Too Hot or Too Cold Air An HVAC system with excess capacity can heat or cool your home faster, but that speed often results in a couple of other issues. First, your home won't benefit from gradual, even
If your AC is too big, it will cool down your home too quickly, and the cycle will shut off before the drip pan is full. A less than full drip pan will not drain, which will cause that water to evaporate and recirculate inside your house, making it feel humid.
Larger unit may be more efficient (larger condensers generally are), but make sure you don't oversize it. If the unit is oversized it'll cycle more frequently, which is hard on it. Oversized can also cause some issues with humidity if you have any outside air connections.
A unit with too many BTU's, will cool the room fast, but leave the room humid. Too few BTU's will never cool the room down and the unit will run incessantly. To be sure you're making the right decision, call us to get answers about air conditioner sizes and efficiency.
You Have an Oversized AC
If the AC unit is too big for your house, it quickly cools the rooms and shuts off. The system will keep turning on and off frequently, and these short cycles prevent good air circulation. The moist air will then condense on the coils and freeze up.
Irregular Temperatures. You'd expect an oversized furnace to produce an excellent heat output. However, when a furnace is too big for a building, it will struggle to maintain the thermostat's settings. Its inefficiency and short cycling will cause the unit to heat the property unevenly.
However, the truth is an oversized system will not do a better job of cooling the house or provide any extra comfort over a properly sized unit. Air conditioner size is calculated in BTU (British Thermal Units) and tons, and measures how much heat the system can remove from the home in one hour.
One of the most used methods is the HVAC duct sizing rule of thumb. In fact, even professional AC contractors might use this method to size the AC ducts in your home. According to this rule, you need to install an air conditioner of one-tonne capacity for every 500 square feet of the floor area of your residence.
When your ducting is oversized, it will struggle to deliver that temperature-controlled air to various areas of your home. In fact, you'll find that your HVAC system has to work much harder to produce enough hot or cold air to get your entire home up to your desired indoor temperature.
An oversized HVAC system cycles on and off more frequently than necessary. This short-cycling leads to increased wear and tear on components, reducing the overall lifespan of the system. It can also result in uneven heating or cooling, creating uncomfortable hot or cold spots in different areas of your home.
But when an oversized unit is in place, it cools far faster and limits the cycle, which causes muggy, damp conditions in many cases due to high humidity. This can also lead to mold formation and a musty, uncomfortable smell.
Oversized.
Here's why that's a problem if the AC unit is oversized: When a space gets too warm, the thermostat triggers the AC to turn on. If the AC and evaporator coil are too large it cools the air down too quickly and then turns off after 2-3 minutes.
My colleague John Puryear teaches the simple “2 Foot Rule” for takeoff placement in his classes. When there is a change in air direction in a duct, it takes roughly 24 inches for airflow to restore its pattern. Because of this, John recommends keeping takeoffs 24 inches away from any turns, transitions, or the end cap.
What size ductwork do I need for a 3-ton unit? 1 ton of cooling is equal to 400 CFM approximately. Therefore, the total area of all the grills must be equal to a minimum of 600 square inches for adequate air supply to the system.
Let's make your job easier - when it comes to commercial systems, many HVAC professionals prefer to use 1 ton per 350-400 sq foot of floor area as a general rule of thumb. This estimation comes in handy when contractors need a quick reference point of HVAC equipment size.
Too Hot or Too Cold Air
An oversized HVAC unit can make your home's inside temperature uncomfortable. An HVAC system with excess capacity can heat or cool your home faster, but that speed often results in a couple of other issues. First, your home won't benefit from gradual, even heating and cooling.
Is It Better to Oversize or Undersize AC Unit? Neither oversizing nor undersizing your AC unit is ideal. Both scenarios can lead to issues with efficiency, comfort, and longevity of the system.
Oversized ducts could cause your HVAC system to work too hard and limit the amount of conditioned air that reaches your home. Forcing your system to work harder than it should leaves it prone to breakdowns and increases your energy usage.
Even a slightly undersized furnace will accomplish the job the majority of the time. Taking things down a few sizes will more than likely solve some of your common heating problems like too high of a utility bill while half of your house is blazing and the other half is an icebox.
No, you should not put a bigger blower motor in your furnace.