HVAC Residential Load Calcs HD Online Help

The HVAC Residential Load Calcs HD app is the first comprehensive HVAC heating and cooling load calculation app for the Apple iPad based upon industry standard calculation methods (ACCA Manual J8-Abridged).

This application allows you to perform comprehensive heating and cooling block and room-by-room load calculations using the extensive built-in database of envelope, window, and skylight types. You can then send the calculated results in an HTML email with a spreadsheet attachment to perform more complete analysis back at the office. It also includes an extensive weather database of 1000+ cities world-wide. See below for comprehensive help on this module.

(For users of the Trane MAP™ iPad app [which is a totally separate app from the Carmel app, but includes the Carmel residential load calc functionality], click here for information specific to it.)

Quick Start

The following is a list of hints and suggestions to quickly get started using the HVAC Residential Load Calcs application:


  1. The app comes preinstalled with a number of sample projects and a "default template" project. The sample projects include a medium-sized and large house. The "default" project is the base project used to create all new projects. You can edit this project at any time and assign values more appropriate to the jobs that you perform.
  2. To create a new project, select the "+" button in the upper right-hand corner of the project list drop-down list. This list automatically appears when the iPad displays in landscape mode, and after you click the "Project List" button in portrait mode. After clicking the "+" button, you can input a new project name or select an existing project to copy from.
  3. You will notice that a number of input values are displayed in a "maroon" color. These signify inputs that are calculated based upon other input selections but may be overridden. For example, the heating floor area is automatically set equal to the cooling floor area. However, you can override the heating floor area by manually inputting a value into the text box (or sliding the slider control). To restore the auto-calculation functionality of the input, just enter 0 or erase the value in the input box. If you want to enter a value of 0 for this input, slide the indicator along the slider control all the way to the left to 0. This functionality applies to all inputs that are auto-calculated.

Using the HVAC Res Load Calcs HD App

When you first open the HVAC Residential Load Calcs HD application, you will see the project input screen. Depending upon whether the iPad is placed vertically (portrait mode) or horizontally (landscape mode), the layout of the various controls will differ. This help documentation will describe the app in "landscape" mode with some side comments on portrait mode if there are any significant differences.



At the very top of the screen are two buttons:

  1. Block Load: With this button selected, you are in the "block Load" mode where all inputs relate to modeling the building or house as one big "block". This is appropriate for sizing cooling and heating HVAC equipment. Please note that you should first define all the properties of your building or house in the "Block Load" mode, then move onto the room-by-room mode.
  2. Room-By-Room: With this button selected, you are in the "room-by-room" mode where all inputs relate to modeling the building or house by each individual room. This is appropriate for calculating airflows and loads for each individual room.
    3. Most users will begin by modeling the house as a "block" load, then calculating individual room loads and airflows under the "room-by-room" mode. The calculated loads from one mode in no way affect the loads in another mode. The only way that these two modes interrelate is that envelopes, windows, and skylights that are defined in the "block load" mode can be selected in the "room-by-room" mode.
Below the two buttons discussed above are four more buttons:

  1. Project Button (Block Load mode): Select this button to display the list of projects on the left and the project inputs/results on the right.
  2. Room Button (Room-by-Room mode): Select this button to display the list of rooms on the left and the room inputs/results on the right.
  3. Envelope Button: Select this button to display the list of envelope items (walls, doors, roofs, ceilings) on the left and the envelope inputs/results on the right.
  4. Window/Door Button: Select this button to display the list of window and glass doors on the left and the window/door inputs/results on the right.
  5. Skylight Button: Select this button to display the list of skylights on the left and the skylight inputs/results on the right.
Along the top right-hand side of the screen are three icons:

  1. Pie-Chart Icon: This icon displays the list of reports that you can display on your screen and also email. See below for more details.
  2. "i" Icon: This icon displays the preferences form that allows you to customize various app preferences and settings. See below for more details.
  3. Question Icon: This icon displays the online help.

Block Load Mode

Project Inputs
When you first start the app, the project input screen will appear. If you are in portrait mode, you can press the "Project List" button to display the list of projects. If you are in landscape mode, the project list will automatically appear on the left and the inputs and results will appear on the right:


The following describes how to create, edit, and delete projects:

  1. Create a New Project: To create a new project, click the "+" button located in the upper right-hand corner of the project list drop-down. A new form will appear allowing you to enter a new project name.


    The "_Default" project is always used as the basis for creating a new project. The HVAC Residential Load Calcs app includes a default project (called "_Default"). This project includes default block load information including one of each of envelope, window, skylight, and room types. This default project is used as the basis for all new projects that are created (except for those that are copied from existing projects). You can edit all of the data in this default project by selecting the "_Default Project" and editing as you would any normal project. However, you cannot add new envelopes, windows, skylights, and rooms within this default project. Also, you can copy from an existing project by pressing the button labeled "Copy from existing Projects >>". A list of all existing projects will appear allowing you to select from one. When you return to the "Add Project" screen, type in a new project name.
  2. Edit an Existing Project: To edit an existing project, select the project name in the project list.
  3. Delete an Existing Project: Swipe your finger across the name of the project that you wish to delete. A "delete" button will appear allowing you to press it to delete the project.
Project Inputs/Results - Screen 1
The following describes the project input information that first appear when you select a project name:

Project Inputs (Page 1, Landscape Mode):

