Commercial Refrigeration II

Course Description

Commercial Refrigeration II further prepares students to demonstrate the skills and knowledge needed for industrial and/or commercial refrigeration positions in HVAC-related jobs and careers, emphasising job site safety, employability skills, proper tool usage, and basic math skills.

Within the SCNS taxonomy, ACR is the Air Conditioning, Refrigeration and Heating prefix, and the 0000-level number marks this as PSAV clock-hour instruction. Daytona State publishes it at 150 clock hours with a $372.68 lab fee, offered fall and spring, with ACR0744C as prerequisite — and it is listed as ACR0744C's corequisite, so the two normally run together. ⚠ It carries no college credit.

This completes the commercial pathway and moves toward the larger and more complex systems — multi-compressor racks, electronic controls, and the equipment that supermarkets and cold storage actually run on. It is also where the trade's current transition becomes most visible: refrigerant regulation is changing, and commercial refrigeration is where the new systems and the new hazards arrive first.

Learning Outcomes

Required Outcomes

• Describe complex and multi-evaporator commercial systems.
• Describe parallel and rack compressor systems.
• Describe capacity control and unloading methods.
• Describe head pressure control and its seasonal importance.
• Describe electronic and programmable controls in commercial refrigeration.
• Configure and interpret electronic controller settings.
• Describe monitoring and alarm systems and respond to their output.
• Diagnose faults in multi-evaporator and rack systems.
• Diagnose electronic expansion valve and controller faults.
• Perform advanced systematic diagnosis on unfamiliar commercial equipment.
• Describe compressor failure modes and diagnose them.
• Perform compressor replacement and system cleanup after failure.
• Describe acid testing and post-burnout procedures.
• Describe refrigerant retrofits and blend handling.
• Describe the regulatory requirements applying to larger charge systems.
• Apply leak inspection and repair requirements for larger systems.
• Maintain refrigerant records to regulatory standard.
• Describe emerging refrigerants and their safety classifications.
• Describe flammable refrigerant handling requirements.
• Describe energy efficiency measures in commercial refrigeration.
• Perform system performance evaluation and optimisation.
• Plan and perform preventative maintenance programmes.
• Communicate with facility managers and document commercial service.
• Apply workplace safety practice throughout.

Optional Outcomes

• Describe ammonia refrigeration systems and their hazards.
• Describe CO2 transcritical system operation.
• Describe supermarket energy management systems.
• Describe commissioning and retro-commissioning of commercial systems.
• Describe refrigeration system design fundamentals.
• Prepare for NATE or CM certification in commercial refrigeration.

Major Topics

Required Topics

• Complex and multi-evaporator systems
• Parallel and rack compressors
• Capacity control and unloading
• Head pressure control
• Electronic and programmable controls
• Controller configuration
• Monitoring and alarm systems
• Rack system fault diagnosis
• Electronic expansion valve diagnosis
• Advanced systematic diagnosis
• Compressor failure modes
• Compressor replacement and cleanup
• Acid testing and post-burnout procedure
• Retrofits and blend handling
• Large-charge regulatory requirements
• Leak inspection and repair requirements
• Refrigerant recordkeeping
• Emerging refrigerants and safety classes
• Flammable refrigerant handling
• Energy efficiency measures
• Performance evaluation and optimisation
• Preventative maintenance programmes
• Facility communication and documentation
• Workplace safety

Optional Topics

• Ammonia refrigeration and its hazards
• CO2 transcritical systems
• Energy management systems
• Commissioning and retro-commissioning
• Refrigeration system design
• Commercial certification preparation

Resources & Tools

• The programme's laboratory, live equipment, and recovery machines — the reason to take this in person. Book every open lab hour; this trade is learned with your hands.
• Refrigeration and Air Conditioning Technology (Whitman, Johnson, Tomczyk & Silberstein) — the standard text for this programme and the one to keep afterwards.
• Modern Refrigeration and Air Conditioning (Althouse, Turnquist & Bracciano) — the other standard reference.
• EPA Section 608 study materials (epa.gov) — free official guidance, plus inexpensive practice tests; the authority for anything in this guide about refrigerant rules.
• ESCO Institute (escogroup.org) — administers the EPA 608 and the Employment Ready certifications this programme carries.
• NATE (natex.org) — North American Technician Excellence; the credential to plan for once you have field experience.
• ACCA (acca.org) — the contractors' association; Manual J, S and D are the industry standards for load calculation, equipment selection, and duct design.
• AHRI directory (ahridirectory.org) — free; verified equipment performance data and matched-system ratings.
• Florida DBPR (myfloridalicense.com) — free; the authority on Florida contractor licensing.
• Florida Building Code — Mechanical and Energy Conservation volumes — what installations are actually inspected against here.
• Manufacturer service literature and wiring diagrams — learn to read a ladder diagram properly; it is the difference between diagnosing and guessing.
• A good multimeter, gauges, and a vacuum micron gauge — the micron gauge is the tool that separates professionals from parts-changers, and beginners routinely skip it.

