
Summertime is here and the living is easy. Except perhaps for that high electricity bill from the incessant cycling of the air conditioner. Sure, you’ve beefed up the insulation, sealed leaks and perhaps installed radiant barrier foil in the attic. But there’s more you can do; you may be able to lower your electric bills with an A/C misting system.
Can a Condenser Coil Mister Save the Day?
I have been intrigued by this concept for a while now and with the South Texas temperatures flirting with triple digits and rising utility rates I decided this was the year to implement it. I already understood the cooling power of evaporating water, having worked with cooling towers and chilled water systems while working as an Engineering Supervisor for Marriott.
But this is a different application although the basic science is roughly the same. The one I installed at my home yesterday is the Cool-N-Save basic kit. Their claim is that the mist will lower the temperature of the air around the coils by as much as 30°F. This means that your HVAC system will not have to work as hard, consequently becoming more efficient and saving you money. Have I saved money yet? I don’t know! I just installed it yesterday. But I do have historic data and I’ll update this post when I have some hard numbers.
Curious about the science? Heat flux, thermal flux, heat flux density, or heat flow rate intensity is a flow of energy per unit of area per unit of time. Call it what you will, heat flux is at its most efficient whenever the outdoor ambient air temperature is lower than the refrigerant flowing through inside the A/C coils. So the evaporative effect of the misting lowers the ambient temperature in the area around the condenser coils and bingo! Efficiency prevails.
How the Cool-N-Save Coil Mister Works

The basic kit comes with:
- 1 Control valve and paddle
- 3 2′ Misting arms (tubing from the control valve/paddle to the misting nozzles)
- 3 Brass misting nozzles
- 1 Cool Release water treatment filter (3 month life)
- 1 20′ flexible water feed line
- 1 Garden hose adapter
The only thing I added was a brass splitter with cut-off valves for my outdoor spigot so I can use the mister and garden hose concurrently.
A dedicated garden hose attaches to the supplied garden hose adapter whose tubing enters the filter. Another hose (cut from the 20′ line) connects the filter to the control valve on the paddle. The three misting arms connect to the control valve/paddle and dangle down three sides of the condenser respectively terminated by the misting nozzles. Use zip-ties in all the obvious places.
When the A/C cycles the fan in the condenser unit kicks off. This blows up the paddle and enables water flow to the misting nozzles. It’s that elementary, Watson. (Pardon the inevitable Sherlock Holmes reference.)
Regular readers of my energy efficiency articles know that I stress incremental changes; it is generally many small to large changes, not just one huge one that will reap savings. An A/C misting system is my latest energy tweak. I’ll be back in touch with results.
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