HVAC question

   / HVAC question #1  

Pixguy

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By the lake in NH & FL
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First, i am a fairly handy homeowner i had to be as im no Brad Pitt. ;)I roughed the new home and my brother, a licensed elec tied in the panel. Bear with my explanation.

We have a home with 2 split systems, 1 is 3 ton EMI I believe and the MB is 1.5 Bryant due to it being upstairs.

The two vertical standing condensers are next to each other outside of course and I always made sure that the leaves are cleared from behind so that it would breath properly and covered for the off season. 3 weeks ago the small unit stopped working during the night. Blowing indoors but nothing out except for an occasional buzzing. I pulled the cover off (while shutoff was pulled) and noticed that the inside of the coils were a good 1/8 thick of dust. Hmmm, why inside and not out?
While plugging in breaker bar(?) it starting to hum and the fan did not blow so I gave it a light push CCW and it started working but I could tell the condenser was not kicking on. But the fan was blowing towards the house instead of the obvious direction(to a novice). I stopped it, pushed the fan the other direction (CW) and it worked that way too.

Finally the plumber who installed it came, I told him the issues including my fan test and he came back a few days later with a new capacitor. All seems fine but I noticed today that the fan is still running CW and it is sucking air in towards the house. Is that correct? shouldn't the fan be pulling the air from the rear through the coils and away from the house, like the other unit does? Thanks for your time.
 
   / HVAC question #2  
In my experience, the fan on the condenser unit should blow out. In other words, it should blow your hair back when you put your face over it. Some are multi directional and can be switched at the fan plug.
 
   / HVAC question #3  
I tend to believe it should force the air in thru the coils, but can you post a picture of this unit?
 
   / HVAC question #4  
murphy1244 said:
I tend to believe it should force the air in thru the coils, but can you post a picture of this unit?

Most condensing units pull air thru coils, doing in essence 2 jobs in 1. Cools coils and compressor, removing the heat caused by the compressor in operation.
 
   / HVAC question #5  
Most condensing units pull air thru coils, doing in essence 2 jobs in 1. Cools coils and compressor, removing the heat caused by the compressor in operation.

Thank you for your vote of confidence.
 
   / HVAC question #6  
Most condensing units pull air thru coils, doing in essence 2 jobs in 1. Cools coils and compressor, removing the heat caused by the compressor in operation.

I would say the condenser fan pulls air through /across the coils, and cools the refrigerant that is circulated through the coils


To the op. It's hard to say (without pics) which way the fan should turn on your A/C unit. some fans turn cc and some turn ccw
 
   / HVAC question #7  
murphy1244 said:
Thank you for your vote of confidence.

I worked on residential hvac units for about 10 years until switching careers. It has been 5 years or so. Units have changed tremendously since. I left just as R410 freon came about.
 
   / HVAC question #8  
I have been a licensed HVAC tech for 28 years and owned my own business. We need pics to be sure of what the op is talking about.
 
   / HVAC question #9  
murphy1244 said:
I have been a licensed HVAC tech for 28 years and owned my own business. We need pics to be sure of what the op is talking about.

Agreed. Just sharing my experiences.
 
   / HVAC question #10  
Deerfan is correct to say most (if not all) residential condensing units blow out. It is probably more correct to say they are set up to draw though the coils, where the coils are upstream and the prop is downstream, in direction of airflow. It is possible to do this in a blow through arrangement where the coils are downstream (prop blows through coils), but I have never seen it in residential units. Not saying it doesn't exist, just haven't seen it - for sure it's not too common. If the prop is turning in reverse rotation there would be heat rejection, but not to full capacity. If the unit is fairly new there should be a rotation decal on the unit casing, the prop itself, or both. If not, a call to the unit manufacturer would clear things up.

There is also a newer prop type referred to as swept blade or swept wing, and it's not as easy to identify proper rotation at a glance. However they are usually installed in the same draw through configuration.

Any chance you could post a photo or two?
 
 
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