AE Calcs Web

document.xls - Index - Printed 04/21/2023 16:57:59 - p.1 of 18

Architectural Engineering Calculations

Discipline Type Description Web Ref:Acoustic Load Ching p228-232 JEMArchitecture Load JEMArchitecture Load Butler 58-59 JEMArchitecture Load JEMElectrical Load Ching 74-79 JEMHVAC Sizing Ching 117-127 JEMHVAC Load Ching 117-127 JEMHVAC Load JEMHVAC Sizing JEMLighting Load Ching 142-150 JEMPlumbing Load Butler 584 JEMProperties JEMProperties JEMStructure Load Ching 238-245 JEMStructure Stress Ching 238-245 JEMStructure Load Ching 238-245 JEMWorkbook JEMWorkbook JEMWorkbook JEM

ByReverberation Time MC SquaredBuilding Gross & $ from Net Arizona StateBuilding Occupancy or Size EstimateBuilding SizeBuilding Watts Required EstimateAir Flow Required & Duct Sizing Online CalcBasic Wall ConductionInfiltration and Ventilation Heat LoadSeasonal Fuel Usage and CostLighting Fixture RequirementsBuilding Water RequirementsConversion FactorsMaterial PropertiesFloor Load EstimatesSimple Beam - Stress & DeflectionTributary Area Load EstimateContributorsFuture WorkRevision History

This spreadsheet gives a number of basic Architectural Engineering (AE) calculations to allow initial quick estimates of loads and sizes for some of the major systems. It is a work in progress and will be updated and corrected. It is not exact and should not be used for a building after initial estimates. Use the professional-level programs for that purpose.

The Calculation column shows how the cell was calcuated using named variables - it should help you understand the logic. In most cases it's just the application of basic math and physics although a few formulae are empirically derived. The hard part is often the units - which are carefully shown.Be sure to look at the "comments" - usually in the "input" column or the description column on this page - you see them by putting the cursor over any cell that has a small red triangle in the upper right corner. They will explain meanings and give typical values.

- To use it click on the hyperlink to the calculation you're interested in (you may make suggestions for future ones on the "FutureWork" sheet).- In each worksheet the white boxes are ones you're intended to modify - "reasonable" default values are provided.- You may "unprotect" the workbook and modify anything you wish.- The "Return to Index" button will bring you back to this sheet.- Note the "grouping" indicators at the top of each sheet. By clicking on the "1" or the horizontal line you may hide the calculations - probably better for printing.

Users are urged to make corrections and additions and send the revised sheet back to J. Mitchell.

http://www.mcsquared.com/homerteng.htm

http://www.asu.edu/aad/manuals/pac/pac316.html

http://www-sci.lib.uci.edu/HSG/RefCalculators4.html#MECH-HEATAIR

B3

Selection Triangles This sheet uses Excel's database capabilities. To see only those things of interest in a column click on the triangle and select what your interested in e.g "Structure" in the Discipline column

D3

Calculation Description ROT = Rule of Thumb

F3

Ching = "A Visual Dictionary of Architecture" - Francis D.K. Ching - 1st Ed. - Wiley Butler = "Standard Handbook of Architectural Engineering" - Robert Brown Butler - 1st Ed - McGraw Hill

G3

Who provided the information.

D4

Calculates the time it takes a sound to decrease by 60 decibels in a space - one preliminary measure of the space's suitability for either music or speech

D5

Estimate the "Gross" building size and cost from the "named" spaces, those that have a specific function. This is often used at the start of a design when "programming" the building and checking the feasibility.

D6

Estimate the number of people (occupants) in a building of a given size and type.

D7

Calculate the gross size of an existing building using measurements of the building dimensions.

D8

Esimate the electrical usage of a building from the types of space within the building

D9

Estimate how much air (CFM) is required to provide a given amount of heat (or cooling). From that calculate the duct size necessary to transport the air.

D10

Calculate the conductive heat flow through a wall and window assembly.

D12

Given the "worst case" heating or cooling load on a small building one can calculate the energy and costs to heat or cool the building for the entire season.

D13

Calculate the number of lighting fixtures required for a space given the lighting level desired and a choice of fixture. Also calculates watts.

D14

Calculate the daily average water required for a building as well as the peak load given the building size and occupancy.

D17

Estimate the "gravity" load for a given area - typically a building "bay" bounded by four columns or a "tributary area"

D18

Calculates the stress and deflection at a point "x" for a simple beam with a uniform dead load applied on a tributary area as well as two point loads along the beam

D19

Estimate the loads on a beam due to the "tributary area" for that beam.

document.xls - Architecture - Printed 04/21/2023 16:58:01 - p.2 of 18

Architecture Calculations

Gross Area & Cost from Net

Input Value Units Calculation User CommentAllocation Offices 4,000 SF #VALUE!Allocation Meeting Room 2,600 SF #VALUE!Allocation Storage 1,500 SF #VALUE!Allocation Eating Area 1,250 SF #VALUE!Allocation Lobby 400 SF #VALUE!Allocation Work Area 6,000 SF #VALUE!Allocation Athletic Area 1,200 SF #VALUE!Allocation Mechanical Electrical 1,500 SF #VALUE!Circulation & Structure Factor 32%Building Cost Per SF $ 130 $/SF

Named Areas Total 18,450 SF #VALUE!Circulation & Structure 5,904 SF #VALUE!Building Gross Area 24,354 SF #VALUE!Building Cost $ 3,200,000 $ #VALUE!CircStr Percent of Gross 24% #VALUE!Building Efficiency 76% #VALUE!

