The Room Data page lets you enter information about how the structure is defined, including the room dimensions, internal loads such as people, as well as the floors, roofs, walls, glass and doors of the room.

Room Name: Type a name for the current room.

System: This selection identifies which system, or air handling unit, that the current room is in. If the building you are calculating has more than one air handler unit, then you should divide the building up into Systems, with one system per air handler. You can define information about the system, such as the indoor temperature and the amount of infiltration, on the System Data page. You can define up to 30 different systems in a project.

Zone Number: Zoning is a grouping technique in which you can group rooms together, yet have them all serviced by one air handler (system). It often refers to an installation where groups of rooms are supplied with conditioned air by VAV boxes, which use dampers to vary the air volume in order to better meet the individual loads of different parts of the house as those loads change throughout the day. There can be up to 10 zones per system.

If you select to put the rooms in a system into multiple zones, Rhvac by default will automatically treat that system as a VAV multizone system, which means that it will use Manual J's Hourly Fenestration Gain (HFG) procedure to determine the sensible gains from glass when calculating cooling loads at the room level.

To use multiple zones but keep the system as a constant volume system and continue to use average loads at the room and zone level, select Yes for the "Use CV if Multizone" input on the System Data page.

Note that the "Average Load Procedure plus Excursion" method is always used in determining the load for the entire system regardless of whether the system is multizone..

Width, Length and Height: These inputs are used to find the conditioned floor area and volume of the room. The floor area is used for reference purposes and check figures while the room volume affects the infiltration CFM and load when infiltration is entered as an air changes per hour quantity.

Note that you can enter 1 X the area of the room as the room width and length if you like. For floors that have a heat loss or gain, you must enter the floor specifically as a Floor material in the Floor section of the Room Data page. Since it is not always the case that the floor width and length are the same as that of the general room dimensions, Rhvac Online allows for different width and length inputs related to the floor loads.

Ppl: This input item allows you to enter the number of people that will usually occupy the room during the maximum expected cooling load. The number of people can range from 0 to 9,999. If you enter a zero into this input item, the program will calculate the load for the room excluding people. Normally you should enter the maximum number of people you expect to occupy the room during the cooling season (since people are only used when calculating the cooling load). Do not specify people in rooms that are normally unoccupied when heat loads and solar loads are at their peak (normally from 1 to 6 pm). Normally the number of people in common rooms (such as the family room and dining room) is twice the number of bedrooms. The amount of cooling load per person is entered on the Outdoor Design Conditions page in the Sensible and Latent People Loads inputs.

S.Eq (Sensible Equipment Cooling Load): Click the Select button beside this input for the Equipment Cooling Loads page. This entry is included to allow you to enter any additional sensible load caused by heat generating appliances or equipment in the room. It can range from 0 to 99,999 Btuh. Normally a value of 1200 Btuh is used in the kitchen. Other candidates for this entry are workshops that are in constant use or rooms with a high density of computers. Normally, rooms with lots of computers have an additional load of 6 Btuh per square foot. If there is no heat generating equipment in the room, you can leave this entry as zero. When specifying this value, remember it will only be used when calculating a sensible (dry bulb) cooling load for the room. Do not specify an additional sensible load if the heat generating equipment is not normally used in the summer. Also, be sure to reduce the load by some appropriate fraction to account for intermittent use of the equipment. And finally, sensible loads due to lighting are entered in the Lighting Watts field.

L.Eq (Latent Equipment Cooling Load): This entry allows you to enter additional latent cooling loads caused by equipment or appliances. Clothes washers, swimming pools, fountains, hair dryers, and steam operated equipment are some examples of equipment that can contribute an additional latent load to a room. This load can be up to 99,999 Btuh.

Infiltration Required in CFM (Infil): You should normally account for infiltration on the Infiltration page. But If you would like to control the amount of infiltration for this room, you can enter an infiltration CFM here. This room's system will still receive the same amount of total infiltration which you enter on the Infiltration page for winter or summer, unless of course the total of what you enter at the room level exceeds that which you specify for the system itself. In that case, what you have entered for the rooms will govern the total system infiltration, and only those rooms (in that system) for which you have specified infiltration CFM will receive any infiltration. Note that this field accepts CFM only, no air changes per hour values are valid.

