2. When You Need It
A new system makes sense in four common situations: a system past its serviceable life, a home addition or conversion with no cooling, chronic uneven cooling traced to sizing or ducts, and a planned replacement before failure. In each one, the assessment must establish the same core facts before any equipment is discussed.
A system at the end of its serviceable life
A system that has needed repeated repairs, or that has lost a major component such as the compressor, condenser or evaporator coil, may be at the point where further repairs stop making sense. The useful question is not age alone but the pattern of failures, the likely cost of the next repair and whether the rest of the system is still sound. If the failures trace to one fixable part, the right answer may be repair, covered on the AC Repair page. The assessment must establish whether the history points to one component or to a system worn throughout, and whether the ductwork and electrical supply will carry a replacement.
A home addition or conversion with no cooling
When a room is added, a garage is converted or an attic is finished, the existing system may not reach the new space at all. The answer may be an extension of the current system, or a separate system suited to the room. The assessment must establish the new space's load, including its insulation, exposure and occupancy, whether the existing ducts can reach the new space, and whether the existing equipment has spare capacity without starving the rest of the house.
Chronic uneven cooling traced to sizing or ducts
Some homes are never comfortable. One room runs hot while another runs cold, and thermostat changes make little difference. Often this is not a fault in the equipment but a mismatch between capacity and the home's load, or a duct system that cannot deliver air to the rooms that need it. The assessment must establish room-by-room airflow, the duct layout, leakage and sizing, and the home's calculated load before equipment is considered.
A planned replacement before failure
The honest advantage of planned replacement is time. A homeowner who chooses a system before it fails can compare options, check the duct condition, understand the permit position and schedule the work without a failing unit setting the pace. The assessment must still establish the load, the duct condition and the electrical readiness, and it should set out the permit route before any equipment is chosen.
3. How the Work Runs
A properly run installation follows six steps, starting with the assessment and ending with a documented handover. Each step is measured, and each one feeds the next, so no equipment is chosen before the home's load and ducts are known, and nothing is accepted until it has been tested.
1. Assessment
The assessment establishes the home's load: its size, insulation, window exposure, roof and attic construction, and how the rooms are used. It also checks the existing duct system's condition and capacity, including leakage, sizing and insulation, and the electrical readiness of the panel and circuit the new equipment will need. Nothing is ordered until these facts are recorded. The assessment comes first because equipment chosen before the load is known tends to repeat old mistakes.
2. System Choice
The system type follows from the home and the homeowner's needs, as set out in Section 4. Capacity follows from the load calculation, never from the label on the old unit by default. The old unit may have been oversized or undersized for the home it served, and copying its size repeats that original problem.
3. Permit Position
The permit position is stated before work begins. For properties in Dallas, a Mechanical (HVAC) permit is required when installing, replacing or modifying HVAC systems. It is pulled by a registered Air Conditioning Contractor in DallasNow, and inspections follow. Properties in other cities are covered by their own municipal permitting, which must be confirmed for that city before any equipment is ordered.
4. Installation
Installation covers removal of the old equipment, setting the new unit, running the line set and condensate drain, connecting the ducts and sealing those connections, and setting the refrigerant charge and airflow to the specification for the installed system. The work follows a sequence that protects both the equipment and the home.
5. Commissioning
Commissioning is full-cycle verification. The system is run through a complete cooling cycle, and its temperatures, pressures, airflow and condensate drainage are measured against the specification. A result that was assumed is not a commissioning result.
6. Handover
At handover the controls are explained, the filter and maintenance route are set out, and the documentation is left with the owner, including permit and inspection records where they apply. The documentation gives the owner a reference for the system's settings, so later service starts from known facts. The owner should leave knowing how the system is meant to run, what to check and when to arrange the next service. The maintenance route is described on the AC Maintenance page. Call American HVAC Pros to arrange the handover walk-through.
4. What's Inside This Service
Four parts of an installation decide how the new system performs: the system type, the sizing and load, the condition of the ducts, and the commissioning that proves the result. Each has a distinct role, and each drives part of the cost, so each is covered in its own part below.
System Types
The four types of cooling system each fit a different home. Central split systems pair an outdoor condenser with an indoor air handler or furnace and an evaporator coil, delivering cool air through ductwork. Packaged units house the main components in one cabinet, usually outside, and suit homes where a single outdoor unit is practical. Ductless mini-splits use an indoor head and an outdoor unit joined by a refrigerant line set, with no ducts needed. Window and portable units are the simplest, least permanent option and seldom suit a whole home. Each type's cost is driven by capacity, ducts and access, not by its name. The type is chosen in the assessment, never by habit, and the ductless option is covered in full on the Ductless Mini-Split Systems page.
Sizing and Load
Capacity should follow the home's calculated load, the heating and cooling demand the house actually places on equipment. That load depends on floor area, insulation, window area and orientation, roof and attic construction, air leakage and how many people use the rooms. The old unit's label records what that system was built to deliver, not what the home needs. An oversized system cools the air quickly and stops before it has removed enough humidity, so the house feels clammy and the equipment cycles often, which wears components and wastes energy. An undersized system runs continuously on the hottest days and never reaches the setpoint, so the house is warm when it matters most. Neither error is fixed by adjusting the thermostat. The correct size comes from the calculation, checked against the ducts that will carry the air.
