We ran our own Manual J calculation using ResLoads (its an app for the iPhone that HVAC contractors use). We wanted something from the industry to help validate our simple energy model.
It shows 27,665 BTU as the heating load. But, the max choice in walls was R27, ceiling R56, Foundation R15. We'll be well above that. We could choose a tight envelope, but likely that doesn't get down to passive house standards. In addition, windows were not as efficient and there was no consideration for the solar heat gain in the winter.
Here's the result:
It shows 27,665 BTU as the heating load. But, the max choice in walls was R27, ceiling R56, Foundation R15. We'll be well above that. We could choose a tight envelope, but likely that doesn't get down to passive house standards. In addition, windows were not as efficient and there was no consideration for the solar heat gain in the winter.
Here's the result:
Compare that with our energy model - which shows 18,805 BTU. Shows that we are within reason for a model. Neither are probably totally correct, but close enough for sizing equipment.