Career Pathways

• Heating, air conditioning, and refrigeration mechanic and installer — SOC 49-9021.
• Residential service technician — the most common entry route, and where diagnostic skill is built fastest.
• Installation crew — new construction and change-outs; physical work with clear progression.
• Commercial and light commercial service — rooftop units, chillers, and building systems.
• Commercial and industrial refrigeration — supermarkets, cold storage, and food service; the best-paid speciality and consistently short of trained technicians.
• Controls and building automation — a growing, technical, and well-paid pathway.
• Maintenance technician in hospitals, hotels, theme parks, schools, and government facilities — salaried with benefits, and a very large Florida sector.
• Marine and transport refrigeration — a Florida-specific niche given the ports and the produce trade.
• Energy auditing and performance testing.
• Service manager, dispatcher, or estimator — the usual progression off the tools.
• Technical sales and manufacturer representation — companies recruit experienced technicians specifically.
• Instruction — teaching in a programme like this one after several years in the field.
• Contracting on your own account — ⚠ a licensed activity in Florida requiring documented experience; see the licensing note.

Special Information

⚠⚠ The refrigerant transition is happening now, and it changes the safety rules

• Refrigerants are being phased down under federal law, and the replacements behave differently. This is the most significant change in the trade in a generation, and it is occurring while you are training.
• ⚠⚠ Many replacement refrigerants are classified as mildly flammable. Equipment using them carries different service procedures, different tooling requirements, different leak detection, and different ventilation and ignition-source precautions from what this trade has assumed for decades.
• Do not apply old habits to new equipment. A technician who brazes near a leaking mildly flammable refrigerant, or uses a non-rated recovery machine, is creating a fire risk that did not previously exist.
• Charge limits and equipment room requirements apply to some of these systems, and they vary by refrigerant and application.
• Read the equipment's service literature and the refrigerant's safety data sheet before working on unfamiliar equipment — this is now a routine step, not a precaution.
• Recovery equipment, leak detectors, and gauges may need to be rated for the refrigerant class you are handling.
• Never mix refrigerants, and never assume a system contains what the label says without checking.
• Training on new refrigerants is a real employability advantage right now, because the workforce broadly has not had it.
• ⚠ Rule 11 applies emphatically. Phasedown schedules, permitted refrigerants, and handling requirements are actively changing. Verify current requirements at epa.gov and with the equipment manufacturer — not from a course guide, a textbook, or an experienced colleague's habits.

⚠ Compressor failure: find out why, or you will do it twice

• A compressor is the most expensive component in the system, and it rarely fails without a cause. Replacing one without finding the cause frequently destroys the new one.
• Establish the failure mode — electrical, mechanical, flood-back, oil starvation, overheating, or acid — before ordering the replacement.
• Acid test the system after a burnout. Acid remaining in the oil and lines will attack the new compressor's windings.
• Clean up properly. Suction line filter driers, flushing where appropriate, and follow-up acid testing — a rushed cleanup is a warranty claim waiting to happen.
• Check the metering device and the whole refrigerant circuit; a restriction or a flooding valve caused the failure and will cause the next one.
• Check the electrical supply and the contactor. Low voltage, phase loss, and a pitted contactor all kill compressors.
• Verify oil return and correct any installation defect causing it.
• Document everything, both for the warranty claim and for the next technician.

⚠⚠ Refrigerant will hurt you in three different ways

• Asphyxiation. Refrigerants are heavier than air and displace oxygen in low and confined spaces — crawl spaces, pits, walk-in boxes, and machine rooms. People have died from this without ever feeling short of breath, because the gas is not toxic and gives no warning; ventilate, and never work a leak in a confined space alone.
• Frostbite. Liquid refrigerant flashing to gas is intensely cold and causes instant severe frostbite on skin and permanent injury to eyes. Safety glasses and gloves, every time you connect or disconnect a hose — not just when you expect a release.
• Pressure. A charged system stores real energy, and a cylinder is a pressure vessel. Never heat a refrigerant cylinder with a torch, never overfill one, never transport one loose in a vehicle, and never exceed 80 percent fill on a recovery cylinder.
• Never braze or apply heat to a pressurised or charged system. Recover first, then purge with dry nitrogen while brazing.
• Refrigerant decomposes into toxic products in contact with a flame — including phosgene — so a leak near an open torch is a chemical hazard as well as a fire one.
• Use a regulator on nitrogen. A nitrogen cylinder at full pressure connected directly to a system will rupture it explosively; this has killed technicians.
• Know where the recovery machine and the leak detector are, and use them. Recovery is both the law and the professional standard.
• Keep cylinders upright, secured, and labelled, and never mix refrigerants in a recovery cylinder.

