Light Commercial HVAC Service in Maryland

COMMERCIAL ROOFTOP HVAC SYSTEMS

Shemtov Systems commercial HVAC, have been services most makes and models since 1981. We provide full service to light commercial, rooftops and split systems. We offer preventative maintenance programs, service, and repairs. Our highly skilled technicians will inspect your systems, and offer you up front pricing before any repairs are made.For rooftop replacements and installation. check with us before making a decision. We will analyze your system for FREE offer you options and pricing.we offer same day installation and will custom make and install new roof curb to accommodate the new unit where needed. Call us for all of your air conditioning needs!

Rooftop hvac products

Shemtov Systems delivers a various products of durable heating and cooling systems for residential and light commercial applications.

We Service

The following areas for HVAC, Heating & Air Conditioning Services for both Commercial & Residential

Light commercial cooling covers the equipment conditioning one building or one tenant suite, from about 2 tons up to the 20 to 25 ton range: packaged rooftop units, commercial split systems, and variable refrigerant flow. Three-phase power, ventilation air, roof access, and the cost of being down during trading hours separate it from house work. Shemtov Systems maintains and replaces this equipment for buildings in Rockville, Gaithersburg, and the rest of Montgomery County. Call 240-355-3333.

Key takeaways

Federal efficiency rules split at 65,000 Btu per hour, or 5.4 tons, and the nameplate metric changes at that line.
Commercial units run on three-phase power and carry ventilation, economizer, and control parts that houses do not have.
Kitchens, server closets, and full-occupancy assembly rooms create loads that residential sizing habits miss entirely.
County commercial mechanical permits are generally issued on payment, though anything needing zoning review waits in a queue.

What counts as light commercial cooling?

The line is capacity and building type, not brand. Single-zone packaged units on a flat roof, split systems with an air handler in a ceiling plenum or closet, and variable refrigerant flow serving a few interior spaces all sit inside it. Above roughly 25 tons, or once a building runs chillers and boilers feeding air handlers, the work becomes full commercial HVAC.

How is commercial cooling different from residential?

Almost everything past the thermostat changes. Power is usually three-phase through contactors, starters, and sometimes a variable frequency drive. Blowers are often belt driven against higher external static pressure. Units bring in outside air for ventilation, often through an economizer that can cool with cold outdoor air alone. Equipment sits on a roof curb, interior zones can call for cooling in January, and longer run hours wear parts out sooner.

How is efficiency rated on this equipment?

Below 65,000 Btu per hour, three-phase equipment built since January 1, 2025 is rated in SEER2 and HSPF2: 13.4 SEER2 for split and packaged air conditioners, 14.3 SEER2 and 7.5 HSPF2 for split-system heat pumps. At 65,000 Btu per hour and above the metric is IEER, a weighted average of four part-load points, and a packaged air conditioner up to 135,000 Btu per hour must reach 14.8 IEER with electric or no heat. Equipment built from January 1, 2029 is rated on a new metric, IVEC.

How do you replace a rooftop unit without closing the business?

The survey comes first: curb dimensions and orientation, unit weight against the roof structure, crane or boom access, staging space in the lot, and the existing gas, power, and condensate connections. A replacement footprint rarely matches an old curb, so the adapter and duct transition are settled before the lift is booked. Permitting runs in parallel, and the equipment on the application has to match the parent building permit drawings.

What does commercial planned maintenance include?

More than a residential tune-up, because there is more to fail. A visit covers belts, bearings, and sheave alignment; economizer dampers, actuators, and the outside air setting; coil cleaning inside and out; refrigerant readings; motor amp draws against nameplate; contactors, relays, and safeties; condensate pans and drains. Curb flashing gets a look, since a leak there becomes a building problem. Our guide covers how often HVAC equipment should be serviced.

What is different about restaurants, retail, and houses of worship?

Restaurants exhaust large volumes through kitchen hoods, so when makeup air is short the building goes negative, doors pull hard, and humid air is dragged in around every gap. That is a job for duct design and installation, not more tonnage. A worship space can sit near empty for days, then fill in fifteen minutes, loading equipment faster than a thermostat manages.

Frequently asked questions

How is commercial cooling capacity sized?

By load calculation using occupancy, lighting, plug and kitchen equipment, required ventilation air, and the envelope. Square footage rules from houses oversize commercial space and leave it humid.

Does the refrigerant change affect commercial equipment?

Since January 1, 2025, new light commercial air conditioning and heat pump systems must use a refrigerant under 700 global warming potential, which is why R-454B appears on new nameplates. Variable refrigerant flow had until January 1, 2026. Existing R-410A equipment can still be serviced, and parts for it are labeled for servicing existing equipment only.

Can the work happen outside our business hours?

Ask when you schedule and say which hours you cannot lose. Shemtov Systems runs a 24-hour answering service, so a no-cooling call can be logged whenever it happens. You can also contact Shemtov Systems.

How long does a rooftop unit last?

Around 15 years is the usual planning figure; run hours and exposure decide the rest. A unit with fouled coils and slack belts ages faster than the same equipment on a regular service agreement.

Talk to Shemtov Systems

To plan a rooftop change-out or set up scheduled maintenance for your building, call Shemtov Systems at 240-355-3333.

Homeowner guides

Straight answers to the questions we hear most from Montgomery County homeowners.