In the world of West Texas HVAC, bigger isn’t always better. Many homeowners in Lubbock assume that a massive air conditioning unit will cool their home faster and more efficiently. In reality, an oversized unit can be just as problematic as one that is too small.
At Nugent Mechanical Contractors, we call the perfect fit the “Goldilocks” unit—not too big, not too small, but just right for your home’s specific square footage, insulation, and layout. Here is how to tell if your current system is the wrong size for your space.
1. Signs Your AC Unit is Too Small (Undersized)
An undersized unit is like an engine that’s constantly “redlining.” It simply doesn’t have the cooling capacity to counteract the Lubbock summer sun.
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It Runs Constantly: If your AC turns on at 10:00 AM and doesn’t shut off until midnight, it’s struggling to keep up.
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Warm Spots: Does your living room feel great while the back bedrooms stay sweltering? While this can be a ductwork issue, it’s often a sign the unit lacks the “oomph” to push cool air to the furthest corners of the house.
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The Thermostat Battle: If you set the dial to 72°F but the indoor temperature never drops below 78°F on a triple-digit day, your unit is likely under-tonned for the heat load.
2. Signs Your AC Unit is Too Large (Oversized)
This is actually the more common problem we see. An oversized unit cools the air so quickly that it creates a host of secondary issues.
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Short-Cycling: If your AC kicks on, blasts cold air for five minutes, and then shuts off, it is “short-cycling.” Because it reaches the thermostat setting so fast, it never completes a full cooling cycle.
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High Indoor Humidity: A major job of your air conditioning is to remove moisture. Dehumidification only happens during the latter half of a cooling cycle. If the unit shuts off too soon, the air stays “sticky,” which can lead to mold and mildew.
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Uneven Temperatures: A quick blast of cold air doesn’t allow for proper air mixing. You might feel a “pocket” of cold air near the vent while the rest of the room remains stagnant.
How the Pros Determine the Right Size: The Manual J Load Calculation
When we visit a home in Lubbock, we don’t just look at the square footage. We perform what’s called a Manual J Load Calculation. This is the industry-standard “math” used to determine exactly how many BTUs (British Thermal Units) your home needs.
We take the following into account:
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Insulation Levels: A well-insulated home requires less cooling power.
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Window Placement: West-facing windows in Texas act like giant heaters; we factor in that solar gain.
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Ceiling Height: Cooling a room with 12-foot vaulted ceilings requires more “tons” of air than a standard 8-foot room.
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Local Climate: We calibrate our math for Lubbock’s specific dry heat and extreme temperature swings.
The Consequences of the Wrong Size
Whether your unit is too big or too small, the result is the same: Higher Energy Bills. An undersized unit burns electricity by running non-stop. An oversized unit burns electricity because the “start-up” phase of an AC motor is the most energy-intensive part of the cycle. Additionally, the constant stopping and starting of an oversized unit leads to premature mechanical failure.
Get a Professional Sizing Assessment
If your home never quite feels comfortable, or if your electric bills are suspiciously high, it might be time for a professional evaluation. At Nugent Mechanical Contractors, we don’t guess—we calculate. We can tell you if your current system is mismatched for your home and help you find a high-efficiency replacement that fits perfectly.
Stop guessing and start saving! Contact Nugent Mechanical Contractors today to schedule a professional cooling load assessment for your Lubbock home.