  1. Project name: This is the name that you originally inputted when you created the project. You can change the project name in this text box. To do so, tap your finger within the text box and the standard iPad keyboard will pop up allowing you to type in a new name. This keyboard will appear anytime you tap your finger within any of the textboxes in this app.
  2. Building name: Input the building name. This name will appear in the comprehensive HTML report (see below for more details).
  3. Contact name: Input the client contact name for this project.
  4. Address 1: Input the street address.
  5. City: Select the icon on the far right to display the weather form. This form contains a list of 1000+ cities worldwide with corresponding weather data.
    The weather form is accessed by selecting the icon next to the city input text box in the "Project Inputs" form discussed above. This form allows you to specify the physical location of the building anywhere in the world. The weather database contains over 1000 cities worldwide. Each city includes information such as its elevation, temperatures, and latitude; all values that are used in the HVAC load calculations. When this screen appears, you can select whether to display US/Canadian cities or any city outside of North America. After making this selection, you can scroll through the list of cities to find the one closest to the location of the building that you are analyzing. As you select each city, the following data is displayed:


    1. Latitude: This is the city's latitude value in degrees North or South Latitude. An "S" for southern latitudes or an "N" northern latitudes is located after the latitude value (i.e. 42N for Boston, USA or 52S for Sydney, Australia)
    2. Elevation (Ft or M): This is the city's elevation above sea level in feet (meters).
    3. Summer dry-bulb (F or C): This is the ASHRAE 1% summer design dry-bulb temperature for the city. This means that the summer temperature has been equaled or exceeded by 1% of the totals hours during the months of June through September.
    4. Summer wet-bulb (Coinc.) (F or C): This is the wet-bulb temperature that occurs coincidentally with the 1% summer dry-bulb temperature listed above.
    5. Winter dry-bulb (F or C): This is the ASHRAE 99% winter design dry-bulb temperature for the city. This means that the winter temperature has been equaled or exceeded by 99% of the total in the months of December, January, and February.
    6. Daily range: This is the average daily temperature swing during the summer. You can select "L" for low (swing less than 16 deg F), "M" for medium (swing between 16 and 25 deg. F), or "H" for high (swing greater than 25 deg F.).

    At any time, you can override any of the values. These overrides will only apply to the current project and will not permanently apply to the selected city for future projects.

  6. State/Province: This input will automatically be filled in based upon the city selection above. You can also override this value.
  7. Country: This input will automatically be filled in based upon the city selection above. You can also override this value.
  8. Phone number: Input the client phone number.
  9. Email: Input the client email address.
  10. Calculation method: Select from one of three options: "Both", "Cooling", or "Heating". If you select "Both", then both cooling and heating loads will be calculated. If you select "Cooling", only cooling loads will be calculated. If you select "Heating", only heating loads will be calculated.
General Inputs:
This section includes overall project inputs including building area, height, occupant, and other related inputs:


  1. Total floor area - cooling (SqFt or SqM): Input the total building floor area that is cooled. You can manually input a value into the textbox by placing your finger within it, and the standard iPad keyboard will pop up. Also, you can slide the indicator along the slider control located just below the textbox. As you slide the indicator, the value will update immediately (This behavior applies to all textboxes with accompanying slider controls). Also, the "Total floor area - heating" input will automatically update as you update the cooling value, since in a majority of cases, the cooling and heating floor areas are the same.
  2. Total floor area - heating (SqFt or SqM): Input the total building floor area that is heated. As explained above, this value is automatically updated according to the cooling floor area input discussed above. You can manually override this value by inputting a value or sliding the slider control. You will notice that the color of the text turns from maroon to black to indicate that the value is overridden. If you wish to have the value "calculated" once again, just input a value of 0 or nothing, and the calculated value will return.
  3. Average room height (Ft or M): Input the average room height of all rooms in the building. This average room height is multiplied by the floor area above to calculate total volume for purposes of calculating infiltration and ventilation results.
  4. Number of bedrooms: Input the approximate number of bedrooms in the house or building. This value is used to to determine the number of people that occupy the building. You will notice that the next input shows the number of people, and it is calculated according to the number of bedrooms plus 1.
  5. Number of occupants: Input the number of occupants (or people) in the house or building. As explained above, this value is automatically updated according to the number of bedrooms. You can manually override this value by inputting a value. You will notice that the color of the text turns from maroon to black to indicate that the value is overridden. If you wish to have the value "calculated" once again, just input a value of 0 or nothing, and the calculated value will return.
  6. Appliance load: Select a high (2400 BTUh) or low (1200 BTUh) appliance load for the entire building. This load includes heat given off by dish washers, dryers, and other household appliances.
  7. Number of fireplaces: Input the # of fireplaces in the home. This information is used to calculate infiltration airflow values.
  8. Construction tightness: Select the icon on the right-hand side of this cell to display a picker control that includes the following options for the quality of construction of the building:
    1. Tight
    2. Semi-Tight
    3. Average
    4. Semi-Loose
    5. Loose

  9. Fireplace tightness: Select the icon on the right-hand side of this cell to display a picker control that includes the following options for the quality of construction of the fireplace:
    1. Tight
    2. Semi-Tight
    3. Average
    4. Semi-Loose
    5. Loose
    Block Load Breakdown:
    This section displays a breakdown of the cooling and heating load results along with a pie chart. The results update as you change the input values. This section appears on the side of every screen going forward (or at the bottom if you are viewing the app in portrait mode). Select the "Cooling" option to display the cooling load breakdown and the "Heating" option to display the heating load breakdown.

