Air conditioners don't last forever. The good news, though, is that if you have an old air conditioning system, replacing it should save you money. Efficiency has improved a lot since that old hunk of metal and noise was installed in your back yard. Beyond just swapping out the old equipment for new, getting a new air conditioner really needs to involve some thought. Here are five things for you to think about and ask potential contractors. If possible, you should use an HVAC contractor who understands building science and will treat your air conditioning problem using a systems approach. An air conditioner is only one component of many that helps with the heating and cooling of your home. Insulation, air leakage, duct leakage, solar gain through windows, radiant heat problems in bonus rooms, and more all affect the comfort, healthfulness, durability, and energy efficiency of your home. To understand the basics, see our article on Building Science 101. If you ask an HVAC contractor how they're going to decide what size air conditioner to put in, there are some wrong answers that should have you yelling, "Next!"

Here are a few: The first answer is bad because they're assuming the original contractor sized the system properly—and that nothing has changed since. The second is bad because they're assuming that bigger is better. The third is bad because using a rule of thumb based on square footage doesn't work, and they should measure the house themselves rather than relying on your number. The proper way to size heating and cooling systems is to calculate the actual heating and cooling loads for your home. working of air handling unit pdfTo do so, the contractor has to measure the house completely, get all the insulation R-values, window types, orientation, infiltration rate, duct leakage, and more. how much is a two ton ac unitThen they put all that into their load calculation software and find out how many Btu's per hour your home needs. ac window unit support kit

The most common way of doing this is to use the Manual J load calculation protocol. Proper sizing is important because an air conditioner does two jobs: (i) cools the air, and (ii) dehumidifies the air. In a humid climate, an oversized air conditioner will cool just fine but won't dehumidify well. Also, oversized systems go on and off a lot, and all those start-ups and shut-downs will shorten the life of your air conditioner. What happens inside the cooling equipment is only part of making your home cool and comfortable. The distribution system plays a huge role, and the typical duct system has a lot of leakage in it. If you're paying a lot of money each month to run your air conditioner, you don't want to waste that cooling through a lot of leaks in your ducts, do you? A duct leakage test will determine how bad your ducts are. Duct leakage isn't the only problem with getting cool air into your home. Many duct systems don't move as much air as they should because of ducts that are too small, kinked, too long, or have other types of constrictions.

At a minimum, your HVAC contractor should measure the total external static pressure and make sure it's within the limits specified for the equipment they're installing. Ideally, they'll also measure the air flow to each room to make sure your home will be heated and cooled uniformly. Remember, it's not all about the air conditioner. The overall performance depends a lot on how well the ducts move the conditioned air. If you're serious about getting a new air conditioner installed for peak performance, head over to the ACCA website and download their Quality HVAC Installation Checklist. Use it as a guide to choose the right contractor. In addition to the checklist, they have a nice page on their website on choosing the right HVAC contractor. Getting an air conditioner replaced is a big investment. It's also an opportunity to improve the comfort, healthfulness, durability, and energy efficiency of your home. It won't happen without your involvement, though, because many HVAC contractors will be happy just to swap out old equipment for new without looking at the bigger picture.

Find one who's willing and able to go beyond the box. Even better, get a full home energy assessment. How to Choose a Company to Do a Home Energy Audit Case Closed: Get Those Air Conditioning Ducts out of the AtticWhat is a 4-ton Carrier air conditioning unit?Heat is measured in BTUs, and 12,000 BTUs equal 1 ton. This unit can remove 48,000 BTUs per hour. What kinds of AC units does Carrier make? What is an HVAC gas pack? A split system consists of two pieces, a condenser that cools the air and sits outside the house to vent heat and an air handling unit that is inside to disperse the cooled air. Residential air conditioning units are available in sizes of 1 to 5 tons, while industrial units are available in sizes of 10 to 75 tons. Can a pool be heated with a heat exchanger? There are several ways to use heat exchangers to heat a pool, including using a solar heating system, the heat produced by a building's heating system or t... How does a Gibson central air conditioner work?

Gibson central air conditioners consist of a cooling unit that utilizes a chemical called a refrigerant to absorb the heat from air in the home and pump in... Which retailers carry split AC units? Who makes Day & Night brand heat pumps? Day & Night heat pumps are manufactured by International Comfort Products, a subsidiary of the Carrier heating and air conditioning group. In addition to D... How does a furnace gas valve work? How do you balance a ceiling fan? Are Thermador exhaust fans designed for commercial kitchens? Can you store firewood in the clearance space around a pellet stove? What companies repair Torpedo heaters? How does a Bosch AquaStar tankless water heater work? 1,531 posts, read 2,369,379 times I will be purchasing a new AC and furnace to take advantage of rebates. But I don't know the difference between 4 and 5 ton. I live in Texas and it gets hot for three months out of the year but I will also have sprayed insulation in the attic with the possibility of radiant barrier also installed depending on the price of the barrier.

Thxs in advance for your input. 26,349 posts, read 68,900,480 times 635 posts, read 2,279,224 times Originally Posted by eyewrist Not to belabor the point, but did someone spec the 4 ton based on an actual cooling load/heat loss calculation? I really do see some old timers say things like, "well, you have 2200sqft and all my years tell me you need 4 ton", but don't take into account the new tech, insulation, etc. I'd get a couple/three calculations done and hopefully they'll all be close. If not, I'd ask questions why. I'd also suggest doing some individual research into pricing and rebates for higher SEER units. When we installed our 15ish SEER unit a couple years back, it was not significantly more expensive than the 13 SEER option. Any pro worth their salt will be happy to do heat loss/cooling load calc for free or a small fee as part of the estimating process. If they refuse, I'd think about sending them on their way. While the SEER 16 may be more expensive than a SEER 14 for example, depending on you electricity rates, the breakeven point might not be that long.