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A 3-ton heat pump has approximately 1200 CFM of air flow. To calculate the filter grill size, divide the airflow, (CFM), by 2. One filter grill or the total area of all grills must equal at least 600 square inches of area to adequately supply the system with the air needed to operate.
How big should my return grill be?
A return air grill should be sized for an air speed of 300-500 FPM(feet per minute). 400 FPM is the median air speed for this calculation. We are after the ability to move 980CFM so you now divide this number by 400 FPM yielding 2.45 or 2.5. Convert this measurement to inches.
How big should return air vents be?
A typical return vent is 16 inches by 20 inches, according to Hunker.
Can a return air duct be too big?
Can an air return be too big? No, an air return cannot be too big, except in extreme cases where a closed room is temporarily under negative air pressure. Return vents maintain air pressure, filter out debris, and are critical to the efficient operation of any HVAC system.
How much return air do I need per ton?
You can never have to much return air, as a HVAC contractor you want no less than 144 square inches per ton. Regarding the 3.5 TON VS 4 TON The average square foot per Ton is 400 so say the house is 1600 SQFT a 4 TON unit should work great.
How many returns do I need for a 4 ton unit?
(Example: 4 (ton unit) x 144 square inches = 576 squared. The square root of 576 is 24. Therefore, your return air duct and grill size will be 24 by 24 inches.).
What size should the return air grill be for a 5 ton AC unit?
x 25-in. Return grilles are the best choice for a five-ton system in order to deliver 2,000 cfm back to the blower without causing the return to hemorrhage.
What happens if there is not enough return air?
If there is not enough return air available, your HVAC system will not heat or cool properly. If not enough air is brought back, your HVAC system will not be able to keep up with temperature demands. In some cases, two returns may be necessary to provide enough return air.
How many vents should a 2.5 ton AC unit have?
For instance a 2.5 ton system (Approximately 400 CFM per ton) would require (2) 14” flexible return ducts or (1) very short flexible 18” duct to move the 1000 CFM required by the 2.5 ton system.
Should return duct be same size as supply?
Yes, return ducts are usually larger than supply ducts to ensure that air within the home is balanced. There are generally more supply vents in the system creating the need for return vents to be larger.
Do I need more return vents?
Having several return vents (ideally one in every room, but even two or three is better than just one) creates consistent air pressure. If you have one return vent, your home is fine. Keep the doors to each room open so air can properly circulate.
How do I know if I have enough return air?
Try this simple test when your HVAC system is running: get a piece of tissue paper and dangle it about six inches from one of the return vents. You should be able to see it being gently pulled towards the vent. Next, place it up against return vent and see if the air suction holds it in place.
What size ductwork do I need for a 5 ton unit?
Using this approach, two 20-in. x 25-in. return grilles will be the right choice for a five-ton HVAC system in order to actually deliver 2,000 cfm back to the blower without causing the return to hemorrhage.
What size should my ductwork be?
The size of your duct work depends not just on the size of your entire house but also on the size of each individual room. Thus, one needs to gauge the square footage of the entire house as well as that of all the different rooms in order to decide duct work sizing.
What size return do I need?
Generally, if you are using a Duct Sizing Chart or calculator (such as the Trane Ductulator), size the re- turn ducts for 0.05 inches/100 ft (0.40 Pa/m) based on the expected airflow through that return air duct. The total sum of air from all the returns should be at least 250 CFM/nominal ton (33 l/s per-kW).
How many CFM’s does a 4 ton AC unit put out?
1 ton of cooling is equal to 400 cubic feet of air per minute. 2 ton of cooling is 800 cfm and so on. So a 4 ton unit will have 1600 cubic feet of air passing through the system every minute.
How many CFM do I need for a 4 ton unit?
1600 CFM Cooling Capacity CFM (Airflow) How many CFM is a 3 ton ac unit? 1050 – 1200 CFM How many CFM is a 3.5 ton ac unit? 1225 – 1400 CFM How many CFM is a 4 ton ac unit? 1400 – 1600 CFM How many CFM is a 5 ton ac unit? 1750 – 2000 CFM.
How many square feet does a 3 ton unit cover?
3-ton is equal to 36,000 BTU. If you apply the 20 BTU per sq ft rule of thumb, you can see that a 3-ton air conditioner cools about 1,800 square feet spaces.
What size air conditioner do I need for a 2000 square foot home?
Step 5: Match your square footage to an HVAC size chart Home Sq Footage Air Conditioner Size (tons) 600 – 1,000 square feet 1.5 tons 1,000 – 1,500 square feet 2 tons 1,500 – 2,000 square feet 3 tons 2,000 – 2,500 square feet 4 tons.
