Low ambient kit ICM325h.______ $125.00
Misc. ________________________NC.
Labor 1 hour __________________$65.00
Total________________________$180.00
The following is a response to a question sent to me over the
internet about a frozen coil and a clogged drain.
I like to get into detail. This will explain most situations
where something ices up.:
Many times the situation develops where the indoor coil also known as the evaporator (in a/c mode) freezes up. the following is a list of reason with explanations. If you are being sent this report it is because this has been a problem or is now. corrective measures either have been recently made of must be made. Good luck Scott Meenen http://toad.net/~jsmeenen mailto:jsmeenen@toad.net
A frozen evaporator has absolutely nothing to do with an overflowing
or clogged drain. The evaporator will condense moisture from the air and
it will run off the coil, and it will go where it may. If the drain is
free and the pan doesn't leak, then "great". If not, you will have a flood.
The refrigeration system doesn't care whether the condensate
goes down the drain or floods the attic and causes the ceiling to
collapse. It will keep right on cooling. However, most attic installations
will have an emergency drip pan with a drain over a window.
The refrigeration system is loaded up (gets its heat from) air passing
over the coils and moisture, condensing. The more moisture condenses the
more work the system does and the warmer the coils get. The more air flows
across the coils, the more load on the system.
These things will cause the indoor coil to ice.
1. Not enough load on the coils for the size
(btu/hr or tonnage) of the system, i.e.., clogged filter, too slow a fan
speed, too low indoor temperature with LOW indoor humidity, restricted
ductwork, the indoor coil being clogged with dirt or any combination thereof.
2. Refrigerant not being metered into the
indoor coil properly. Which will grow ice, i.e.., system is short of refrigerant
due to a leak or never being charged properly from the get-go, clogged
or improper metering device, (TEV, capillary or orifice) low head pressure
caused by low outdoor temperature, low head pressure caused by low indoor
load, such as a dirty coil (this is a wicked cycle, aggravated with capillary
or orifice feed).
3. Trying to run the unit in air-conditioning mode when it is too cold
outside. This condition causes very low head pressure and poor refrigerant
flow to the indoor coil, causing ice to start to form. Once ice starts
to form the head pressure will fall even more and the coil will soon become
a block of ice and risk slugging the compressor with liquid refrigerant.
The solution is to add a low ambient kit to the unit if it is
to be operated when outside temperatures are below 65 degrees F.
In general, a properly operating a/c system will never
ice unless you intentionally cause the coil to run cold to try to strip
moisture.
Or, by design, it runs cold.
This practice is great for humidity removal but hurts efficiency.
Full airflow is great for cooling efficiency but if the
coil runs above or near dew point then little or no moisture will be removed.
NOTE: If the coil should become iced, the process
of defrosting the coil can cause a large portion of ice to fall off the
coil and crash into the unit. When this ice melts it will make a mess.
This is often mistaken for a leak or a clogged drain.
SURPRISE: If the coil is filthy~dirty and should
happen to freeze up, when the ice falls off, it can take the dirt with
it. Then, when the coil is pulled out for inspection, it can look 'factory
new'.