Sizing your central air conditioning unit can be one of the most frustrating parts of the process of installing a new air conditioner. Customers that solicit price quotes from multiple companies are routinely given different sizing recommendations and different reasonings for those sizes. So how are you supposed to know what size air conditioner you actually need? I’ll give you some simplified guidelines for how central air conditioning units are sized here in Denver, but... The bottom line is that it’s not your responsibility to try and figure out what size your central air conditioner should be. Find a company you can trust, make sure they offer 100% money-back satisfaction guarantee in writing, and let them take responsibility for sizing the unit properly! The company you choose to install your new ac unit will use a long-form calculation called a Manual J Load Calc to determine the optimal size of your new unit. But it’s understandable to want a general idea of the approximate size your central air conditioner should be without going to an engineering class, and that’s actually a pretty simple equation.

Here in Denver, you can get a rough approximation of how many tons your central air conditioner should be by dividing the square footage of your home by 600. cost of replacing ac unit compressorIt’s important that you not include any square footage in the basement in this calculation, regardless of whether your basement is finished or not.air master air handling unit Dividing your home’s square footage by 600 does not work for homeowners outside the metro Denver area. new compressor for ac unit costThe 600 figure is higher than the figure that would be used in other parts of the country because it has been adjusted upwards to account for Denver’s higher altitude. Approximate Sizing Equation For Central Air Conditioners In Denver

Example: 1,500 s.f. / 600 = 2.5 ton ac unit 1,800 s.f / 600 = 3 ton ac unit 2,100 s.f. / 600 = 3.5 ton ac unit 2,400 s.f. / 600 = 4.0 ton ac unit Over 2,4000 s.f. / 600 = 5.0 ton ac unit Newer, more energy efficient homes can sometimes require slightly smaller units than the approximate sizing equation would suggest, but that depends on a number of factors related to the construction and style of home. Please keep in mind, this gives you a general approximation on sizing for your air conditioner. Your heating and air company should attempt to fine-tune the size by performing a Manual J Load Calc. The load calculation may confirm that your home needs the same size as the Approximate Sizing equation produced, or it could indicate that you need a slightly smaller size. If you are given a quote that recommends installing an ac unit that is more than 1/2 ton smaller than what the approximate sizing equation suggests, and that quote does not include a 100% money-back satisfaction guarantee, you are taking a huge risk.

It’s pretty rare that a load calculation will suggest installing a unit that is more than 1/2 ton smaller than the size you’ll get from the approximate sizing equation, but if it happens, you’ll want the contractor to make sure you have sufficient return air to handle the extra cooling capacity. To be honest, allowing any company that doesn’t offer a 100% money-back satisfaction guarantee in writing to install your new air conditioner is like rolling the dice. You have to cross your fingers and hope that they will install the correct size ac unit, as well as doing a good job on the installation itself. Without that 100% money-back guarantee you are basically on your own if there’s a problem. If you haven’t read it yet, check out our blog post titled How Does Size Affect The Cost Of A Central Air Conditioning Unit?What size house will a 3.5-ton air-conditioning unit cool? A 3.5-ton air-conditioning unit cools homes from 1,801 to 2,300 square feet, depending on location.

The unit cools 1,801 to 2,100 square feet in southern states from Georgia to California, and it covers 2,101 to 2,300 square feet in northern states. For existing systems, model numbers reveal the unit capacity. What is a ductless air-conditioning system? What is retrofit air conditioning? Manufacturers use a code in the model number of outdoor units instead of listing unit capacity on the air conditioner. If the model number is CKL42-1, for example, the unit is 3.5 tons. The number 42 means the unit is 42,000 British thermal units; when divided by 12,000 Btu per ton, the result is 3.5 tons. Alternatively, residential load calculations can scientifically determine the proper size air-conditioning unit. How do you read an HVAC thermostat wiring diagram? The most common programmable HVAC wiring systems in homes contains a furnace and an air conditioning unit. In this case, the thermostat wires are color-cod... How much space can a 2-ton air conditioning unit cool?

