Rooftop Unit Replacement: When Is It Time and What Does It Involve in Las Vegas?

Rooftop unit replacement is usually the right call when the unit is past roughly 15 years, needs a compressor or heat exchanger, uses phased out R-22 refrigerant, or fails every summer. The job involves removing the old unit, often with a crane, fitting a curb adapter if the new unit has a different footprint, connecting power, gas, ducts and controls, and starting up and testing the new system.

Rooftop units, often called RTUs or package units, are common on Las Vegas restaurants, shops, offices and many older homes and townhomes. Because the whole system lives on the roof, replacement takes more planning than a ground level swap.

When Is It Time to Replace a Rooftop Unit?

Look at age, repair history and safety together.

Repair or replace?

A simple test helps. If a repair costs more than about half the price of a new unit, and the unit is past the middle of its life, replacement usually wins. Our guide on when to replace heating and air conditioning explains the same idea for homes.

What Does Rooftop Unit Replacement Involve?

Most jobs follow the same steps.

1. Site survey. Measure the unit, curb, duct openings, power and gas, and check roof access.
2. Load check. Confirm the right tonnage for the space and how it is used.
3. Permits. Mechanical, electrical and sometimes crane permits.
4. Crane scheduling. Many lifts happen early in the morning before heat and traffic.
5. Removal. Disconnect power, gas and ducts, recover refrigerant and lift the old unit off.
6. Curb adapter. If the new unit has a different footprint, an adapter matches it to the old curb.
7. Set and connect. Set the new unit, seal the curb, connect ducts, power, gas and controls.
8. Startup. Check refrigerant charge, gas pressure, airflow, economizer and thermostat.
9. Roof check. Make sure the curb and penetrations are sealed against monsoon rain.

Refrigerant rules

Old refrigerant must be recovered by certified technicians under EPA Section 608. New units use newer refrigerants under EPA technology transition rules.

How Do You Plan a Replacement Around Business Hours?

Good planning keeps the doors open.

• Schedule the lift for early morning or a closed day.
• If you have several units, replace one at a time so part of the space stays cool.
• Plan replacements for spring or fall, not the middle of summer.
• Ask about temporary cooling for critical spaces like server rooms.

What Affects the Cost of Rooftop Unit Replacement?

Each job is priced at a site visit. The main factors are:

• Unit size in tons
• Gas pack, heat pump or electric heat
• Efficiency rating
• Crane size and lift distance
• Curb adapter needs
• Electrical or gas line updates
• Permits and after hours work

A written quote should list each of these. Our commercial HVAC maintenance guide explains how good maintenance helps a new unit last.

Is a Rooftop Unit Better Than a Split System?

For many commercial buildings, yes. A packaged unit keeps everything on the roof, saves floor space and is easy to service. Some homes and small offices may be better served by a split system if there is room for an indoor unit. Our guide on why a roof AC unit fails in Las Vegas heat covers the common problems with rooftop systems.

A Typical Las Vegas Case: Replacing One Unit at a Time

A retail space with three aging rooftop units. Replacing all three at once would have closed the store for a day.

The owner replaced one unit per week with early morning crane lifts. The store stayed open and cool the whole time.

Get a Rooftop Unit Replacement Quote in Las Vegas

We connect businesses and homes across the valley with independent providers who replace rooftop package units, gas packs and heat pumps. Ask them to plan crane lifts around your hours. See commercial HVAC in Las Vegas. For homes with rooftop systems, see AC installation in Las Vegas. For repairs, start with AC repair in Las Vegas.

Frequently Asked Questions

How long does a rooftop unit last?

Many rooftop units last about 15 to 20 years with good maintenance. Heat, dust and long run hours in Las Vegas can shorten that.

When should a rooftop unit be replaced?

Common signs are age past about 15 years, a failed compressor on an older unit, a cracked heat exchanger, R-22 refrigerant, rust and frequent repairs.

Does rooftop unit replacement need a crane?

Most do. A crane lifts the old unit off and sets the new one. Lifts are often scheduled early in the morning.

What is a curb adapter?

A curb adapter is a metal frame that lets a new rooftop unit fit an existing roof curb when the footprints do not match.

How long does rooftop unit replacement take?

Many single unit replacements are done in one day once permits and the crane are scheduled.

Can a rooftop unit be replaced without closing the business?

Often yes. Early lifts, closed day scheduling and replacing one unit at a time help keep the business open.

Do I need a permit to replace a rooftop unit in Las Vegas?

Yes, rooftop unit replacement usually requires permits for mechanical and electrical work, and sometimes for the crane.

Is R-22 a reason to replace a rooftop unit?

Often. R-22 is no longer produced in the U.S., so leak repairs on R-22 units get expensive.