I am about to build a new house and have been reading as much as possible to make sure I get the HVAC/ventilation/DE-humidifacation system right. I'd like a little advice based on what I've concluded due to my reading please. I am building a 3000 sq. ft., single story home with a 'half' basement. Only about 800 sq ft. of basement will be "finished". The other areas will be unfinished store rooms.
This house is on Lake Lanier NE of Atlanta, GA. and is replacing a small, worn out cabin we have lived in for some time.
Some other details of the house are:
1. Even though it is around 3000 sq. ft. it will only have a master BR and one guest BR. Only my wife and I will be in the house 99% of the time (and the dog). We're not concerned with resell as this is where we intend to live until the end.
2. The master BR is around 400 sq. ft and has a double doorway into the main part of the house in the hall area between the MBR and her MBath. His MBath is on the side of the house and is accessed through a door off the MBR. All doors would normally be open except "his" Mbath and closets.
3. The house will have a large three car garage that will be insulated but not to the level of the house. It will be fed conditioned air but right now I have no plan to return air from it. The idea is to minimally condition it so it is not scorching hot in summer and does not freeze in the winter. Comments?
4. Since the back of the house faces the lake, it will have a lot of windows. This is the North facing side of the house which means solar gain is minimum during the summer but it gets a lot of cold wind during the winter as the house sits on a hill about 50 feet above and 400 feet from the lake. The house sits next to a protected area that is all woods and always will be. This area runs from SW to NE with 100+ foot tall trees. This shades the house and yard from about 4:00 pm or so until dark in the Summer. Most trees are deciduous so in winter there is minimal shading. In fact, all trees around the house are deciduous.
Here is my current plan with my builder (we're still in the design phase)...
1. Spray foam all walls and roof with closed cell foam
2. Build basement walls using ICFs
3. Insulate the slab/basement floor with foam board if allowed by code (still trying to find out about legality of this).
4. Seal all joints (concrete-wood interfaces) as well as possible.
5. Install a minimum of 16 SEER A/C with dual speed fan
6. Install a 90+ efficient gas furnace
7. Install Ultra-Aire XT205H to handle DE-humidifacation and fresh air.
8. Install insulated, low-e windows
9. Install only energy star rated appliances and equipment
10. The house will be brick on three sides and the front will be rock with stucco accents.
I selected the Ultra-Aire unit due to my location, which is in what some call a "mixed-humid climate" with the understanding that I will likely need to DE-humidify to remain "comfortable" during the cooling season based on the house being sealed. I looked at ERV's but I don't believe they DE-humidify anything but the incoming air, if at all. I assume I'll need more than that thus my choice. I might be wrong about this.
All HVAC and Ultra-Aire equipment will be located in the attic space which is a large space due to roof design. It will be conditioned space with closed cell foam on the underside of the roof and gable sides.
Some questions I have regarding the Ultra-Aire unit and how to best have it installed. My reading says for optimum performance and best humidity control as well as good fresh air dispersion, I should have a separate ducting system for this unit rather than tie it into the central A/C system. I'm fine with spending the money to do that if that is indeed optimum. The House is very open with the Kitchen, DR, LR, BfastR, and FR all open - no doors. If I read correctly, I should make sure the unit is installed with feed air going to the bedrooms and family room and pull air out of the large central space - dining room, foyer, and living room. I'm not sure how many vents/returns and exactly what size these feeds/returns should be for best performance.
I also read that it is usually best to directly vent the bathrooms and kitchen to the outside. Should the operation of these fans somehow be tied to the Ultra-Aire unit to tell it to pull in more air when they are running (if possible)?
I'm trying to find a qualified HVAC company that understands how to properly size the system given this type home and insulation and supply, install and set up the equipment I've outlined here, if that is what I end up with. So far, I haven't found one yet. Email me if you know of a good one in this area (or you would like to quote it).
Thanks for any comments!