Is charcoal or the smoker at fault for low temperature smoking? I recently received a charcoal smoker for my cake day. I attempted to smoke pork ribs, here are the steps I followed. 


Cured the smoker with 2 Lbs of charcoal. (6 hours) 
Cleaned the smoker. 
Prepped 3 Lbs of charcoal in charcoal chimney. 
Put water used to soak hickory chips in the water reservoir.
Position ribs on the two racks
Once charcoal was red hot with white ash, transferred it to the charcoal pan.
Smoked for about 5 hours and temperature started dropping.
Added 2 Lbs more of Charcoal Chimney prepped charcoal.
Smoked for 3 more hours.


The problem I experienced is the temperature never went above 180F (82C), at the end of the 8 hours total smoking time, the internal temperature of the ribs sat at 120F (49C).
I ended up finishing them off in an oven set to 360F (182C) for about 25 minutes to raise the meats internal temperature to 145F (62C).

Is the charcoal at fault for the temperature?
I used: Cowboy Brand Hardwood Lump Charcoal 

Is the smoker the issue?
I used: Char-Broil Vertical Charcoal Smoker

One note, the smoker smoked from around the door to what I would think might be excessive. Should I look into sealing around the door? This smoker has no smoke stack on it's top.

Ribs turned out great either way, but finishing them in the oven caused fat to drip into the bottom of the oven and now the wife is mad because when we use it, it smokes the house.
It's the smoker. I had one of these, and it is extremely flawed in design. The pan that holds the charcoal does not allow for proper air flow to the fuel. Contrast this with a Weber grill, where you put your fuel on an elevated grate with plenty of air beneath it. This Char Broil instead just has a pan that you put on a shelf. Before long your coals are buried in ash, and barely smoldering. FWIW, if you were to attempt sealing the doors, it would only exacerbate your problem, as the issue is with not enough air, versus too much. I replaced my Char Broil with a Weber Smokey Mountain, but I had considered some hacks to make it better. Your best bet would be to ditch the pan-on-shelf system, and fashion your own charcoal grate that is elevated from the bottom of the smoker. You want something that will both allow air flow to the fuel and allow the ashes to fall away from the fuel. Then you would be able to properly manage temperatures with the air vents.