What’s included in professional AC installation

Professional AC installation is much more than setting a condenser outside and connecting a thermostat. Done right, it blends engineering calculations, permitting, safe electrical and refrigerant work, precise airflow setup, and documented commissioning. These steps protect comfort, energy efficiency, equipment life, and insurance compliance—and they help ensure healthy air at home in Southern California’s diverse climates.

Pre-install assessment and design

Load calculation and climate factors

Every project starts with a Manual J load calculation to size the system based on your home’s envelope, windows, orientation, occupancy, and local weather. In Southern California, coastal humidity, marine layers, and hotter inland valleys demand careful sizing to avoid short cycling, poor dehumidification, and comfort swings.

Equipment and system selection

Pros match capacity and efficiency using Manual S, choosing between central air conditioners, heat pumps, or ductless mini split systems. Consider seasonal efficiency (SEER2), cold-climate performance for heat pumps, sound ratings, electrical requirements, and future upgrades like zoning or smart thermostat control.

Duct design and airflow

When ducts are involved, Manual D guides sizing and layout so rooms receive the right airflow. Technicians also evaluate sealing, insulation, and returns to reduce static pressure and improve comfort. In homes without ducts or where ducts are impractical, ductless or multi-zone solutions are designed for each space.

Permits, code compliance, and insurance

Licensed contractors pull permits and install to California and local codes across Los Angeles County, Orange County, Ventura County, and Western Riverside County. Inspections document safety and performance. Many insurers require permitted, licensed HVAC work; unpermitted DIY or non-licensed installations can jeopardize claims after water, electrical, or refrigerant-related damage.

Site preparation

• Protective floor coverings and careful access planning
• Mounting pad or stand for the outdoor unit with proper clearance and drainage
• Vibration isolation to reduce noise
• Pathways for line sets, condensate drains, and conductors
• Verification of attic or crawlspace safety and ventilation

Step-by-step installation

1. Electrical readiness: dedicated circuit, properly sized breaker, outdoor disconnect, grounding, and surge protection.
2. Mount indoor equipment: air handler or furnace coil, or wall/ceiling cassette for ductless systems; add isolation and condensate safety switches.
3. Set outdoor condenser or heat pump on a leveled pad or stand, maintaining manufacturer clearances for airflow and service.
4. Run and insulate refrigerant lines; route neatly to minimize oil traps and pressure loss; protect with UV-rated insulation and line covers where exposed.
5. Install condensate drain with slope, cleanout, and trap; add secondary pan or float switch over finished areas to prevent water damage.
6. Duct connections: seal with mastic or approved tape, verify return sizing, add balancing dampers, and insulate as required.
7. Electrical connections: control wiring, thermostat cabling, proper polarity and terminations; verify GFCI or AFCI requirements where applicable.
8. Vacuum and dehydration: pull deep vacuum to remove moisture and non-condensables; verify micron levels hold before releasing refrigerant.
9. Charge verification: weigh in or fine-tune via subcooling/superheat to manufacturer specs; check for leaks and compliance with EPA refrigerant handling rules.
10. Controls setup: program thermostat or smart controls, set fan profiles, comfort curves, zoning dampers, and schedules.

Commissioning and performance testing

• Airflow verification across the coil and at key registers
• Static pressure measurements to diagnose restrictions
• Temperature split across evaporator and heat rise where applicable
• Electrical checks: voltage, amperage, and wire sizing
• Refrigerant system diagnostics for stability under load
• Noise and vibration assessment indoors and outdoors
• Safety tests: condensate switch function, proper drainage, and disconnect operation

Documentation and homeowner orientation

• Permit closeout and inspection reports
• Startup and commissioning sheets saved with model and serial numbers
• Warranty registration and maintenance schedule
• Filter types and replacement cadence (by MERV rating)
• Homeowner training on thermostat, modes, and best practices

What is typically not included

• Major duct redesigns or asbestos abatement
• Electrical panel upgrades beyond the HVAC circuit
• Structural changes, drywall, or painting
• Hazard remediation (mold, vermiculite, or pest damage)
• Energy upgrades unrelated to the AC (windows, insulation)

Safety and why DIY can be risky

• Refrigerant handling requires EPA-certification; incorrect charging harms equipment and the environment.
• Electrical work at 240V can be hazardous and must meet code.
• Poor condensate management can flood ceilings and walls.
• Improper duct static pressure burns out blowers and raises bills.
• Unlicensed installs can void manufacturer warranties and lead to insurance claim denials.

Who we are

#1 AC Guys is a fourth-generation family of engineers with 80+ years of engineering expertise, serving residential and commercial projects, especially large and complex systems. Our mission is healthy air at home for a healthy life. Our team has factory training at Fujitsu (Japan), Mitsubishi Elektrik (Thailand), Midea (China), Gree (China), and Hier (China). We serve Los Angeles County and nearby areas including Orange County, Ventura County, and Western Riverside County.

Service area highlights

From coastal neighborhoods to inland valleys, we work across Los Angeles County and adjacent communities in Orange County, Ventura County, and Western Riverside County, including varied microclimates and building types.

Timeline and homeowner prep

Most single-system replacements take 1–2 days; multi-zone ductless or complex commercial systems take longer. Clear access to electrical panels, attic or closet equipment, and outdoor unit locations speeds the process. Secure pets, move fragile items, and plan for brief power interruptions during electrical work.

Aftercare for comfort and healthy air

Replace filters regularly, keep outdoor coils clear of debris, maintain proper clearances, and schedule annual professional checkups. Balanced airflow, correct refrigerant charge, and clean coils preserve efficiency and indoor air quality while keeping warranty coverage intact.

When all these steps are followed—design, permits, safe installation, and thorough commissioning—you get the efficiency and comfort you paid for, documented for warranties and insurance, and the clean, healthy air your home deserves.