DIY Home Improvement Forum banner
1 - 20 of 20 Posts

· Registered
Joined
·
146 Posts
Discussion Starter · #1 ·
What is the lowest temperature for running a heat pump in AC mode? I'd like to do a foam cleaning of the evaporator coil after a careful vacuuming. The temperature will be around 60° during the week.
 

· Hvac Pro
Joined
·
25,212 Posts
You can run them down to 50 deg F but you need a good steady load of 70 deg F in the house. In the colder climates we use a 50 deg F low ambient temp cutoff control. Make sure you rinse the coil with fresh water so no soap residue is left and check the drain port from the coil for blockage last.
 

· HVAC / Plumbing
Joined
·
1,801 Posts
What is the lowest temperature for running a heat pump in AC mode? I'd like to do a foam cleaning of the evaporator coil after a careful vacuuming. The temperature will be around 60° during the week.


You shouldn't have to run A/C to clean the coil.. For evap. coils I use a self rensing cleaner. I may take a sprayer & spray it with a little water If it's not used for a few days
 

· In Loving Memory
Joined
·
42,671 Posts
You shouldn't have to run A/C to clean the coil.. For evap. coils I use a self rensing cleaner. I may take a sprayer & spray it with a little water If it's not used for a few days
If you wash the coil, and don't rinse, or run the A/C to rinse it.
The cleaner can become covered with dust, and not rinse right later, when you use the A/C.

Causing more headaches.
 

· HVAC / Plumbing
Joined
·
1,801 Posts
If you wash the coil, and don't rinse, or run the A/C to rinse it.
The cleaner can become covered with dust, and not rinse right later, when you use the A/C.

Causing more headaches.

Know what you mean.. Cleaned 1 this am. Alot of cat hair..Pulled the stuff off in shests. Then I used self rinse coil cleaner to Clean then run a/c
 

· Registered
Joined
·
146 Posts
Discussion Starter · #8 ·
If you wash the coil, and don't rinse, or run the A/C to rinse it.
The cleaner can become covered with dust, and not rinse right later, when you use the A/C.

Causing more headaches.
I plan on using the CAL-SPRAY "evap foam no rinse" evaporator coil cleaner. After spraying the evaporator coil, how long should I wait before turning the AC on to aid in rinsing? How long of a run time before the coil would be deemed fully rinsed?
 

· In Loving Memory
Joined
·
42,671 Posts
Before you use foaming spray.
better have some plastic. Yo prevent it from running on to the furnaces HX.

It tends to over flow the drain pan.

How long to let it on, depends on how dirty the coil is.

10 to 15 minutes run time, depending how humid the day is.
 

· Registered
Joined
·
146 Posts
Discussion Starter · #10 ·
Before you use foaming spray.
better have some plastic. Yo prevent it from running on to the furnaces HX.

It tends to over flow the drain pan.

How long to let it on, depends on how dirty the coil is.

10 to 15 minutes run time, depending how humid the day is.
The coil sits under the blower and above the filter rack. I have already vacuumed and brushed the coil and the fins don't look overly dirty. What would be an average foam spray set time according to this information? This Friday will have temps in the low 70's with relative humidity over 50%. Am I right to assume this would be an ideal time to run the heat pump in AC mode to aid in rinsing the coil?
 

· In Loving Memory
Joined
·
42,671 Posts
It should be a good time.

Can't predict how long it will take to clean, from a descrition.

What you call not overly, may be pretty bad.

You may be surprised at how much dirt is inbetween those fins.
 

· Registered
Joined
·
146 Posts
Discussion Starter · #12 ·
I cleaned the evaporator coil with CAL-SPRAY, http://www.acmeref.biz/public/acmepu...l_evapfoam.pdf "evap foam no rinse" evaporator cleaner. After much research, I found that the proper way to clean the evaporator coil for my upflow heat pump was from underneath the A-Frame. The outdoor temp was 75° and ideal for running the AC for thirty minutes to rinse the coil after applying the no rinse foam spray (allowing 10 minutes for foam to set on the coil). I went one step further by utilzing a garden hose to thoroughly rinse the evaporator coil from underneath. Done!
 

· In Loving Memory
Joined
·
42,671 Posts
One quick question.

Has anyone added refrigerant to the system i the last couple years.
 

· In Loving Memory
Joined
·
42,671 Posts
Lots of techs gas and go systems that have dirt indoor coils. Because they are either too lazy to clean the coil, or don't know any better.

But, after the coil is cleaned, it can hurt the compressorif its over charged.
 

· Hvac Pro
Joined
·
25,212 Posts
And the flip side that I have seen a LOT, is when the condensor coil is washed, it then drops the head pressure and suction pressure and shows that the system is undercharged. Why some people won't spend less than $100 to get a check and catch problems AND save energy is beyond me.
 

· In Loving Memory
Joined
·
42,671 Posts
I know what you mean.

They clean their coils. First time in 10 years.
Because they're tired of the high cooling bill for the last 6 years.

And then after it runs and becomes a block of ice.
Call you out, and complain about how much it cost to thaw the coil, find, fix the leak, and recharge the system.
 

· Hvac Pro
Joined
·
25,212 Posts
I got fooled by that once and only once when I was a junior tech. Pressures fine but only 10 deg drop across coil. Plugged condensor simulated a load on the unit and gave me proper pressures. Plugged evap coil can be misleading also. Impossible to talk my junior techs thru all the different scenarios. Nothing beats experience.

Cheers
 

· Hvac Pro
Joined
·
25,212 Posts
Actually it is a bit slow now. What is west of Toronto> Hamilton (too smelly LOL). They doubled the size of the Red River Floodway so we are okay. Going to be hordes of mozquitoes if it stays wet, oh Joy!
 
1 - 20 of 20 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top