Commercial HVAC questions, answered. Schaumburg, IL.

Get people out of the area, don’t operate switches, thermostats or equipment, and call your gas utility or 911 from outside. In most of the northwest suburbs that utility is Nicor Gas.

Don’t go back in or onto the roof until the utility or fire department says it’s safe. Once it is, Velocity HVAC-R can inspect the equipment, find the cause and repair it.

Get everyone out of the building and call 911. Don’t try to find the source yourself or ventilate the space first.

After the fire department clears the building, have all fuel-burning equipment (boilers, furnaces, rooftop heat sections, make-up air units, water heaters) inspected before it’s used again. Cracked heat exchangers, blocked flues and failed venting are common causes.

Call for service right away, then protect the building: keep doors closed, open ceiling-space and cabinet doors where pipes run along outside walls, and watch for pipes in vestibules, stairwells and loading areas.

Never use gas ovens, grills or open-flame heaters indoors for heat. Portable electric heaters should be used only as their manufacturer allows and never left unattended. Don’t attempt burner, gas valve or control repairs yourself.

Keep the door closed, check that it isn’t propped or blocked, make sure the condenser outside isn’t buried in snow or debris, and call for service. Move product to another cooler if the temperature keeps rising.

Note what you see: ice on the evaporator coil, water on the floor, a unit running nonstop or not running at all. That helps the technician find the fault faster. Don’t chip ice off coils or touch refrigerant lines.

It can be either. On a rooftop unit, the usual HVAC causes are a clogged condensate drain, a cracked drain pan, a failed curb seal or a duct connection leaking, especially in humid summer weather.

Turn the unit off at the thermostat or BAS if water is near lights or electrical equipment, and call. We check the unit, drain and curb first and tell you plainly if it’s a roofing issue instead.

No. Velocity HVAC-R works on commercial and industrial buildings only: offices, retail, restaurants, industrial plants, warehouses, hotels, schools, churches and similar facilities.

That focus is why our technicians spend their days on rooftop units, boilers, chillers, refrigeration and building automation rather than home furnaces.

Commonly 15 to 20 years, but the range is wide. Maintenance, run hours, corrosive industrial air and how well the unit was sized all move that number.

Age alone isn’t a reason to replace. Repair history, refrigerant type, parts availability and efficiency matter more. A maintenance report that tracks condition over time is the best basis for planning.

Compare the repair cost against the unit’s remaining life and operating cost. A large repair on an old unit with an outdated refrigerant is usually money better spent on replacement; a moderate repair on a sound unit usually isn’t.

We give you both options with clear numbers after diagnosis, so the decision is yours and it’s an informed one.

Yes, but it gets harder every year. U.S. production and import of new R-22 ended on January 1, 2020, so servicing relies on recovered, reclaimed or stockpiled refrigerant, which is limited and costly.

R-22 systems can keep running as long as they hold their charge. If one develops a significant leak or a major component fails, it’s usually time to plan replacement rather than recharge it again.

Under the federal AIM Act, the EPA is phasing new air conditioning and refrigeration equipment off higher-global-warming refrigerants such as R-410A. Much new comfort-cooling equipment now uses lower-GWP refrigerants like R-454B or R-32, classed A2L (mildly flammable). Dates differ by equipment type.

Your existing R-410A equipment can keep running and be serviced. The change mainly affects replacements: new equipment, different refrigerant, sometimes different line sets or safety requirements. We plan replacements with that in mind.

A crane lift, usually scheduled early in the day; disconnecting and capping the old unit; a curb adapter if the new unit’s footprint differs; electrical, gas and controls connections; then start-up and checkout.

Permits and, in busy areas, lot or street closures are part of the plan. Done well, a single-unit change-out often fits in one day of downtime for that zone.

Start with an equipment inventory: every unit, its age, refrigerant, condition and repair history. That turns surprise failures into a schedule you can budget against.

Velocity HVAC-R’s maintenance visits include a detailed report, which builds exactly that picture over time.

For most commercial buildings, at least twice a year: a cooling check before summer and a heating check before winter. Filters often need changing more often, and critical equipment like chillers, boilers and refrigeration may warrant quarterly or monthly visits.

ANSI/ASHRAE/ACCA Standard 180 sets out recognized minimum inspection and maintenance tasks for commercial HVAC systems and is a good basis for a plan.

It depends on the equipment and the plan, but typically coil cleaning, filter replacement, belts, motors and bearings, drains, refrigerant-circuit checks, burner and safety checks on heating equipment, and controls checks.

Every PM visit ends with a detailed report of what we checked, what we found and what we recommend, so you have a record and nothing is a surprise.

Dirty coils cut heat transfer, which raises head pressure, energy use and wear on compressors, and reduces capacity on the hottest days, exactly when you need it.

Condenser coils on rooftops collect cottonwood, dust and debris every season. Cleaning them on schedule is one of the cheapest ways to protect the most expensive part of the unit.

Many commercial systems run MERV 8 to MERV 13. Higher MERV filters catch finer particles, but only if the fan and filter rack are suited to the added resistance.

We’ll recommend the highest rating your equipment can handle without starving airflow, and a change interval that matches your building.

Check the heat section, igniter, flame sensor and venting; make sure economizer dampers close tight and freeze protection works; and confirm outside-air intakes and condensers aren’t blocked by snow.

Units with hot-water or chilled-water coils need freeze protection checked too. A freeze-stat trip or a burst coil in January is far more expensive than a fall inspection.

What was inspected, what was found, what was fixed on the spot, and what needs attention later, with priorities. Readings and photos make it useful rather than a checklist.

