But we do n’t take the idea any far. Those of you with forced-air furnace ducts in place worry that modifying the heating system will be dearly-won and solution in inefficiency. And if you do n’t have ducts, you ca n’t imagine how they ‘re going to be added without destroying the house and costing a bundle. But adding central air is easier and less dearly-won than you might think .
How Much Does it Cost to Install Central Air?
When added to an existing forced-air inflame organization, central tune for a 2,000-square-foot home costs $ 3,500 to $ 4,000 and can be done by two technicians in two to three days, often with little or no change to the ducting .
The Basics of Home Air Conditioning Systems
For a house that needs ducts, the costs and workplace time double. But a contractor experienced in retrofitting can cleverly hide ductwork behind walls, in the back of closets and up in the attic with minimal cuts into walls and the ceiling and very short mess .
How to Select the Best Central Air Unit
The first order of business — and possibly the most important decision in having central tune conditioner installed in your home — is selecting the right field equipment .
All cooling contractors should start their evaluation of your family by performing an Air Conditioning Contractors of America Manual J burden calculation. This determines the heat gain your home is subject to. The calculation is relatively slowly to perform and will reveal what size unit you need. Move on to another contractor if the one you ‘re considering wants to determine the right unit for your house entirely on have. Though powerfully influenced by where you live, several factors affect the size unit of measurement required, including the sum of wall and attic insulating material you have ; the types and placement of windows and doors ; and the orientation of your home to the sun. The calculation can besides alert you to the possible benefits of upgrading the insulation in your theater. By making your home plate more energy effective, you may be able to reduce the size of the breeze conditioner you need .
How Big of a Central Air Unit Is Needed?
Take these steps when determining how boastful of a central atmosphere unit is needed for your family ’ sulfur size .
Sizing the unit
Using the heat-gain calculation, your contractor will recommend an publicize conditioner size, expressed either in tonnage or Btu per hour ( Btu/h ). One long ton equals 12,000 Btu per hour. Why is getting the proper size whole sol authoritative ?
An undersize whole wo n’t be able to cool rooms down completely on the hottest days and will cost more to operate because it has to run longer than a correctly sized unit. An outsize compressor besides costs more to operate because it merely takes more electricity to run a bigger unit. And an outsize whole does n’t lower humidity efficaciously. That ‘s because it cools the air so quickly that it shuts off before it has a casual to circulate the proper volume of air past the coils to extract the necessary moisture. The leave is a room that does n’t seem angstrom aplomb as the temperature indicates. In fact, the room can feel clammy and dampen .
After determining the size of the unit of measurement, your contractile organ should talk to you about efficiency, which is expressed by the seasonal energy-efficiency denounce ( SEER ). The SEER rates how many Btu an atmosphere conditioner will remove for each watt of electricity it consumes. The higher the SEER, the less it costs to operate .
federal police requires that fresh A/C units have a SEER of at least 13. These units have lower operate costs, tend to be higher quality, have more guard features, better sound shields and lower electric potential requirements. In general, the higher the SEER, the higher the initial cost for the unit .
future, you must decide what character of system to buy. There are two kinds. A “ package system ” gangs the condenser, which cools the refrigerant and exhausts warm air, with the fan-and-coil system, which cools and blows the air. The ducting connects directly to the unit of measurement. This is basically a big wall air conditioner with ducts. But software systems are rare .
With a “ rip system, ” the condenser is outside the house and the fan-and-coil system are inwardly ; they ‘re connected to each other by pipes that carry refrigerant. If you have a forced-air furnace, the refrigerant pipes are connected to a cool handbuild system fitted into the furnace atmosphere handler.
sometimes it goes right into the existing plenum. If that wo n’t work because of space limitations, the contractor will fabricate a divide sheet-metal plenum. If you do n’t have forced atmosphere, the fan-and-coil system is typically placed in the attic, where it will deliver cool air out through ducts. The 20- to 30-foot-long pipes that carry the refrigerant are disguised to look like a downspout .
even the quietest condensers make randomness, then work with your contractor to find a placement that ‘s not near a bedroom or home-office window. Do n’t place the condenser under a deck or completely enclose it because it exhausts warm air out the top. Any airflow restriction will lower the unit ‘s efficiency. You can, however, hide the condenser in the landscaping, ampere long as air can freely circulate around it .
No Ducts? No Problem
Most central air conditioners are burst systems : The condenser is outside and the fan-and-coil system is inside, connected to the condenser by pipes that run up the outside of the house. The pipes can be disguised as function of the gutter-and-downspout organization. Ductwork services second-floor rooms through ceiling registers. Ducts run through closets on their way to first-floor rooms .
Delivering the Air
furnace ducts that deliver hot air in cold months can be used for air-condition .
If you have ducts
You should have your ducts inspected. many times, modifications are required to accommodate the greater volume of air travel produced by air-cool. Ironically, older duct systems, which tend to be larger, work well when retrofitting cardinal air-condition. ( As the heat industry has learned more about the dynamics of airflow and size furnaces and delivery systems, ducting has gotten smaller. )
here ‘s a number of typical modifications that existing ducts require :
- Upsizing the furnace blower (rated in cubic feet per minute, or cfm) to move the cubic feet of cool air required for your house. An undersize blower won’t move enough air through the coils, and they can freeze.
- Sealing the ducts to boost efficiency. This is a job best left to a pro, as an imbalanced system can lead to hazardous backdrafting during the heating season or pockets of warm air during the cooling season.
- Swapping out older supply registers for ones that allow a greater volume of air to pass. Old register grilles with slits just 1/4 inch wide offer too much resistance to airflow; new grilles can improve airflow by 15 to 25 percent.
If You Need to Install Ducts
Because the fan-and-coil unit of measurement is mounted in the loft in most retrofit air-condition systems, the challenge is to get supply and render ducts to ceiling registers in the first- and second-floor rooms below .
Ducts that feed second-floor rooms are typically run across the attic floor and plunge down between the attic floor joists, where they are connected to ceiling registers. Ducts that feed first-floor rooms run down through second-floor closets wherever potential .
The first base step your contractor will take to determine the position of ducts is to draw a floor design of the second floor and lay it over a floor design of the first floor. “ In 99 percentage of homes, ” says Frank Scarangello, of Staten Island, New York-based Scaran Heating and Air Conditioning, “ second-floor closets will give you access to locations for first-floor ceiling registers. ”
Ducts running in closets take up less space than you might think. Because most ducts are 12×6 inches or 10×8 inches, even in a relatively small 2×4-foot wardrobe, they take up just 4 of the 64 available cubic feet. Some cooling contractors might suggest using “ flex duct ” ( a small, cheap compromising hose ) rather of fixed feather ducts. But avoid bend duct in active agent wardrobe spaces — it does n’t stand improving well to wear and tear and is well punctured.
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What kind of mess can you expect if you have to have ducts installed ? In most cases, wall and ceiling surfaces are left largely untouched. Holes do have to be cut in first- and second-floor ceilings for registers, and some second-floor cupboard floors will undergo operation to accommodate the new ducts. But these holes are relatively little, and the fix is well contained .
even if there ‘s no ductwork in your home, if air-cool will make your house more pleasant in the summer months, contact HVAC contractors to review the cost of adding A/C and the methods they would use. Choosing the right pro and equipment will ensure you years of comfort, and it ‘s often less expensive and less intrusive than you might imagine .
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