What Size AC Do I Need?
Air-conditioner capacity should follow a home-specific cooling-load calculation and duct evaluation, not square footage alone or the size of the old unit.
What changes the answer
The most important variables should be identified before comparing proposals or choosing equipment.
- Orientation, windows, insulation, air leakage, roof and attic conditions
- Indoor and outdoor design conditions and humidity goals
- Occupancy, internal loads, additions, renovations, and room use
- Duct capacity, return air, static pressure, and zoning
- Equipment sensible and latent performance at design conditions
How to evaluate your options
Oversizing can cause short cycling and weak humidity control; undersizing can miss temperature during design conditions. Load calculations still require judgment, equipment selection, airflow, and commissioning.
Maintenance and ownership considerations
Preserve load and selection documents so future repairs, additions, and replacements do not revert to a nominal tonnage guess.
Local planning note
Long cooling seasons, attic heat, humidity, dust, occasional freezes, local permit requirements, equipment availability, and labor conditions all shape South Central Texas projects. J3 is preparing to launch residential heating and cooling services in select service areas. Residential appointments and emergency dispatch are not currently available. These guides are educational. This is a launch-information request, not an appointment or emergency service request.
Frequently Asked Questions
Is there one reliable answer for what size ac do i need??
Should I compare quotes by equipment price alone?
Do online cost ranges include every project expense?
Can J3 provide a residential quote today?
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