Duct Condition
The existing ductwork is half the system. A new unit can only deliver the air the ducts will carry, so leakage, sizing and insulation decide what the installation achieves. Leaky ducts in an attic or crawlspace lose conditioned air before it reaches the rooms. Undersized runs restrict airflow, which strains the new equipment and reduces comfort in the rooms furthest from the unit. Ducts passing through hot spaces without adequate insulation add further loss. The assessment measures these conditions rather than assuming them. Sealing connections is part of the installation, but sealing alone does not correct undersized runs or a poor layout. Where ducts cannot carry the required airflow, duct remediation becomes part of the job and one of the main drivers of its cost.
Commissioning
Commissioning is the step that separates an installation from a delivery. A delivered system has been placed and connected. A commissioned system has been proven. The refrigerant charge is checked against the specification for the installed system, because an incorrect charge reduces capacity and can damage the compressor. Airflow is measured at the registers, and the static pressure of the duct system is checked against what the equipment needs. Controls are tested through a full cooling cycle, and the condensate drain is confirmed to carry water away from the unit. The sequence matters: airflow and controls are verified after the charge is set, so one reading does not mask another. Temperatures and pressures are recorded as a baseline for the owner and any later technician.
5. Installation and the Texas Framework
Air conditioning and refrigeration contractors are licensed by the Texas Department of Licensing and Regulation (TDLR) under Texas Occupations Code Chapter 1302 and the rules in 16 TAC Chapter 75. Offering ACR services in Texas requires that licence. A company must employ an ACR contractor in each permanent location, and technicians must be TDLR-registered or certified and supervised. This framework gives the homeowner a verification right. Before signing anything, anyone can check a contractor's licence through the [TDLR licence lookup](https://www.tdlr.texas.gov/LicenseSearch/). In the lookup, a homeowner can confirm that a company holds an ACR licence and see its class before any agreement is signed. This page describes the framework only. Verify any company's licence through that lookup before work begins.
For properties in Dallas, the City of Dallas requires a Mechanical (HVAC) permit when installing, replacing or modifying HVAC systems. The permit is pulled by a registered Air Conditioning Contractor in DallasNow, and each trade needs its own permits and inspections. City guidance states that the contractor must hold an active TDLR state licence and a current City registration before pulling the permit. For the homeowner, this means the permit is pulled by a City-registered contractor before installation starts, and the work is inspected. The homeowner therefore has a permit record in the City's system, tied to a registered contractor, before any equipment goes in. The Dallas permit route is described on the Dallas city page.
Other cities run their own permitting. A property outside Dallas must have its permit route confirmed with its own city before work begins, and the homeowner should not assume that the Dallas process applies. Permitting is confirmed for the property's own city, and a Dallas permit is not evidence of a permit anywhere else. Call American HVAC Pros to confirm which permit route applies to a specific property.
6. What AC Installation Costs Depend On
The cost of an installation depends on the factors below, all of which come from the home and its site. This page gives no figures. The assessment establishes which factors apply to a given home and how much each one changes the scope of work. Each factor is explained below with its effect on the job.
- System type and capacity. The type chosen and the capacity set by the load calculation both shape the equipment and the work around it.
- Duct remediation. Leakage, undersizing, poor layout or inadequate insulation may require changes to the ductwork before the new system can perform. Remediation is weighed against the capacity the home needs, since a system cannot deliver more air than its ducts carry.
- Electrical readiness. The panel, circuit and disconnect must support the new equipment. Any upgrade needed is part of the scope. Where the panel or circuit is at its limit, the upgrade must be done before equipment can be connected.
- Access. Attic, crawlspace, roof and yard access affect how much labour and preparation the installation requires.
- Permit requirements. The permit route depends on the property's city, and any inspections required form part of the work.
The assessment comes before any equipment conversation. Load, duct condition and electrical readiness are measured first, because each one changes what the job involves. Only after those facts are established is the system type chosen and the scope described. No cost is promised before that assessment is complete. Call American HVAC Pros to book the assessment before any equipment discussion begins.
7. Questions People Ask
What are the four types of AC?
The four common types are central split systems, packaged units, ductless mini-split systems, and window or portable units. Central split systems suit homes with ductwork that can carry the air. Packaged units suit homes where one outdoor cabinet is practical, often where indoor space is limited. Ductless mini-split systems suit homes without ducts, room additions and rooms that need their own control. Window and portable units are the simplest option and generally suit single rooms rather than whole homes. The right type depends on the home's load and ducts, which the assessment establishes.
Can a new AC be connected to my existing ducts as they are?
Sometimes, but not automatically. The existing ducts must carry the airflow the new system needs, which depends on their size, sealing, insulation and layout. An assessment measures these conditions. If the ducts leak, are undersized or are poorly insulated where they pass through hot spaces, they will reduce what the new unit delivers, and duct work becomes part of the installation scope. Connecting a new system to unchanged ducts without checking them is not a sound starting point.
Is a permit needed to replace an AC in Dallas?
Yes, for properties in Dallas. The City of Dallas requires a Mechanical (HVAC) permit when installing, replacing or modifying HVAC systems. The permit is pulled by a registered Air Conditioning Contractor in DallasNow, and inspections follow. Each trade has its own permit. Properties in other cities are covered by their own permitting, which should be confirmed with that city before work starts. The Dallas city page sets out the local context.
Should the new system match the old one's size?
Not by default. The old unit's label records what that system was built to deliver, and it may have been oversized or undersized for the home it served. The new capacity should come from a load calculation that accounts for insulation, windows, orientation, occupancy and the existing ducts. Copying the old size repeats any original error, so the right size is confirmed in the assessment before any equipment is chosen.