Over a few seasons, those reports become a condition history for every unit, which is the basis for honest repair-or-replace decisions and capital budgets.

Common causes are an oversized boiler for the load, poor control settings or sensor placement, low water flow, air in the system, or a failing component. Short-cycling wastes fuel and wears out burners and controls.

We troubleshoot the boiler and the hydronic loop together, because the cause is often in the piping or controls rather than the boiler itself.

Yes. Most commercial boilers and pressure vessels in Illinois are regulated by the Office of the State Fire Marshal’s boiler and pressure vessel safety program and need periodic inspection and a current certificate of inspection.

Inspections are typically arranged through your insurer or a state inspector. Keeping the boiler maintained and its safety controls working keeps it ready to pass.

An air-cooled chiller rejects heat to outside air with fans and coils, usually from a rooftop or pad. A water-cooled chiller rejects heat to water that’s cooled by a cooling tower; it’s typically more efficient on large loads but adds the tower and water treatment to maintain.

Both need seasonal start-up and shutdown, clean heat-transfer surfaces and attention to alarms. Which one you have shapes your maintenance plan.

The usual causes are door gaskets that don’t seal, doors left open, a failed defrost heater, timer or control, a blocked drain line, or a low refrigerant charge.

Ice is a symptom, not the fault. We find the cause so the coil stays clear instead of just defrosting it and leaving.

Under EPA Section 608, owners of larger air conditioning and refrigeration systems must repair leaks that exceed set leak rates within set time frames and keep records. A 2024 EPA rule extends leak-repair requirements to more systems that use HFC refrigerants starting in 2026.

Thresholds depend on the system type and refrigerant charge. We’ll tell you which of your systems are covered and keep the service records the rules call for.

Usually both, for different things. Hood and duct cleaning is done by specialized cleaners under fire code (NFPA 96). Exhaust fans, make-up air units, belts, motors, controls and the balance between them are HVAC work.

If smoke rolls out of the hood, doors are hard to open or the kitchen is cold in winter, the cause is usually mechanical. Velocity HVAC-R troubleshoots kitchen exhaust systems and make-up air.

BACnet is an open communication protocol for building automation. It lets equipment and controllers from different manufacturers share data and be controlled from one building automation system (BAS).

BACnet integration means your BAS can see alarms, temperatures and run status for each unit and adjust schedules and setpoints, instead of someone checking equipment on the roof.

A variable air volume (VAV) box sits in the ductwork above the ceiling and controls how much conditioned air reaches a zone, opening or closing a damper to hold that zone’s temperature. Many also have reheat.

When a VAV box’s damper, actuator, airflow sensor or controller fails, the result is a zone that’s always too hot or too cold, no matter what the thermostat says.

When existing boxes have failing pneumatic or obsolete controls, when the floor plan has changed and zones no longer fit, or when you want the boxes on your BAS. A retrofit often keeps the box and replaces the controls and actuators.

We survey the boxes, controls and airflow first, then recommend repair, retrofit or replacement box by box.

Usually zoning and controls: VAV boxes that have failed or are out of calibration, thermostats in the wrong place after a remodel, or one zone serving spaces with very different loads.

VAV troubleshooting and repair fixes most of these. Measuring airflow at the boxes tells us whether it’s controls, airflow or capacity.

An economizer lets a rooftop unit use cool outside air for free cooling instead of running the compressor. Its dampers, actuators, sensors and controls fail often, and failures go unnoticed because the unit still runs.

A stuck-open economizer can over-ventilate and freeze coils in winter; a stuck-closed one wastes energy and can starve the building of fresh air. We check economizers on every maintenance visit.

Illinois does not issue a statewide HVAC contractor license. Licensing or contractor registration for mechanical work is set locally, by each city or village, and requirements vary.

Technicians who handle refrigerant must hold federal EPA Section 608 certification. When you hire, ask about local registration where your building is, EPA certification and a current certificate of insurance.

Look for commercial and industrial experience with your type of equipment, clear written proposals, a maintenance report you can actually use, proof of insurance, and a team that works well with your other trades.

Ask how they explain diagnoses, how they document maintenance, and who you call when something goes wrong. A good contractor makes the answer to all three easy.

Usually, yes. Most northwest-suburban municipalities require a permit to replace or add commercial heating and cooling equipment, change ductwork or add gas piping, and some require inspections at completion.

Each village sets its own process. We confirm requirements for your address and include the permit in the schedule.

Often. ComEd and Nicor Gas both run energy-efficiency programs for business customers in northern Illinois, and qualifying equipment, controls and tune-ups may be eligible.

Programs and amounts change, so check the current offerings with the utility before you buy. We can provide equipment details the applications usually ask for.

For larger commercial units, IEER (integrated energy efficiency ratio) reflects part-load performance, which is how units actually run most of the year; EER reflects full-load. Smaller units are rated in SEER2. Boilers are rated by AFUE or thermal efficiency.

Ratings are only part of the picture. Correct sizing, working economizers and good controls often save more than a slightly higher rating.

Ventilation requirements for commercial buildings are set by the mechanical code your municipality adopts, which is generally based on ASHRAE Standard 62.1. The amount depends on the space type, floor area and occupancy.

Too little outside air hurts indoor air quality; too much wastes energy and can freeze coils in winter. We check that dampers, economizers and controls actually deliver the designed amount.

Yes. Velocity HVAC-R collaborates closely with other commercial trades, including BAS, electrical, plumbing, carpentry and test-and-balance teams, so projects finish cleanly.

On installations and retrofits we coordinate schedules, controls points and start-up so the system works the first time it’s balanced.