What size air conditioner do I need for my house? The size of the unit should be just large enough to cool the square footage but not be larger than needed. Therefore, the first thing to consider when choosing the best AC unit is the size of the house. There is not a one-size fits all guide to what size unit a home will need. An experienced HVAC technician evaluates the home and the area to help an individual make the best choice. In the southern-most portion of the U.S., a 2.5 ton unit will cool 1,200 to 1,500 square feet. The same unit will cool a 1,400 to 1,650 square foot home in the northern-most states. The size of an AC unit is measured by tonnage, and residential air conditioners can range from 1 to 5 tons. The efficiency of a unit is measured by the seasonal energy efficiency ratio. This is how much cooling a system will provide per dollar spent on utilities. The energy efficiency ratio is the ratio of the output to electrical power. A more efficient unit will have a higher SEER and EER rating than a lower one.

Combined together, the two numbers represent the type of performance expected for typical weather in an area for any given year. A higher rated AC unit will cost more money up front, but the unit will pay for itself over time in energy savings. An individual can also receive a tax credit for purchasing an energy-efficient HVAC unit. How much do Trane XB14 air conditioners cost? The price of the Trane XB14 air conditioner may vary by dealer, but base prices for this model can be found to be around $1200 to $2100 depending on the si... Measure the square footage of all the rooms in the home that will be cooled, and then compare that number to the government's recommended British thermal u... What is the correct method for residential air conditioning sizing? The correct method of residential air conditioning sizing uses the square footage of the area the unit is cooling. After calculating the area, compare it t... Can you control a Honeywell heating system from a smart phone?

Where can you find replacement parts for your furnace? How do you find local places to buy dry ice? What are some popular house plans with courtyards? What are some gas fireplace logs available at Lowe's? How do you get fleas out of your house?Step 1 / 3:Edit First, tell us little about your home: Tell us about your needs and we'll recommend the right system for you and your home. WHAT TYPE OF SYSTEM ARE YOU LOOKING FOR? Continue to Step 2 Continue to Step 2 Dealing with Wintertime Dryness Ways to Improve Indoor Air Quality Climate Zones for HRVs & ERVsHow Much Does it Cost to Install Solar on an Average US House? Will it run occasionally or most of the time? Check the appliance nameplate's for running watts and volt-amps. Running Watts / Starting Volt-AmpsWhen you look at your monthly electricity bill, you probably focus on the number with a dollar sign in front of it. But there’s another value listed: how much energy you actually used.

If you are a perfectly average American living in a perfectly average household, your monthly electricity bill will read 911 kilowatt hours (kWh), which costs $114. But most of us don’t live in perfectly average households. (The state that comes closest to matching the average monthly electricity usage is Ohio).deck over air conditioning unit Depending on whether a state is hot or cold, urban or rural, an average household can use as little as 506 kWh a month (Hawaii) or as much as 1,291 kWh (Louisiana). air conditioning units average costCosts vary state-by-state, too. best coastal ac unitsHawaiians, even though they use the least, pay the most for electricity ($188 a month) and New Mexicans pay the least ($78 a month).

As for our Inside Energy focus states: How is energy use and cost changing? Nationwide, average monthly electricity use rose 8 kWh per household between 2012 and 2014 and prices rose three-quarters of a cent per kWh. As a result, average monthly bills went up about $7 per household between 2012 and 2014. How does your electricity bill measure up? A kilowatt hour isn’t an intuitive unit, so we also have a post explaining what you can do with a month’s worth of electricity. Editor’s note: This post was originally published on May 22, 2014 and included 2012 data. We published an updated version with 2014 data on October 27, 2015. Data source: Energy Information Administration, 2012 and 2014One of the most frustrating parts of my job as a Home Energy Rating (HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code.

A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5.) provider is dealing with the size of air conditioners installed in Energy Star homesA U.S. Environmental Protection Agency (EPA) program to promote the construction of new homes that are at least 15% more energy-efficient than homes that minimally comply with the 2004 International Residential Code. Energy Star Home requirements vary by climate.. My frustration has spilled over in the Energy Vanguard blog several times, and the topic in all its manifestations (HVAC sizing, Manual J load calculations, the HVAC industry...) has been one of my favorites to write about.

I've got an idea of how to make things better now, though. Today it happened again. I was checking HERS rating files, and, as I usually do, I applied my AC sizing rule of thumb to see if the HVAC contractors treated the homes as a true high performance homes. Turns out they didn't. For the three homes in question, the air conditioning capacity was one ton for each 529 square feet, 544 sf, and 781 sf. Those numbers are not good. The first two, actually, are terrible. In case you're new to this subject, air conditioners should be sized to meet the cooling load of the house, and bigger is NOT better. If the AC is too big, it doesn't run long enough to dehumidify well, and the constant on-and-off cycles will shorten the life of the equipment. A Manual J load calculation is how you find out what size air conditioner the house needs. So, here's my idea, and I'm starting a campaign for it. HVAC contractors like rules of thumb, so let's take that idea and adapt it. If you're a builder, home buyer, HVAC contractor, or real estate agent, here's a way that you can do a quick analysis to see if the air conditioner is oversized: Find the conditioned floor area.

Find the air conditioner's capacity in tons. Divide the former by the latter. What you get is the number of square feet of conditioned floor area per ton of AC capacity. I told you above that 529, 544, and 781 aren't good, so what is a good number? As a rough guide, you can use the following: High Performance Home = 1000 sf/ton or more We've done a lot of load calculations here at Energy Vanguard, and I don't think we've had a single new home come in lower than 1000 sf/ton. I built a house here in Georgia that came in at about 2000 square feet per ton, and we recently worked on another one that was higher than that. This number, 1000 sf/ton, should be your baseline. Nothing lower than that should be acceptable. Now before you get all in a huff and accuse me of being a hypocrite for promoting a rule of thumb, let me explain that I'm not saying the rule of thumb above is a subsitute for Manual J. Yeah, we could come up with a number for each location (e.g., 1100 sf/ton in Dallas, 24,000 sf/ton in Seattle

, 0.00000000000000000000000001 sf/ton in Hell...), but you still have to do a room-by-room Manual J load calculation to select equipment and design ducts properly. Where this rule of thumb could really shine is for these three things: 1. Helping home builders know if their HVAC contractor is in the ballpark of proper HVAC sizing If a home builder is taking care of the building envelopeExterior components of a house that provide protection from colder (and warmer) outdoor temperatures and precipitation; includes the house foundation, framed exterior walls, roof or ceiling, and insulation, and air sealing materials., getting the ducts sealed, and doing all the things you have to do to build a high performance home, they can use this as a guide in negotiating with their HVAC contractor. When the HVAC contractor tells the builder what they want to install, the builder can quickly see how it compares to our benchmark. (Of course, if the builder uses a third party for HVAC design, then they don't need to use this benchmark because they'll have a better number.)

2. Helping home buyers know if they might be buying a home with an oversized air conditioner Home buyers can get their calculators out and do this simple calculation. If they're buying what's supposed to be an energy efficient home and the number is far below 1000 sf/ton, then either the house isn't really so efficient or the system is oversized. In either case, they can steer clear of it and look for a real high performance home. 3. Simplifying programs like new homes The ENERGY STAR new homes program has been great for moving the whole new homes market toward greater energy efficiency. If you've taken a look at the new Version 3 guidelines, however, you probably felt a bit woozy afterward. They've made the program too complex, especially for HVAC. A rule of thumb like this could reduce everyones' headaches. You know what's really good about this new rule of thumb? It satisfies our natural urge to believe that bigger is better! No one wants to say to their neighbor: