Commercial HVAC replacement and installation in Savannah.

Most commercial buildings in Savannah cool through packaged rooftop units. They condition close to half of all commercial floor area in the country, so this decision repeats across the whole portfolio.

Managers often wait until a unit fails, needs constant service, or stops holding the space. That habit costs money: planned replacement with a more efficient unit usually comes out ahead of replacing on failure, and often ahead of a like-for-like swap at end of life. There is also a middle path. If a unit still has life in it, retrofitting advanced controls can capture savings without buying a box.

Savannah's mild winters open the third option below. Heat pump rooftop units run most efficiently in mild-to-moderate heating weather, and across the South they can handle most or all of the winter heating load.

No two roofs price the same, so treat these as the lines to interrogate rather than a total. Ask the contractor to show each one separately. Anything bundled into a single number is where the surprises hide.

Start with the load, not the nameplate. A unit installed twenty years ago was sized for a building that no longer exists in the same form: different occupancy, different plug loads, different lighting, sometimes a different envelope. Carrying the old tonnage forward carries the old mistake forward with it.

Then decide how the space gets heated. A gas-heat rooftop unit and an all-electric heat pump unit look similar from the parking lot and behave differently on the balance sheet. The right answer depends on your electricity and gas prices, your winter load, and what the panel can carry. In a mild coastal climate, a heat pump unit can cover most or all of the heating season, which is why the question is worth asking rather than defaulting.

Efficiency tier is the last big lever. The high-efficiency rooftop units built to a federal challenge specification were designed to cut energy use by up to half against the standard in force at the time, and equipment sold today meets a far stronger floor than the one your old unit was built to. That gap is where the payback lives.

Two projects with the same tonnage can be a week apart on schedule and far apart on price. The difference is almost never the box. It is what the box has to land on, connect to, and get past.

A quote written from a nameplate photo is a starting number. A quote written from a roof visit is a price. The visit exists to answer the questions that change the scope, and there are only a handful that matter.

The first is structure and fit. Does the new unit land on the existing curb, does it need an adapter, and can the roof carry the weight where it sits. The second is infrastructure. Electrical capacity surprises people most, especially on an all-electric conversion, because the panel and the service were sized for the old equipment. Gas line status matters in the other direction: if the new unit is electric, the gas service to it gets properly abandoned, not capped and forgotten.

The third is access. Crane reach, lot layout, closure window, and how much of the parking lot goes out of service for a morning. The fourth is the old unit itself. Its refrigerant has to be recovered by certified technicians under federal rules, and the paperwork is part of the job.

Georgia building departments treat a commercial equipment swap as permit work, not maintenance. A contractor who replaces or alters a mechanical, electrical, or gas system has to pull a permit before starting, and the mechanical exemptions are narrow: portable heating and cooling appliances, and minor parts that do not change the equipment's approval. A rooftop unit replacement is not on that list.

Two published timing rules shape scheduling. Emergency replacements can proceed, but the permit application has to be filed the next business day. And an application is treated as abandoned if work has not started within six months of filing. That second one matters when equipment lead time is long. Pulling the permit too early can cost you the application.

A rooftop unit is a long-horizon decision usually made in an afternoon, under pressure, with the space already too warm. The two questions below get skipped in that moment, and they are the ones that decide whether the building is better off in year five.

Neither is technical. Both come down to who pays, who benefits, and whether the next unit gets replaced on a plan or in an emergency. Answer them once for the whole roof, and every unit after this one becomes a scheduling question instead of a scramble.

Order around availability, not around the calendar you wish you had. Equipment availability is a real selection criterion, not a footnote, and a unit you can get in three weeks may beat a slightly better unit you cannot get until winter. Ask for the quoted lead time in writing next to the model number, and ask what happens to the price if that date slips.

If several units are aging out together, phase them. Ranking the roof by age, service history, and running cost gives you a replacement order you can spread across budget years. It also lets you standardize, and matching equipment across a roof simplifies parts, service contracts, and training for whoever maintains it.

Then look at the long number. First cost is one line in a decision that runs well over a decade. The unit you buy sets the energy bill for every one of those years, and the gap between an old inefficient unit and a current high-efficiency one runs from hundreds to thousands of dollars a year, per unit. If a rebate program is in play, confirm what it requires before the order goes in. Some will not pay on equipment that has already been bought.

Two quotes are only comparable when both show the same five things. If one of them is missing, you are comparing a scope to a hope. Ask for the missing line before you compare totals.