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Commercial HVACVery Small AC

Weathermaker PA4SAP536**NB Commercial HVAC Unit Manual

Setup, everyday use, maintenance and troubleshooting for the split-system light commercial air conditioner, with verified specifications.

  • SEER216.0
  • EER213.0
  • ConfigurationSplit system
  • RefrigerantR-454B

About the Weathermaker PA4SAP536**NB

Weathermaker model PA4SAP536**NB is a split-system light commercial air conditioner that meets ENERGY STAR efficiency requirements.

It is rated at 16.0 SEER2 and 13.0 EER2. Commercial units under 65,000 Btu/h use the same SEER2 and EER2 metrics as residential central systems: SEER2 reflects seasonal cooling efficiency, EER2 efficiency on a 95 °F day.

It is listed with an electric resistance heating section. The ratings on this page apply to the outdoor unit matched with indoor unit QFVA5D4821X*; other matches have their own ratings.

Its SEER2 is higher than 38% of the 551 Very Small AC models in our database. It uses R-454B (GWP 470), an A2L (mildly flammable) refrigerant with much lower global-warming potential than R-410A.

Specifications

BrandWeathermaker
Model numberPA4SAP536**NB*
Model name / series13.4 SEER2 AC
Equipment categoryVery Small AC
ConfigurationSplit system
Product series13.4 SEER2 AC
SEER216.0
EER213.0
Heating section typeElectric resistance
Matched indoor unitQFVA5D4821X*
RefrigerantR-454B (GWP 470)
Meets ENERGY STAR peak cooling requirementYes

Certified matched systems

123 certified matched systems are listed for the Weathermaker PA4SAP536**NB, sorted by SEER2. The 25 most efficient are shown below. Each row links to a page with that system's full ratings and guidance.

Indoor unitFurnaceSEER2EER2
QFVA5D4821X*—16.013.0
CVAVA4924XMA*PG80MS(A,L)A60110D**15.513.0
CVAVA4224XMA*PG80MS(A,L)A60110D**15.512.5
CVAVA4224XMA*PG80MS(A,L)A60110C**15.512.5
PF5TNXC48L*—15.212.5
PF5MN*C48L*—15.212.5
FMA5X36**AL*—15.212.5
FJ5AN*C48L*—15.212.5
CVAVA4924XMA*PG97VTAA66120D**15.212.5
CVAVA4924XMA*PG97VTAA60100C**15.212.5
CVAVA4924XMA*PG97VTAA60080C**15.212.5
CVAVA4924XMA*PG96VTAB66120D**15.212.5
CVAVA4924XMA*PG96VTAB60100C**15.212.5
CVAVA4924XMA*PG96VTAB60080C**15.212.5
CVAVA4924XMA*PG96MSAA66140D**15.212.5
CVAVA4924XMA*PG96MSAA66120D**15.212.5
CVAVA4924XMA*PG96MSAA60100C**15.212.5
CVAVA4924XMA*PG95MSUA60100C**15.212.5
CVAVA4924XMA*PG95MSUA60080C**15.212.5
CVAVA4924XMA*PG92MSAA60120D**15.212.5
CVAVA4924XMA*PG92MSAA60100C**15.213.0
CVAVA4924XMA*PG92MSAA60080C**15.213.0
CVAVA4924XMA*PG80VTLB66135D**15.213.0
CVAVA4924XMA*PG80VTLB66110C**15.212.5
CVAVA4924XMA*PG80VTLB60090C**15.212.5

View all 123 matched systems

Safety information

  • Installation and service must be performed by a licensed commercial HVAC contractor following the manufacturer's instructions and applicable mechanical, electrical, fuel-gas and building codes. Refrigerant work requires EPA Section 608 certification.
  • Commercial units run on high-voltage, often three-phase power. Open and lock out the disconnect before servicing, and remember that capacitors and variable-speed drives can hold a charge after power is removed.
  • Fans and belt drives can start automatically. Never operate the unit with access panels removed or reach into fan sections while power is on.