    Setpoint and System Inputs (Page 2, Landscape Mode):
    Swipe your finger from right to left on page 1 to arrive to this page. This screen includes all building setpoint and other system-related inputs:


    1. Indoor cooling setpoint (F or C): Input the house or building cooling (summer) setpoint. You can manually input a value into the textbox by placing your finger within it, and the standard iPad keyboard will pop up. Also, you can slide the indicator along the slider control located just below the textbox. As you slide the indicator, the value will update immediately.
    2. Indoor heating setpoint (F or C): Input the house or building heating (winter) setpoint. You can either input a value or slide the indicator along the slider control located just below the textbox.
    3. Indoor relative humidity: Input the indoor relative humidity value. This value is important for calculating latent infiltration and ventilation load contributions. In most cases, this value is between 45 and 55%.
    4. Number of fireplaces: Input the # of fireplaces in the home. This information is used to calculate infiltration airflow values.
    5. Burner input (BTUh or W): Input the total furnace burner input in BTUh or W. This value is used to calculate infiltration airflow values in certain situations.
    6. Blower heat gain: Select "Yes" or "No" to specify any heat contribution to the cooling load due to heat given off by the blower. Specify "Yes" if the blower is a "draw-through" blower, meaning that the fan is in the path of the airflow. This adds about 1700 BTUh to the total system load.
    7. AC/HR and Airflow/Code This combination selector and input box allows you to specify the quantity of outside air. If you select "AC/HR", input the number of air changes/hour of outside air entering the house through the furnace or blower. If you select "Airflow/Code", input a total airflow value (CFM or L/s) of outside air entering the house through the furnace or blower. This value may or may not be used to calculate the total ventilation cooling and heating loads, depending upon the option selected next.
    8. Ventilation provided by (per code): This option allows you to select from 3 combinations of ventilation types:
      1. None: No ventilation is calculated
      2. Ventilation only: Only the ventilation quantity inputted above is used to calculate the total heating and cooling load contribution due to ventilation.
      3. Ventilation and Infiltration: A combination of the infiltration airflow and the ventilation airflow inputted above are used to determine the total ventilation airflow used to calculate heating and cooling loads due to ventilation.
    9. Duct heat loss/gain (%): Input a percentage value from 0 to 100% to represents the approximate heat loss and gain due to airflow friction along the duct work. Usually, this value is between 5 and 10% of total cooling or heating loads.
    Block Load Breakdown - Cooling and Heating (Page 3, Landscape Mode):
    Swipe your finger from right to left on page 2 to arrive to this page. This page displays calculated cooling and heating load breakdown values.


    It includes the following cooling load component items:
    1. Window and glass doors
    2. Skylights
    3. Wood and metal doors
    4. Above grade walls
    5. Partition walls
    6. Below grade walls
    7. Ceilings
    8. Floors
    9. Infiltration
    10. Internal gain
    11. Duct heat gain
    12. Ventilation
    13. Blower heat gain
    14. Totals

    It includes the following heating load component items:
    1. Window and glass doors
    2. Skylights
    3. Wood and metal doors
    4. Above grade walls
    5. Partition walls
    6. Below grade walls
    7. Ceilings
    8. Floors
    9. Infiltration
    10. Duct heat loss
    11. Ventilation
    12. Totals

    Envelope (Walls, doors, floors, ceilings, and roofs) Inputs
    The envelope input screen will appear when you press the "envelope" button at the top of the screen. If you are in portrait mode, you can press the "envelope List" button to display the list of envelopes. If you are in landscape mode, the envelope list will automatically appear on the left and the inputs and results will appear on the right:


    The following describes how to create, edit, and delete envelope items. Envelope items are defined as external walls and roofs, interior partition walls and ceilings, and below-grade walls:
    1. Create a New Envelope: To create a new envelope item, click the "+" button located in the upper right-hand corner of the envelope list drop-down. A new form will appear that displays the next available alphabetic letter to be assigned to the envelope. Each envelope has a unique alphabetic letter assigned to it. Click the "Save" button to add the new envelope. The new envelope is based upon the envelope item located in the "_Default" project. If you wish to copy from an existing envelope already located in the current project, select the "Copy from existing Envelopes" to display a list of all existing envelopes then select the envelope you wish to copy.


    2. Edit an Existing Envelope: To edit an existing envelope, select the envelope name in the envelope list.
    3. Delete an Existing Envelope: Swipe your finger across the name of the envelope that you wish to delete. A "delete" button will appear allowing you to press it to delete the envelope.
    Envelope Inputs/Results - Screen 1
    The following describes the envelope input information that first appear when you select a envelope name:
    Envelope Inputs (Page 1, Landscape Mode):
    1. Envelope id: This is a read-only input that displays the alphabetic id that was automatically assigned to the envelope item.
    2. Description: You can input a short description that describes what the current envelope item is (East Wall, etc.). This description is displayed on the envelope list page described above, and it is also displayed in the HTML report described below. It has not effect on the calculated results.
    3. Envelope panel type: Select the icon located on the far right hand side of this cell, and a picker control will appear that allows you to describe the type of envelope item. The following is the list of options:


      1. Wood/Metal Door: Select this option if the envelope item is an envelope-colored door (not a 50%+ glass door)
      2. Above Grade Wall: Select this option if the envelope item is an outside above-grade wall.
      3. Basement Wall (Below Grade): Select this option if the envelope item is a basement wall where a majority of the square area is below grade.
      4. Partition Wall: Select this option if the envelope item is an internal partition wall that is adjacent to an unconditioned space like a garage or storage room.
      5. Ceiling: Select this option if the envelope item is a ceiling that is part of an external roof system.
      6. Partition Ceiling: Select this option if the envelope item is a partition ceiling adjacent to an unconditioned space like an attic.
      7. Floor: Select this option if the envelope item is an on-grade or above-grade floor over an unconditioned space like a basement.
      Depending upon the envelope type option that you choose will determine the types of inputs that appear on this and the following screen. All the variations are described below.
    4. Construction #: Select the icon on the far right-hand side of this cell to display a new form that allows you to select a construction type from a construction list that is applicable to the selected envelope type. The following is a list of descriptions of each of the construction number lists:
      1. Wood/Metal Door List: This list of envelope door construction numbers ranges from "11A" to "11Q" according to the ACCA Manual J8 handbook. The u-value and a longer description of the construction item appear below the picker control.


      2. Above Grade Wall List: This list of envelope wall construction numbers range from "12A-0b" to "15A19-8ocw" according to the ACCA Manual J8 handbook. One or two u-values, the exterior code ('b' for brick and 's' for stucco), and a longer description of the construction item appear below the picker control.


      3. Basement Wall (Below Grade) List: This list of below-grade wall construction numbers ranges from "15A-0oc" to "15A19-8ocw" according to the ACCA Manual J8 handbook. A list of depth-dependent u-values and a longer description of the construction item appear below the picker control.
      4. Partition Wall List: This list of partition wall construction numbers range from "12A-0b" to "15A19-8ocw" according to the ACCA Manual J8 handbook. One or two u-values, the exterior code ('b' for brick and 's' for stucco), and a longer description of the construction item appear below the picker control.
      5. Ceiling List: This list of ceiling construction numbers ranges from "16B-0" to "18A-38" according to the ACCA Manual J8 handbook. One u-value and a longer description of the construction item appear below the picker control.


      6. Partition Ceiling List: This list of partition ceiling construction numbers ranges from "16B-0" to "18A-38" according to the ACCA Manual J8 handbook. One u-value and a longer description of the construction item appear below the picker control. This option differs from the one above in that you are able to specify a cooling and heating partition temperature values in the next screen.
      7. Floor List: This list of floor construction numbers ranges from "19A-0tp" to "22B-15pl" according to the ACCA Manual J8 handbook. A longer description of the construction item appears below the picker control.

      Depending upon the envelope panel type selection you made above will determine which of the following input options appear:
    5. Width and Height (Ft or M): These two options will appear with corresponding slider controls if the "Wood/Metal Door", "Above Grade Wall", "Basement Wall", "Partition Wall", and "Floor" options are chosen. These inputs should be self explanatory.
    6. Length and Height (Ft or M): These two options will appear with corresponding slider controls if the "Ceiling" and "Partition Ceiling" options are chosen. These inputs should be self explanatory.
    7. Subtract out opening area (SqFt or SqM): This input and its accompanying slider control allow you to specify the area of any opening(s) in the envelope. For example, if you select an above-grade wall, you can specify the total area of the window and door openings. This value is subtracted from the total area of the envelope calculated from the inputs discussed above.
    8. Shaded (Yes or No): This selector appears only if you select the "Above Grade Wall" option. It allows you to specify whether the wall is shaded (i.e. - a northern-facing wall or one that is shaded by trees or other buildings).
    9. Below grade floor depth (Ft or M): This option appears only if you select the "Basement Wall" option. It allows you to input the number of feet or meters the basement wall is below-grade.
    10. Partition cooling and heating temperatures (F or C): This combination of inputs appears if you select the "Partition Wall" or "Partition Ceiling" envelope types. These two inputs represent the temperatures of the space adjacent to the current envelope item during cooling or heating seasons, respectively. For example, if the current partition wall is adjacent to a garage, the summer partition temperature may be around 95 deg F and the winter partition temperature may be around 45 deg F.
    11. Slope: This input appears if you select the "Ceiling" or "Partition Ceiling" envelope types. If allows you to input the slope, angle, or pitch of the ceiling (roof) in degrees from 0 (horizontal) to 90 (vertical).
    12. Length of exposed edge (Ft or M): This input appears if you select the "Floor" envelope type. It allows you to input the total length of exposed edge of floor to the surrounding grade. Please note that this input only applies to floor types "Floor-28" and beyond (concrete slab-on-grade floor). For all other floor types, this input is ignored, and the floor area is used to calculate cooling and heating loads.
    Envelope Totals:
    This section appears only in landscape mode. It displays the following results:
    1. Envelope cooling load contribution: This displays the total cooling load contribution due to the specific envelope item.
    2. Envelope heating load contribution: This displays the total heating load contribution due to the specific envelope item.
    3. Total block cooling load: This displays the total block cooling load.
    4. Total block heating load: This displays the total block heating load.
    5. Total airflow: This displays the total cooling airflow.

    Block Load Breakdown - Cooling and Heating (Page 2, Landscape Mode):
    Swipe your finger from right to left on page 1 to arrive to this page. This page displays cooling and heating load breakdown values (described above).

