What Does AC Installation Include? A Complete Breakdown for San Antonio Homes
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What’s Covered on This Page
- What a Complete AC Installation Covers
- How Installers Decide What Size AC Unit You Need
- The Condition of Your Ductwork Changes the Job
- How do I know if my AC unit is the wrong size for my home?
- Why does bigger AC not always mean better cooling?
- What is a load calculation and why does it matter?
- Why is ductwork important during an AC installation?
- Why do so many San Antonio AC units sit in the attic, and does that cause problems?
- What should be included in a complete AC installation quote?
What a Complete AC Installation Covers
This calculation factors in the number of windows, the level of insulation in the attic, square footage, the condition of the ductwork and the direction in which the home faces. Comprehensive air conditioning installation entails more than meets the eye. Some steps in the process are not listed on your quote, which might explain why they’re unfamiliar to you.
We often find units already installed in San Antonio that are one size too big. Usually, the previous installer figured the AC should be as big as possible “for the heat,” not realizing that an oversized unit will short cycle and leave your home clammy. Yes, your home will get cold, but an oversized system will have a hard time controlling humidity, providing inconsistent comfort, and will be under greater strain on hot, muggy days.
So what exactly IS included in a complete residential installation from start to finish?
- When replacing equipment, perform load calculation and select matched equipment. Replacement is not necessarily like-for-like based on existing equipment.
- Recover existing refrigerant from system. Remove old condenser and dispose of. Remove existing indoor unit and dispose of.
- Installed new pad for condenser, leveled, ensured proper clearances for air flow and serviceability.
- Where applicable, indoor coil(s)/air handler(s) installed with sealed and properly sized plenum connection.
- Refrigerant lineset new or flushed. New filter drier installed. Refrigerant lineset nitrogen pressure tested. Vacuum tested.
- electrical disconnect, properly sized breaker, flex whip and neat LV line run.
- Condensate drain with proper trap and slope, include secondary pan or float switch when installing in attic.
- Thermostat ServiceIncludes thermostat installation, set up to fit your equipment.
- Permits and inspections will be done where required by the city.
- Verified refrigerant charge weighed in during system startup, temperature split, and airflow.
Charge and airflow settings make the difference between an exemplary and a hasty job. Identical pieces of equipment will perform differently depending on how conscientious the installer was in properly setting the charge and airflows.
In San Antonio most HVAC units are located in the attic. For this type of setup to perform well and operate safely one area that needs to be addressed is draining. We come across drains without traps and rusted out secondary pans all the time. Float switches go unwired as well. It goes unnoticed by homeowners until one day the stain appears in the ceiling.
Also, discuss ductwork. Make sure you know whether the ducts are OK or need to be replaced. Sometimes all that’s needed are new connections to the unit. Other times the return is undersized and a new unit will not reach rated efficiency. Whatever the situation, don’t be surprised about ductwork after a system is installed.
Ask about cleanup and haul-off: Removing packaging, disposing of the old unit, and recovering the refrigerant should be part of the job rather than a service the installer performs for a fee.
Put scopes in writing side-by-side for easy comparison. One quote will be significantly cheaper than another? Chances are items on the more expensive quote are missing from the cheaper quote.
How Installers Decide What Size AC Unit You Need
Determining the right size of AC for your house happens before picking up a tool. How well the system performs, how long it will run, whether it will keep you comfortably cool in August, is decided before you start. Many projects succeed or fail at this point.
On the flip side, we also see many instances where an AC is too large for a home. Many times when San Antonio homeowners replace their AC, they’ll replace their 3-ton AC with a 4-ton AC assuming bigger is better. It’s not. When the AC is too big it’ll blow the air down quickly and shut off, not running long enough to properly remove the humidity in the area. The end result is a cold and clammy house.
Conversely, an undersized system will continue to run in 100-degree weather and still not meet the cooling load adequately.
But how do contractors make a sizing decision? They follow an industry-accepted process commonly referred to as a load calculation or Manual J. The latter is a technical term referring to a sizing guideline published by the Air Conditioning Contractors of America.
- Measure the conditioned square footage directly rather than just relying on the tax record, room by room.
- Also count and measure the windows. Especially note which way they face. In San Antonio west-facing windows are a heat problem.
- Check depth of attic insulation. Determine type of wall insulation.
- Inspect the ductwork for proper size and leakage. How many supply registers serve each room?
- Bear in mind ceiling height. A room with 12-foot ceilings will hold considerably more air than the same amount of space with 8-foot ceilings.
- Account for local design temperature, accommodating triple-digit afternoon temperatures in this area.
- Once you’ve calculated the figures, select the closest standard system size available.
Also, heating/cooling equipment is made in half-ton capacities, so it’s highly unlikely that the correct size will fall on a nice, neat, readily-available number. That means somebody has to make a choice as to whether to round up or down. A good installer will tell you which way he/she went, and why.
Items a technician might inspect during an on-site walkthrough.
- Common in older homes in San Antonio, insulation has settled leaving only two or three inches.
- Problem: Some of the rooms in question were additions to the building and have inadequate ductwork.
- Ducts are smaller than equipment – The return air side is smaller than the equipment calls for. Choked airflow no matter the size/tonnage.
- Portions of property sunny, mature trees provide shade in some areas of property.
- How big is the existing system and was it correctly sized for this house?