⚠⚠ Electrical work is the part of this trade that kills people

• HVAC technicians work on live 240-volt equipment routinely, and electrocution is a leading cause of death in the trade.
• ⚠⚠ Capacitors store a lethal charge after the power is off. A run or start capacitor can hold enough energy to kill after the disconnect is pulled. Always discharge capacitors before touching terminals, using the correct method, and treat every one as charged.
• Lock out and tag out, and verify the circuit is dead with a meter you have just tested on a known live source. Test the meter, test the circuit, test the meter again.
• One hand in a pocket when you must probe live, so a shock cannot cross your chest.
• Know that the disconnect may not de-energise everything — control circuits, crankcase heaters, and separately fed components can remain live.
• Wear the right personal protective equipment, use insulated tools, and stand on a dry surface.
• Never bypass a safety control to make a unit run. The control exists because the failure it prevents is serious, and a bypassed safety left in place is a hazard you created.
• Do not work energised when you can avoid it. Convenience is not a justification, and the pressure to keep a customer's system running is exactly when accidents happen.

⚠⚠ EPA Section 608 is a legal requirement, not a nice-to-have

• Under Section 608 of the federal Clean Air Act, technicians who maintain, service, repair, or dispose of equipment containing regulated refrigerants must be certified — and certification is required to purchase regulated refrigerant at all. Without it you cannot lawfully do the central task of this trade.
• The certification has types — Type I (small appliances), Type II (high-pressure), Type III (low-pressure), and Universal (all three). Sit the Universal examination if you can; it costs little more and it closes off no employment.
• It does not expire, which makes it unusually good value among trade credentials.
• ⚠⚠ Venting regulated refrigerant is a federal violation carrying substantial civil penalties, and the obligation is on the individual technician as well as the employer. Recover, never vent — this is the single rule that most defines lawful practice in this trade.
• Recordkeeping obligations attach to refrigerant purchase, recovery, and disposal, and to leak repair on larger systems.
• This programme also carries ESCO Employment Ready certifications — brazing and soldering, system recovery and evacuation, gas heat, and heat pump — and OSHA 10 Construction Site Safety. Employers recognise these by name; collect every one the programme offers.
• NATE certification is the widely recognised next credential once you have field experience, and it frequently carries a pay differential.
• ⚠ Rule 11 applies. Refrigerant regulation is actively changing — see the note on the refrigerant transition. Verify current EPA requirements at epa.gov rather than relying on a course guide.

⚠⚠ Budget for the laboratory fees and the tools — they are substantial and easy to miss

• Daytona State publishes a laboratory fee of roughly $315–$407 for each course in this programme. Across the seven courses documented in this repository that is over $2,500 in fees alone, on top of tuition and before any tools are bought.
• PSAV programmes advertise low tuition, and the fees are where the real cost sits. Ask the programme for a complete cost sheet — tuition, every course fee, tools, textbooks, certification examination fees, uniforms, and boots — before you enrol, not term by term.
• The fees cover consumables that are genuinely expensive — refrigerant, brazing gas and rod, copper tubing, filter driers, and the wear on gauges, recovery machines, and vacuum pumps.
• You will need your own hand tools, and employers expect a technician to arrive with them. Ask for the programme's required tool list early and buy over time rather than all at once.
• Certification examination fees are usually separate from course fees, including EPA 608 and the ESCO assessments.
• Ask about financial aid, Pell eligibility for clock-hour programmes, and Florida workforce funding. Trade programmes frequently have funding routes that degree students do not, including employer sponsorship and apprenticeship arrangements.
• Buy quality on the tools you use daily — gauges, a good vacuum pump, and a decent meter — and cheaply on the rest. Bad gauges produce bad diagnoses.

