Category Archives: Clogged condenser

Air Conditioner Efficiency = Clean Condensor and Furnace Filter!

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Cottonwood season and spring in general can be brutal on your outdoor air conditioning unit!  This before and after picture from one of Air Mechanical’s yearly maintenance calls displays how important an annual equipment service call really is!  In our northwestern suburb region of Anoka and Washington counties (Ham Lake, Blaine, Andover, Anoka, Forest Lake) cottonwood trees are “blooming” this time of year.  Their particular brand of cotton fluff accumulates everywhere including onto your condenser.

An air conditioner needs to breath meaning a proper flow of air is necessary to keep your system working efficiently.  If the area where warm, indoor air is clogged; like this before picture; the fan motor on your furnace will be working very hard to push out that warm air through all of this gunk.  Eventually, the motor will wear out prematurely.

Similarly, your furnace filter should also be relatively clean and free of debris for the same reason.  A build up of debris causes the furnace to work harder to move the air inside your home.  This raising of static pressure is damaging to your equipment and causes a real dollar loss in utility dollars.


Two simple things to ensure optimal efficiency and life span of  your heating and cooling equipment:

  1. Have your equipment professionally cleaned and maintained annually (furnace in the fall, air conditioner in the spring).
  2. Change your furnace filter regularly.  (Generally monthly for a 1″ filter, quarterly for a 4″ filter.)
cottonwood on condenser

Is your a/c unit clogged with cottonwood seeds? Keep your condensor clean to increase efficiency

The cottonwoods are blooming all over the north Minneapolis metro region:  Anoka, Blaine, Andover, Ham Lake, Coon Rapids are in a blizzard of white fuzz.  In addition to this cottonwood “snow”; our recent Minnesota storm activity have driven oak bloom, maple whirligigs, leaf particles, bugs, sticks and all kinds of flotsam onto our yards, driveways, gutters and into our outside air conditioning units!  Besides being a mess, this can be quite damaging to our air conditioning system and at the very least, cost you utility dollars as your unit loses its efficiency

If you are an Air Mechanical Preferred Customer Agreement customer, your air conditioning condenser (the unit outside) has been professionally cleaned along with the rest of your system.  HOWEVER, after this cottonwood blizzard (is it just me or does it seem extra-flurrious this season?!) you will want to spend a few minutes to make sure to clean out those pesky seeds and fluff that have been flying around your unit this spring.  If too much of this debris gets sucked into your condenser, it will slow down the air flow over your coil, cause the condenser to work harder and eventually wear it out.  A few minutes of prevention could save you the inconvenience, discomfort and expense of a burned out blower on a humid 90 degree Minnesota summer day.

While on your Preferred Customer Agreement Maintenance service call, your Air Mechanical Service Technician will remove the unit’s cover and clean your condenser from the inside out. A condenser sucks outdoor air in toward its center, along with anything else in it’s path.  It then expels the air out the top. A thorough cleaning by a technician will remove a year’s worth of debris in a professional manner.  However, to clean the cottonwood seeds and fluff that have arrived since your AMI technician, your garden hose will do very nicely.  First, try to direct the spray along the bottom where hopefully the seeds have fallen, and they should wash right out from under the condenser.  Then try to wash off the accumulated fuzz on the outside of the condenser. 

You can keep your heating and air conditioning system working efficiently:

  1. Change or clean your furnace/air cleaner filters regularly to ensure optimal air flow.  (You can even sign up for filter reminder emails at the link above.)
  2. Keep your outdoor condensing unit clear of debris to ensure optimal air flow.
  3. Have your heating/cooling/indoor air quality system professionally maintained yearly.

Three simple things you can do to keep your utility costs low, extend the life of your equipment and most importantly, ensure a healthy and comfortable indoor climate system for your family.

Andover, Blaine and Ham Lake Residents: Air Conditioner Freezing Up or Not Cooling Properly During the Heat Wave?

It is HOT in Andover, Blaine and Ham Lake, Minnesota! Your air conditioner is running overtime to cool your house.  An extended heat wave with temperatures in the 90’s like we’re experiencing over the 4th of July week will expose your system to any weakness and the potential for a freeze up in the coilAir conditioner “freeze up” is a relatively common but preventable problem.  It is caused often by a restriction of air flow over the evaporator coil, the unit inside your house installed above the furnace.  The coil does not receive enough warm air from the blower to cool and begins to freeze the condensation before it can drain away through the plastic hose attached to your furnace.  Since the coil is sealed inside your plenum, a service technician that is EPA certified to handle refrigerants would be needed for a repair.  BEFORE that happens, here are some tips to give your air conditioner every chance to perform well, avoid expensive service calls and keep your family cool during this week of 90 degree heat!

