Why You Should Clean Your Evaporative Coil (If it’s Dirty)

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Neglecting to keep your evaporative coil clean (along with your air ducts), is always going to result in one of three bad options:

  1. Expensive air conditioning repairs
  2. Having to replace your air conditioner
  3. Wasting money on higher energy bills

Most people have never heard of an evaporative coil, and have no idea what it is or where to find it. Your evaporative coil is one of the components of your air conditioning system, and it sits just above your furnace. Some coils are contained inside it’s own case, and others are held inside a hand-fabricated sheetmetal compartment called a plenum. There are coils inside, much like the radiator coils in your car. The evaporative coil gets very cold when your air conditioner is running, and then the blower in your furnace pushes air through the coils and out into the ductwork into your home.

Dirty Evaporative Coil Will Cause Expensive Repairs

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Accessing the evaporative coil is usually very difficult and time-consuming, even for experienced HVAC professionals. That’s why evap coils aren’t usually cleaned as part of the regular maintenance on your HVAC system. If your air ducts are dirty, particles of dust can make their way past the filter where they end up coating your evaporative coil.

Here in Denver, a dirty evaporative coil is very likely to freeze or ‘ice over.’ The inside of the coil becomes a solid block of ice, and this can damage the compressor inside your air conditioning unit.

If you’ve ever had to replace the compressor in your air conditioner, you know it’s very expensive. You can expect to spend $2,500 – $3,500 to have any of the well-known, reputable air conditioning repair companies here in Denver replace your compressor. Even if your compressor is technically still covered under warranty, the manufacturer will deny the warranty claim because you neglected to maintain your system by keeping the evap coil clean. So you’ll end up footing the entire bill for the new compressor.

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The financial pain caused by a dirty evaporator coil doesn’t end there however. You will still have to have your dirty evaporative coil cleaned in order to keep from voiding the warranty on that expensive new compressor.

So no matter what, you’ll have to get that dirty evaporative coil cleaned eventually. You just have to decide whether you want to have the coil cleaned before it causes expensive damage to your air conditioning system.

A dirty evaporative coil can also damage the blower motor in your furnace in much the same way a dirty furnace blower will. A dirty evap coil causes the blower motor to work harder to push the required volume of air through the coil, and this over-taxing of the blower motor will eventually cause it to fail. Having a reputable furnace repair company in Denver replace your blower motor will cost at least $1,000, and if your furnace has a variable-speed fan, replacing the motor can cost in excess of $2,000.

Dirty Evaporative Coils Cause Early AC Replacement

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If a dirty evaporative coil ruins your compressor, and you air conditioner is more than 7 or 8 years old, you’ll probably end up just replacing the air conditioner altogether. Most of the time, it doesn’t make sense to dump $2,500 – $3,500 into an old air conditioner. In this situation, replacing the entire air conditioning system is the best of two unpleasant options. If you want to have any of the top reputable air conditioning companies in Denver install a new air conditioning system for you it’s going to cost at least $5,000 and as much as $10,000 depending on your home, the type of air conditioner you have, and the company you choose to install it.

That’s a huge expense, and it could have been easily avoided by having that dirty evaporative coil cleaned before it damaged your system.

Dirty Evaporative Coils Cause Higher Utility Bills

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When your evaporative coil gets coated with dust, the system has to work much harder to maintain temperature levels inside your home. Your air conditioner will run longer, and turn on more frequently, which results in wasting a considerable amount of money on higher utility bills.


It can be a very difficult job to remove and clean your evaporative coil, but fortunately it’s not the kind of thing anyone would consider a do-it-yourself project. So if you’re already considering having your air ducts cleaned, have the technician take a look at your evaporative coil.

IF the coil is dirty, have it cleaned along with your ducts, on one condition… as long as the technician doing the work is actually qualified to work on your air conditioner, AND has his EPA license to handle and recover the refrigerants in your system. You’ll save money having your evaporative coil cleaned at the same time as your ducts, and you won’t have to worry about that dirty coil leading to expensive HVAC repairs.

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