing that a new homeowner often doesn't have tons of money to throw at a problem. The fact that they're familiar with how Chicago bungalows work, and how renovators and rehabbers sometimes cut corners with the HVAC systems really helped us in the end.