    Window/Glass Door Inputs
    The window/glass door input screen will appear when you press the "Window/Door" button at the top of the screen. If you are in portrait mode, you can press the "Window/Door List" button to display the list of windows and glass doors. If you are in landscape mode, the window/door list will automatically appear on the left and the inputs and results will appear on the right:

    The following describes how to create, edit, and delete windows/glass doors:
    1. Create a New Window/Door: To create a new window/glass door, click the "+" button located in the upper right-hand corner of the window/glass door list drop-down. A new form will appear that displays the next available alphabetic letter to be assigned to the window/door. Each window/door has a unique alphabetic letter assigned to it. Click the "Save" button to add the new window/door. The new window/door is based upon the window/door item located in the "_Default" project. If you wish to copy from an existing window/door already located in the current project, select the "Copy from existing Windows/Doors" to display a list of all existing windows/doors then select the window/door you wish to copy.


    2. Edit an Existing Window/Door: To edit an existing window/door, select the window/door name in the window/door list.
    3. Delete an Existing Window/Door: Swipe your finger across the name of the window/door that you wish to delete. A "delete" button will appear allowing you to press it to delete the window/door.

    Window/Door Inputs/Results - Screen 1
    The following describes the window/door input information that first appear when you select a window/door name:
    Window/Glass Door Inputs (Page 1, Landscape Mode):

    1. Window/Glass door id: This is a read-only input that displays the alphabetic id that was automatically assigned to the window/glass door item.
    2. Description: You can input a short description that describes what the current window/glass door item is (East-facing window, etc.). This description is displayed on the window/glass door list page described above, and it is also displayed in the HTML report described below. It has no effect upon the calculations.
    3. Construction #: Select the icon on the far right-hand side of this cell to display a new form that allows you to select a window or glass door type. The window/glass door construction numbers range from "1A-c" to "10B" according to the ACCA Manual J handbook. As you select each one, the full description displays below the picker list. After selecting the desired window or door type, press the button in the upper right-hand corner to close the form. The selected construction # will appear in the cell.


    4. Window/Glass door type: Select the icon on the far right-hand side of this cell to display a picker control that allows you to select the window/door type. The following are the list of options:
      1. Default
      2. Bay Window
      3. Garden Window
      4. French Door
    5. Frame type: Select the icon on the far right-hand side of this cell to display a picker control that allows you to select the frame type. The following are the list of options:
      1. M - Metal No Break
      2. MB - Metal With Break
      3. W - Wood
      4. V - Vinyl
    6. Orientation: Select the icon on the far right-hand side of this cell to display a picker control that allows you to select the orientation of the window/glass door type. The following are the list of options:
      1. North
      2. South
      3. East
      4. West
      5. NE
      6. NW
      7. SE
      8. SW
    7. Window/glass door area (SqFt or SqM): Input or slide the indicator along the slider control to specify the total area of one of this type of window or glass door. As you input or update the value, the calculated results will immediately update.
    8. Window/glass door quantity: Input the number of windows or doors of this type. This value is multiplied by the area inputted above to calculate the total window area.
    Window/Glass Door Interior Shading:
    The following inputs are used to determine the effects of any interior shading on cooling loads.
    1. Number of panes: Select the number of window panes: "Single", "Double", or "Triple".
    2. Insect screen: Select "Yes" if an insect screen is located adjacent to the window. This affects internal shading factors.
    3. Shading type: Select the icon on the far right-hand side of this input cell to display a picker that allows you to select from three different internal shading options:
      1. No internal shade
      2. Blinds w/slats at 45 deg.
      3. Drapes or rollers half drawn
    Window/Glass Door Exterior Shading:
    The following inputs are used to determine the effects of any exterior shading on cooling loads. If no exterior shading such as window overhangs exist, enter 0 for all these inputs.
    1. Window height (H) (Ft or M): Input the height of the window or glass door opening in feet or meters.
    2. Overhang length (X) (Ft or M): Input the length of the overhang that is shading the window or glass door.
    3. Distance below overhang (Y) (Ft or M): Input the distance below the overhang that the top of the window or glass door is located.
    Window/Glass Door Totals:
    This section appears only in landscape mode. It displays the following results:
    1. Win/door cooling load contribution: This displays the total cooling load contribution due to the specific window/glass door item.
    2. Win/door heating load contribution: This displays the total heating load contribution due to the specific window/glass door item.
    3. Total block cooling load: This displays the total block cooling load.
    4. Total block heating load: This displays the total block heating load.
    5. Total airflow: This displays the total cooling airflow.

    Block Load Breakdown - Cooling and Heating (Page 2, Landscape Mode):
    Swipe your finger from right to left on page 1 to arrive to this page. This page displays cooling and heating load breakdown values (described above).

    Skylight Inputs
    The skylight input screen will appear when you press the "Skylight" button at the top of the screen. If you are in portrait mode, you can press the "Skylight List" button to display the list of skylights. If you are in landscape mode, the skylight list will automatically appear on the left and the inputs and results will appear on the right:


    The following describes how to create, edit, and delete skylights:
    1. Create a New Skylight: To create a new skylight, click the "+" button located in the upper right-hand corner of the skylight list drop-down. A new form will appear that displays the next available alphabetic letter to be assigned to the skylight. Each skylight has a unique alphabetic letter assigned to it. Click the "Save" button to add the new skylight. The new skylight is based upon the skylight item located in the "_Default" project. If you wish to copy from an existing skylight already located in the current project, select the "Copy from existing Skylights" to display a list of all existing skylights then select the skylight you wish to copy.