⚠⚠ This is a PSAV clock-hour course — it carries no college credit

• The leading zero in the course number is the signal. Under the Florida Statewide Course Numbering System, a 0000-level number denotes postsecondary adult vocational (PSAV) instruction, measured in clock hours rather than semester credit hours. These courses carry zero college credit.
• ⚠ A catalog may display the clock-hour figure under a heading that reads "credit hours." It is not credits. When you see a number like 187.5 attached to a 0000-level course, that is hours of instruction — no course is worth 187.5 semester credits.
• PSAV hours do not transfer as college credit to an associate or bachelor's degree, and they do not satisfy general education requirements.
• What they produce is a workforce credential — a career certificate plus, in this programme, a set of industry certifications that employers ask for by name. For a trade like this that is frequently exactly the right outcome, and it is reached far faster and more cheaply than a degree.
• Some institutions offer articulation from a PSAV certificate into a related associate degree. ⚠ These are institution-specific and they change. If you intend to continue to a degree later, get the articulation in writing from the receiving institution before you enrol, not after you finish.
• Financial aid rules differ for clock-hour programmes — eligibility, disbursement, and satisfactory-progress rules are not the same as for credit programmes. Ask the financial aid office specifically about clock-hour programmes.
• Attendance is the currency. Clock-hour programmes track attendance directly and hours missed generally must be made up.

The Daytona State HVAC/R PSAV sequence

These courses form part of one career certificate, taken in sequence. The clock-hour figures and fees are the catalog's own:

⚠ Confirm the current programme structure, total hours, and complete cost with the programme. Florida PSAV programmes are defined by state curriculum frameworks that specify a total length, and the exact course list can change.

⚠⚠ Florida heat is the occupational hazard nobody warns you about

• Attics in a Florida summer routinely exceed 130°F and can approach 150°F, and a large share of residential HVAC work happens in them. Heat stroke is a genuine risk and it is a medical emergency.
• Learn the difference and the response. Heat exhaustion — heavy sweating, weakness, nausea — means stop, get cool, hydrate. Heat stroke — confusion, hot dry skin, no sweating, collapse — means call emergency services and cool the person aggressively while waiting. Confusion in a hot attic is an emergency, not tiredness.
• Hydrate before you are thirsty and keep doing it. Thirst lags dehydration badly in this climate.
• Work attics early. Experienced Florida technicians schedule attic work for the morning for exactly this reason.
• Take breaks in air conditioning, and set a limit on continuous time in a hot space before you go up rather than while you are up there.
• Never work an attic alone without someone knowing where you are and roughly when you will be down.
• Watch each other. The person suffering heat illness is frequently the last to recognise it.
• Roofs, ladders, and confined spaces carry the trade's other physical risks, and heat degrades the judgement you need for all three.

Why this trade is durable employment in Florida

• Air conditioning is not optional here. Florida's cooling demand is year-round and effectively non-discretionary, which makes the work markedly less cyclical than most construction trades.
• The installed base is enormous and ageing, so replacement and service work continues regardless of new construction activity.
• Hurricane and storm recovery generates episodic surge demand.
• New construction in Florida has been sustained, and every unit needs installing and then servicing.
• The workforce is ageing and replacement demand is real — this is a trade with more openings than entrants.
• Commercial refrigeration is the better-paid speciality — supermarkets, restaurants, and cold storage all need it, and fewer technicians are trained for it.
• Emergency and on-call work pays a premium, and in Florida there is a great deal of it in summer.
• The path to self-employment is real in this trade — but see the licensing note, because contracting for yourself is a licensed activity.

⚠⚠ Working as a technician and contracting for yourself are different things in Florida

• You may work as an HVAC technician for a licensed contractor without holding a contractor licence yourself — that is how essentially everyone starts, and this certificate prepares you for it.
• ⚠⚠ Contracting on your own account is a licensed activity in Florida, regulated under Chapter 489, Florida Statutes, through the Department of Business and Professional Regulation and the Construction Industry Licensing Board. Advertising, bidding, or contracting for air conditioning work without the required licence is unlicensed contracting, which is an offence and carries escalating penalties.
• Air conditioning contractor licences are classed by scope — broadly, one class covers unlimited capacity and another is limited to a stated tonnage and heating capacity. Confirm the current classes and their limits with DBPR; do not rely on a course guide's summary.
• Licensure typically requires documented experience, an examination, financial responsibility evidence, and insurance, and the experience requirement is measured in years — which is why the sequence is: certificate, then employment, then licence, not certificate then business.
• Local jurisdictions add requirements — county and municipal registration, permits, and inspections.
• Permits and inspections are required for most installations, and pulling a permit requires a licensed contractor.
• Working under someone else's licence improperly is a serious matter for both parties.
• ⚠ Rule 11 applies. Licensing classes, experience requirements, and fees change. Verify with DBPR (myfloridalicense.com) before making any career or business decision.

ACR0746C is 150 clock hours, offered fall and spring, with a $372.68 lab fee and ACR0744C as prerequisite — and it is listed as ACR0744C's corequisite, so the two normally run together. ⚠ Clock hours carry no college credit.

It completes the commercial refrigeration pathway of the certificate.