Round Rock has grown into one of the largest cities in Williamson County, and its neighborhoods span everything from established homes near Old Settlers Park to the newer subdivisions spreading east. What they all lean on is air conditioning that runs hard for most of the year. When your system quits in the middle of a Texas summer, the goal is simple: a licensed company that answers the phone and gets you cool again fast.
This list of the best HVAC companies in Round Rock is built on public information, not paid placements. Every company below was reviewed for verified customer ratings, Texas HVAC licensing, years in business, and range of services. Nobody paid to be here, and we refresh this list each year as companies and their reviews change.
1. Koala Cooling & Plumbing
Address: 1102 S Industrial Blvd Ste C, Round Rock, TX 78681
Website: koalacooling.com
Years in Business: Since 2019
License: TACLA26515E (plumbing RMP-37834)
Google Rating: 4.9 stars (1,000+ reviews)
Services Offered:
- AC repair and diagnostics
- AC and heating installation
- Heat pumps and mini-splits
- Plumbing service
- Maintenance and tune-ups
What Sets Them Apart:
Founded by Scott and Stacie Feller in 2019, Koala is based right in Round Rock and has built a reputation on transparent, published pricing and honest recommendations. As a Carrier and Lennox authorized dealer, they’ve won Best AC Repair and Installation in the 2024 and 2025 Best of Round Rock Awards, and reviewers consistently praise techs like Evan and Isaiah for explaining the work and never pushing an unnecessary replacement. With both HVAC and plumbing in-house, they’re a strong one-call option.
Why They’re #1:
A Round Rock company with over a thousand reviews at 4.9 stars, back-to-back local awards, and pricing you can see before you call. For homeowners who want a proven, transparent local team, Koala sets the bar.
2. Aire Serv of Round Rock
Address: 600 S I-35 Frontage Rd, Round Rock, TX 78681
Website: aireserv.com/round-rock
Years in Business: Locally owned, nationally trusted
License: TACLB96490E
Google Rating: 4.9 stars (300+ reviews)
What Stands Out:
Part of the respected Aire Serv network but locally run, this Round Rock team has earned a 4.9-star rating largely based on honesty. Reviewers repeatedly credit Chris for same-day and weekend response, straight talk about whether to repair or replace, and no upsell on extras they didn’t need. As an ENERGY STAR partner handling repair, replacement, and indoor air quality, they’re a dependable, no-pressure choice.
3. Altruistic AC, Heating & Plumbing
Address: 14408 Citron Cove, Pflugerville, TX 78660
Website: altruisticac.com
Years in Business: Since 2015
License: TACLB63701E
Google Rating: 4.9 stars (800+ reviews)
Services Offered:
- AC repair and emergency service
- AC installation and replacement
- Heating and furnace service
- Ductless mini-splits
- Indoor air quality
- Plumbing and water heaters, including tankless
Why They’re Listed:
Based next door in Pflugerville, Altruistic covers Round Rock with fast response times, often having a technician at the door within about an hour, even on nights and weekends. Across more than 800 reviews, homeowners describe technicians who explain the options without pressure and work to fit a budget rather than jumping to a costly replacement. Tech Ramon is named again and again for his patience, and the company texts a photo and short bio of your tech before arrival. With both HVAC and plumbing under one roof and certification to service older R-22 systems, they’re a well-rounded option for Round Rock homes.
4. Cool Arrow Heat & Air
Address: 1310 Chisholm Valley Dr Ste 410, Round Rock, TX 78681
Website: coolarrowhvac.com
Years in Business: Since 2025
License: Licensed and insured
Google Rating: 5.0 stars (170 reviews)
Local Reputation:
Locally owned by Brent Ford and Josh Gonzales, Cool Arrow holds a perfect 5-star rating and a hard-earned reputation for straight answers. In one standout review, they gave a homeowner four options instead of one and pointed out a full replacement wasn’t needed since the furnace was still solid, saving thousands. Brent brings nearly three decades of hands-on experience, and Josh is NCI-certified in duct design and airflow. A great pick for an honest second opinion.
5. AiRCO Mechanical
Address: 1000 S I-35 Frontage Rd, Round Rock, TX 78681
Website: aircomechanical.com
Years in Business: Since 1983
License: TACLA51950C
Google Rating: 4.8 stars (1,000+ reviews)
Why They’re Included:
One of the longest-running names in the area, AiRCO has served Central Texas since 1983 and covers HVAC, electrical, and plumbing under one roof and is open 24/7. Reviewers highlight the smooth Lennox installations, crews that correct poor original ductwork left by builders, and advisors like Jeremy who make a big purchase feel manageable. For homeowners who want a large, deeply established full-service company, AiRCO is a reliable option.
How We Chose the Best HVAC Companies in Round Rock
We don’t accept payment for rankings. Every company here earned its spot on public information alone.
We looked at:
- Verified customer reviews, read for consistent patterns rather than raw star counts
- Current Texas HVAC licensing and insurance
- Years in business and a steady local track record
- How quickly they respond to Round Rock homeowners
- Range of services, from emergency repair to full installation
If a company couldn’t hold up across those factors, it didn’t make the list. We update these rankings each year to keep them accurate.
Best HVAC Companies in Round Rock FAQs
Most AC repairs in Round Rock run between $150 and $600, depending on the part and labor involved. A capacitor sits near the low end, while compressor or coil work costs more. Full system replacement typically ranges from $6,000 to $12,000. Always get a written estimate before approving work.
Yes. Several companies here, including Altruistic, AiRCO, and Koala, offer emergency or 24/7 service, which matters when a summer breakdown turns dangerous fast. Expect after-hours rates to run higher than a standard visit, but for a dead system in July it’s well worth the call.
Because Round Rock systems run so many months a year, once-a-year service is the minimum and twice is better: cooling in spring, heating in fall. Regular tune-ups catch small problems early, keep energy bills down, and extend the life of a system working overtime in this climate.
If your system is under about 10 years old and the fix is minor, repairing usually makes sense. Once a unit passes 12 to 15 years or faces a major cost like repairing a compressor, replacement is often the smarter investment. A trustworthy local tech will walk you through both options honestly.
Yes. Every company on this list holds a Texas HVAC contractor license or operates as licensed and insured. Before any work begins, you can ask for the license number and proof of insurance, which any reputable company will share without hesitation. Licensing protects you and ensures the work meets state code.
Want to Be Featured?
Do you run a licensed, well-reviewed HVAC company serving Round Rock homeowners? We update this list each year and are always looking for reputable local pros to consider. There’s no cost and nothing to buy. We don’t sell rankings. Reach out and we’ll take an honest look at your work and credentials.