And now, the stealth air-conditioner. A new generation of machines is nearly or totally invisible from the exterior of buildings and is being aggressively marketed this summer, mostly to people who live in apartment buildings where no window is available or where air-conditioning is not allowed by the landlord. Mounted on casters and advertised as ''windowless,'' these air-conditioners may, in fact, be hidden easily from landlords. But they also have drawbacks, say engineers, who much prefer conventional window models. The machines are sold in appliance stores in cities around the country for $700 to $900, substantially more than window models of the same cooling capacity. The important point for consumers to remember, engineers say, is that windowless air-conditioners, like all air-conditioners, create cold only by moving the heat somewhere else. They employ electricity to drive a compressor, a device that takes a gas and puts it under pressure to turn it into a liquid and simultaneously squeezes out the heat.

The heat is then released from the rear of the air-conditioner, and the coolant, now a liquid, is released from pressure and boils back into a gas. 15000 btu window air conditioner reviewsIn that step, the coolant absorbs heat, thus producing cold air that is blown into a room. hvac unit life expectancyBut there is a catch.lg room air conditioner home depot ''There has to be somewhere for the heat to go,'' said Dean R. Keuch, a senior engineer at Consolidated Edison. In addition to moving heat around, he said, an air-conditioner makes heat, because its electric motor and other parts get warm. A Chill in the Air ''If you're not putting it out somewhere, obviously you're not doing yourself good, and maybe you're doing some bad,'' Mr. Keuch said.

Conventional air-conditioners, he pointed out, can be set to chill air from the room, making it colder and colder on each pass and sending the heat out of the building. But a windowless model often does not segregate the heat it is rejecting from the air it takes in for cooling. So the heat stays in the room. The process is a little like trying to bail out a boat with a leaky bucket: some of the water gets handled more than once. The windowless air-conditioners vary in how they get rid of heat. Some come with hoses, which can be routed out a window or into the space above the acoustic ceiling tiles in an office or even into a windowless master bathroom to get rid of heat from the bedroom. ''If the heat stays there, what's the difference?'' said Mel Tillman, the owner of S&S Sound City, an appliance and electronics store in Manhattan. ''You go into the bathroom once, but you're in the sack eight hours.'' One model, the Cold Front, has an optional window vent, 2.5 inches high, that is almost invisible from the exterior.

But it will also work with no vent at all, according to the manufacturer, Bionaire of Montreal. The proper use, said Juergen Puetter, company chairman, is to sit in the ''cold zone'' in front of the machine. ''As long as you have a door or window cracked open, the heat can ultimately get out,'' he said. The Bionaire can also remove humidity, he said, making the room more comfortable. The Bionaire is like a dehumidifier that suburbanites use in musty basements. In this case, a tank that holds just under a gallon of water must be emptied - on humid days, as often as every few hours. ''It is not a full replacement for a regular air-conditioner,'' Mr. Puetter said. ''But in many areas you cannot use a regular air conditoner.'' Another model, the Pinguino, built by DeLonghi, can be filled with water, which it uses to help remove heat. It has an exhaust pipe that can be put out a window or into another room. Another type of windowless air-conditioner is meant to be connected to a water faucet, sending the heat into running water.

This is extremely efficient in terms of electricity use, because water conducts heat far better than air does. But these air-conditioners use large amounts of water. For that reason they are illegal in many areas, including New York City. They are nonetheless popular. Windowless air-conditioners have been known to industry for years as spot coolers, the opposite of portable heaters. In a huge, hot factory, they are sometimes used to blow cool air where a worker stands. But they are far newer to the consumer market. Windowless models that are not cooled by water tend to be far less efficient than window models. The window air-conditioners commonly available, for instance, deliver almost 20 percent more cooling power than the Bionaire does for a given amount of electricity. Con Edison, for example, recommends that consumers buy air-conditioners with an energy efficiency ratio of 9.5 or higher; the windowless models run less than 9. They are not required to list an energy efficiency ratio, and some do not.

This inefficiency has two consequences. The first is higher electric bills. The other is that a windowless air-conditioner will challenge a fuse box more than a conventional air-conditioner of equal size will. So, like the stealth bomber, the windowless air-conditioner may not show up on radar. But particularly in a building with old wiring, its presence will eventually become obvious. Photo: Mel Tillman, at left, showing a windowless air-conditioner to a customer at his store in Manhattan (Steve Berman for The New York Times); The Cold Front windowless air-conditioner by Bionaire, which can also remove humidity from a room. It has an optional window vent, but the manufacturer says it will work with no vent at all.Those of you who read our articles regularly, know that we are a small, U.S. Veteran-Owned company in Southern California, and pride ourselves in giving people honest, straight answers to their questions.  This will be no different.  So, what is dirty sock syndrome? 

“Dirty Sock Syndrome” is when your air conditioner gives off a foul, moldy or mildew-like smell when you turn it on.  If you notice that your house smells like your son just put his gym socks into your air conditioner or if your house generally smells musky or like a gymnasium when your air conditioner kicks on, then you could have dirty sock syndrome.  I think it is important for me to point out at this point that no, I am not joking.  This is a real problem that people face and it is actually called ‘Dirty Sock Syndrome’ in the HVAC industry.  In Santa Clarita, we get questions about this from time-to-time, usually in the springtime when people are transitioning their HVAC units from heating to cooling mode.  So, what causes dirty sock syndrome, and is it dangerous to me or my family?  In this article we will briefly explain what it is, what causes it, if dirty sock syndrome is dangerous, and what you can do to fix it. Dirty sock syndrome is the foul, moldy smelling odor that comes from your air conditioner when you first turn it on.  

