Apparently, I haven't written a single article this summer about oversized air conditioners. I've written several in previous summers, mostly about how HVAC contractors bypass the HVAC design process by using rules of thumb and how they mess up the Manual J load calculations when they do go the preferred route. I've never written an article focusing on the reasons to size an air conditioner properly, though, so here it is. When an air conditioner runs, it does two jobs. It lowers the temperature of the air, and it removes moisture from the air. To do the second one, the AC has to run for a while. As the air passes over the evaporator coil, it encounters a very cold surface. Ideally, when the air passes over that cold surface, the air temperature drops about 20° F. In places where we have higher relative humidity in the summer, the other important process that happens when the air hits the coil is that the temperature of the coil is below the dew point of the air. As a result, water vapor condenses on the coil.

Here's the thing, though. Water vapor condenses on coils in oversized air conditioners, too, but you have to get enough condensation on the coil for the water to start dripping down into the pan below the coil. Even then, you're not there yet. You still have to get enough water in the pan for it drain to the outside. Until the water that condenses actually makes it to the outside, you haven't really dehumidified the air. Because that water on the coil can evaporate and get back into the air in the home. If you make the mistake of leaving your thermostat in the Fan-On position instead of Auto (Don't do that!), the water on the coil gets back into the air even quicker. Oversized air conditioners don't run for a long time because they satisfy the cooling load quickly and then shut off. Properly sized air conditioners run longer, so if you want your air conditioner to dehumidify your home as well as cool it, don't let the HVAC contractor oversize it. If you live in the desert, what I just said above doesn't matter to you.

There's no water vapor to condense on the coil, and if there were, your dew point is probably close to absolute zero. (Well, OK, that might be a bit of an exaggeration.) The second reason definitely should matter to you, however. The thing that wears equipment out is starting up and shutting down. The more it happens, the shorter the life of the equipment. When an air conditioner is oversized, it starts up and shuts down a lot more because it runs for only a short time to meet the thermostat setpoint. Then a few minutes later, it comes on again and runs for a short time. Over the course of a day, an oversized air conditioner can have a lot more start-ups and shut-downs than a properly sized air conditioner. That means you'll probably be repairing it more often and replacing it sooner. People in the industry used to think you'd save money on your air conditioning bills with a properly sized air conditioner, but that thinking has changed. John Proctor wrote an article for Home Energy Magazine that shows only a small savings for the homeowner (but the utilities benefit by lower peak loads).

You should save money on the upfront cost, though, because you're putting in a smaller AC. (As Proctor points out in his article, oversizing isn't always the worst problem, though. car ac repair national cityYou have to be a subscriber to Home Energy Magazine to read the article, but it's well worth the read if you can get it.)how much is an air conditioning unit cost For new homes, use the full HVAC design process, which starts with Manual J, the heating and cooling load calculation protocol from the Air Conditioning Contractors of America, the trade association for AC contractors. ac unit vs central airFor existing homes, the best way to do it is to see how long your current air conditioner runs when it's at the design conditions.

Of course, you want to do this while your AC is still in good shape, not when it's on its last legs. If it runs for only 5 to 10 minutes before shutting off, it's definitely oversized. If your runtimes are over half an hour at design conditions, it's probably sized close to the actual cooling load. If you're building a new home, remodeling an existing home, or just getting a new air conditioner in an existing home, ask your builder, remodeler, or HVAC contractor how they're planning to size the air conditioner. If they tell you they're basing it on the size of your house, don't let them do it. There's a lot more to it than square footage of conditioned floor area, and of course, I haven't touched at all on the capabilities of different types of equipment (single speed, fixed capacity, multi-stage, mini-splits...). More on that in future articles. Oversized AC, Screwed-up Manual J, ENERGY STAR HVAC Tirade!Don't Assume It's Correct. An Oversized Cooling System Isn't Always a Bad Thing

The Zero Breeze is the World’s First Portable, Smart, Multifunctional Air Conditioner that also functions as a bluetooth speaker, a night light, and a smartphone charging station. Zero Breeze is capable of cooling a 50 square feet room down to 44 ℉ making it perfect for your home, office, tent, RV, college dorm, and so much more. How to get it!Become a backer of this project and Pick a Reward. You will be pre-ordering the Zero Breeze. You'll get a special backer discount!  Want to buy more than one? Check out How to Back this Project. The Zero Breeze is effective, lightweight and easy to use. We use a rotary compressor making Zero Breeze efficient and portable allowing you to stay cool anywhere, anytime.Similar products in the market don’t have a real air conditioning function. A majority just add water or ice into their device to create the cooling effect. Most of all, none are portable because they all need to be plugged in using an adapter to be used. Plug Zero Breeze in at home or use the battery pack to power it while you’re mobile.