Ventilation Required in CFM (Vent): You should normally enter ventilation on the System Data page and not in this input at the room level. You should only use this input if you understand the purpose of it and your particular situation calls for entering your ventilation air on a room-by-room basis. Otherwise, leave this input at zero and enter your ventilation in the summer and winter ventilation inputs on the Ventilation page. Ventilation air is fresh air that is mechanically brought in through the return side of the air handler.

This input is only used when you have the relatively rare situation of needing to specify your total system ventilation on a room-by-room basis, where rooms in the system may have different outdoor air requirements, such as in a light commercial project. If you do use this input, the program will use either the total amount entered here for the rooms, or the amount entered for the system, whichever is greater. Note that this field accepts CFM only, no air changes per hour values are valid.

Lighting in Watts (Light): This entry is intended to be filled in primarily for commercial projects since residential heat gain calculations typically do not account for lighting. Enter the total heat gain, in Watts, that the light fixtures in this room will produce, including heat produced by lamps, ballasts, etc.. The wattage you enter here will be converted to Btuh by the formula 1 Watt = 3.41 Btuh. Note that if the building is lighted by fluorescent lights (as is the case in most light commercial jobs) then you must enter in the lighting load for each room here. To determine the lighting load, add up the Wattage and then add another 100-200 Watts per fixture for the ballast load. The valid range of values for this field is 0 to 99,999 Watts.

Occurrences of Room (Occ): Determines the number of times this room occurs in the building. The usual value for this input is "1." However, if you have a room that is repeated frequently throughout the building, such as an office with just internal loads, rather than entering it over and over again, you should input the room just once, then using this input declare how many times it occurs in the building. Note that if you wish to temporarily deactivate a room so that you could use it again later, you should enter that it occurs zero times.

Calculation Mode (Mode): Determines whether this room is to be heated, cooled or both. If a room is to be heated but not cooled, that room will be completely ignored in the cooling calculations, including those that have to do with the area and volume of the rooms, such as an air changes per hour of infiltration entered for the system.

Rad.F: Specifies the radiant floor Btuh per square foot output for this room's radiant floor. Click the Select button to open the Radiant Floor Properties page, which lets you enter additional data.

Notes about this room: This box lets you type in notes about the room.

All Materials (Floors, Roofs, Walls, Glass and Doors)

M, S, D, C and Delete Buttons: These buttons to the right of each of the Material inputs let you select a material (M), save the material to the Default Room (S), insert one of the default material from the Default Room Data page (D), copy the above row (C), or delete the entire row for that material (X). The "C" button to copy the above row is disabled for the first material (row 1). Note that the D button is actually a menu, so after you add one or more default materials when you move your mouse over the D button a popup menu of your default materials will let you select which one you want to insert. If you have not added any default materials, the text of the one popup menu item says, "(empty)".

Viewing Floors [Roofs, etc.]: This dropdown list lets you select the range of rows you want to see. Each room has forty (40) material rows available.

Floors

These entries should only be used if some portion of the floor of the room is over an unconditioned space such as a crawl space or ground slab. If the entire floor is over a conditioned space such as is normally the case in second story rooms, then you should not enter a floor for the room.

Floor Material: Specifies the Manual J or custom construction code for the floor.

U-Value: Specifies the U-value of the material, which indicates how well heat flows across the material.

Width and Length: The width and length of the floor should correspond to the area of the floor that is exposed to an unconditioned space (either the ground, a basement, or an open crawl space). In cases where the floor is not rectangular and it is not possible to give a single length and width, you should consider entering the length as 1 foot and the width as the actual area. The main point to remember is that the product of the floor length and width entries should be equal to the actual floor area exposed to an unconditioned space.

Note: The room area corresponds to the total conditioned area of the room while the floor area corresponds to the total area of floor that has an unconditioned space beneath it. Therefore, it is entirely possible for the floor area entered here to be substantially different from the room area entered above. (The room, not floor area, is used when determining check figures such as the square foot per ton, and CFM per square foot).