It is caused by the build up of mold and bacteria on your evaporator coil.  Mold and mildew can grow due to the moisture that builds up on your coil through continued use, is fueled by the dust that collects in your air conditioner over time from inadequate filtration and is especially common when your unit goes from a period of heating to cooling.  Especially in the Springtime in Southern California and the southern states, it is not uncommon for the heat to be on in the night and morning, only to transition to a period of cooling later in the day.  This heat mixed with dust and moisture in the darkness of your AC unit is the perfect recipe for dirty sock syndrome.  These are some of the reasons that it is so important to prevent mold and to provide adequate filtration for the air entering your air conditioner.  In fact, did you know that the air conditioning filter that you replace every few months is actually for your air conditioner, not for you?  Here are a couple of articles on preventing mold in your AC unit and how to properly choose your air conditioning filter:

How Do You Prevent Mold? These 5 Tips Can Help. Air Conditioning Filter – How Dirt and Debris Can Affect Your Air Conditioning System. Before going to general quarters, it is important to rule out some other possibilities before jumping to the conclusion that you have dirty sock syndrome.  Here are a few things to rule out before calling your local HVAC contractor: If you have done these things and are still suffering from moldy, noxious smells when your air conditioner kicks on, then it might be time to call your local HVAC contractor.  For information on choosing the right contractor, make sure you take a look at: How to Choose a Contractor – 5 Tips You Must Know. The short answer is, it depends.  Usually the answer is no, dirty sock syndrome is not dangerous.  Dirty sock syndrome is caused by a variety of bacteria and mildews, none of which are harmful to your health under normal circumstances (normal immune system, etc).  Where you can get into a dangerous area is if mold gets introduced into your HVAC system and begins to grow.  

Mold can be a health risk to you and your family and should be handled appropriately.  Don’t go crazy just yet though – as a general rule, the CDC reports that most molds are only mildly toxic to humans and that symptoms in even heavily infested homes rarely progress past chronic coughing and wheezing.  This is obviously not desirable though, so mold should be reported to your landlord or properly handled as soon as possible.  After I just got your blood pressure up, it is important to keep in mind that just because you have dirty sock syndrome doesn’t mean that you have mold, so don’t go off the deep end; just open up your system and see what you’re dealing with. Where we start to run into problems with dirty sock syndrome is if someone in your family suffers from asthma, severe allergies or has a compromised immune system (chemotherapy, etc).  For instance, my wife suffers from moderate asthma and we take mold and allergens very seriously because we have to, using only high-quality air filters and I even clean our evaporator coil once every few months (I’ll show you how to do this in the next section).  

We’ve added a stand-alone air purifier to our bedroom and a UV air purifier to the air conditioner as well just to be safe and it works pretty well for us.  You have customizable options – your household might be different, so it is worth a little looking into (if you have questions, just give us a call and ask).  Dirty sock syndrome doesn’t automatically mean that you have mold, but it does mean that your AC unit is providing the right conditions for mold to grow and thrive, so keep an eye on it.  We will address how to deal with it in the next section. Dirty sock syndrome isn’t usually dangerous and it isn’t going to kill you, but you should still address it if it becomes a problem to say nothing of the fact that it just plain stinks!  For more information on mold and possible side affects of living with mold, take a look at the CDC: If you have a loved one who suffers from severe allergies or from asthma, try reading up on this: How to Reduce Asthma Symptoms and How Your Air Conditioner Can Help.

The most important factor in preventing dirty sock syndrome is to make sure that you choose a high-quality air conditioning filter.  Mold, mildew and bacteria need dust and other porous substances to thrive.  Removing these from the air before they get into your coils is one of the key ways to prevent dirty sock syndrome. The second way to prevent mold and bacteria from growing on your cooling coils (called evaporator could) is to use a UV air purifier.  These air purifiers have been used in hospitals for decades and quickly kill bacteria, mold and it’s spores.  At All Systems Mechanical, we install a UV air purifier on any job where our client reports allergy, asthma problems or a compromised immune system, so it might be worth asking your HVAC contractor if you have a problem with these as well.  There are several companies on the market that make UV air purifiers, but I have always been a fan of Honeywell.  They make quality products and are reliable.  A list of their UV air purifiers can be found below:

Start by checking your drainage pan for standing water and make sure it is draining properly.  You can buy dissolvable tablets at a hardware store or online that will keep these drains clear.  After ruling out the drainage pan and other possible contributing factors, you should start by adding the preventative measures listed above (quality air filter and UV air purifier) as these are key to keeping it from coming back (what’s the point of cleaning it if it is just going to be back in a few months).  Then, you’ll have to clean your evaporator coil to get rid of the dirt, mold and bacteria that is already there – here’s how: Is dirty sock syndrome dangerous?  Not usually, but it can be annoying and downright embarrassing.  After all, who wants their house to smell like a locker room?  These smells and odors are a direct result of the mold and bacteria that can collect in your air conditioner, but there are several ways to prevent and treat them.  If something your contractor is telling you doesn’t seem quite right, or you need a second opinion, consider using our Online Air Conditioning Consultation Service.