It could range from relatively easy to complicated. Is there a crawl space or basement under the bathroom where you would have access to the ductwork?

Mike - The house is located in NJ in a climate zone labeled 4. The house is 2800 square feet plus a 1400 square foot unfinished basement. The house will have two HVAC systems.. The first system will run the first floor and is sized to handle the future finished basement.. The other system will be dedicated to second floor... The reason for the hi/lo as per the project manager is that the hot air should come in lower in the room so that it will rise and warm the room.. And then putting the cold air supply higher it will blow out and across the room and then get lower to cool the room.. He also mentioned that by doing this you avoid having a "draft" feel because ceiling vents will blow down onto you vs the wall vents that blow out above your head.. Theoretically what he is saying does make sense, however the placement of these vents sounds very unsightly, and again, not something I have ever seen before.. I have only ever seen floor or ceiling vents.. My thing is that the way he was saying that this setup is more money just doesn't make sense.. I would think that this is the cheapest route since you are running the duct work to the same wall cavity.. This would be compared to running floor and ceiling vents.. Unless I am mistaken that you only get one or the other.. I was under impression that HVAC utilized both floor (heat)and ceiling vents(cooling), however I was reading online and it looks now like you either do floor OR ceiling vents.. With that being said, perhaps the project manager is speaking correctly.. As for system setup goes, they are putting the second floor HVAC system in the attic.. At this point in the build and large part my fault and architect, is that there was never a section put in to have everything run from the basement.. I thought it was weird that many house plans online had an area that was blacked out or had an "X" and my plans did not.. Not being fully knowledgeable on the subject I didn't think anything of it.. Now I realize it was just that putting the system in the attic around here is just common practice so unless its specified differently you just go that route..

A two story home with one AC will always have a design challenge to over come when temps start climbing. The simple reason is mostly science and physics. Cool air falls and hot air rises. If the temp is 70 degrees on lower level, the thermostat satisfies and shuts the system off. You go upstairs and it's a balmy 80 degrees up there / some cases worse. Might be as bad as 85. The thermostat has no clue how hot it is upstairs. (Move the thermostat to upstairs and the down stairs becomes a meat locker and cooling bills require a brinks armed truck to collect your utility bill.) < means you pay for it one way or another. Comfort: no two people are alike. Some like 80 degrees some like 70. If you like 70 and you want 70 through out your house, that is either going to cost you some design dollars or a lot of frustration. Choices: The most cost efficient method is zoned AC. This is not considered cheap, and more often than not it's put in with junky control boards, has static pressure issues which will cause further damage to the system and possibly the controls. The other problem with a zone system is trying to cram too much cooling into spaces not large enough to handle it. Realize this is very scientific and relates to things you can't see such as 'air flow'. 400 CFM (cubic feet per minute) per ton of air conditioning. If you have a 5 ton air conditioner that is 2000 CFM of air per minute for a unit that size. (Size means capacity). So if you select the zone system choice, your work is cut out for you. There is a myriad of junk on the market and worse yet those junk dealers that install it because they know going in that cost is a big hurdle. (so let's install something that needs replacing every 5.5 years or so.) ----------- Another way to zone: install dedicated equipment to cool the upstairs area. The problem with this is: that most people add more AC to the home. Leave the existing system because cost is even more to have to rip this older system out and replace it too. Then the home is over cooled. The system(s) are oversized for the structure do not run properly (short cycle) which can cause a myriad of failures the worst of which is inadequate oil return to the compressor. (leads to compressor failure) Other problems with this scenario is damp musty problems develop in the home because the AC's do not run long enough to pull humidity from the home. -------- With that said: zoning for AC and heat can work. I have zoning in my own home. I don't quote zone systems on the cheap. I quote them so they will work for years and years and years with rarely any trouble. It's not uncommon for me to stumble across zone systems installed by others with myriad problems, not working properly, causing system failures and the list goes on and on. Realize I stumbled across many of these zone system problems 'before' I installed a zone system in my own home. Most zone systems rarely make it to year 6 before needing replacement. The system I installed in my home is 12 years old and still going strong. Design is very important as well as equipment that you are trying to control via a zone system. -------- what causes flooring to warp? moisture. too wet. What causes flooring to crack? dryness. too dry. With that said, I'm not a flooring expert. But these are common sense things. (an engineered wood floor product) is probably designed to over come a lot of these problems. If you bought a regular wood floor product? time will tell. Any wood product naturally expands and contracts so some of the problems with wood floors is due to installation of the product. If there wasn't enough room for the floor to expand, this can cause it to buckle (warp up & crack). I service the Katy, Texas area. Here's a video (embedded below) I made '5 YEARS AGO' covering HVAC zone systems for 2 story structures. Realize the website 'PAGE' this video points to is no longer in operation. People don't want to spend the $$ to do it right. They would rather complain about how junky things are and don't work as advertised with the cheaper junk options others sell... yada, yada, yada. I leave the video up as a 'see I told you so' type moment. The video does a good job of explaining the problem if you're unaware and curious. OR you have a similar problem with your home. Again I service the Katy, Texas area.

UV lights don't work. The volume of air passing through is too great. I suggest adding a GPS system to the unit, Global Plasma Solutions. We've done this to three of our homes HVAC systems. It takes care of any musty, moldy odors and mold in your house. Also, check the humidity in your house. You may need a dehumidifier. If humidity is too high, mold can grow. It should be below 40%. Here is another theory that needs to be eliminated. If the smell is a dirty sock smell, it can be an oil leak burning off. Is there any component of the system that uses oil or hydraulic fluid? Both smell like dirty socks and the fumes are quite dangerous to your health.