Rooftop Unit Service in Charleston, SC

Rooftop unit service in Charleston comes down to three things an owner has to stay on top of: who is responsible, what the records say and when the work gets done. Aero Air Techs repairs and maintains the rooftop package units found on small offices, retail strips, restaurants and churches.

A unit on the roof is easy to forget until it stops. This page is the owner's side of that job, with our scope laid out plainly.

What does an owner answer for on a commercial rooftop AC unit?

Start with the risks that sit with you, whoever does the wrench work. This is plain guidance and not legal advice, so confirm anything binding with your attorney, insurer or the agency named.

• The lease. It decides who pays for service, repair and replacement. Read it before the first breakdown.
• Safe access. OSHA's general industry rule, 29 CFR 1910.28, ties an employer's fall protection duty to unprotected sides and edges 4 feet or more above a lower level. Know what your roof has and ask anyone working up there how they handle it.
• The roof itself. Foot traffic and curb work can touch your roof warranty terms. Ask your roofer before planned work.
• Refrigerant. Under EPA Section 608, refrigerant may not be vented and the people handling it must be certified technicians. EPA also says its HFC leak repair rule has applied since January 1, 2026 to appliances with a full charge of 15 pounds or more, and that the residential and light commercial air conditioning and heat pump subsector is not included. Read the nameplate charge and confirm with EPA where your unit falls.
• Gas heat. A gas-fired heat section needs its flue, burners and heat exchanger looked at, because combustion problems can reach occupied space.
• Storms. NOAA puts Atlantic hurricane season at June 1 to November 30. Loose panels and failed curb fasteners are your problem before they are anyone else's.

RTU maintenance records worth keeping

Good records settle arguments with tenants, insurers and manufacturers. Keep one file per unit, starting with these.

Record	Why it matters
Unit tag, model, serial and install date	Warranty questions and parts orders start here
Refrigerant type and nameplate charge	Shows which rules apply and what a leak means
Filter size, count and change dates	Proves the upkeep, and speeds every visit
Belt size and last change	Saves a return trip for a part
Service reports with readings	A slow drift shows up long before a failure
Repair invoices and leak notes	Separates a repeat fault from a new one
Space served and tenant contact	Tells a technician who loses cooling when the unit is off

Ask the manufacturer what upkeep it expects you to document, because warranty terms differ. Keep the file with the building and not with one manager, so it survives a sale or a staff change.

Package unit service: what is in scope and what is not

A clear scope keeps surprises out of the quote. Here is how we divide the work.

Usually in scope for RTU repair and upkeep:

• Electrical checks on contactors, capacitors, motors and controls
• Belts, blower, filters and airflow
• Condenser and evaporator coil condition, with cleaning where needed
• Condensate pan, trap and drain line
• Refrigerant readings and leak searches
• Heat section checks on gas or electric units
• A report on what was found

Usually outside the HVAC scope, so plan for it separately:

• Roof membrane, flashing and curb repairs, which belong with your roofer
• Crane lifts and street closures for a rooftop HVAC replacement
• Structural review if a new unit is heavier than the old one
• Large central plant equipment of any kind

Replacement raises its own questions. Each jurisdiction runs its own permits, so start with yours. Downtown, the City of Charleston's Board of Architectural Review guidelines call for HVAC units to stay out of view from the public right-of-way and to be screened. Those rules apply to the City's historic districts, so ask staff before you change what sits on the roof. Our rooftop replacement planning guide covers the rest.

When should rooftop unit service in Charleston be scheduled?

Book around your calendar, not the first failure. No agency sets a timetable for a small building, so treat this as a starting point.

When	Focus
Early spring	Cooling startup, coils, belts and drains before the first hot stretch
Early fall	Heat section, safeties and a coil check after a season of salt and dust
After a strong storm	Panels, curb, debris and standing water
Before a tenant moves in	Confirm the unit serves the space it should

Coastal roofs need extra attention. Salt film builds on rooftop coils near the harbor and the islands, and our coastal corrosion AC repair page explains the damage and what can be saved. For the longer view, see our piece on equipment life near salt water.

How a rooftop visit runs

1. Share the basics. Unit count, roof access, hatch keys and the hours to avoid.
2. Agree on a time. We will say when someone can get there, and you confirm it works.
3. Inspect and test. The unit gets tested with the power isolated where needed.
4. Report and quote. You get the findings and a clear, upfront quote before work begins.
5. Do the approved work. Then we restart the unit and check what reaches the space.

What moves the price of rooftop work?

Access tends to lead the list. Roof height, hatch or ladder condition, the number of units, the failed part and how soon it can be ordered all change the quote. After-hours timing does too, so ask about it when you call. A crane or roof repair is priced on top of the HVAC work.

Why owners bring rooftop units to Aero Air Techs

• A 4.9 Google rating on 16 reviews, as of October 2026.
• We quote before work begins, so the lease holder can approve it.
• Open 24 hours, per our Google profile, when a unit quits overnight.

From our Charleston base we reach owners in Mount Pleasant, North Charleston, Ladson and Moncks Corner, among other nearby places. Trouble somewhere other than the roof belongs with commercial HVAC repair. To set up a calendar, look at commercial HVAC maintenance.

Roof work is planned around weather, tenants and exposure, and each of these areas leans on one more than the others.

• Mount Pleasant: units near the harbor end take salt, so check coil fins and fasteners first.
• North Charleston: the city's mechanical permit office handles change-outs at 2500 City Hall Lane.
• Ladson: three counties meet here, so have the parcel's county ready for any curb adapter or swap.
• Moncks Corner: the county permitting office at 1003 Highway 52 covers unincorporated sites.
• Hanahan: our shortest trip, useful when a crane or a lift has a tight booking window.
• Goose Creek: the city wants a business license on file for permitted work.
• James Island: marsh air and summer storms make condensate and curb seals a priority.
• Summerville: pollen loads filters in spring, so count them before the season starts.