Designing for better heating and cooling
I am converting an existing 2-storey attached garage into self-contained living quarters with its own heating and AC. Given that a ducted system is too expensive to install I am considering heating with a natural gas stove located on the main floor and cooling with a DC inverter equipped with 2-3 separate indoor units.
http://us.sanyo.com/industrial/HVAC/downloads/catalog_pdf/27809SanyoACcatalog_10.pdf
Because the front of the garage is still used for cars, that leaves the second floor around 70% larger than the main floor. Main floor is 20 x 20, second is 40 x 13 (kneewalls account for the discrepency). My concern is about circulating the warm or cooled air properly throughout the two floors. I’ve thought of constructing the second floor rooms with walls that do not reach the ceiling, hopefully allowing for circulation. Others have suggested that standard overhead fans are sufficient to circulate the air, but I have my doubts. The main floor is one room so no problems there, the real problem is the second floor.
I’d appreciate some concrete ideas and since I am at the design phase, anything goes.
Thanks
Replies
"cooling with a DC inverter equipped with 2-3 separate indoor units."
Where are you getting the DC from?
After looking at the Sanyo flyer I think that what you are saying is that you are installing a compressor unit with a veriable frequency drive system that runs on 115 or 230 volts (depending on the model) 60 Hz AC.
BIG, BIG, BIG difference.
If that is what you are talking about then the term "dc inverter" is menaingless. What is important is the variable frequncy (speed) drive system.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Saw the "DC inverter" & went "Hunh" ,too.....
The drive systems take incoming, single phase AC and rectify it (DC), then they feed the DC to a three-phase, variable frequency inverter to drive the motor. So technically it can be called a "DC inverter"
But it is not very good quality DC.And calling it a DC-inverter makes it sound like the SYSTEM runs on DC. When I first say that I though of solar cells. And it leaves out a critical part of the SYSTEM. The rectifier.That is like saying that I have this great new car. It is driven by a veriable speed transmission.Well a car with a variable speed transmission might be a great car. But if all it has to drive the car it ain't going anyplace. It needs something to transission such as a gas, diesel, steam, or electric engine.That said VARIABLE SPEED DRIVES (not DC-inverters) are a great idea for AC compressors. I wonder when they are going to be commonly available on split AC compressors as they are now on air handlers..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Edited 6/24/2007 1:54 pm by BillHartmann
The mini-spit in my office has an inverter driven compressor. Japanese and EU manufacturers adopted variable speed inverter technology long ago. It's more energy efficient, shows a constant power factor to the AC main, and it can tolerate brownouts much better than the single or two speed motors used in most A/C units here.
Somewhere I saw in a book what looked like a good idea--instead of overhead fans, they used squirrel cage blowers at floor level that drew the hot air down from the ceiling using a tall duct, and the blower blew this out along the floor. I suppose you could reverse the process for cooling (but maybe squirrel cage blowers only work in one direction)--may need another located near the ceiling?
i'll stay out of the heating and cooling and just express concern about proper fire separation between garage and living quarters
carpenter in transition
"I am considering heating with a natural gas stove"
I hope you mean something other than a cooking stove...
They make mini splits that are also heat pumps.
"My concern is about circulating the warm or cooled air properly throughout the two floors."
A much bigger problem for you (and your lawyers) is keeping a fire separation between the vehicle/shop space and the living space, which is not possible if the spaces share the same conditioned air.
Oh, and a little thing called carbon monoxide will also be an issue.
Time to scrap those plans.