Manual D/J questions
Awhile back, I had a Manual D/J performed. I reviewed it the best I could at the time but now that I’m looking into a system change-out and getting ready to lean on the D/J, I find some wall configs and windows are not correct and some of the basement numbers don’t add up.
So if anyone out there is a D/J wizard, I have some specific questions:
1. Is there any way to back of the napkin the reduced load for the walls/windows that were entered with standard efficiencies instead of enhanced efficiencies?
2. Why would the basement room loads not be the sum of their wall and window component? Is loss to the slab handled elsewhere? I’m seeing higher btus/sf loads for the basement than some upstairs space. It’s hard to believe that the slab loss is greater than exterior wall loss.
3. With highly insulated walls, is there any point to the wall loads? Since the Manual D/J is generally considered to be conservative in sizing, could you just size for glazing?
4. I certainly can calculate U factors and look up glazing SHGCs but I don’t know how to incorporate these values with aspects and orientation. Are these calculations common property somewhere that a smart person can find to perform their own calculations?
If it matters, the software that was used was WrightSoft.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part