Pre-Summer Rooftop Prep for Valley Businesses
Every commercial HVAC failure in July was visible in March. A structured pre-season inspection for Valley property.
Commercial rooftop units should receive a full pre-summer inspection in February or March covering coil cleaning, belts and bearings, electrical connections and amp draws, refrigerant charge, condensate drainage, economizer operation, and curb and flashing condition before monsoon.
The business case, stated plainly
A restaurant that closes for a July afternoon, a retail floor that empties because it is 88 degrees inside, a salon rescheduling a day of appointments — those costs dwarf any maintenance contract.
Commercial rooftop equipment in Phoenix lives harder than residential: full sun on the cabinet, ambient temperatures on a dark roof well above reported air temperature, high runtime, and belt-driven components residential systems do not have.
And nobody goes on the roof until something breaks, which means problems have months to develop unobserved.
The pre-summer scope
- Condenser coils cleaned properly — chemically where loaded, not just rinsed. Grease-laden coils near kitchen exhaust need specific attention.
- Evaporator coils and drain pans inspected and cleaned.
- Belts checked for cracking, glazing, and tension; replaced on condition rather than after failure.
- Bearings inspected and lubricated where applicable.
- Electrical connections tightened and amp draws compared against nameplate on every motor and compressor.
- Capacitors measured and contactors inspected for pitting and insect damage.
- Refrigerant charge verified by superheat or subcooling.
- Condensate drains cleared and secondary protection verified.
- Economizer dampers, actuators, and controls tested through their full range.
- Filters replaced and the filter rack checked for bypass.
- Curb seals, flashing, and panel gaskets inspected ahead of monsoon.
The economizer, again
We raise this every time because it causes more expensive, invisible waste than anything else on a Valley roof.
An economizer brings in outside air when outdoor conditions are favorable, which saves money in mild weather. In Phoenix that window is narrow. The rest of the year it should be closed.
Stuck open in July, the unit continuously draws 110-degree outside air into a building you are cooling to 74. The cooling bill climbs dramatically, the space never gets comfortable on hot afternoons, and the compressor runs continuously.
It produces no obvious symptom from inside the building except discomfort and a high bill. Testing it through its full range every spring is a few minutes of work against a very large potential cost.
Building pressure and make-up air
For restaurants and any space with significant exhaust, pre-summer is also the time to verify building pressure.
A kitchen exhaust hood removes a large volume of air that has to be replaced. When the make-up air unit is undersized, broken, or — very commonly — switched off by staff who find it drafty, the building goes negative and pulls 110-degree outside air in through every gap including the front door.
Verify the interlock that starts make-up air whenever the hood runs. A broken interlock is common, easy to miss, and expensive all summer.
Documentation for property managers
A pre-summer inspection should produce a written report per unit: nameplate data, readings taken, condition assessment, work performed, and a prioritized list separating what must be addressed now from what can be budgeted.
That document does several jobs. It supports capital planning, it supports warranty claims, it demonstrates diligence to tenants, and it gives you a baseline for comparison next year.
Photographs matter too, especially of curb and flashing condition before monsoon. If a leak develops in August, documented pre-season condition is genuinely useful.
The replacement conversation
Spring is when to decide about equipment that struggled last summer. A unit that lost ground on hot afternoons, needed repairs, or is past its useful life is not going to be better this year.
Replacing commercial rooftop equipment in March or April is dramatically easier than replacing it in July: crane scheduling is available, crews are not working in 115-degree heat on a dark roof, and the business is not operating without cooling while it happens.
If a unit is marginal and the space is between tenants, that is the ideal moment — no disruption, flexible scheduling, and new equipment is a legitimate leasing point.
A realistic ongoing cadence
| Frequency | Scope |
|---|---|
| Monthly (staff) | Filter check and change; note any unusual noise or performance |
| Quarterly (professional) | Coils, belts, bearings, drains, electrical, charge, economizer |
| Pre-summer (Feb–Mar) | Full inspection and performance verification |
| Pre-monsoon (May–Jun) | Curbs, flashing, panel gaskets, drainage |
| Annual | Full condition report with photos and capital planning input |
Frequently asked
When should commercial HVAC be serviced before summer in Phoenix?
February or March for the full pre-summer inspection, with a separate pre-monsoon check of curbs, flashing, and drainage in May or June. Quarterly service through the year is the right ongoing cadence for Valley rooftop equipment.
What is the most commonly missed commercial HVAC problem?
A stuck economizer. It continuously draws 110-degree outside air into a building being cooled, which dramatically raises the bill and leaves the space uncomfortable on hot days — with no obvious symptom from inside except discomfort.
Is it cheaper to replace rooftop units in spring?
Substantially easier, which usually means cheaper. Crane scheduling is available, crews are not working in 115-degree heat on a dark roof, and the business is not operating without cooling during the changeout.