March 20, 2026
Choosing a Rooftop Unit for Commercial AC: A Complete Guide
If you own or manage a commercial building in Loganville, GA or the greater Gwinnett County area, choosing the right rooftop HVAC unit (RTU) is one of the most important decisions you'll make for your property. A properly selected rooftop unit improves comfort, reduces energy costs, and ensures long-term reliability.
In this guide, we'll break down everything you need to know when selecting a rooftop unit for your commercial AC system.
What Is a Rooftop Unit (RTU)?
A rooftop unit (RTU) is a self-contained HVAC system installed on the roof of a commercial building. It typically includes heating, cooling, and ventilation components all in one unit, making it ideal for businesses like restaurants, retail stores, offices, and warehouses.
Why Rooftop Units Are Popular for Commercial Buildings
- Space-saving: Installed on the roof, freeing up indoor space
- All-in-one system: Heating and cooling combined
- Easy maintenance access: Technicians can service units without disrupting operations
- Scalable: Multiple units can be installed for larger buildings
Key Factors to Consider When Choosing a Rooftop Unit
1. Proper Sizing (Tonnage)
Choosing the correct size is critical. An undersized unit won't cool effectively, while an oversized unit can short cycle and increase energy costs.
Factors that affect sizing include:
- Square footage of the building
- Ceiling height
- Number of occupants
- Heat-generating equipment
- Insulation quality
Pro Tip: Always have a professional load calculation performed before selecting a unit.
2. Energy Efficiency (SEER & EER Ratings)
Energy efficiency directly impacts your monthly operating costs. Look for units with higher SEER (Seasonal Energy Efficiency Ratio) and EER (Energy Efficiency Ratio) ratings.
Benefits of high-efficiency units:
- Lower energy bills
- Reduced environmental impact
- Potential rebates and incentives
3. Type of Heating System
Rooftop units can include different heating options:
- Gas heat: Common and cost-effective
- Electric heat: Easier installation, but higher operating costs
- Heat pumps: Energy-efficient for moderate climates like Georgia
4. Building Usage
Your business type plays a big role in choosing the right system.
- Restaurants: Require strong ventilation and cooling due to kitchen heat
- Offices: Focus on consistent comfort and quiet operation
- Warehouses: May need larger capacity and zoning
5. Ventilation & Indoor Air Quality
Proper ventilation is essential, especially in commercial environments. Look for units that offer:
- Fresh air intake options
- Advanced filtration systems
- Humidity control
6. Installation Requirements
Not all roofs are the same. You'll need to consider:
- Roof structure and load capacity
- Ductwork compatibility
- Electrical requirements
A professional HVAC contractor can evaluate your building and ensure proper installation.
7. Maintenance & Serviceability
Choose a unit that is easy to maintain and has readily available parts. Regular maintenance will:
- Extend system lifespan
- Improve efficiency
- Prevent costly breakdowns
Common Mistakes to Avoid
- Choosing based on price alone
- Skipping professional load calculations
- Ignoring energy efficiency ratings
- Not planning for future expansion
How Long Do Rooftop Units Last?
Most commercial rooftop units last between 10-20 years, depending on usage, maintenance, and installation quality.
Why Work with a Professional HVAC Company?
Choosing and installing a rooftop unit isn't a DIY project. Working with a trusted local HVAC company ensures:
- Accurate system sizing
- Proper installation
- Compliance with local codes
- Ongoing maintenance support
Commercial Rooftop Unit Installation in Loganville, GA
At Henson Heating, Air and Plumbing, we specialize in commercial HVAC solutions across Loganville, Snellville, Grayson, Lawrenceville, Buford, and the greater Metro Atlanta area.
Whether you're replacing an old unit or installing a new system, our team can help you choose the right rooftop unit for your business and budget.
Our Services Include:
- Commercial HVAC installation
- Rooftop unit replacement
- Preventative maintenance plans
- Emergency HVAC repair
Get a Free Commercial HVAC Quote
Ready to upgrade your commercial AC system? Contact Henson Heating, Air and Plumbing today for a free consultation.
Call now or schedule service online to get started.