    2. Edit an Existing Skylight: To edit an existing skylight, select the skylight name in the skylight list.
    3. Delete an Existing skylight: Swipe your finger across the name of the skylight that you wish to delete. A "delete" button will appear allowing you to press it to delete the skylight.
    Skylight Inputs/Results - Screen 1
    The following describes the skylight input information that first appear when you select a skylight name:

    Skylight Inputs (Page 1, Landscape Mode):

    1. Skylight id: This is a read-only input that displays the alphabetic id that was automatically assigned to the skylight item.
    2. Description: You can input a short description that describes what the current skylight item is (East-facing skylight, etc.). This description is displayed on the skylight list page described above, and it is also displayed in the HTML report described below.
    3. Orientation: Select the icon on the far right-hand side of this cell to display a picker control that allows you to select the orientation of the skylight. The following are the list of options:
      1. North
      2. South
      3. East
      4. West
      5. NE
      6. NW
      7. SE
      8. SW
    4. Frame type: Select the icon on the far right-hand side of this cell to display a picker control that allows you to select the frame type. The following are the list of options:
      1. Metal Sash No Break
      2. Wood, Alum Clad Wood
    5. Skylight area (SqFt or SqM): Input or slide the indicator along the slider control to specify the total area of one of this type of skylight. As you input or update the value, the calculated results will immediately update.
    6. Skylight quantity: Input the number of skylights of this type. This value is multiplied by the area inputted above to calculate the total skylight area.
    7. Glass tilt angle: Input the horizontal tilt (or slope) of the skylight from 0 to 90 degrees.
    8. Curb height (inches or cm): Input the height of the curb around the skylight in inches or centimeters.
    9. Number of panes: Specify the number of window panes using the selector: "Single", "Double", or "Triple".
    Skylight Totals:
    This section appears only in landscape mode. It displays the following results:
    1. Skylight cooling load contribution: This displays the total cooling load contribution due to the specific skylight item.
    2. Skylight heating load contribution: This displays the total heating load contribution due to the specific skylight item.
    3. Total block cooling load: This displays the total block cooling load.
    4. Total block heating load: This displays the total block heating load.
    5. Total airflow: This displays the total cooling airflow.

    Block Load Breakdown - Cooling and Heating (Page 2, Landscape Mode):
    Swipe your finger from right to left on page 1 to arrive to this page. This page displays cooling and heating load breakdown values (described above).

    Room-By-Room Mode

    The room-by-room mode can be access by pressing the "Room-by-Room" option at the very top of the app screen. The room-by-room mode allows you to create individual rooms and assign thermal properties to them so you can determine the cooling and heating loads, and airflows for each room. Please note that in no way do the loads from the block load mode described above affect the loads in the room-by-room mode. They are totally separate. The only way one mode relates to the other is that the envelope, window, and skylight types defined in the block load mode can be accessed in the room-by-room mode, and then specific areas and dimensions can be assigned to those components. When you press "Room-by-Room" button, the 4 buttons below it all turn blue to indicate that you are in the room-by-room mode. The list of room names will appear on the left-hand side of your screen (in landscape mode). The following describes how to create, edit, and delete rooms:

    1. Create a New Room: To create a new room, click the "+" button located in the upper right-hand corner of the list. A new form will appear allowing you to enter a new room name. The default template room called "A Room" located in the "_Default" project is always used as the basis for creating a new room. Also, you can copy from an existing room by pressing the button labelled "Copy from existing Rooms >>". A list of all existing rooms will appear allowing you to select from one. When you return to the "Add Room" screen, type in a new room name.
    2. Edit an Existing Room: To edit an existing room, select the room name with your finger and the room information will appear on the right.
    3. Delete an Existing Room: Swipe your finger across the name of the room that you wish to delete. A "delete" button will appear allowing you to press it to delete the room.

    Room Inputs
    At the top of every screen in the room-by-room mode, both the project name and the room name display in large white text. The following describes the general room input information that appear when you select or add a room:


    Main Room Inputs
    1. Name: This is the name that you originally inputted when you created the room. You can change the room name in this text box.
    2. # of occupants: Input the average number of people that will occupy this room. The total of all people entered in all rooms for a building should be equal to the total number of occupants inputted in the Block Load mode discussed above.
    3. Appliance load (BTUh): Input the approximate appliance load for the room (for purposes of cooling). This could include heat given off by a lamp, dishwasher, stove, oven, washing machine, or any other household device. For any rooms that do not include a household device, input a value of 0.
    Room Totals
    The section displays total room results, including:
    1. Total room cooling load: This displays the total room cooling load.
    2. Total room heating load: This displays the total room heating load.
    3. Total airflow: This displays the total room cooling airflow to be used for sizing duct work.
    Block Load Totals
    The section displays total block load cooling and heating loads and airflow results. This is used for your reference, only, and these values are in no way affected by the room inputs.

    Envelope Inputs
    Select the "Envelope" button to display a list of envelope items on the left-hand side of the screen. These envelope items apply only to the room that you are currently working on.


    Envelope List
    The envelope list displays a list of walls, doors, roofs, floors, or ceilings associated with the current room. The following describes how to create, edit, and delete envelopes:
    1. Create a New Envelope Item: To create a new envelope item, click the "+" button located in the upper right-hand corner of the list. A new form will appear that allows you to input a unique name for the envelope item. Click the "Save" button to add the new envelope. The new envelope is based upon the envelope item located in the default room of the "_Default" project. If you wish to copy from an existing envelope already located in the current room, select the "Copy from existing Envelopes" to display a list of all existing envelopes then select the envelope you wish to copy.


