Written One potential problem with portable air conditioners is the condensation back flow which should be exhausted outside through a hose - dirt and debris can accumulate if not properly cleaned; depending on the design. A unit used for one season shouldn't be a problem, though, and they generally last quite a long time - essentially indefinitely if it's well designed and constructed, and properly maintained. Buying used is always a crapshoot so it's really a value-judgement decision: is saving $100 amortized over a few years worth the risk of potentially buying a lemon without a warranty. I'd feel comfortable enough to buy used because I feel sufficiently knowledgeable to know what to look for and fix it if it breaks - a risk I'm willing to take.    EASY ANSWER:Plug it in, and make sure it is working!NOT SO SHORT ANSWER:Bring a thermometer to take the temperature of the air. You want to measure the Outside Air temperature, the Condesner Air temperature, the Supply (cold) Air temperature, and the Inside Air temperatre. 

You want to measure that heat is being transfer across both coils, and that the unit is doing work.Example:80F Outside Air95F Cond. Air Temp= 15 degree difference70F Indoor Air Temp55F SUpply Air Temp= 15 degrees differenceYou are rejecting heat from inside to outside and doing work.  Example of no work being done, but "feeling cold air"60F Outside Air70F Cond Air Temp=10 degrees80F Indoor Temp70F Supply Air Temp= 10 degreesYou seem to be doing a 10F split across both coils, so WOHOO, BUT WAIT!!!!If we think about this more clearly we can see the outside temperature is colder than the indoor temperature and we are unable to cool the indoors, AND have a paltry 10F  split.  So what is likely happening is that your AC system is acting more like a dry cooler, meaning that you are cycling the refrigerant outside, rejecting some heat and bringing it back in, but your compressor is acting more like a pump and this only seems to be working because the outside temperature is so low you are naturally going to have a heat transfer toward the outside. 

The Indoor Temp should be 70 and the Supply Temp should be 60 or lower.  Other factors could be present and things could get more complicated as far as heat loads etc.  But the key thing to be mindful of is that the compressor is in the system to force some work to be done, raising the pressure on the high side, so that we can capitalize on this through the evaporator.  ac unit plug inSo regardless of heat loads and more complicated aspects of HVAC, you should be able to feel that some SIGNIFICANT work is being done and you should bring a thermometer because it is easy to feel the blowing and think it feels colder when in fact you are doing a mere 5 degree split or maaaybe a paltry 10 degrees, but likely from the fan more so than the unit working well.top selling ac units Keystone Energy Efficiency Alliancebuy ac unit nyc

Copyright © 2015 The Keystone Energy Efficiency Alliance a »message agency siteBuying a Used Car: What Does "Air Conditioning Needs a Charge" Mean? If you're interested in buying a used car, you may have seen advertisements stating that the car's air conditioning needs a charge. This terminology can be confusing, so we decided to explain exactly what to expect when you see (or hear) this phrase.Needs a ChargeWhen sellers say that an air conditioning system needs a charge, what they mean is that the air conditioning is out of refrigerant fluid. Most likely, this means the system has a leak. The fluid in an air conditioning system simply does not get used up like gasoline. A home refrigerator works much like an air conditioning system. How often you need to "charge it up?" What Does It Really Need?Unfortunately, the simple explanation that the air conditioning "needs a charge" rarely tells the whole story. For one thing, air conditioning systems are supposed to be closed;

they aren't designed to lose any fluid, and they shouldn't need replenishing. With that said, it's possible for air conditioning systems to lose some fluid over time, but even that likely means a small leak in the system. So it is possible that "charging it up" will help the air conditioner blow cold air, but if the leak isn't properly fixed, you're running on borrowed time. We've seen A/C systems get a fresh shot of fluid and work well for several months, but there's really no way to be sure unless you take the car to a qualified air conditioning repair shop. More likely, however, the car's air conditioning system needs more than just some fluid. After all, if fixing the air conditioning were as easy as adding fluid, wouldn't the seller do that before listing the car for sale?How Can You Know for Sure?Unfortunately, it isn't always easy to find out exactly what a car needs to get its air conditioning system working again. Pouring additional fluid into a leaky system will cause the air conditioning to operate temporarily, until it drains out again from the leak.

As a result, the only way to know with certainty what a car needs when it comes to air conditioning is to take it to a trusted mechanic, who can inspect the entire system for leaks or faults. We suggest a mechanical inspection anyway when you're buying a used car. If air conditioning is important to you, a potentially faulty system is all the more reason to make sure to get an inspection before signing the papers. The implication of "just needs a charge" is that the problem is a simple one with a very inexpensive fix. The truth is that it's a lot more complicated than that. If you're looking at a car from the 1990s, the system may have to be converted to a new kind of refrigerant that's better for the environment. Even if you're looking at a newer car, a qualified shop will have to find and repair the leak, which could get expensive. If you really want that specific car, ask a local shop for their hourly repair rate and then factor that into the price of the car you want to buy. We offer a full range of mobile air conditioning equipment.

Choose from this complete line-up of products: Air Handlers & Chillers  | When you need a portable air conditioner, Sunbelt Rentals Climate Control Services is your single source for portable air conditioning equipment. Our air-cooled and water-cooled portable air conditioners, available for rent or purchase, provide a wide range of cooling options, from spot cooling applications, to ceiling-mounted units, to skid/trailer mounted air conditioners for commercial applications and special events. Our portable cooling equipment includes our Mobile Cool Series for large area cooling and our MovinCool Series for spot cooling. Suitable applications for our Mobile Cool Series portable A/C units include tents & special events, process cooling, aerospace & aviation, and the motion picture industry. Suitable applications for our MovinCool Series spot coolers include server/telecom, healthcare, offices/schools, and outdoor events. Our highly trained and knowledgeable staff provides innovative solutions for all your cooling needs.