Sizing A/C Units and Ducts Notice how "square footage" is never mentioned. Important Warning to Home Buyers! How to Recognize a "Soft" Home Inspection Report. Need a home inspection in Tennessee? listing of Tennessee certified home inspectors. Re: Sizing A/C Units and Ducts He does a good job of explaining oversizing but I stay away from calculation. opps watched the wrong one first but Similar. Originally Posted by jbushart If you are designing a new system, that video applies. When you are just changing the condensing unit/air handler, it is a different matter. The existing duct work will dictate what sized unit can be used efficiently. A home built in 1970 with with inefficient windows may require a larger, 1 ton larger according to the guy in the video, won't work as the duct work was not designed for it. The square foot method is a basic guesstimate for certain regions and when it is all said and done, in most instances, once you add in all the variables, isn't that far off.

I recall doing an inspection on a 900 sq ft condo. The guy installed a 5 ton unit! I told my clients that it should be replaced to a properly sized unit. During the inspection, the unit came on for five minutes and shut off. It did this all through the inspection. That is what is known as short cycling! Magnum Inspections Inc Website Originally Posted by evandeven The dynamics of heat loss as opposed to the loss of cooled air are quite different. What might be the rule of thumb in Florida is folly in Maine. To further prove my point, our home is 1,700 sq ft. The rule of thumb is 1 ton per 600 sq ft. That is roughly a 3 ton unit. When you factor in all the variables, the total cfm required comes to 1200, which is a 3 ton unit. Our duct work was designed for a 2 ton unit, which is why it was replaced. The 3 ton unit was installed to compensate for the, at the time, insufficient attic ventilation and insulation, no "drops" in the bathrooms or laundry room,etc.

Originally Posted by jbraun We did that on our home along with installing a ridge vent and a radiant barrier,along with the new duct work. The ridge vent/radiant barrier brought the attic temperature down significantly, and then, by planning out the duct work properly, it is now balanced. If I were to put a flow meter in front of the vents, it would probably be very close to equal on every vent. A 1000 sq ft home with lots of single pane windows and little insulation may need a larger sized unit than a well-insulated home twice that size Originally Posted by jhugenroth Take two homes with 1500 sq ft on the same street. One sits on a hilltop with no trees or wind barrier, 150 sq ft of single paned windows facing north and west, 75 sq ft facing south and east, R-19 attic with 80% of the ductwork outside of the thermal boundary (no mastic at the seams and joints and uninsulated). Second sits in a valley, fully shadded on the south and east, Low-E windows facing south and east (150 sq ft) and regular double paned facing north and west (75 sq ft), R-38 attic with all of ductwork inside of the thermal boundary (no mastic at the seams and joints and uninsulated).

How many contractors (and home inspectors) would walk off the 1500 sq ft and apply their "rule of thumb" to determine the adequacy of the cooling capacity of the a/c? ac window unit safetyI think most, and for at least one of these two units....they would be wrong.average life of a window ac unit Air Conditioner or Heat Pump Sizing Chart3 ton ac unit Preparing your sizing chart:Print out this page. Leaving the page intact, carefully cut out the holes on the dotted lines. For operating instructions see bottom of page. 1 1/2 to 2 ton 2 1/2 to 3 1/2 ton 4 to 5 ton Sizing Chart Operating Instructions Stand on the curb.* Hold the sizing chart approximately one foot from your face. Look at the house through each hole.

If the house fits in a hole, that's the size unit to use. *If the curb is not available - ask the homeowner where a curb would be if there was one. Would you like a little more accuracy? Or see our Table of Contents Please Visit the InterNACHI Awards page I recommend all Ontario NACHI members read this and form their own opinion on OntarioACHI . Cyberbullying is the act of harming or harassing via information technology networks in a repeated and deliberate manner. This fits a very unprofessional group From OntarioACHI Un like some that has never accomplished anything but sit behind a desk its hard for them to comprehend that when someone has done that same thing day in and day out for most of their adult life that one simply has the ability to walk through a home view the windows, doors and insulation based on SQ footage that is typical for the local area and determine the exact tonnage required . There are always unusually designed homes that will require the J program but by all means not every home as some would lead to believe.

Oh BTW Bushy tell me the foot print of your house SQ ft the type of windows and age how much insulation and type in the attic and I will tell you how many tons of A/C your contractor is going to install and I have never seen your house Originally Posted by cbottger Sure you will, but you will still be wrong, Chucky. You represent the contractor who every prudent inspector needs to be wary of before agreeing with the equipment he installed as being "adequate" or not. Like you, many feel confident that they can correctly guess the proper system...often oversizing the unit to compensate for error and adding to its inefficiency. But you will still be wrong, Chucky. NEO Inverter Split AC with Multijet Plus Technology 1.5 TR 10 meter Long air throw Tender Lilly Blue Pattern Capacity (Cooling, Min - Max, Btu/hr) 1,065 x 298 x 243 880 x 638 x 310For those looking to buy LG AC online but don’t know the portal that is selling your favourite LG model at the lowest price, this page can give you just that.

Taken from all the leading e-commerce portals like Amazon, Snapdeal, Flipkart, Infibeam, etc., this page provides the best possible price for the customers to buy.Check out the below price list of LG Air Conditioners in India, How to buy the best AC online?Comparing the prices and features before buying an AC is a smart move. Before you start your search, it is important that you know what kind of weather prevails in your part of the country exactly. If it is mostly dry, then there is no need to worry about humidity features. Some parts of the country can become extremely humid during summers. If you belong to a humid zone, check for dehumidification modes in your AC. Also, if the surroundings are dusty, you should install an AC that comes with a dust filter. Another important feature is the size of your AC. A room that is lesser than 150 Sq. Feet needs a 1 ton AC while any area higher than that will require a 1.5 or 2 ton AC. Also, make sure your AC saves electricity by going for higher star-ratings.

To compare ACs, Check for features like Type (Split or Window), Capacity (Usually it is between 1-2 ton), and energy rating. To further find out the best AC, look for features like the type of filter, or find out if it is an inverter AC. An inverter AC consumes much lesser power compared to a normal AC. ACs can be quite expensive. Hence, it is important to do a price comparison before buying one. While most e-commerce portals will mostly be selling the AC you have shortlisted, the price on each of these portals will usually vary. Thus, to ensure you get a good deal, it is important to know the best AC prices. Also, look for payment terms. Some might offer COD or EMI payment options for the ease of buyers. LG Electronics is a Korean company with an impeccable reputation all over the world. Not only do their products last much longer than any other within the same price range, they also provide amazing customer support. LG ACs have some great features that are unique and energy-efficient.