What Size AC Do I Need in Shreveport, LA?

ByMuzaffer Caner Ankaralı

Short answer: Shreveport combines hot summers with a broader seasonal swing than South Florida. That distinction affects equipment selection, but it does not eliminate humidity work: infiltration, crawlspaces, attic ducts, and outdoor air can still produce a meaningful latent load. Square footage alone cannot determine what size AC a Shreveport home needs. Shreveport capacity should follow measured construction and seasonal design data rather than a regional shortcut.

What the Shreveport climate record can—and cannot—tell you

NOAA/NWS climate evidence for Shreveport Regional Airport lists 1991-2020 July normal temperatures of 94.3°F/73.5°F and August values of 94.9°F/73.0°F. The record reports 2676.1 annual base-65°F cooling degree days. The station is about 3.1 miles from the Census place center; it is identified by its real name rather than relabeled as a Shreveport station. Shreveport Regional supplies a long local series suitable for context, though monthly averages are never peak design values.

The 2024 American Community Survey (ACS) places the median year built for Shreveport housing at 1974. One-unit detached structures account for about 67.0% of units, while units in buildings with two or more homes account for about 24.8%. Shreveport’s detached share supports attention to attics, floors, and perimeter leakage, but every assembly still needs verification.

Calculate before selecting

The number on the old condenser is an observation, not a load input. Develop new room-by-room Manual J evidence from construction, orientation, glazing, shade, occupancy, infiltration, outdoor air, and ducts. Preserve both sensible and latent results. With Manual S, compare them to the exact matched product at the selected indoor and outdoor conditions. With Manual D, verify supply and return design against room peaks. This sequence lets a reviewer locate disagreement instead of arguing over rules of thumb.

Survey the actual Shreveport home

Older Shreveport houses deserve assembly verification rather than age-based guessing. Inspect crawlspace or slab boundaries, wall cavities, attic insulation, and duct runs; note whether repairs or additions created discontinuities. Measure windows and shade, determine orientation on site, and ask how many people use each zone at the design hour. A return leak from an attic or a pressure imbalance across a closed bedroom door can change delivered performance. If the building has fireplaces, floor penetrations, or exhaust equipment, document their relationship to infiltration assumptions.

Diagnose the existing Shreveport comfort problem

Shreveport comfort investigations should include both the cooling season and the building’s construction transitions. A crawlspace boundary can affect floors and infiltration differently from a slab addition; an attic trunk may serve both sections with unequal resistance. Use smoke or pressure testing only under an appropriate procedure, and record what each result actually shows. Inspect return plenums, filter racks, accessible ducts, insulation, fireplace dampers, and exhaust paths. Log room temperatures and humidity during representative weather, noting occupancy and door position. If the existing equipment is older, its current performance cannot be inferred from original nominal capacity; coil condition, charge, blower operation, and leakage all matter. Likewise, a cold front or mild test day cannot prove design-day output. The diagnostic record should identify repairable defects and unresolved inputs so the replacement calculation does not absorb them as arbitrary load.

Separate temperature load from moisture load

Two houses with the same total load can require different performance splits. Sensible energy and latent moisture add to total cooling demand, and sensible divided by total gives the building SHR. The chosen equipment has its own SHR that varies with the operating point. Where the evaporator surface falls below airstream dew point, vapor condenses and can drain; elsewhere the surface may remain dry. Selection and setup must therefore support both calculated components, not merely a nominal total.

Hypothetical example for Shreveport

A hypothetical 2,060-square-foot Shreveport house has a pier-and-beam original section, a slab-on-grade rear addition, five occupants, and one return grille near the center hall. The two floor boundaries and roof transitions require separate inputs. The rear bedrooms may peak after the front rooms, while closed doors may limit return air. The designer should calculate each room, inspect the transition, and measure the existing system before choosing a matched replacement. This scenario deliberately omits enough detail that no responsible tonnage can be stated.

Prove the duct and airflow operating point

Distribution errors often masquerade as undersizing. Measure system pressure, identify where it is spent, and use the correct blower chart to determine airflow. Test remote rooms and returns under normal operating conditions, including closed bedrooms. Seal leakage and correct restrictions before concluding that the condenser is too small. The final fan setting must satisfy equipment limits because both insufficient and excessive airflow can shift capacity and moisture performance.

Use matched equipment performance

Evaluate candidate systems at the condition they will face, not only at AHRI’s standard rating condition. Expanded data for the exact indoor coil and outdoor unit should show total and sensible performance at a supported blower airflow. Document any interpolation. If a table omits an operating point, report that limitation instead of making up capacity. Minimum airflow, icing protection, refrigerant charge or metering, multi-stage logic, and fan-off delays may influence whether the intended sensible/latent split is achievable.

Permit and code context

Shreveport’s 2026 permit and inspection guide describes local code administration, and Louisiana publishes the state uniform construction-code framework. Confirm the project’s current requirements with those authorities. The code path should accompany—not stand in for—the residential load, selection, duct, and startup documents.

Final Shreveport verification points

Shreveport completion review should preserve separate assembly inputs for the original house and later slab addition. Check that crawlspace, attic, fireplace, and duct leakage assumptions match the inspection record. The selected system should provide supported sensible and total capacity at the local design point, with airflow that the existing or revised ducts can deliver. Record how bedroom return paths behave when doors close and whether balancing changed the remote-room result. Any repair completed after the first calculation should be reflected in the final load file before the equipment decision is archived.

Compare proposals and verify startup

Do a calculation review before ordering and an operating review after startup. The first should trace rooms and assemblies to loads and loads to a supported matched system. The second should capture controls, refrigerant verification, static pressure, fan airflow, room delivery, indoor humidity, outdoor weather, runtime behavior, and condensate flow. Keep outstanding limitations visible. A proposal that cannot provide its assumptions cannot be compared reliably with one that does.

Questions to ask before approving the job

  • Which weather source and indoor targets were used for this Shreveport calculation?
  • Were insulation, windows, solar gain, orientation, occupancy, infiltration, ventilation, and duct losses documented?
  • Does the equipment-approved airflow range cover the proposed setting at measured external static pressure?
  • Can the contractor show sensible, latent, total, and room-by-room results?
  • Which exact indoor unit, outdoor unit, blower setting, and controls were evaluated?
  • What expanded-performance row supports capacity at the selected conditions?
  • How will total external static pressure, airflow, return paths, and condensate operation be verified?

Related sizing and design guides

Primary and official sources

A Shreveport decision is ready when the calculation respects both the building’s mixed construction and the local summer moisture burden. Repeating an old nameplate or adding a reserve is not an engineering explanation.

Technical note: Shreveport is discussed in 3A — warm-humid context. Shreveport reports should identify crawlspace, slab, and attic boundaries without combining unlike assemblies, while preserving the seasonal condition and occupancy associated with each comfort observation.

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