residential a/c efficiency help for dummies
residential a/c efficiency help for dummies
(OP)
I'm an HVAC dummy...help.
The unit that sits outside of my house with the big fan it it...is that the condenser (compressor)? Anyway, it's surrounded by radiator fins and the large fan draws outside air across these fins and exhausts out the top. I'm guessing the air flow across the fins cools some fluid - freon?
Anyway, today its over 100 deg F outside so the air being drawn in is already hot. If I set up a water misting system so that it wets down the fins, will this "help" my a/c system?
Thanks everyone for your help!
The unit that sits outside of my house with the big fan it it...is that the condenser (compressor)? Anyway, it's surrounded by radiator fins and the large fan draws outside air across these fins and exhausts out the top. I'm guessing the air flow across the fins cools some fluid - freon?
Anyway, today its over 100 deg F outside so the air being drawn in is already hot. If I set up a water misting system so that it wets down the fins, will this "help" my a/c system?
Thanks everyone for your help!





RE: residential a/c efficiency help for dummies
That is pretty high temperature for a condenser. (That is condenser you are talking about and it will extract heat from freon gas and makes it liquid which is called a phase change) Certainly the cooler the air temperature the better the efficiency. Try putting water elsewhere before condenser instead of forming water film on condenser fins. But before that check your wet bulb temperature.
Regards,
Truth: Even the hardest of the problems will have atleast one simple solution. Mine may not be one.
RE: residential a/c efficiency help for dummies
However, if you continually spray water on it, a couple of problems will likely occur. The first is increased dust, fiber, etc. accumulation on the coil. This will block airflow, but can be easily removed. The second is if you have hard water, you can form mineral scale on the condensor. This will insulate the coil and prevent heat trasfer. It will also be very difficult to remove by any means that won't also damage the coil. :(
Your best bet is probably to use the garden hose to clean the coil well, removing any dust, lint, or vegetation on it, but don't leave a continuous spray on it.
RE: residential a/c efficiency help for dummies
p.s. - afterthought - refrigerant type plays a role also. 110°F might be plenty cool to operate condensers for some types of units...
RE: residential a/c efficiency help for dummies
I want to spray "conditioned" water on the coil intermittantly regulated by monitoring the evaporation. Once sprayed for a defined duration the temp should cycle form high to a low and then begin rising at which point I will spray the coil again.
As you mentioned the wetbulb temp will determine how much of a temp dip occurs and the duration of the dip.
The conditioned water will come from a reverse osmosis device to remove all comtaminants. Yes from time to time I will have to clean the coil from the inside.
Does anyone see a kink in my logic?
RE: residential a/c efficiency help for dummies
This sort of arrangement is much cheeper.
Regards,
Truth: Even the hardest of the problems will have atleast one simple solution. Mine may not be one.
RE: residential a/c efficiency help for dummies
Regards
RE: residential a/c efficiency help for dummies
RE: residential a/c efficiency help for dummies
RE: residential a/c efficiency help for dummies
RE: residential a/c efficiency help for dummies
Typically in evaporative condensers, the air is forced in from below the coil, and excess water is caught in a pan.
Also, as mentioned previously, I would be extremely cautious about the build up of dirt & mineral scale.
RE: residential a/c efficiency help for dummies
Your logic is correct, but unfortunately all of you efforts probably won't make your townhouse noticeably cooler. Nominal Capacity of A/C compressors are rated at a 45 F evap temp and a 130 F condensing temp. The 130 F condensing temperature corrsponds to a 100 of 105 F design ambient air entering the condenser. A decrease in condensing temp increases compressor capacity, and power consumption. However, that is only when you consider the compressor by itself. Residential A/C systems are designed for low first cost, there isn't a whole lot of wiggle room in the system sizing. To make a longer story longer, you may reduce the condensing temp, but because of the sizing of the rest of the system, you won't significantly increase the capacity of your system. You probably will draw less power, but at the cost of water, and the a forementioned risk of wrecking the coils and fan. Evaporative cooling pads can "precool" the air, but they also give you a static pressure drop penalty that will reduce the airflow. Unless you have super low wet bulb temp, the benefits are canceled out by the cost (I have tried this, only worked on a system I built in Las Vegas).
BTW- The unit outside is called a "condensing unit" (compressor/condenser package.)
If your the curious type, try what you were thinking of anyway. Maybe it will help a bit. Makes for an interesting afternoon.
Clyde the Mule
RE: residential a/c efficiency help for dummies