Hi Everyone! I was recommended this site by a co-worker after discussing some of my recent HVAC issues…
I’ve read through some of the recent posts, looking for answers, and while I’ve seen some that are similar, haven’t really seen a post related directly to my issue…
Details: I live in Charlotte, NC (where the summers are HOT and the winters are cool/cold), in a fairly new (9mo old) townhome (brick exterior, minimal windows), roughly 1,200 sqf, 2 bedroom (upstairs) 2.5 bath (one in each bedroom, ˝ bath located downstairs).
System Configuration: The HVAC unit is located in the attic. Upstairs is fed by two “main” ducts, one to each bedroom, controlled by a manual damper. In addition to the two main ducts, there are also smaller lines, to each of the following: master bathroom, master closet, guest bathroom, and guest closet. Downstairs is fed by one large line, and is split into three lines, one in the kitchen, one in the dining room, and the last (and furthest) in the living room. The unit is controlled by a digital thermostat, located downstairs, in a central location.
Issue: Unlike the typical issues I’ve read here, and discussed with others, my issue is that upstairs is cool, and downstairs is warm/hot.
Steps to Resolution: The HVAC contractor came out and adjusted the dampers to limit the airflow upstairs, resulting in more downstairs, made sense to me!
He suggested that this might need to be adjusted throughout the year, as once it began to get warm, we would want more airflow upstairs rather than downstairs, b/c naturally heat rises, cool air falls, so downstairs would be comfortable and upstairs would be warmer. Again, made sense to me…
Unfortunately, I have been unsuccessful with balancing the system. The dampers upstairs are about 25% open, which keeps upstairs comfortable, actually a little cool. Any less and upstairs gets too warm for my comfort level. My assumption is that the remainder of the air would be going downstairs, but this doesn’t seem to be the case. Downstairs is on average 7-10 degrees warmer than upstairs. I’ve tried closing the upstairs dampers, assuming that ALL of the air would be forced downstairs. This has resulted in a warm upstairs, and a warm downstairs.
The HVAC contractor has come out SEVERAL more times and has suggested that the system is operating normally, which I’m not convinced of. I would like to have the inside temperature maintain at 72 degrees, upstairs and down, which would seem reasonable with properly adjusted dampers.
I’ve been told that it is best not to install a programmable thermostat, and to set it on your desired temperature and do not touch it. This is exactly what I have done. The thermostat is set at 72 degrees, and in the morning, the house is fairly comfortable. As the day warms up, the inside temp rises, and rises (while the system continues to run). By noon downstairs is typically 74/75 and upstairs is roughly 70. By 5:00 PM, downstairs is 75/77 and upstairs maintains at 70. The system runs pretty much all day long, and into the evening. Sometime around midnight, shuts off for the night.
The temperature from the vents downstairs is about 63 degrees, which appears to be pretty good, however the airflow is barely noticeable. While the airflow upstairs is extremely noticeable.
This has brought me to the conclusion that there is something prohibiting the air from freely flowing downstairs.
The HVAC contractor disagrees. They have suggested that I have a zoned system installed, controlled by electric dampers, with an additional thermostat upstairs. At first this sounded like an excellent solution, however after thinking it through, I am still not convinced that would resolve my issue.
Question: Given my current configuration and issues – would a zoned system resolve my issue of a warm downstairs, and a cool downstairs?
Based on my limited knowledge and understanding, I disagree that it would. I make this assumption based on my experience with closing the dampers upstairs, forcing the cool air downstairs, which did not work, and I ended up with a warm house, down/up.
Could there be either a leak or blockage in the main trunk going downstairs and/or in the distribution box? I assume the HVAC contractor would rather not go there b/c in order to access these items, a lot of drywall would have to be removed/replaced. The system is under their full warranty for another three months, and I would like to have this issue resolved before the warranty expires.
Sorry for the LONG post – my intention was to provide you (the experts) with as much information as possible w/o having to go back and forth. I do look forward to hearing back from you all!