Things YOU can do to help your air conditioning run optimally during the heat wave:

  • Have both your heating and cooling systems checked yearly by a qualified Service Technician.  This is the best thing you can do to prevent breakdowns during a heat wave.
  • During extreme heat conditions, it is less stressful on your system to keep your thermostat set at a consistent temperature.  It is more energy efficient for your air conditioner to MAINTAIN your home’s temperature at a constant rather then COOL DOWN an overheated house.  Think of a car and gas mileage:  you burn less fuel on the highway driving at 65 mile per hour rather than accelerating and de-accelerating in the city.
  • Make sure your air cleaner or furnace filters are absolutely clean so as not to obstruct air flow.  If they are dirty, replace as soon as possible. Furnace filters can be ordered and delivered right to your door!  This is the number one reason for restricted air flow to furnace causing a freeze up in the coil.  It is absolutely, 100% avoidable by changing your furnace/air cleaner filters on a regular basis.
  • Make sure all registers and return air vents are not blocked by furniture, boxes, toys, books, backpacks, etc.  Air flow is crucial for your air conditioning system to work optimally.
  • Make sure condensate line (the plastic tube running out of the sheet metal in front of your furnace) is free-flowing and free of clogs.
  • Keep shades drawn during the day to minimize solar heat.
  • Open doors as little as possible and close them immediately to prevent heat loss.
  • Cook outside on the grill!  Try to run your stove/oven as little as possible to keep your house cooler.
  • Use dryer and dishwasher at night when it is cooler to reduce the heat load on the air conditioner.
  • Make sure your outdoor condensing unit is free from debris such as overgrown shrubs, lawn clippings, mulch and dirt around pad.  The outdoor unit is equally important and needs proper air flow to remove the heated air from your home.


The very best thing you can do to keep your air conditioner working optimally during the hottest days of summer is to have your system checked yearly by a certified technician.  Most larger, progressive heating/cooling companies have yearly maintenance agreements available to their customers which has many benefits.  The amount you spend on a Preferred Customer Service Agreement can pay for itself in many ways by:

  1. Prevention is ALWAYS better then an expensive emergency service call!  A yearly checkup on your equipment can catch problems before they cause a breakdown of your air conditioner.  Invariably, that weak or worn-out part will break during the hottest days of the summer ….right when everyone else’s system has failed!
  2. You will extend the life of your system when maintained on a yearly basis.
  3. You receive 15% savings on all parts that need replacing.
  4. You will receive priority service if your equipment does break down.  Being a PCA customer automatically pushes you to the top of the list when we are over-loaded with a/c calls!

There is not a heating/cooling company who can staff for the temperatures we are experiencing this week.  Although the service technicians work hours and hours of overtime, there is still a backlist of customers waiting for service on their broken-down air conditioner.  You can be one of the smart ones who has consistently cool indoor air by having your system serviced and maintained BEFORE it is hot out!  And here’s a cooler thought …. it won’t be too many  months before the temperatures reverse and it is below zero.  These temps put stress on your furnace just like the heat is stressing your air conditioning equipment right now.  A full Preferred Customer Service Plan will ensure you year-round, consistent comfort and a long-lasting system.


Clogged Air Conditioner? Simple maintenance tips for keeping your air conditioner condenser outdoor unit clog-free.

Does your air conditioner condenser look anything like this?!

Air Conditioner Outside Unit completely clogged with debris

Does your a/c unit look like this?

There is no way air could circulate properly through this debris-clogged condenser to take the heat out of your home. The condenser and compressor are located in this outside unit and work together with the inside coil to remove heat from your home. There are many working parts inside that outside unit and un-restricted air flow is vitalto the cooling process!  High efficiency air conditioning systems of today are especially sensitive to proper maintenance and optimal air flow to save you energy dollars.

Air Conditioning System

In Ham Lake, Minnesota, there are a variety of cottonwoods, dogwoods, maples and other “messy” trees that emit all kinds of condenser clogging chaff. When mixed with ordinary grass clippings, dirt and dust, this creates a deadly blanket that can coat your outdoor unit, completely stopping the airflow which will eventually stop the compressor and condenser from working at all. The manufacturer of your air conditioner considers cleaning the outside unit of debris to be a part of home maintenance and is the responsibility of the homeowner. A unit that is clogged by debris is not covered under warranty.

You can prevent this kind of matted coat of debris from building up on the outside of your condenser by:

  • Always mow AWAY from your condensing unit to keep grass clippings from matting the unit.
  • Keep dogs from urinating on or near the condensing unit. The acid in the urine will corrode the aluminum and copper.
  • Trim bushes and trees near the condenser to keep tree droppings to a minimum and prevent restricted air flow.
  • Keep fallen debris such as acorns, pine needles & cones, leaves, etc from accumulating on your condenser. Use a broom to gently sweep this debris away.
  • Watch landscape mulch, dirt or rock buildup around the bottom of the condenser as there are drainage ports. The condenser pad should be visible and kept clean.
  • As long as you are out checking your condenser, it is a good idea to check 
ALL of your exhaust hoods for air-flow clogging debris. Birds like to nest in those warm dryer vents!
  • Change your furnace filter, air cleaner filter or clean air cleaner cells to maximize air flow and indoor air quality.  This will also trap any debris that makes it inside your home.  Remember that your air conditioner is part of your entire indoor air quality system and that the parts all work together to create the best and healthiest indoor air for your family.

Some debris will eventually get inside your unit no matter how vigilant you are. You can see in the picture above, that there are many working parts to your outside air conditioning unit.  (Additionally, there is an evaporator coil on top of your furnace that is part of this system.) Cleaning and maintaining the inside of this unit is best done by a qualified and EPA certified HVAC technician trained to handle all refrigerants. Once you remove the outer cover of the outdoor unit or air conditioning condenser, you are exposing yourself to 240 volts of electricity. The inner workings of a condenser are under pressure and any puncture can cause a leak of refrigerant leading to costly repairs. A once yearly maintenance check-up is all that is needed to keep all the parts of your system working properly.  Enjoy a worry-free summer of comfortable indoor air with a properly running air conditioning unit!