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Commercial · Commercial HVAC Filter ChangeCommercial HVAC Filter Change Service
A commercial HVAC filter change service replaces every filter in every unit on a schedule and leaves a dated record. The starting intervals are monthly for restaurants, salons and dusty industrial units, and every two to three months for offices and retail. The real trigger is pressure drop: when the reading across the filter bank reaches about twice its clean value, the filters are done, whatever the calendar says.
Interval follows what is in the air. A restaurant loads filters with grease aerosol, a salon with hair and product, and a woodworking or fabrication unit with dust that can blind a pleated filter in weeks; an office mostly sheds paper dust and whatever comes in through the economizer. That is why one plaza can need monthly changes in two units and quarterly changes in the others. We set a first interval by occupancy, then adjust it from pressure-drop readings taken at each visit.
MERV 8 pleated is the baseline for commercial rooftop units: it protects the coil and holds a reasonable amount of dust without choking the fan. MERV 13 captures much finer particles and is worth using where the fan and the filter rack can take it, which usually means a 4-inch rack or a unit with fan capacity to spare. Forcing 2-inch MERV 13 filters into a unit built around MERV 8 can cut airflow enough to ice the coil in summer and trip the heat limit in winter. We measure static pressure before and after an upgrade, and MERV ratings explained has the background.
Rooftop units take filters in sets, so the count matters more than people expect. A typical unit holds four 20x25x2 filters, larger ones hold six or more, and some have a second bank or a washable metal mesh screen in the outdoor-air hood. A ten-unit plaza can be forty-plus filters per change in three or four different sizes. On the first visit we open every unit and build a filter schedule — size, quantity and MERV per unit, per building — so every later visit arrives with the right cases on the truck.
A filter-only visit includes the new filters, removal of the old ones, a belt check for tension and cracking, a look at the coil face and drain pan, and a dated entry in the service log. It does not include coil cleaning, combustion analysis, refrigerant readings, economizer testing or repairs; those belong to a full maintenance contract. Anything we notice with the panel open is written up with a photo, so you can decide before it becomes a breakdown.
Property managers running several buildings usually fold filter changes into the plan described on our property management HVAC page. Single-tenant shops and offices can book filter changes alone. See commercial HVAC for everything else we do on a roof, or send us the address and unit count for a written per-visit price.
Equipment we install and service
The standard 2-inch disposable filter in most rooftop units. Inexpensive per filter, quick to change, and adequate for coil protection in offices and retail. Fibreglass throwaways rated below this let enough dust through to foul the evaporator coil.
Finer media for clinics, offices that want better particle capture, and buildings affected by wildfire smoke. Higher resistance means the unit's static pressure must be checked, and deeper 4-inch filters are preferred because they carry the efficiency with less pressure drop.
Washable aluminum mesh screens in economizer hoods, filters on make-up air units, and the small filters in ductless heads and fan coils. These are the ones left out of a casual filter change, and a plugged outdoor-air screen starves the building of ventilation.
A differential gauge or a technician's manometer across the filter bank shows how loaded the filters are. A permanent gauge on a large unit lets your own staff see the reading between visits.
What goes wrong in these buildings
- Nobody knows how many filters are on the roof or what sizes they are.
- The cleaner says he changes them, but there is no date on any filter and no log.
- The landlord wants proof of filter changes before he will talk about the dead compressor.
- Head office audits ask for a dated record for every store.
- The dining room unit ices up every July and the filter is always grey.
- We bought MERV 13 filters and the airflow at the back offices dropped.
How it works
Every unit is opened once: filter sizes, quantities, rack depth, belt size and a clean-filter pressure reading are recorded. You get a one-page filter schedule for the building.
Filters go in with the airflow arrow pointing the right way and the change date written on the frame. Old filters are bagged and taken off the roof, belts are checked, and the pressure reading is logged.
The dated log goes to whoever needs it — tenant, landlord, insurer or head office. If readings show filters loading early or lasting longer, the interval changes to match.
Common questions
What does a commercial filter change cost?
The price is per visit and depends on four things: the number of filters, their size and MERV rating, how the roof is reached, and how often we come. A hatch with a fixed ladder is quicker than an extension ladder on a two-storey wall. Once the units are counted we give a fixed written price per visit, so the annual cost is known.
Can our own staff change the filters instead?
On units reachable from inside the building, yes, and we will leave the schedule and sizes. Rooftop work is different: it involves roof access, electrical panels and moving belts, and most landlords and insurers want it done by an insured contractor with a record. A common split is staff handling indoor fan coils while we handle the roof.
Will MERV 13 filters damage our rooftop unit?
Not if the unit has the fan capacity and rack depth for them. The risk is 2-inch MERV 13 filters in a small unit already near its static pressure limit: airflow falls, the cooling coil can freeze and the heat exchanger can overheat. We measure static pressure with the new filters in place and tell you whether the unit accepts them.
How do we know the filters were really changed?
Each filter is dated on its frame in marker, the log lists the unit, the date, the filter count and the pressure reading, and photos are available on request. That record is what a landlord, an insurer or a head-office audit accepts, and it also supports a warranty claim when a compressor or heat exchanger fails.
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