A building's energy efficiency, including air leak... As of 2014, the cost of installing an air conditioning unit in a 1,600-square-foot house falls between $3,000 and $5,000. If the duct work of the central a... To put Freon in an air conditioner you will need a Freon kit with compatible refrigerant, gloves, goggles, a mask and access to your air-conditioning unit.... Can you install your own forced air furnace? Where do you find the price of a wood burning furnace? How do you clean air ducts by yourself? What is the standard size of a house brick? What are the total supplies needed to paint the exterior of a house? What type of HVAC systems does Rheem make?It seems like Tesla might be making a battery for your house. Would that be cool? But why would you need a house battery? I can think of a couple of uses: For an off-grid house you might like to power it with solar or wind power. Unfortunately, neither of these two sources provide constant energy.

If you could store the energy in a battery, you could use this during the night or calm weather. Many people keep a gasoline powered generator for their house. I have one that I don’t use too often, but it’s awesome when you need it. What if you had a battery that you could use for your house in times of power outages? That would be cool. It seems like the power company would like everyone to have a battery. With a house battery, you could reduce power spikes on the grid. When you turn your air conditioner on, it draws a large current for a short period of time(here’s an explanation of why the current spikes). With a battery this current demand could be leveled out (I guess). But that’s not why you are here, is it? You want to know how big of a battery you would need. We need some starting values. First, how long do you want to run your house on a battery? I think Elon Musk (from Tesla) said one week. The next big thing is the power usage. I think a fair assumption is a constant 2000 Watt power usage.

Clearly a house would need more than 2000 watts at some point in the day. However, at night you wouldn’t need much power such that the average for the day could be 2000 watts. If you don’t like that value, you can put your own numbers into the calculations. If I know the power and the time, I can use the definition of power to calculate the energy stored in the battery. Having the power in Watts is fine (since a watt is a Joule per second) but I need the time in seconds. Now I can calculate the stored energy in the battery.But what the heck is a Joule? Sure, it’s a unit of energy but is that a large amount? Here’s a simple experiment you can do yourself. Take a textbook and put it on the floor. Now pick it up and put it on a table. In order to lift the book, you need energy (to change its gravitational potential energy). A book is about 1 kg and you lifted it about 1 meter. That makes a change in energy of about 10 Joules (don’t forget the gravitational field is 9.8 N/kg).

So now you know about Joules. Now for the battery size. The dimensions of the battery will depend on the type of battery. The current Tesla vehicles use a lithium ion battery. According to Wikipedia, the lithium ion battery has an energy density from 0.9 – 2.23 MJ/L (mega Joule per liter). I would imagine that Tesla would only use THE BEST BATTERIES! That would put its energy density at 2.3 x 109 Joules per cubic meter. If I call the energy density σ, then I can find the battery volume: Putting in values for the energy density and the battery energy: So just half a cubic meter. That’s not too bad. If you want to put this inside your house, you could make it as tall as a wall (let’s say 2.5 meters). Now from a design view maybe a battery should be just 5 cm thick. This means that it would have to be about 4 meters wide. Ok – that wouldn’t work. If increase the thickness to 10 cm, it would just be 2 meters wide. Of course, this only really works because of the high energy density for a lithium ion battery.

If you used an akaline battery (like AAs) it has a lower energy density at around 1.8 MJ/L such that it would be slightly larger house battery (but not rechargable). You can look at the Wikipedia page on energy density to get an estimate for house batteries of different materials. Just for fun, what if you made a penny battery (from copper-zinc pennies and acid)? How big of a battery would you need in that case? Here is your answer. This is just a perfect story for homework. It won’t be too difficult, so don’t delay and start soon. What if you wanted to run your house on AA Cell batteries? From my previous investigation, I found that a AA battery has about 10,000 Joules of stored energy. How many AA batteries would you need and how much space would it take up? What if you wanted to run your house on a nuclear power plant that used Thorium? How much Thorium would you need? Use the energy density from Wikipedia. According to this news, Apple will build a 130 MegaWatt solar farm to use for its stores and stuff.