Commercial Rooftop Unit (RTU) Installation in Fullerton, CA

Why Fullerton Businesses Choose #1 AC Guys

When comfort, air quality, and operating costs matter, a properly engineered rooftop unit is the backbone of a reliable building. As a fourth-generation family company with more than 80 years of engineering know-how, #1 AC Guys delivers commercial rooftop unit (RTU) installations that meet Southern California codes, stand up to real-world loads, and keep teams and customers comfortable through peak heat.

Based in the Greater Los Angeles area and serving Fullerton and all of Orange County, we’re built for large and complex projects—multi-RTU buildings, tight roof access, occupied spaces, and aggressive timelines. Our mission is simple: healthy air for a healthy life, delivered with precision and care for your business.

End-to-End RTU Installation—No Hassles, No Guesswork

From the first site walk to final commissioning, we manage every critical step:

• Load calculations and system sizing: We right-size capacity, airflow, and ventilation to protect comfort and efficiency.
• Equipment selection: Factory-trained experience with Fujitsu (Japan), Mitsubishi Electric (Thailand), Midea (China), Gree (China), and Haier (China) helps us match features to your application—economizers, low-ambient kits, demand-control ventilation, and more.
• Title 24 and local code compliance: Documentation, controls requirements, and acceptance testing support to keep your project permit-ready.
• Roof work and rigging: Crane lifts, curb adaptors, seismic bracing, and weatherproofing handled safely and efficiently.
• Electrical, gas, and controls: Coordination with trades for clean power, gas piping, thermostats, and building controls integration.
• Commissioning and balancing: We verify temperatures, static pressure, airflow, and ventilation rates for steady performance.

Engineered for Fullerton’s Real Conditions

We design for hot rooftop environments, coastal influence, and busy business schedules. That means coil protection, durable coatings when needed, thoughtful placement for service access, and control strategies that minimize energy waste during non-business hours. Whether you run a restaurant on Harbor Boulevard, manage a warehouse near the Fullerton Industrial Center, or operate a campus near CSU Fullerton, we tailor each RTU to your use case.

Healthy Indoor Air, Lower Lifecycle Costs

Our focus on healthy air starts with balanced ventilation, proper filtration options, and clean duct transitions that reduce particulate buildup. Tightly engineered installs reduce short-cycling, protect compressors, and stabilize humidity—cutting maintenance surprises and extending service life.

Replacement, New Install, or Multi-Unit Upgrade

Whether you’re replacing a single aging rooftop unit or converting an entire building to high-efficiency packaged systems, we plan for continuity. We map changeouts to minimize downtime, sequence crane work to avoid peak hours, and provide temporary conditioning when practical. For multi-tenant buildings, we coordinate access and staging to keep businesses operating safely.

Transparent Proposals and Clear Communication

You’ll receive a clear scope, equipment submittals, and a project schedule that aligns with your business hours. We can also advise on utility-friendly configurations and documentation that may help you pursue available local incentives.

Service Area

Headquartered in Los Angeles County and serving the wider region, we proudly install commercial RTUs in Fullerton, Anaheim, Brea, Placentia, Buena Park, La Habra, and across Orange County—plus Los Angeles County, Ventura County, and Western Riverside County.

Brands and Training You Can Trust

Our engineers have completed factory training with leading global manufacturers, including Fujitsu (Japan), Mitsubishi Electric (Thailand), Midea (China), Gree (China), and Haier (China). That background helps us apply best practices for setup, commissioning, and long-term reliability across a wide range of RTU models and control platforms.

Preventive Care After Install

Protect your investment with planned maintenance. Seasonal inspections, coil cleaning, filter changes, and control checks maintain efficiency, reduce emergency calls, and help forecast capital planning.

Ready to Get Started?

Get a professional, on-site assessment for your commercial rooftop unit installation in Fullerton. We specialize in big and challenging projects and make them feel easy—through careful planning, safe execution, and engineering-first workmanship. Contact #1 AC Guys today to schedule a walkthrough and receive a detailed proposal tailored to your building, budget, and timeline.