Perimeter: This value is only used if you specify a floor type 22 or 23 - concrete slab on grade, and can be 0.0 to 999.9 feet long. So if the floor of a room is NOT concrete slab on grade, you should leave the perimeter as zero. The perimeter value is needed for concrete slab on grade type floors because such floors lose heat through the perimeter and not through the center. So the perimeter of the floor in feet will be used when determining the heating load due to the floor. Note that the heat gain (cooling load) through such a floor will always be zero.

STD, WTD: The floor Summer Temperature Difference (STD) and Winter Temperature Difference (WTD) inputs are only for situations where you have a floor over an unconditioned space and you do not want it to be treated like any of the conventional floor types. If you enter a value greater than zero here, the program will treat the floor in the same way that it does a partition wall, where it will determine the loss or gain by multiplying the u-factor times the area times the TD value you enter.

Note that if you enter a number greater than zero for either the STD or WTD, the floor will automatically be treated as a partition for both the heating and cooling load calculations.

Scrollbar: Use the scrollbar to scroll up and down through the list of floors for the room.

Plus and Minus Buttons: Click the plus and minus buttons to increase or decrease the number of floors visible at a time.

Roofs

These inputs are only used if you have some portion of the ceiling of the room that is exposed to outside air or to an unconditioned space. If the ceiling of the room is exposed to a conditioned space (as occurs on first floor rooms of a two story building), you should not specify a roof for the room. Ceiling number 18 should be used with suspended ceilings and ceiling number 17 should be used any time the ceiling and the roof are one part with no dead air space between them. A complete list of the various material types is also shown in pages 83-84 (Table 4) of Manual J. Mobile home information is shown in Appendix A-1 of Manual J.

Roof Material: Specifies the Manual J or custom construction code for the roof.

U-Value: Specifies the U-value of the material, which indicates how well heat flows across the material.

Width and Length: The width and length of the ceiling should correspond to the area of the ceiling that is exposed to an unconditioned space (either the outside air or an attic area). In cases where the ceiling is not rectangular and it is not possible to give a single length and width, you should consider entering the length as 1 foot and the width as the actual area. The main point to remember is that the product of the ceiling length and width entries should be equal to the actual ceiling area. Note that the ceiling area of a room can be different from the floor area.

Direction: This entry is only used when a skylight has been included on the roof. If there is no skylight on the roof, simply leave this entry at its default value of UP. If there is a skylight on the roof, you should enter the direction the skylight faces since the direction will affect the solar load. If you specified a horizontal skylight be sure to enter the roof direction as UP. For the other skylights (30 degrees, 45 degrees, or 60 degrees) simply enter the direction the skylight faces. If you do not know what direction the skylight faces, a northeast (NE) or northwest (NW) direction is a good mid range value to choose. Note that the lowest HTM values are for north facing skylights, following by south facing skylights. Also note that east and west facing skylights have the highest HTM values of all. Valid directions are:

NW - Northwest	N - North	NE - Northeast
W - West		E - East
SW - Southwest	S - South	SE - Southeast

STD, WTD: The roof Summer Temperature Difference (STD) and Winter Temperature Difference (WTD) inputs are only for situations where you have a roof under an unconditioned space and you do not want it to be treated like any of the conventional roof types. If you enter a value greater than zero here, the program will treat the roof in the same way that it does a partition wall, where it will determine the loss or gain by multiplying the u-factor times the area times the TD value you enter.

Note that if you enter a number greater than zero for either the STD or WTD, the roof will automatically be treated as a partition for both the heating and cooling load calculations.

Scrollbar: Use the scrollbar to scroll up and down through the list of roofs for the room.

Plus and Minus Buttons: Click the plus and minus buttons to increase or decrease the number of roofs visible at a time.

Walls

These inputs should only be used if some portion of the wall in a room is exposed to an unconditioned space such as an unconditioned room, a vented room, the outside air or if the wall is an exterior below grade wall. If the entire wall is exposed to a conditioned space (as is normally the case for interior walls, for example), then you should not enter the wall. Note that if you specify a below grade wall, the cooling load due to the wall will be zero. Directly below the word Wall is a column of numbers; these numbers are the wall reference numbers of the various walls of the room and cannot be changed. Note that each glass section and door entry requires a wall reference number.

