Chilled water air handlers
Does anybody know of someone who can educate me on chilled water air handlers here in Texas??
It is a box with pipes on one end and a fan on the other.
cold or "chilled water" is pumped through the pipes and the fan blows air across the pipes and into the space to be cooled.
the amount of cooling depends on the temperature of the water how fast it flows through the pipes, the temperature and humidity of the air and how fast it blows across the pipes.
Every air handler has literature that shows what all the variables should be for it to work correctly. Find the variable that is not within specifications and change it to the correct specifications.
If the air handler is sized and installed properly then you will be nice and comfy.
"Do not let what you can't do interfere with what you can do"
"Do what you can do the best that it can be done and no one will ever know what you can't do"
some safetys are freezestat, flow switch, high and low pressure, and oil.
in cold climates there is also a freezestat on the AHU
I dont warranty Tinkeritus
Generally if your control valve is 100% open you'll get around a 10 degree rise in water temp... example 43 deg inlet water 53 degrees outlet temp.
more than a 10 degree rise tells you you either have too few gpm water flow or your airside cfm is too high.... if you're getting less than a 10 degree rise in water temp..... too many gpm water flow or too few cfm airflow....
common problems are:
Air in the coil, plugged strainers, balance valves set incorrectly, control valve problems, dirty air filters, dirty coil fins, loose belts.
knowing the design GPM through the piping and design CFM on the airside is important.
Your airside temp drop depends on design but, can range between 15 to over 30 degrees drop
How can you have any pudding if you don't eat your meat?
air flow is Important
Be careful the design air flow. Most consultant over estimated the external static pressure. I saw some of them with 40% more flow than design. Then, the water and air temp. will be wrong.