    2. Edit an Existing Envelope: To edit an existing envelope, select the envelope name with your finger to edit the information associated with this envelope item.
    3. Delete an Existing Envelope: Swipe your finger across the name of the envelope that you wish to delete. A "delete" button will appear allowing you to press it to delete the envelope.
    Select the envelope item that you want to edit. The following describes each of the inputs for room envelopes:
    Room Envelope Inputs


    1. Envelope name: This is the name that you originally inputted when you created the room envelope type. You can change the name in this text box.
    2. Envelope area: Input the area of the envelope item as it pertains to the current room. For example, if in the block load mode you created an above-grade wall that spans many rooms in a home, input just the area of the above-grade wall that is adjacent to the current room. You can also slide the indicator on the slider control located below the text box to increase or decrease the area value.
    3. Envelope type: This option allows you to select from one of the envelope items that you created in the block load mode discussed above. Press the icon on the far right of this cell to display a picker control that allows you to select from the list of envelope items. Once you have selected the envelope item, it will appear in this cell.


    Room Envelope Totals
    This section appears only in landscape mode. It displays the following results:
    1. Envelope cooling load contribution: This displays the total room cooling load contribution due to the specific room envelope item.
    2. Envelope heating load contribution: This displays the total room heating load contribution due to the specific room envelope item.
    3. Total room cooling load: This displays the total room cooling load.
    4. Total room heating load: This displays the total room heating load.
    5. Total airflow: This displays the total room cooling airflow.
    Block Load Totals
    The section displays total block load cooling and heating loads and airflow results. This is used for your reference, only, and these values are in no way affected by the room inputs.

    Window/Glass Door Inputs
    Select the "Window/Door" button to display a list of window/glass door items on the left-hand side of the screen. These window/glass door items apply only to the room that you are currently working on.


    Window/Door List
    The window/door list displays a list of windows and glass doors associated with the current room. The following describes how to create, edit, and delete the window/door list:
    1. Create a New Window/Door Item: To create a new window/door item, click the "+" button located in the upper right-hand corner of the list. A new form will appear that allows you to input a unique name for the window/door item. Click the "Save" button to add the new window/door. The new window/door is based upon the window/door item located in the default room of the "_Default" project. If you wish to copy from an existing window/door already located in the current room, select the "Copy from existing Windows/Doors" to display a list of all existing window/doors then select the item you wish to copy.


    2. Edit an Existing Window/Door: To edit an existing window/door, select the window/door name with your finger so as to edit the information associated with the window/door.
    3. Delete an Existing Window/Door: Swipe your finger across the name of the window/door that you wish to delete. A "delete" button will appear.
    Select the window/door item that you want to edit. The following describes each of the inputs that appear to the right of the window/door list:

    Room Window/Glass Door Inputs

    1. Window/Glass door name: This is the name that you originally inputted when you created the room window/door type. You can change the name in this text box.
    2. Window/Glass door area: Input the area of the window or door item as it pertains to the current room. For example, if you created a window that spans a couple of rooms in a building, input just the area of the window for the current room. You can also slide the indicator on the slider control located below the text box to increase or decrease the area value.
    3. Window/Glass door type: This option allows you to select one of the window/door items that you created in the "Block Load Info" section of the app. Press the icon on the far right of this cell to display a picker control that allows you to select from the list of window/door items. Once you have selected the item, return to the previous form.



    Room Window/Glass Door Totals
    This section appears only in landscape mode. It displays the following results:
    1. Win/Door cooling load contribution: This displays the total room cooling load contribution due to the specific room window/glass door item.
    2. Win/Door heating load contribution: This displays the total room heating load contribution due to the specific room window/glass door item.
    3. Total room cooling load: This displays the total room cooling load.
    4. Total room heating load: This displays the total room heating load.
    5. Total airflow: This displays the total room cooling airflow.
    Block Load Totals
    The section displays total block load cooling and heating loads and airflow results. This is used for your reference, only, and these values are in no way affected by the room inputs.

    Skylight Inputs
    Select the "Skylight" button to display a list of skylight items on the left-hand side of the screen. These skylight items apply only to the room that you are currently working on.


    Skylight List
    The skylight list displays a list of skylights associated with the current room. The following describes how to create, edit, and delete the skylight list:
    1. Create a New Skylight Item: To create a new skylight item, click the "+" button located in the upper right-hand corner of the list. A new form will appear that allows you to input a unique name for the skylight item. Click the "Save" button to add the new skylight. The new skylight is based upon the skylight item located in the default room of the "_Default" project. If you wish to copy from an existing skylight already located in the current room, select the "Copy from existing Skylights" to display a list of all existing skylights then select the item you wish to copy.


    2. Edit an Existing Skylight: To edit an existing skylight, select the skylight name with your finger so as to edit the information associated with the skylight.
    3. Delete an Existing Skylight: Swipe your finger across the name of the skylight that you wish to delete. A "delete" button will appear.
    Select the skylight item that you want to edit. The following describes each of the inputs that appear to the right of the skylight list:

    Room Skylight Inputs

    1. Skylight name: This is the name that you originally inputted when you created the room skylight type. You can change the name in this text box.
    2. Skylight area: Input the area of the skylight item as it pertains to the current room. For example, if you created a skylight in the block load mode that spans a couple of rooms in a home, input just the area of the skylight for the current room. You can also slide the indicator on the slider control located below the text box to increase or decrease the area value.
    3. Skylight type: This option allows you to select one of the skylight items that you created in the "Block Load Info" section of the app. Press the icon on the far right of this cell to display a picker control that allows you to select from the list of skylight items. Once you have selected the item, return to the previous form.


