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anyone familar with hvac zoning?

broadway

New Member
Hello everyone,hopefully someone can shed some light on this subject. I have a 2 story home with a basement approx 3/4
finished. Each level is approx 1500 sq ft. My heating and cooling unit is a Trane XV
80 two stage gas valve and variable speed blower motor along with an XL 1400 air conditioner with 2 speed motor that was installed about 5 yrs ago by the previuos owners.
The house is about 15 yrs old so I dont think the insulation is all
that bad. My problem is that about 30% of the first floor which is the
family/tv room and stair case that goes up to the 2nd floor wrap around hallway that overlooks the family/tv room has a vaulted ceiling, and the master bedroom on the 2nd
floor sits directly above a 2 car garage. It still gets extremely cold in the master bedroom, I guess

from the garage ( We live in NJ so it can get pretty cold ). I had
installed an R-30 in the attic on top of the existing R-19, so the
combination of the two should be good. I am also going to remove the
ceiling in the garage and do the same (this should help with the
bedroom), and go for 2 new and well insulated garage doors.I am going to assume ( yes I do know the ass out of you and me saying ) that the unit that was
installed is sufficent. I did do some homework and found that the 2nd
stage wasnt even hooked up, not even a jumper, so I jumped the
terminals and the 2nd stage comes on after a delay of about 10 min.
There was a big difference in the fan speed and made somewhat of a
difference in the heat. Would it be worth putting the 1st and 2nd floors on two zones? I would like to lower the upstairs temp during the day and lower the downstairs temp at night. We keep all the vents in the basement closed because that space is rarely used. I have all the access to both main feeds in the unfinished portion in the basement and I can "do it myself", also would wrapping the ductwork also be worth it? Sorry for the long story, but I wanted you to have all the information to base your answer. Thanks for any info on this subject
 

pete

Active Member
. . . sounds like your in good shape, the 2 stage equipment is what most people lack when they decide they want to zone their system . . .

. . . adding the insulation and wrapping the duct will both be benificial, especially if the equipment is marginally sized (do you know the BTU ratings?) . . .

. . . you mentioned "two main feeds" . . . is this supply and return duct, or seperate supply runs for each floor ? ? ?

. . . are you able to determine, get to and work on, the duct where it splits for the different floors . . . you'll need to install dampers & actuators . . .

. . . you might want to consider three zones . . . up & downstairs, with the master bedroom it's own zone as well . . . because of it's different heat loss, if you put a t-stat in the master BR the rest of space might over heat , or visey versy if you locate the t-stat in, say, a hallway . . .

. . . the zone controller will listen to the t-stats, then open the appropriate damper and light up the 1st stage when one zone calls, and the 2nd stage and dampers if 2 or more zones call . . .



Pete C

I love my country, but fear my government.
 

markthomas

Active Member
I had part of my Master Bedroom over the garage. Insulating the garage ceiling and replacing the garage door with a top-of-the-line insulated one made a BIG difference. You may find that to be enough.

offtopic, but FYI: we used a Wayne-Dalton door with TorqueMaster torsion bar and had an iDrive installed. That thing was great! No more noise in the bedroom above the garage when the door opened! (it's in the past tense because I moved to a house with three individual garage doors. We decided to save money and get belt drives instead. Big mistake! They're not nearly as quiet as the iDrive--I miss it.)
 
Do you have more than one furnace and A/C pair? 4500 sq ft seems like a bit much for one split system to handle. You should probably check the specific model numbers for those units to see if they are are the correct size for your house.

If you just have one split system, I would look into a 4 zone controller with a thermal equalizer. You can put your basement and first floor on their own zone. The basement can be set to a wider temperature range. The second floor would have 2 zones (one for the master bedroom and one for everything else). The Thermal equalizer anticipates heat rising from the first floor, so the second floor doesn't become over heated. Zoning it this way should improve comfort and reduce your energy cost.

The multistaged furnace and A/C will help you in your zoning effort. You may still have to install a bypass zone. I'm currently researching zoning my system and will try to post a starter guide in the next few weeks.
 

broadway

New Member
You guys rock, the most helpful bunch of people on any of the chat rooms that I have been on, thank you very much. Here are some answers to your questions. The 2 main feeds are the one for the 1st floor/basement and one for the 2nd floor, the return is also right there. As far as access to the bedroom duct above the garage, I will have access to the branch off the main when I remove the ceiling in the garage to add more insulation. I guess it would be wise to install an access hatch for the damper just in case. Thanks for the 3rd zone idea in the bedroom. Thanks for the heads up on the garage door and opener, I have 2 doors, 1 that is broken and the other that sounds like a 747 and wakes up the entire house. I have 1 furnace and 1 a/c unit, the specs for the furnace are 65,000 BTU 1st stage, 100,000 Btu 2nd stage and the a/c unit is a 3 ton unit. As far as zoning the basement seperately my problem is that 1 main feeds both floors, the basement vents are cut directly into the main and the 1st floor has 6 different branches off the main which would mean (correct me if I'm wrong) 6 more dampers. I'm not trying to go cheap or dodge work but what if I bought a 4 zone controller, just kept the basement vents closed and used the 3 zones ( 1st floor, 2nd floor and master bedroom) for now and I could always zone the basement down the road. Has anyone with good basic construction skills and good low voltage skills( I install automatic doors and elect locks so I deal with motors relays and trans. on a daily basis) done any work like this? I'm never afraid to take on any project as long as I do my homework and with the help of this web site makes it so much better. I have also heard that installing a system like this lessens your furnace and a/c life, is that true? Thanks again for the support.
 
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