1880s house updating hvac no duct work
#1
10-04-08, 06:52 PM
1880s house updating hvac no duct work
I have a 1880s house. 2500 sq ft no duct work. two story house. Just purchased a 4 ton heat pump and air handler. How do i figure what size duct work to install. I was wanting to put in flex duct. I will have a run under the house for main floor. Then a run for the attic to get to the second floor. How many registers per room. what size duct for supplies and returns. what size duct for main trunk for supply and return. Im clueless on everything. cfm??? How many returns or just one big one on main floor. the pass way through the upstairs to down stairs is in center of house and it is a open hall from upstairs to down about 6 foot wide. Im mechainicly inclined I just need a starting point and a little insight into the cfm per room per duct per return and supply. Please help my wife says it is starting to get cold here
#2
10-04-08, 09:08 PM
Member
I am guessing you did a heat load (manual J) of your home to come up with the size unit! You will need to size the duct work using the heat load per room. You will have this if you did the heat load cal. You can do a manual D to get your duct sizes.
#3
10-05-08, 06:26 AM
"heat load", "manual J" I have know idea. I looked onlineat different heat pumps and the size for a 2500 sq house was suggested to be a four ton unit. other than that all i have is a route to run duct work from one floor to the next.
#4
10-05-08, 09:11 AM
Member
Using square footage of a home has not been an excitable approach to size equipment for YEARS. It just doesn't work. You need to do a manuel J on the home to size the equipment correctly. Do you have somebody to install the equipment. Also equipment bought over the net will not come with a warranty if you installed it yourself.
