Packaged rooftop units are the workhorse of light-commercial HVAC in Columbia: mounted on flat commercial roofs with steel roof curbs, they contain compressor, condenser coil, evaporator coil, blower, and heat source (gas burner or heat pump) all in one weatherproof cabinet. RTUs simplify installation compared to split systems (single unit rather than separate indoor and outdoor components) and consolidate service into a single access point. PolarCore installs, replaces, and services packaged rooftop units ranging from 3-ton units on small retail spaces up to 25-ton units on larger office buildings, restaurants, and light-industrial applications. Installation includes crane rigging for RTU placement, roof curb installation or modification, electrical and gas connections, refrigerant configuration, condensate management, ductwork transitions, thermostat and control wiring, permit coordination, warranty registration, and commissioning with airflow verification.
Most common commercial configuration in Missouri due to natural gas availability. Gas-fired heating (typically 80% AFUE burner in older units, 92% AFUE or 90%+ condensing burner in newer units) and electric cooling via traditional compressor and condenser. Sizes 3–25 ton typical for light commercial. Applications: retail, restaurants, offices where natural gas is available and reliable, and buildings where heat pump wouldn’t provide adequate winter capacity.
All-electric heating and cooling via heat pump, sometimes with electric strip resistance backup for arctic outbreak conditions. Advantages: no gas piping required (simplifies installation in gas-limited locations), all-electric operation aligns with electrification initiatives, cold-climate heat pumps (Trane XV, Bosch Climate, Lennox VP-J) maintain rated capacity down to about 5°F outdoor. Applications: buildings without natural gas service, tenants pursuing electric-only operation, new construction where heat pump makes economic sense.
Heat pump primary heating and cooling with gas backup for arctic outbreak conditions. Thermostat automatically switches between modes based on outdoor temperature (typical crossover 25–35°F depending on equipment and utility rate ratio). Best-of-both-worlds configuration but higher upfront cost. Applications: buildings where owner wants heat pump efficiency for most of the year with gas security for extreme cold.
Cooling-only unit; heating provided by separate source (typically existing boiler in older office buildings, or dedicated electric strip heat). Uncommon in Columbia due to climate but occasionally appropriate for specific applications.
PolarCore installs and services all major RTU manufacturers. Universal-fit replacement parts (capacitors, contactors, motors, control components) cover most repair scenarios regardless of brand.
RTUs weigh 500–3,000+ pounds depending on capacity and configuration. Crane rental with rigging typically $685–$1,485 depending on crane size, boom reach requirements, and rigging complexity. Larger commercial installations (10+ ton units, high building placements, tight urban locations) may require larger cranes and more elaborate rigging.
Steel roof curbs provide structural support for the RTU, weather sealing at the roof penetration, and ductwork transition point between building ductwork and RTU. New installations require curb sized to match RTU footprint and building deck configuration. Replacements often reuse existing curbs when the new RTU matches the old footprint; new curbs or curb adapters when footprint changes.
RTU installations require: dedicated electrical circuit sized to unit nameplate MCA (typically 208V or 460V three-phase for commercial, 208V or 240V single-phase for smaller units), gas line sized per unit BTU input and gas type, condensate drainage to roof drain or building drain, thermostat and control wiring to indoor space, and permit-required inspections.
Existing ductwork may need modification to match new RTU airflow requirements or to accommodate different RTU footprint. Ductwork transitions include: return and supply duct connections at the curb, transition fittings to match different duct sizes, insulation and vapor barrier at the curb interface, and air balance verification after installation.
Common RTU repair scenarios PolarCore handles:
Rooftop unit service and installation scheduling runs through the Corona Road office in southwest Columbia. Call (573) 615-6659 for service. Bradley Hollander (Operations Manager) handles commercial RTU account setup, load calculation, and service contract arrangements.