The house is cold and clammy at the same time
A classic oversizing signature. No repair addresses it, because the fault is the capacity rather than the condition of the equipment.
Replacement cooling done properly
AC Installation in Gregory, TX
- Room by room load calculation
- Permits pulled, inspections attended
- Documented evacuation and charge by weight
- Warranty registered in your name
The most consequential decision in a cooling installation is made before any equipment arrives, and it is the capacity figure. Get it wrong and no amount of careful workmanship afterward will produce a comfortable house.
Getting it wrong is the norm rather than the exception. Matching the tonnage of the outgoing unit simply inherits whatever error the last contractor made, and sizing from square footage ignores insulation, glazing, orientation, air tightness and occupancy, which are the things that actually determine the load.
From calculation to commissioning
01 02 03 04 05 06 07
An installation is three distinct pieces of work: establishing what the building needs, selecting equipment and the alterations required to support it, and then proving at startup that the installed system delivers what was specified.
Most quotes address only the middle piece. The first and third are where the difference between a system you forget about and a system you argue with actually lies.
What the outgoing system tells you
The equipment being removed is the best available evidence about the building, provided it is read as evidence rather than copied as a specification. A compressor that failed at nine years, a coil fouled on the upstream face, an evaporator that has been freezing, a condensate pan showing a long history of overflow: each of those points at a condition that will still be present the day the new system starts.
Run time behavior matters just as much. A household that describes short bursts of cooling followed by long silences, and a house that still feels damp at the set temperature, has described oversizing without using the word. A household that describes the system running almost continuously through the afternoon and still losing ground has described either undersizing or a serious loss of capacity, and the distinction between those two is worth establishing before anything is ordered.
The installation quality of the outgoing system is the third source. A line set with no trap where one was needed, an outdoor unit sited with no clearance behind it, a plenum transition that necked down sharply, a return that was clearly added as an afterthought. Those are the defects most likely to be reproduced by a contractor working quickly, because the easiest installation is always the one that reuses every existing compromise.
Why oversizing is the default failure
Cooling equipment removes heat and moisture, and the moisture removal only happens while the system runs. An oversized unit satisfies the thermostat quickly, shuts down, and the air in the house never spends enough time passing over a cold coil for meaningful dehumidification to occur.
The household experiences that as a house which reads seventy two degrees on the thermostat and still feels clammy and unpleasant. The instinctive response is to set the temperature lower, which increases the bill, shortens the cycles further and makes the humidity problem worse rather than better.
There is a mechanical cost too. Every start is the hardest moment in a compressor's operating life, drawing several times running current. A system cycling on and off repeatedly through an afternoon accumulates those starts far faster than one running longer and steadier, and it wears out sooner for it.
The correction is arithmetic. A room by room calculation using the actual envelope, the real glazing area and type, measured or estimated air tightness, ceiling heights, occupancy and the regional design temperatures. The result is frequently one size below what is currently installed, and it always explains the behavior the household has been living with.
What a correct installation includes beyond the box
Equipment is specified as a matched pair, indoor and outdoor, because a condenser paired with a mismatched coil does not deliver its rated capacity or efficiency regardless of what the label on either component claims.
The line set is sized for the run length and lift, and where an existing set is reused it is only reused after it has been proven suitable and cleaned or flushed appropriately. A system is evacuated to a documented vacuum, held, and then charged by weight rather than topped up until the gauges look about right.
The work around the equipment is part of the job rather than an extra. Plenum transitions built to suit the new cabinet, a condensate route with genuine fall and a safety switch, electrical supply confirmed adequate for the new equipment, and the outdoor unit sited with the clearance the manufacturer requires for air to move through the coil.
The decisions you will be asked to make, and how to weigh them
Once capacity is established, a handful of genuine choices remain. They are worth understanding before the quote arrives, because they are where the price range in most proposals actually comes from.
Single stage, two stage or variable capacity. A single stage system is either off or running at full output, which is fine in a well sized application and poor in a building with widely varying load. Two stage equipment spends most of its time on the lower stage, which lengthens run times and improves dehumidification noticeably. Variable capacity modulates continuously and delivers the most even temperature and the best moisture control, at the highest price and with more electronics to eventually service. The right answer depends on how long you intend to keep the house and how much the humidity bothers you.
Efficiency tier. Higher rated equipment achieves its numbers through longer, lower load operation, which only works if the distribution can carry the airflow and the building envelope is reasonably tight. Fitting premium equipment to a restrictive duct system buys very little, and the survey will say so plainly rather than selling the upgrade anyway.
The indoor coil. Replacing an outdoor unit while retaining an old indoor coil is cheaper on the day and frequently a mistake. The pair is rated together, the older coil may be sized for a different refrigerant, and warranty terms often depend on a matched installation. Where a mismatch is being proposed by anyone, ask what rated capacity the combination actually delivers.
Controls. A thermostat needs to match the equipment staging and, on a heat pump, the heating configuration. A variable capacity system paired with a basic thermostat will run as though it were single stage, which wastes most of what was paid for. Where a common wire does not exist, it gets run properly rather than worked around with a power stealing adapter.
