Commercial HVAC replacement and installation in Lehi.

Most buildings have three real options, and a single lump-sum bid rarely tells you which one you are being sold. A like-for-like swap puts the same class of equipment back on the same curb — fastest, simplest, and it inherits every sizing decision made twenty years ago. A high-efficiency upgrade keeps the same fuel mix but buys down operating cost; the market is deep enough now that more than twenty rooftop models exceed DOE's high-performance specification. A heat pump rooftop unit changes the heating source itself, either all-electric or dual fuel with a gas backup. That third path needs the most homework, because it turns on electrical capacity at the roof, your site's winter design temperature, and whether gas service stays. Price at least two of the three. The spread between them tells you more about your building than any single number will.

No two roofs price the same, and the lines below are where quotes separate from each other. Ask every bidder to show them as their own numbers instead of folding them into one figure. That is how you tell a thorough bid from an optimistic one.

The most expensive mistake in commercial HVAC is not overpaying for a unit. It is waiting for the unit to die and then taking whatever is on the truck. DOE guidance is blunt about this pattern: facility managers usually delay replacement until the equipment fails, needs constant service, or stops conditioning the space. Replacement-on-failure is the worst version of the purchase. You lose the ability to compare equipment, you lose access to incentive programs that require pre-approval, and you take whatever lead time the market happens to be running that week.

Planning ahead changes what you are allowed to buy. Rooftop units condition close to half of all commercial floor space in the country, so the model field is deep and the efficiency spread between units is wide. A proactive replacement lets you price a high-efficiency unit against a baseline one and decide with real numbers in front of you. A failure replacement almost always ends in a like-for-like swap by default, because there is no time for anything else.

Start with age and service history, not with a bid. If a unit is past fifteen years, has needed repeat repairs, and misses setpoint on design days, it belongs on a replacement schedule this year rather than on the emergency list next July.

Two buildings with identical tonnage can be a two-day job and a two-month job. The difference is almost never the equipment itself. It is what the replacement touches on the way in.

A quote written from a nameplate photo is a starting point, not a price. Before anyone commits to equipment, someone should be on the roof answering a specific list of questions.

Start with load. Twenty years of tenant changes, added plug load, lighting retrofits, and envelope work mean the original tonnage describes a building that no longer exists. Confirm it against how the space is used now. Then work through the physical constraints DOE flags for any rooftop replacement: curb dimensions and condition, structural capacity for the new weight, a clear path for the crane, and whether adjacent equipment blocks the set.

Infrastructure comes next, and it is where heat pump projects live or die. Electrical capacity at the panel and at the service, existing gas line routing, and whether either has to change all belong in the walkthrough notes. Finally, confirm the contractor has installed the equipment class you are actually buying. DOE treats contractor availability and knowledge as its own consideration for heat pump rooftop units, which makes it a fair thing to ask about directly.

Installation decisions outlive the installation. The two questions below shape what the building costs to run for the next fifteen to twenty years, and both are far easier to answer before equipment is ordered than after it lands.

The first is refrigerant. New commercial equipment ships on newer low-GWP refrigerants, and EPA regulations under Section 608 of the Clean Air Act govern how refrigerant is handled, recovered, and recycled in stationary cooling and heat pump equipment. On a single-unit building that is a footnote. On a roof with a fleet, it becomes a service and parts planning question worth answering now.

The second is who owns performance after startup. A unit that runs is not the same as a unit that performs to spec, and the gap between them usually surfaces as comfort complaints in month two.

If your building carries more than one rooftop unit, the smartest version of this project is rarely all of them at once and rarely one at a time forever. Group them by age and condition, replace the worst two together, and let a single crane day carry both. One mobilization split across two units costs less than two separate mobilizations, and the permit and inspection work overlaps instead of repeating.

Procurement rewards lead time. Equipment availability is one of the standard considerations DOE lists for rooftop replacement, and it is the variable most buyers discover far too late. A unit ordered in winter for a summer install gets you model choice and an efficiency decision. The same unit ordered in July gets you whatever is warehoused.

Lifetime cost is the frame that makes the rest coherent. Purchase price is one line; the energy the unit burns for the next two decades is a much larger one. The DOE Advanced RTU Campaign tracked more than 43,000 upgraded units across 200-plus organizations, and those upgrades cut a combined $37 million a year from energy bills. That is the argument for spending more on the unit and less on the emergency.

Bids only compare when they show the same things. If one quote is a single number and another is itemized, you are not choosing between contractors — you are choosing between levels of disclosure. Ask for these five in writing.