Originally Posted by childers2
I purchased a home where the HVAC system is missing.. It likley needs some duct work is missing to..
What do i need to know when looking for a unit.. Is this a DIY project?
A Manual J is a heat loss and gain calc, which will tell you what size/capacity heating and or cooling units you need. Manual D will tell you what friction rate to use with a slide duculator to size your duct.
There are people that can rebuild an engine themselves, and there are people that can't change a spark plug. The former will have no trouble replacing a fuel pump, and them latter wouldn't know how to turn the socket. How mechanically inclined you are determines what you can do.
Best to start out by determining what how much time you want to put into doing it yourself, and if that is enough time.
Then a load calc, pick out and get teh equipment, then proper duct sizing.