Installation and commissioning

Installation quality largely determines whether the Weathermaker PA4SAP536**NB achieves its certified efficiency in the field. Use these points when reviewing bids and the start-up documentation.

  1. Load and ventilation calculation

    Size the equipment from a commercial load calculation (such as ACCA Manual N or an engineer's ASHRAE-based calculation) that includes occupancy, lighting, equipment and the outdoor-air ventilation the mechanical code requires. Replacing like-for-like without a calculation often perpetuates oversizing.

  2. Matched components

    Install the exact indoor coil the rating is based on (indoor unit QFVA5D4821X*). Other combinations may be certified with different efficiency, so confirm the match before purchase.

  3. Outdoor unit and line set

    Set the outdoor unit level with the listed clearances, and keep the refrigerant line set within the manufacturer's length and lift limits. Pressure-test, evacuate to 500 microns or below and charge as specified.

  4. Electrical supply

    Size conductors and overcurrent protection from the nameplate minimum circuit ampacity (MCA) and maximum overcurrent protection (MOP), and install a disconnect within sight of the unit. On three-phase equipment, verify phase rotation at start-up — scroll compressors running backward are noisy, do not pump and can be damaged.

  5. Condensate drain

    Install a trap sized for the unit's fan pressure (draw-through coils need a deeper trap), pitch the drain away from the unit and protect it from freezing. A dry or undersized trap lets air prevent drainage and causes water to back up into the unit or building.

  6. Commissioning

    Ask for a start-up report showing airflow and static pressure, refrigerant charge (superheat/subcooling), economizer and outdoor-air settings if equipped, and thermostat or building-automation schedules, plus a functional test of the refrigerant leak detection system.

Using your air conditioner

Schedules and setpoints

Program occupied and unoccupied schedules that match business hours. Widen setpoints when the building is empty (for example, allowing the space to drift several degrees warmer in cooling and cooler in heating), and use optimal start so the space reaches setpoint just as occupants arrive rather than hours early.

Fan and ventilation

Most codes require ventilation air whenever the space is occupied, so the supply fan normally runs continuously during occupied hours and cycles with demand afterward. If the unit has an economizer, it uses cool outdoor air for "free" cooling in mild weather; make sure dampers move freely and settings match your climate.

Managing peak demand

Commercial electric rates often include demand charges based on your highest 15- or 30-minute draw. This unit's EER2 of 13.0 describes its efficiency at that hot-weather peak. On sites with several units, staggering start times after unoccupied periods avoids stacking compressor starts.

Care and maintenance

A written maintenance agreement with a qualified contractor is the most reliable way to keep commercial equipment efficient. The schedule below is typical; follow the manufacturer's manual where it differs.

WhenWhat to do
Monthly to quarterlyReplace air filters — monthly in dusty environments, restaurants or retail with heavy traffic; quarterly in clean offices.
QuarterlyInspect belts and pulleys on belt-drive units, clean the condensate pan and trap, and check for water leaks at the curb or ductwork.
SpringClean the condenser coil (more often near cottonwoods, construction or kitchens), check refrigerant pressures, contactors and electrical connections, and test economizer operation.
FallCheck heating equipment serving the space and verify controls switch over correctly.
Every yearInspect fan motors and bearings, cabinet and curb seals, and insulation; clean the evaporator coil if airflow or temperature split has dropped.
Per manufacturer scheduleTest the refrigerant leak detection sensor and mitigation sequence as the installation manual requires.

