Original message
| Dann757
 |  "Heating System Design"
, posted Tue 9 Sep 18:52  
I need to install a gas furnace in the garage I'm living in. There are two rooms and a bathroom behind my shop which is 2 bays. Entire building is around 950 sq/ft. I want to heat the living area constantly and the uninsulated garage area on demand. There is about 20" crawlspace under the living area to run ductwork. Living area totals about 500 sq/ft. Ceiling insulated to r-23. Two rooms in living area are about 10' x 22'(3 windows) and 12' x 15'. (1 window) Bath is 5'x 10'.(1 window) Any ideas about BTU sizing and duct system design? I know it can get pretty involved.
|
|
Replies:
|
| drumwizard
| "Re(1):Heating System Design" , posted Wed 10 Sep 22:42:
Well I, I spent about $13,000.00 on heat and air tech school and graduated out with a 97.5 gpa and a state journeymans license. but maybe I could help you out . Lets start out at the very beginning with some questions. After you know you heating and cooling loads,and are able to select the correct size and configuration of hvac equipment, are you wanting to install the ductwork your self. and are you able to get the materials and do the job your self. if not we can skip the duct part of this job. and moove on. If so, the duct design and install will insure that your equipment selection will work past the warranty date and will function the way your wanting it to. and will insure that your system won't freeze up in the middle of the night. and will insure that you wont be frying and blowing up compressors in the first six months of operation while burning and cracking your heat exchanger and or burning down the structure that you are installing it in, and and it will insure that the system will perform on the coldest night of the winter and perform on the average hottest day of summer in the area of the united states that your in. You can see that this process is complicated and is not a job for a discriminating home owner unless you are a hvac engineer or contractor, and then you wouldnt be asking these general questions and expecting specific answers to a complicated question. NO DIS-RESPECT HERE. I UNDERSTAND WHAT YOUR SITUATION IS HERE.so lets moove on.
second of all im assuming that the garage area (non living space) is un-insulated compaired to the living area that is going to be occupuied. you will possibly need two separate zoned systems to handel two loads out of ballance with each other. your best bet is to insulate the non occupuied area so it matches BTU per Sq. foot the same as the occupuied space. In this event you may use one single system that can handel all of the total non and occ. space at the same time.... that is if you can find a spot in the space that will have a representation of the root mean square(rms) return air temprature of all the total space so as to put a thermostat in that area. If not you will need a multistage system with some zone sensors and damper controls and an air bypass circuit and zone module controller.
Any way to make is simple according to what you have posted you need a two and one half ton to three ton A/C system. and 2.5 to 3.0 tons of duct work and a 70k or 100k gas furnace. nominally. be careful not to over size as is the tendancy of most.
[this message was edited by drumwizard on Wed 10 Sep 22:48] |
| | Jojo98
| "Re(2):Heating System Design" , posted Fri 12 Sep 00:00
State Journeyman license? Journeyman certifacation is issued by the Dept. of Lobor, not the state. Nice try.
|
| Jojo98
| "Re(1):Heating System Design" , posted Wed 10 Sep 22:08
Yes, it is a very involved question and response. You could run duct for a furnance for the livimg quarters, and install a gas radiant heater in the garage. So you would only have to run gas line and exhaust.
|
| | Dann757
| "Re(2):Heating System Design" , posted Wed 10 Sep 23:46
Hey drumwizard, why don't you rip my head off for asking for heating advice. Sorry, I shouldn't have posed a question that can't be answered without elaborate engineering measurements and calculations. I restored a 20 yr. old RUUD oil furnace last year and ran that with a homemade plenum and a few 6" ducts.
|
|
|