One mistake we see homeowners making is asking us to give them pricing or recommend a tonnage size over the phone. We cannot size a home accurately without coming out to inspect. If somebody gives you a recommendation based on square footage that’s a rule of thumb and not a calculation.
Remember that no matter what unit you put in your house it will not perform as expected if you have 1/3 of the airflow dumping into your attic! Load calculations assume that the air gets to the location its supposed to get to but cannot correct for poor leaking ducts.
Ask to see the load calculation for a given installation. This will tell you how they came up with the final size of the equipment. If they can’t explain how they arrived at that number it will likely be indicative of the quality of their install.
The Condition of Your Ductwork Changes the Job
On every job, We look at the duct work before quoting. Many times, homeowners are surprised to learn that their new AC will not correct the issue of hot rooms because the ducts are leaking or are not sized properly. Homeowners frequently do not realize that the equipment is only half of their HVAC system, since the ducts distribute the cool air to the rooms.
In most cases in San Antonio the ductwork is in the attic. Flexible ductwork can get crushed or sag or come off it’s boot and blow cool air directly into 130+ degree heat in July. That’s a lot of money being wasted to cool air that’s going into your attic.
And what do we find up there?
- Duct boot falling off is This happens when the duct falls off of the register box. Usually found in a room that will not cool properly.
- Seams opened up at the plenum as a result of the cloth tape drying out.
- Sharp bends and/or sags in flexible ductwork inhibit airflow to far bedrooms.
- Duct above the drywall has compressed or torn insulation which is making it sweat and drip onto the drywall.
- Return ducts that are too small for the new system will also cause increased noise and a strained blower.
People are very surprised when told that connecting a larger and/or more efficient HVAC unit with a smaller than needed return will make the unit operate excessively loud and have a lower actual airflow and blower motor being over worked. Problems caused by undersized return are a match up problem NOT a manufacturer’s problem!
homeowner complains that one particular bedroom is always 5-8 degrees warmer than the rest of the house. The homeowner thinks that the old A/C is probably going out. We go into the attic and find that the ductwork to that particular bedroom is kinked behind a truss and torn near the boot. New A/C wouldn’t have solved this problem.
A duct inspection is part and parcel of an initial conversation about installation, not an upsell.
Sometimes a run is in such great shape that we leave it alone, which is more common with newer construction on the north side of San Antonio, where the ductwork has been better supported and people haven’t walked on it. Other times we seal the joints at the plenum and boots, replace a damaged run with a new one, adjust the size of some of the returns, add runs to rooms that have been under-serviced in the past, etc.
How are our estimates different from others? Many homeowners call HVAC Companies and are given a quote over the phone. We always look at your ducts before finalizing our estimate and tell you in writing how bad or not they are. When we show up for install, there’s no homeowner surprise. We’ve been in your attic and know what to expect.
You need good ducts and a good mechanical system. If you have one without the other, you’re going to experience hot rooms and high utility bills, and there’s no way to determine what’s not performing well.
Frequently Asked Questions
Common questions about What Does AC Installation Include? A Complete Breakdown
How do I know if my AC unit is the wrong size for my home?
You’ll notice a wrong-size AC through uneven cooling, high humidity, or short cycling. An oversized unit cools the air fast but shuts off before removing humidity, leaving your home cold and clammy. An undersized unit runs constantly on hot San Antonio afternoons but never quite catches up. Both problems point to a skipped or rushed load calculation. If your current system behaves this way, ask about a full load calculation before replacing it. The parent page on AC installation explains how proper sizing fits into the full process.
Why does bigger AC not always mean better cooling?
Bigger is not better because an oversized AC cools the air too quickly and shuts off before it pulls humidity out of your home. This creates a cold, clammy feeling instead of real comfort. It also causes more wear from constant starting and stopping, called short cycling. San Antonio homeowners often upsize from a 3-ton to a 4-ton unit thinking it helps, but it usually creates more problems than it solves. The right size depends on a proper load calculation, not guesswork.
What is a load calculation and why does it matter?
A load calculation, often called a Manual J, is the process installers use to figure out the exact AC size your home needs. It looks at square footage, insulation, window direction, ceiling height, and ductwork condition. San Antonio’s triple-digit summer afternoons make this step even more important, since undersized systems can’t keep up with the heat. Skipping this step is one of the most common reasons homeowners end up with an AC that runs poorly for years.
Why is ductwork important during an AC installation?
Ductwork matters because your new AC can only perform as well as the ducts connected to it. Leaky, undersized, or damaged ducts can stop a new unit from reaching its rated efficiency, even if the equipment itself is high quality. Sometimes only new connections are needed. Other times the return has to be resized. Ask your installer to inspect the ductwork and explain any needed repairs before installation day, so there are no surprises afterward.
Why do so many San Antonio AC units sit in the attic, and does that cause problems?
Most San Antonio homes have HVAC equipment in the attic because of how local homes are built, but attic installs need careful drain work to prevent damage. Without a proper trap, slope, secondary pan, or wired float switch, a slow leak can go unnoticed until a ceiling stain appears. This is a common issue we find during inspections. A complete installation always includes correctly built drain protection for attic units.
What should be included in a complete AC installation quote?
A complete quote should include load calculation, permits, old unit removal, refrigerant recovery, new lineset work, electrical connections, drain protection, thermostat setup, and a final startup check. If one quote is much cheaper than another, some of these steps are likely missing. Comparing written scopes side by side helps you see exactly what each contractor plans to do. For a full breakdown of every step involved, the AC installation guide walks through the entire process.
