Instructions

Instructions for Online LoadCalc:

Start by entering the sq. ft. of Outside Walls including windows and doors corresponding to the correct direction in type 1. Windows and doors will automatically be deducted during the calculation process. If there is a second type of outside wall use type 2 for that number, if not just leave it blank. Next go to right to Windows & enter in the sq. ft. just like you did for the walls.
Do the same for Glass Doors & Doors. Then go to the next direction & repeat the same steps.
Lets say you had 500 sq. ft. of North facing outside walls, 75sq. ft of North facing windows, 42 sq. ft of North facing glass doors & 20 sq. ft. of North standard doors.
The line should look like this:

Outside Wall: North

1: 2:

Windows:

1: 2:

Glass Doors:

1: 2:

Doors

Some wall directions use the exact same calculation factors so they are included together on the same line such as: E & W, NE & NW, or SE & SW
If you have 600 sq. ft. of East outside walls, 75sq. ft of East windows, 400 sq. ft. of West outside walls, 25sq. ft of West windows with no doors,
The line should look like this:

Outside Wall: E & W

1: 2:

Windows:

1: 2:

Glass Doors:

1: 2:

Doors

When you get to windows & glass doors south, east-west & southeast-southwest there will be a small dropdown list to choose from for shading.
If you have 800 sq. ft. of South facing outside walls, 100 sq. ft. of windows & 25 sq. ft of glass doors the next line would look like this.

Outside Wall: South

1: 2:

Windows:

1: 2:

Glass Doors:

1: 2:

Doors

Shading:
By default shading will be used & calculated depending on the roof overhang & distance from the top of the windows to the overhang you selected on the structure page. Notice that the boxes for North, NE & NW windows & glass doors are colored light yellow to show that shading is not factored for those directions. The other boxes where shading is used will be colored gray. If you decide that shading should not be factored in on certain windows or glass doors just click on the drop down button next to windows or glass doors & change the shading selection. Any box where you choose not to use shading will turn light yellow also. There is an option to use no shading at all & a another option to use shading but only on type 1. This could help if you have some windows or glass doors facing the same direction but obviously will not be shaded by an overhang while others will. A two story house for example, the second story windows will be much closer to the roof overhang & more likely to get some shading where the first floor would not get any shading from the roof overhang. If they were the same type glass you could make the same choice on the structure page for type 1 windows & type 2 windows, then you have the option to not use shading for those type 2 windows & still use shading for type 1 when you enter the sq. ft.
Skylights: If you chose flat skylights then it doesn't matter what direction you use to enter your sq. ft. . The calculations will not make any difference but if you chose 45 degree angle skylights then the correct direction the skylights face is important so be sure to use the box to the right that corresponds to the correct direction.
Floor: Enter the sq. ft. of flooring over a crawlspace, garage, basement or exposed area. If the house is on a slab then enter the linear ft. of the perimeter.
Example: 50ft. by 50 ft. floor over a crawlspace you would enter "2500 " but 50 ft. by 50 ft. slab you would enter "200 ".
Ceiling: Enter the sq. ft. of all ceilings exposed to an attic or roof joists.
Appliances: Enter the number of appliances that will add heat to the structure, usually one or two.
Fireplaces: Choose the number of fireplaces if any in the structure up to a maximum of three.
People: Manual J recommends 1 person per bedroom plus 1 in the living area so a three bedroom house you should enter "4" people.
Sq. ft.: Enter the sq. ft. of heated space.
Cubic ft.: Enter the above ground cubic ft. of heated space except basement. Do not enter any cubic ft. of basement area that is above grade. That should be entered in the basement section . There is a calculator on the menu bar in the middle of the page that can be used for sq. ft. & cubic ft.

** Heated or Conditioned Basements Only **
*Above Grade: walls: Enter the sq. ft. of any basement walls above grade. Cubic ft.: Enter any cubic ft. of any basement area that is above grade.
*Below Grade: walls: Enter the sq. ft. of basement walls below grade. Floor: Enter the sq. ft. of basement floor ***( if the floor is less than 2 ft. below grade (grade level) , enter LINEAR ft.). width: Choose the width of the shortest side of the floor.
feet below grade: Choose the feet below grade of the floor. *** If the floor is less than 2 ft. below grade then choose "grade level" & enter LINEAR ft. instead of sq. ft. for Basement Floor.

Construction: Choose the tightness of the construction for the purpose of estimating outside air infiltration.
Ducts: There are three different type of drop down choices to make to figure the amount of duct loss.
First choose the location where the ducts will be. Next choose the R- value of the ducts. Then choose the tightness of the duct system.
Calculate Load: Clicking the button will display the total calculations. It will also display a BTU break down of each group on the bottom left of the page.
Fresh Air Ventilation(optional): The tighter the structure the more fresh air is recommended for a healthy home. The amount of people, cubic ft. & outside infiltration are factored in first before arriving at a recommended amount. When the load calculation is totally completed & calculated then a recommended amount will be shown in the "Fresh air recommended box". You can then decide what amount if any to enter and then recalculate the load.
* Changing default conditions: You can change the temperatures & humidity level if you decide not to use the default conditions.
**Saving your Work: Click on the menu bar to save your work. Clicking it will give you an option to name the file and download it to your computer. It only saves data you entered that has been calculated, so be sure to calculate the load before saving the file. Once the file is saved, the session can then be restored at a later date from the Start up page where the state and city are selected.
**Restoring your saved Work: On the initial start up page where you elect the State and City there is an button that once you click will give you the option to find the file on your computer and upload it. Once the file is uploaded successfully then the session will be restored and all the data should be just as it was when you saved it.
**Size Equipment: You can go to the sizing calculator by clicking on the menu bar. It will take you another page and will import any totals that have already been "calculated".