Over the years our company has been asked about best practices for cleaning coils.
- When should coils be cleaned?
- How to tell if the coils were properly cleaned?
This is the first in a short series of blogs that addresses these issues.
A primary variable that determines ones coil needs to be cleaned is the pressure drop across the coil itself. Usually, higher pressure drops are indicative of a coil that is fouled with dirt and/or organic growth.
Sometimes the coils appear visibly dirty, this in itself might be reason to go through a coil cleaning. Another factor is that the AC unit doesn’t cool as it should.
For example, a brand new through-the-wall AC unit, such as found in many hotels, might take 3/4 hour to drop the room temperature 8 degrees. The same unit with a dirty coil might take several hours to cool the same room. One major drawback is the unit is running several times longer to do the same work. Occupants can be dissatisfied with the slow cooling. In my own experience, I actually left my hotel room because it took several hours for the temperature to go down.
As mentioned, the unit works strenuously when it is dirty. This increased usage of power raises the electrical costs monthly. All this unnecessary work & money out of your pocket, when you have a solution as simple as cleaning the coil.
Over the past decades, we all have intuitively known that dirty coils drive energy costs up, but few know how much or if it was of any true financial consequence. Since up to 50% of a buildings electrical usage is consumed by the HVAC system, it would be good to know from actual studies how dirty coils affect your bottom line. Is it substantial or not?
Fortunately, the ASHRAE society did a complete engineering study specifically on this matter & published it in their journal.
While the results are not surprising, the affect on your bottom line is. If you do not have the article, feel free to contact us.
Drop us a line with comments, questions, suggestions, feedback on what you do with your coil. Any experiences you can comment with?
Lynn Burkhart – President of Controlled Release Technologies