    Room Skylight Totals
    This section appears only in landscape mode. It displays the following results:
    1. Skylight cooling load contribution: This displays the total room cooling load contribution due to the specific room skylight item.
    2. Skylight heating load contribution: This displays the total room heating load contribution due to the specific room skylight item.
    3. Total room cooling load: This displays the total room cooling load.
    4. Total room heating load: This displays the total room heating load.
    5. Total airflow: This displays the total room cooling airflow.
    Block Load Totals
    The section displays total block load cooling and heating loads and airflow results. This is used for your reference, only, and these values are in no way affected by the room inputs.

    Reports

    The HVAC Residential Load Calcs HD app allows you to display and email a number of different types of reports. Touch the small "pie" icon located in the upper right-hand corner of the app. It will display a small dropdown menu with the following options:


    1. Individial Reports: This option allows you to display and email 5 different types of reports. See the explanation below.
    2. Complete HTML Report: This option allows you to display a complete HTML report that includes all inputs and results in a tabular format. This report replicates the report format located in the ACCA Manual J8 handbook.
    3. Email HTML Report: This option allows you to email the complete HTML report described above. The email also includes a spreadsheet attachment that you can open in Microsoft Excel so as to create custom reports.

    Individual Reports
    This menu option allows you to display 5 individual reports. You can navigate from one report to the next by swiping the screen with your finger from right to left. Also, you can email a PDF version of the report by touching the envelope icon to open your email client. The following is an explanation of each report:
    1. Summary Report: This report displays project summary information including demographic info about the home you are modeling and also total cooling and heating loads and airflows. This report is most appropriate for your clients.

    2. Checksum Report: This report displays summary, rule-of-thumb and checksum values for both cooling and heating. For example, it includes total cooling loads, airflows, BTUh/SqFt, and CFM/Ton values.


    3. Block Load Breakdown Report: This report displays detailed and complete cooling and heating load breakdowns. It is more detailed than the breakdown reports described above since it further itemizes individual envelope components (by wall, floor, etc.).


    4. Room Heating and Cooling Report: This report only displays if you have defined individual rooms (discussed above). It displays a list of all of the rooms defined, and cooling, heating, and airflow values for each room.

    5. Block Load Breakdown (Pie-Chart) Report: This report displays the cooling and heating load breakdown using a pie chart. These charts are similar to the ones discussed above.


    Touch the "Done" button in the upper right-hand corner to return to the main app screen.

    Complete HTML Report
    This option allows you to display a complete HTML report that includes all inputs and results in a tabular format. This report replicates the report format located in the ACCA Manual J8 handbook. You can also email this report with a spreadsheet attachment. The following is a screenshot that displays a sample HTML report.

    Preferences

    The preferences form is accessed by pressing the small "i" icon located in the upper right-hand portion of the screen on all of the main input forms. This form allows you to specify various global settings that apply to all projects. The following is an explanation of each input:

    1. Units: This selector allows you to specify whether to display all values in IP (Imperial or English) or SI (Metric) units. When you return to the main input screens, all values will reflect the new units.
    2. Digit Group Separator (Thousands Separator): This selector allows you to specify whether a thousands separator (ie - a comma - "1,000.00") should be utilized in all the input and output values. Specify "On" to include it, and "Off" to not include it. This option is important for international users of this application, where a comma is often not used as a digit separator.
    3. Display units for total cooling: Select either "BTUh(W)" or "Tonnage". This selection determines the units displayed for all of the total cooling load values.
    4. Floor area maximum value (SqFt or SqM): Input the maximum allowable floor area value that is displayed on the slider control that accompanies the floor area inputs.
    5. Floor area step value: Input the "step" value for the floor area input. This value is the amount that the floor area increases or decreases as you move the slider indicator along the slider control. If you specify 0, then incr/decr is continuous.
    6. Opening area maximum value (SqFt or SqM): Input the maximum allowable opening (window, skylight) area value that is displayed on the slider control that accompanies the opening area inputs.
    7. Opening area step value: Input the "step" value for the opening (window, skylight) area input. This value is the amount that the opening area increases or decreases as you move the slider indicator along the slider control. If you specify 0, then incr/decr is continuous.
    8. Dimension maximum value (Ft or M): Input the maximum allowable width/height/length values that are displayed on the slider controls that accompany these various inputs.
    9. Dimension step value: Input the "step" value for the dimension inputs. This value is the amount that the dimension value increases or decreases as you move the slider indicator along the slider control. If you specify 0, then incr/decr is continuous.
    10. Temperature maximum value (F or C): Input the maximum allowable temperature values that are displayed on the slider controls that accompany the temperature inputs.
    11. Temperature step value: Input the "step" value for the temperature inputs. This value is the amount that the temperature value increases or decreases as you move the slider indicator along the slider control. If you specify 0, then incr/decr is continuous.
    12. Unit occupant sensible load (BTUh or W): Input the amount of sensible load that one person contributes to the cooling load. This value is multiplied by the number of people to determine the internal cooling load contribution.
    13. Unit occupant latent load (BTUh or W): Input the amount of latent load that one person contributes to the cooling load. This value is multiplied by the number of people to determine the internal cooling load contribution.
    14. Company Inputs: This section allows you to input your company demographic information. This information is displayed on the HTML and summary reports discussed previously. It includes the following inputs:


      1. Company name
      2. Company contact
      3. Address 1
      4. Address 2
      5. City
      6. State
      7. Zip Code
      8. Country
      9. Phone
      10. Fax
      11. Email
      12. Website

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