Troubleshooting

ProblemPossible causeWhat to try
Unit not runningDisconnect or breaker off; thermostat or building-automation schedule in unoccupied mode; safety lockout.Check the disconnect, breaker and schedule. Do not repeatedly reset lockouts — have a technician find the cause.
Running but not cooling enoughDirty filters or coils; low refrigerant charge; failed compressor stage; economizer stuck open in hot, humid weather.Replace filters and check that outdoor-air dampers close properly; call a technician for coil cleaning and refrigerant checks.
Very loud compressor after installation or electrical workReversed phase rotation on a three-phase scroll compressor.Shut the unit off immediately and have an electrician or technician correct the phasing.
Water leaking into the buildingClogged or dry condensate trap; drain pan overflowing; curb or duct seal leak; ice melting off the coil.Clear the drain and trap; have the curb and ductwork resealed if leaks continue.
Ice on the evaporator coil or suction lineLow airflow from dirty filters or a broken belt; low refrigerant charge.Turn cooling off and let the coil thaw with the fan running; replace filters and inspect belts before restarting. Persistent icing needs a technician.
High energy billsSchedule not matching occupancy; economizer fault; dirty coils; units fighting each other in adjacent zones.Review schedules and setpoints, have the economizer tested, and coordinate setpoints between neighboring units.
Short cyclingOversized equipment; thermostat in a poor location; control or refrigerant problem.Relocate or recalibrate the thermostat; have the contractor review sizing and staging.
Refrigerant leak alarm or mitigation modeThe leak detection system sensed refrigerant.Leave the fan running, ventilate the area, keep ignition sources away and call a qualified technician.

Energy use and running costs

The certification record does not list this match's capacity, so the estimate is per ton (12,000 Btu/h). Assuming 1,200 equivalent full-load cooling hours a year (our assumption for a moderate climate with business-hour occupancy), each ton at 16.0 SEER2 uses about 900 kWh a year, roughly $153 per ton at $0.17 per kWh. Multiply by the unit's nominal tonnage for a total.

At full load on a hot day each ton draws roughly 0.92 kW (12,000 Btu/h divided by its EER2 of 13.0).

Actual consumption depends on climate, building loads, operating hours, ventilation rates and control settings, and these estimates exclude fan energy outside cooling hours and any demand charges. Use them to compare units rather than as a bill forecast.

Frequently asked questions

What are the efficiency ratings of the Weathermaker PA4SAP536**NB?

The Weathermaker PA4SAP536**NB is rated at 16.0 SEER2 and 13.0 EER2 when matched with indoor unit QFVA5D4821X*.

Which indoor unit is the Weathermaker PA4SAP536**NB rated with?

This listing pairs it with indoor unit QFVA5D4821X*. Weathermaker certifies other indoor matches separately, each with its own ratings, so check the match before relying on these numbers.

Does the Weathermaker PA4SAP536**NB provide heat?

Yes, it is listed with an electric resistance heating section.

Is the Weathermaker PA4SAP536**NB a packaged unit or a split system?

It is a split system: the outdoor condensing unit connects by refrigerant lines to an indoor coil and air handler, and its ratings apply only to the certified indoor match.

What refrigerant does the Weathermaker PA4SAP536**NB use?

It uses R-454B (GWP 470). It is an A2L (mildly flammable) refrigerant, so service must be done by A2L-trained technicians, and systems above certain refrigerant charges include leak detection.

When was the Weathermaker PA4SAP536**NB ENERGY STAR certified?

It appears on the ENERGY STAR certified light commercial HVAC list with a certification date of September 2026.

Sources and disclaimer

Specifications on this page come from the ENERGY STAR certified commercial hvac dataset published by the U.S. Environmental Protection Agency (record certified September 13, 2026), retrieved October 7, 2026.

The setup, operating, maintenance and troubleshooting guidance is written by ManualHarbor's editors for this specific product type and configuration. It is an independent guide — not a reproduction of the manufacturer's manual — and ManualHarbor is not affiliated with Weathermaker. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact Weathermaker or an authorized service provider for warranty repairs and replacement parts.

Running-cost figures use assumed U.S. average utility prices and are estimates for comparison only. See our editorial methodology for details.