Warranty terms. Parts coverage is generally longer than labor coverage, and registration within the manufacturer's window is frequently a condition of the longer term. Registration is handled on your behalf here, but it is worth asking any contractor directly, because an unregistered system can quietly lose years of coverage that the owner assumed they had.
None of these decisions is presented as an upsell with a deadline attached. You get the trade off in each case, a figure against each option, and the time to think about it.
What the quote covers and why each item is there
| Element | What it involves | Why it is not optional |
|---|---|---|
| Load calculation | Room by room, using the real envelope | Capacity is the decision everything else depends on |
| Matched equipment pair | Condenser and coil rated together | A mismatched pair does not deliver its labeled performance |
| Line set assessment | Sized for run and lift, cleaned or replaced | The wrong line set limits capacity and risks oil return |
| Plenum and transition work | Built to suit the new cabinet | A poor transition adds static pressure and noise permanently |
| Condensate route and safety switch | Fall, trap and float protection | The alternative failure mode is water through a ceiling |
| Documented evacuation and weighed charge | Vacuum held and verified | Moisture and non condensables destroy systems slowly and silently |
| Commissioning sheet | Measured startup values recorded | It is the only proof the system delivers what was specified |
How the project runs
01
Survey the building
Envelope, glazing, distribution, electrical supply and the siting constraints are recorded. The outgoing unit is evidence, not a specification.
02
Calculate and specify
Room by room load, then equipment selection along with every alteration the installation depends on.
03
Quote a written scope
A flat rate against a scope written out in full, so nothing becomes a disputed extra later.
04
Install
Old equipment recovered lawfully, new equipment set, line set and condensate routed properly, electrical and plenum work completed.
05
Commission and hand over
Airflow, charge, static pressure and temperature split measured and recorded, controls configured, warranty registered, documents given.
Indicators that replacement is the right call
Refrigerant has been added more than once
A system losing charge has a leak. Repeated recharging is an annual expense that also shortens compressor life through poor cooling and lubrication.
The equipment uses an obsolete refrigerant
Availability falls and price rises every year. That changes the arithmetic on any significant repair to an older system.
Repair costs are approaching a meaningful share of replacement
Particularly where the equipment is past its middle life and the existing capacity was wrong anyway, since replacement is the only opportunity to correct that.
Rooms have never been comfortable regardless of setting
That is usually distribution rather than capacity, and it needs identifying before new equipment is specified, or the new system inherits the same complaint.
Energy costs have climbed without a change in habits
Falling efficiency shows up in the bill before it shows up in comfort. Where maintenance has already ruled out charge and airflow faults, the equipment itself is usually the remaining explanation.
Parts for the equipment are becoming hard to source
Once a manufacturer discontinues support, an ordinary repair turns into a search. That risk belongs in the replace or repair arithmetic alongside the repair cost itself.
Installation questions
What to Establish Before Choosing a Contractor
Installation quality becomes invisible the moment the panels go back on, so these questions have to be asked beforehand.
A room by room calculation, and you receive it with the assumptions it rests on. Matching the outgoing unit is not sizing, it is copying, and it perpetuates whatever mistake was made last time. Ask every contractor bidding for the document. The ones who have done the work will hand it over without hesitation, and the ones who have not will explain why it is unnecessary, which is your answer.
Sometimes. It depends on the diameter being correct for the new equipment, the run length and lift being within limits, the insulation being intact and the set being clean. Where the previous system suffered a compressor burnout, reusing the line set risks carrying contamination into new equipment. Where it is reused, it is flushed or cleaned and pressure tested first. The assessment is made on site and the reasoning is explained either way.
A straightforward changeout is generally one working day. Projects that include plenum modification, electrical upgrades, condensate rerouting or duct work run longer, and the schedule is agreed before work starts. Where the job extends beyond a day, what the property will have available overnight is discussed in advance rather than improvised on the second afternoon.
That the installed system delivers the specified performance. Measured airflow, charge verified by weight and confirmed against subcooling, total external static pressure recorded, temperature split across the coil, and amp draws within rated values. Those figures go on a sheet you keep, and they become the baseline that any future technician can compare against to see whether something has drifted.
It depends on run hours and on whether the rest of the system can deliver the conditions the rating assumes. High efficiency equipment achieves its numbers with variable capacity and longer, lower load run times, and that only works if the distribution can carry the airflow and the house is reasonably tight. Fitting premium equipment to a duct system that is already restrictive buys very little. The survey establishes which situation you are in before any equipment tier is recommended.
Worth considering, and worth deciding on the numbers rather than on the convenience. The argument for doing both is that the indoor coil sits on the furnace, the labor overlaps substantially, and a variable speed blower is what lets high efficiency cooling equipment actually deliver its rating. The argument against is straightforward: if the existing furnace is sound, correctly sized and has years of life left, replacing it early buys very little. The survey gives you the age, condition and heat exchanger assessment so the decision is informed rather than bundled.
Also in the catalog
Work That Often Accompanies a Cooling Replacement
New equipment on old distribution inherits every defect the distribution already had, so these questions come up together.
Specification before price
Book a Survey and Get the Capacity Figure Before the Quote
The calculation is what determines whether you are comfortable in five years. Everything else in the quote is downstream of it.
Financing is available on larger projects, subject to approval, and declining it changes nothing about the price or the scope.