Question:
Can I add water to my home air conditioner to make it more efficient?
My wife saw on Tv where they added a water mist to the air conditioner to make it more efficeny. Will this work and how do I find out more about it?
Answer:
The heat absorbed from the inside of the house by the freon in your AC system, must be discharged to the outdoors to complete the refrigeration cycle. This is accomplished with a heat exchanger on your AC unit outside. It looks like a bunch of tubes with aluminum fins on them.
What is being suggested is that by spraying a mist of water on this heat exchganger, you will make your unit more efficient. Technically speaking this is correct, because the water mist will absorb the heat from the coils more efficiently than ambient air.
There are two problems that make this idea unfavoreable. The first is that the heat exchanger has small fins on the tubes that are necessary to promote good heat transer. They are also subject to corrosion. Your household water supply will simply accelerate that corrosion. In addition, most household water supplies have calcium and magnesium hardness in the water. As you spray this water mist over the cooling coils, you will slowly precipitate a layer of calcium and magnesium on the metal fins, and this will reduce their ability to transfer heat, thus reducing the efficiency of your AC system.
If you want to insure your system is operating efficiently, be sure that it has the correct amount of freon. If you have too little the unit will have to run much longer to reduce the inside temperature of your home. Also, keep the filters clean, because if you reduce flow to the expansion coils in the attic, you will further reduce efficiency.
And finally, if you have an attic that is accessable, adding a layer of fiberglass insulation on top of what you already have will help a great deal. At today's current energy prices, they savings will pay for the insulation in just a few months.