It’s the best way to stay cool and beat the heat. , & Regular Fan Airflow. Zero Breeze has easy access charging ports on each side of the control panel. If you’re using the Zero Breeze inside, simply attach the hose and extend the other end outside. To use the bluetooth speaker, simply lift the front panel and connect to your phone. You can adjust volume levels and skip songs straight from the Zero Breeze. The Power Bank contains 64 cells of 18650s, the same cells that Tesla uses. It is a 5-Hour Battery, allowing you total portability without having to worry about outlets. The warm LED light provides the perfect amount of illumination for camping and other outdoor activities. Zero-Breeze is perfect for RV traveling, BBQs, outdoor family get togethers in the summer, and so much more.Choose a reward level.Everybody can choose one (and only one) reward level to back this project. You cannot choose 2 reward levels. You will get all items in that reward—you cannot swap things that you don't want for things that you do want.

2. Relax, you're done for now.All details like shipping information and color preference will be collected via survey after this campaign has ended. During our two year development of Zero Breeze, we extensively tested and improved the concept of a rotary compressor to achieve the smallest possible form factor and maximum air cooling results. After several iterations, we built a fully functioning portable air conditioner that works. As you can see, we use a thermometer to test our working prototype during normal fan and cooling fan modes producing the temperature of 85.8F and 47.4F(outlet air) respectively. We used thermometer to make a quick test to check out Zero-Breeze's working temperature during normal fans and cooling fans. The above video captures the temperature of a prototype compressor, whose provide cooling air at 47.4 F(outlet air). Our team has improved the mini rotary compressor to meet and realize the cooling requirements of an air conditioner over the last 2 years of research and design.

By breaking traditional concepts of fan or electronic cooling and realizing portable and DC powered compressor cooling, we've created a fully functioning portable air conditioner. High efficient cooling conversion ratio of frequency conversion (120W of power comes out 400W of refrigerating capacity) fully meets the outdoor requirements and makes outdoor activities more enjoyable. The device has a Bluetooth speaker for entertainment and a night light & mobile charging for practical functions. Zero Breeze is small self-funded company with limited resources. We’ve poured our hearts over the last 2 years into creating a great product fit for the masses and we’re looking to leverage Kickstarter to spread the good word. In order to get the costs to a price we believe creates value for our customers, we need to have a large initial production run. We have already invested substantially in the design process as well as getting ready to bring Zero Breeze to the market and need your help to make this happen.

Your support will allow us to place our first large order with our manufacturers so that we can reduce production costs and get Zero Breeze in the hands of people everywhere. Congrats to our giveaway winner! Theresa M. you won! We will reach out to you directly to get you your free Zero Breeze. Although we already have manufacturing and fulfillment partners set, there is always the risk that unforeseen obstacles may get in the way. If an issue does arise that will slow down production or shipment of your order, we will let our backers know. We appreciate you being an early supporter and will work hard to maintain your trust through communication and transparency. Learn about accountability on Kickstarter Yes, the product comes with an adapter for wall outlet. It would be a perfect product to cool your boat cabin. The adapter input is 100-240V 50/60 Hz, please check if you need a transformer for shore power. We are scheduled to deliver the first batch of goods to Kickstarter backers on Mar, 2017.

And then the product will be on market. The lowest temperature of outlet air is 44.6°F. All details like shipping information and color preference will be collected via survey after this campaign has ended. No 'Zero Breeze - SUPER EARLY BIRD' does not come with a battery, but 'Zero Breeze PLUS- SUPER EARLY BIRD' does include a battery. When using it indoors you must run the hose out your window. The hose is designed to release the hot air that Zero-Beeze generates, so it requires an exhaust pipe when using it indoors. No, you won't be able to run Zero-Breeze without being "plugged in" if you don't purchase the additional battery. They will be shipped via multiple combinations of shipping companies by boats and inland express to avoid restriction of shipping batteries. Yes, the battery and device will come with individual adapters, so the battery is able to be charged while it's connected to the device. However, we don't recommend charging in this way.

There is no maintenance required. The device is similar to a home AC unit. The exhaust pipe filters out hot air and the drain pipe is for the condensation. No, the $349 reward level does not include a battery. You will need to plug it in to run the device. The $568 reward level does come with a battery and can function without an outlet. At a future retail price, the battery will be $289 and $219 on Kickstarter. However, if you pledge the "Zero-Breeze Plus" reward level, which includes a battery, then add $219 on top to get another battery, then your Zero-Breeze will come with 2 batteries. There will be two Aviation connectors that come with Zero-Breeze which allow you to connect a DIY power cord to the device along with your battery pack. The battery has 40AH capacity to run for up to 5 hrs on Low. The unit has two levels that affect the temperature output which can go as low as 48F, depending on the surrounding temperature in the room. Yes, the batteries will be sold when our Kickstarter campaign has ended.