What Size Return Duct For 5 Ton Ac

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Your air-conditioning nib might be high considering information technology's drawing likewise much air from outside. This might be due to an improperly sized return air duct. And so, to deal with information technology you need to summate the proper return air duct size.

How to calculate return air duct size?

Information technology'll depend on what blazon of duct you use. If yous're using a rectangular duct the math is simple. Multiply the size of your arrangement past 144 sq. inch and and then sq. root the value. You'll get the required measurement. For a circular duct, calculate the CFM and and so compare information technology to a chart for duct size.

In short, that is how you go the duct size. Keep reading though. I'm going to break down the process in more detail.

How Do You Summate Return Air Duct Size: 3 Footstep Guide

Calculating the return air duct size is simple. I've described the entire process in a few steps for your convenience. Just follow along.

Step i: Gathering Necessary Information

The size of the return air duct volition depend on your ac system's size. Check the label on the condenser. Y'all'll see a model number.

There'll be a ii-digit even number in the model number. Have this number and multiply by 1,000. Then divide the answer by 12,000. The answer you get is the tonnage or size of your system.

Permit's say there'due south a 24 in the model number. Then the tonnage is (24,000/12,000) or 2 tons.

If you're putting in a central air workout unit you'll be incurring quite an extensive toll. Yous'll need to sympathize the costs associated with central Air conditioning.

Step two: Picking Your Duct Shape

Depending on what shape your air duct is, your adding volition defer. Therefore, you'll first need to make up one's mind on the shape of the duct. It can either be rectangular or circular.

You'll need to consider the space available in the walls, installation costs, and air pressure level. If you're using a low-pressure system you're amend off with a rectangular duct. Most residential systems are low pressure.

The rectangular ducts will cost more to install. However, they'll seal ameliorate and create a tighter system. Circular ducts on the other mitt will create a more efficient flow of air.

They are also easier to install. Nonetheless, they practice crave heavier sealing and more space. On top of that, you'll demand to insulate your ductwork. That'll take even more than space.

Choose a duct shape based on these considerations.

If you do choose a circular duct yous'll need a good sealant. Here are a few I recommend:

Production ane
Production 2

Either of these volition work similar a charm and go on your ducts from leaking any air.

Step iii: Computing the Duct Size

One time you've picked the duct shape, you can finally become to the size calculation. The calculations aren't hard. I'll break down the formulae so you can easily understand the process.

Size of Rectangular Duct

If y'all're using a rectangular duct, multiply the system size by 144 sq. inch. That'll give you lot the total area of the duct. Y'all can either foursquare root the number to go the dimensions of a square duct. Or you can decide on a height × width measurement.

For Case: You have a 2-ton system. The duct size will be two 144 = 16.97 sq. inches. Yous can round this up to 17 inches. However, since 17 × 17 is non a standard size, you can use an xviii × eighteen duct.

Size of Circular Duct

For a circular duct, you'll kickoff demand the CFM rating of your system. If you don't have the actual rating employ 400 CFM per ton. Follow the duct size nautical chart to notice the diameter of the round duct.

Standing with my 2-ton system instance, airflow = (2 × 400) or, 800 CFM. Now comparing it to the chart I become a diameter of 16 inches.

You'll see tables for both metal ducts and flex ducts on charts for circular ducts. The lists are generally for supply air ductwork. Withal, even for render air flex duct is an option.

Why Practice Yous Need Return Air Ducts?

The return air duct (RAD) moves air from the room. It takes the air within the room and feeds it into your air-conditioning system. Basically, the purpose of the return air duct is to broadcast the air in your room.

At present, why is that done?

Cost Considerations

Your air conditioner spends free energy to oestrus upwards or cool downward the air. The greater the difference between the air temperature and the desired temperature the greater the price. That'south considering the organization will need to use upwardly more than power to change the temperature.

The RAD lowers cost by circulating air that is already near the desired temperature. Since previously heated or cooled air is used, less energy is expended. Every bit a result, you lot save upwards on power bills.

Air Circulation

Return Air Ducts work by circulating air in your rooms. This is very important to ensure proper air pressure inside the house. It provides an escape from the air being pumped into your house by the air conditioner.

The supply and render air ducts together ensure proper circulation. Supply air duct brings in conditioned air and the return duct removes the already nowadays air. Thus creating a proper circular flow.

Air Purification

Circulated air picks up dust and debris inside your home. This droppings can damage your air conditioner. The vent for the return air duct comes with a filter that helps remove these particles. This ensures the quality of air in your rooms.

That concludes my thoughts on air render ducts.

FAQs

Question: Is going under the required size okay?

Answer: No. If you lot lower your duct size, your airflow will be restricted. In that location will be greater resistance within the duct. This resistance will result in college dissonance. Information technology volition also cause greater power consumption.

Question: Can a duct be too large?

Answer: Yes. At that place is such a thing as a duct that is too large. A duct significantly larger than the optimal size will crusade loss of pressure, and inefficient performance.

Question: How oftentimes should I supersede my air filters?

Answer: It depends. In a house with one person changing the filter once a yr is enough. But when there are more than people and pets, it should be changed one time every two months.

Determination

I've provided the respond about how to calculate the return air duct size. Everything you lot need to consider and even the formulae you'll need is all here.

All you gotta do is follow along. Just remember, information technology is okay to go a lilliputian in a higher place the recommended size not nether.

Well, I hope I've helped you effigy out what size render air duct yous need.

Goodbye!

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By profession, I've been a Cytogenetic Technologist for nigh 24 years of my career. For those who don't understand what on globe that is, Cytogenetic technologists, are laboratory specialists who study normal and abnormal chromosomes in cells, and their human relationship to disease and human development.