Wall Material: Specifies the Manual J or custom construction code for the wall.

U-Value: Specifies the U-value of the material, which indicates how well heat flows across the material.

Length and Height: The length and height of the wall should correspond to the gross area of the wall that is exposed to an unconditioned space (either an unconditioned room or the outside air). In cases where the wall is not rectangular and it is not possible to give a single width and height, you should consider entering the height as 1 foot and the width as the actual area. The main point to remember is that the product of the wall length and width entries should be equal to the actual wall area. The wall width and height can be 0.0 to 999.9 feet each. Note that you should always enter the gross wall area here as Rhvac Online will automatically subtract the appropriate glass and door areas for each wall section. If a wall consists of two material types (as when a short face brick section is used, for example), you should enter each different material type as a separate wall. The area of each wall section you enter should be equal to the gross area of one material type only.

Note that for basement walls, type 15, where the number of feet below grade is indicated by the number at the end of the construction code after the final dash, the height includes the above and below grade part of the wall. Rhvac Online will automatically calculate from the height you enter how much of the wall is above and how much is below grade.

Direction: Specifies the compass direction the wall faces, which affects the cooling load for the wall if the Peak calculation method is used. Also affects the cooling load for any glass items located in this wall.

STD, WTD: To designate this wall as a partition, enter the temperature difference across the wall in the summer (STD) and winter (WTD). If this wall is not a partition leave both of these inputs at zero.

If the space on the other side of this wall is heated but not cooled, enter only the WTD. Or if it is cooled but not heated, enter only the STD.

Note that if you enter a number other than zero for either the STD or WTD, the wall will be automatically treated as a partition. But in the case of basement walls (type 15), only the above grade part of the wall will be treated as a partition. The below grade part will be treated as a regular below grade wall.

If you want to make it so the temperature difference is appropriate for a shaded wall exposed to the outdoor air based on the current indoor and outdoor design conditions, enter -1 for the STD. The calculations will then use the appropriate partition CLTD table from Manual J's Table 4B to determine this wall's sensible gain.

Scrollbar: Use the scrollbar to scroll up and down through the list of walls for the room.

Plus and Minus Buttons: Click the plus and minus buttons to increase or decrease the number of walls visible at a time.

Glass

These inputs should be used for windows, skylights, sliding glass doors, and French doors. Note that each glass section has a wall reference number. This tells Rhvac Online which direction the window faces and allows the program to subtract the glass area from the appropriate wall. Directly below the word Glass is a column of numbers; these numbers are the numbers of the various glass entries in the room and cannot be changed. Note that the term "double pane" refers to two sheets of glass with dead air space between them, while the term "triple pane" refers to three sheets of glass with dead air space between them. Double pane and triple pane windows are also called double glazed and triple glazed.

Glass Material: Specifies the Manual J or custom construction code for the glass.

U-Value: Specifies the U-value of the material, which indicates how well heat flows across the material.

Width and Height: The width and height of the window or glass door should be measured from the inside of the frame and should include the material (either wood or metal) that surrounds the glass. In cases where the window is not rectangular and it is not possible to give a single width and height, you should consider entering the height as 1 foot and the width as the actual area. The main point to remember is that the product of the glass height and width entries should be equal to the actual window or glass door area including the frame. The glass length and width can be 0.0 to 999.9 feet each. Note that the area entered here will be subtracted from the wall area of the reference wall.

Reference (Ref): This entry is a number that corresponds to one of the walls entered above. Every glass entry should have a wall reference number. This number tells Rhvac Online what direction the glass faces (which is critical when determining the cooling load) as well as allowing the program to subtract the total glass area from the appropriate wall. (Be sure the area of the glass entry does not exceed the wall area!) Valid wall reference numbers are 1 to 20. Remember that Construction Material types 7A - 7L are skylights and valid roof reference numbers are 1 to 8. Note that when you type or select a valid glass construction code, the reference defaults to 1.

If you are entering a skylight the wall reference number will actually be a roof reference number. Remember that glass entries will be skylights if the construction type is skylight specific. The area of the skylight will be subtracted from the area of the roof. Note that shading coefficients 49, 53, and 57 correspond to horizontal roofs - so the roof direction for these three shading coefficients must be "UP". But for other skylight tilt angles, you must specify a roof direction corresponding to the direction the skylight faces. If you do not know which direction the skylight faces you should use northeast to provide a mid range value. East and west facing skylights have the highest HTM values while north facing skylights have the lowest HTM values.

If you are entering a glass wall, you will still have to define a wall facing the correct direction. When you define this wall, make sure the gross area of the wall exactly equals the gross area of the glass. This will cause the Rhvac Online program to correctly calculate the solar gain and heat loss of the glass wall. If the glass entry is surrounded by two different wall types then you should enter it in two parts corresponding to each wall type. For example, suppose you entered a sliding glass door on a building that had a four foot high face brick portion. The sliding glass door would then be entered as two glass sections; the first door being a four foot section referencing the face brick wall and the rest of the sliding glass door referencing the wall without the face brick section. Whenever you enter glass doors or windows in sections be sure the total area of the sections adds up to the actual area of the glass window or door.

Solar Heat Gain Coefficient (SHGC): Specifies the generic or NFRC-rated solar heat gain characteristic of the glass. Lower numbers mean that the glass produces less solar gain..

Occurrences (Occ): Determines the number of times this glass occurs in the wall or roof. The normal value for this input is "1". But if you have a glass that occurs several times in the same wall or roof you can enter the glass only once and enter the number of occurrences of the glass here. The maximum allowed value is 99.

Overhang Projection and Offset (O.Proj and O.Off): These inputs are only used if there is an external overhang installed over the window. The overhang projection represents the maximum horizontal distance in feet that the overhang projects out from the glass. The overhang offset represents the distance that the overhang is above the top of the glass. If the overhang is directly above the window, the offset should be zero. If the glass is a skylight, both of these inputs must be zero.

Scrollbar: Use the scrollbar to scroll up and down through the list of glass items for the room.

Plus and Minus Buttons: Click the plus and minus buttons to increase or decrease the number of glass items visible at a time.

Doors

You should only specify an exterior, non-glass door with this entry. Glass doors are entered into the Glass frame above. Directly below the word Door are the door reference numbers which cannot be changed. Each door has a wall reference number. This number tells Rhvac Online which direction the door faces and allows the program to subtract the area of the door from the appropriate wall.

Door Material: Specifies the Manual J or custom construction code for the floor.

U-Value: Specifies the U-value of the material, which indicates how well heat flows across the material.

Width and Height: The width and height of the door are entered in feet, and should correspond to the gross area of the door that is exposed to the outside air. In cases where the door is not rectangular and it is not possible to give a single width and height, you should consider entering the height as 1 foot and the width as the actual area. The main point to remember is that the product of the door width and height entries should be equal to the actual door area. Note that the door area entered here will be subtracted from the wall area of the reference wall. The width and height of a door can be 0.0 to 999.9 feet each.

Wall Reference Number for Door (Ref): This entry is a number that corresponds to one of the walls entered above. Every door must have a wall reference number. Valid wall reference numbers are 1 to 20. This number tells the Rhvac Online program what direction the door faces as well as allowing the program to subtract the area of the door from the appropriate wall. (Be sure the door area does not exceed the wall area!) If the door is surrounded by two different wall types you should enter the door in two parts corresponding to each wall type. For example, if the building had four foot high face brick and the rest of the wall was wood frame, you would enter the first four feet of the door referencing the face brick wall and the rest of the door referencing the wood frame wall. Be sure the total area of the two door sections does not exceed the actual area of the door. Note that when you type or select a valid door construction code, the reference defaults to 1.

Scrollbar: Use the scrollbar to scroll up and down through the list of doors for the room.

Plus and Minus Buttons: Click the plus and minus buttons to increase or decrease the number of doors visible at a time.