Building Gross Size - Measured

Input Value Units Calculation Length Floor 1 80.0 FtWidth Floor 1 60.0 FtHeight to Next Floor 1 11.0 FtLength Floor 2 80.0 FtWidth Floor 2 60.0 FtHeight to Next Floor 2 11.0 FtLength Floor 3 80.0 FtWidth Floor 3 60.0 FtHeight to Next Floor 3 11.0 FtLength Floor 4 80.0 FtWidth Floor 4 60.0 FtHeight to Next Floor 4 11.0 Ft

Area Floor 1 4,800 SF #VALUE!Area Floor 2 4,800 SF #VALUE!Area Floor 3 4,800 SF #VALUE!Area Floor 4 4,800 SF #VALUE!Total Area 19,200 SF #VALUE!

#VALUE!Volume Floor 1 52,800 CF #VALUE!Volume Floor 2 52,800 CF #VALUE!Volume Floor 3 52,800 CF #VALUE!Volume Floor 4 52,800 CF #VALUE!Total Volume 211,200 CF #VALUE!

Building Occupancy Estimate

Input Value Units Calculation

When designing a building a critical number is the building size because it affects both the building cost and issues like siting the building and zoning coverage requirements. While this number can be determined a number of ways one "usual" starting point is to add up the individual areas for each "function" that must happen in the building - this produces the "Named Areas Total". The calculation shown takes some typical functions (be sure to check the comments) then shows how to determine the Building Gross Area, and thus the cost.

Calculating the total Area and Volume is straightforward. You can add as many more floors or pieces of floor as you wish.The "Height to Next Floor" is often called the "Floor-to-Floor" height.

Function Breakdown

Allocation Offices

Allocation Meeting Room

Allocation Storage

Allocation Eating Area

Allocation Lobby

Allocation Work Area

Allocation Athletic Area

Allocation Mechanical Electrical

B6

Default example show 40 people at 200SF/office Offices can range from 80SF clerk to 250 SF middle manager to 1000SF CEO

B7

Default example show 4 rooms at 400SF and 1 @ 1000SF The 400SF might hold 20 people and the the 1000SF might hold 60

B13

Mechanical & Electrical Allocation is best determined from looking at the actual equipment needs, but a reasonable starting point is 3% of the expected building gross area.

B14

A percentage, determined from experience for different building types that makes allowance for the necessary corridors, stairs, wall thicknesses, chases etc. Typical values are: - Efficient apartment bldg. 15% - Typical Office Building 35% - Hospital 80%

B15

This number is obtained from cost estimating books such as the many R.S. Means series. In 2002 typical values are: Laboratory $350/SF Institutional Classroom $220 Institutional Dormitory $180/SF Speculative Office Building $130/SF Large Scale Residential $90/SF

B17

The sum of all the areas for which you can define a specific function: - rooms - storage closets - lobbies - etc But not wall thicknesses and corridors or mechanical chases. Note that this is actually refined another level in detailed architectural programming to consider at a suite level first.

B19

This is the area that is critical when developing a cost for the job. It is the one multiplied by the $/SF for a building type in a specific location of specific quality level to arrive at the estimated cost during preliminary design stages. Of course a detailed "take off" of the building is used later.

B21

Note that this is less than the "Circulation and Structure"% because it's based on the whole building. This is the number that you calculate from building plans after the fact.

B38

These dimensions would normally be the "gross" dimensions to the outside faces of walls.

B40

This is often measured in a stairwell from one floor level to the next.

document.xls - Architecture - Printed 04/21/2023 16:58:04 - p.3 of 18

OC Building Type OfficeOc SF per Occupant 160 SF/OccOc Building Gross Area 19,200 SF

Oc Number of Occupants 120 Occupants #VALUE!

Oc Known Occupants 120 OccupantsOc Building Size from Occupants 19,200 SF #VALUE!

Knowing how many people will be in a building is important in many other calculations (HVAC and Plumbing particularly). This calculation assumes that you know the building gross size and want to know how many people it will accommodate for a particular use.

You can go the other direction equally well.

B72

See the SF/Occupant entry below to choose a building type

B73

SF/Occupant Estimates For preliminary purposes the following numbers may be useful in the USA, but should be checked with a client or more detailed source. The numbers given produce "Gross" areas. Apartment - 340 SF/Occ Hotel - 170 SF/Occ Assembly Area (movies, lecture halls) - 25 SF/Occ Gymnasiums - 70 SF/Occ Meeting Room - 30 SF/Occ Restaurant - 20 SF/Occ Offices - Cubicles - 160 SF/Occ Ref: Standard Handbook of Arch Eng. 1st Ed. p58-59

B76

Limitation of this Estimate: This estimate assumes a single use in the building, but most buildings have multiple uses. You must estimate the area for each use to come up with a good estimate of total occupancy. If, for example, the ground floor has a restaurant in it, or there is a meeting room, then the total occupancy would be much greater than this estimate.

document.xls - Structure - Printed 04/21/2023 16:58:05 - p.4 of 18

Structures Calculations

Floor Load Estimates

Input Value Units Calculation User Comment

Space Width 20 FtSpace Length 35 FtSpace Floor to Floor 12 FtSpace Floor Thickness 8 InchesMax Furniture Weight 2,400 Lb #VALUE!Max Floor Equipment Weight 2,400 Lb #VALUE!Max People Weight 4,000 Lb #VALUE!Built-In Cabinet Weight 8,000 Lb #VALUE!Hung Equipment Weight 1,600 Lb #VALUE!Floor Weight per CF 150 Lb/CF #VALUE!Ceiling Weight per SF 3 Lb/SF #VALUE!Partition Weight per SF Vertical Face 5 Lb/SFV #VALUE!

Space Area 700 SF #VALUE!Space Volume 8,400 CF #VALUE!Space Perimeter 110 LF #VALUE!Partition Area 1,320 SF #VALUE!Built-In Equipment Weight 9,600 Lb #VALUE!Floor Assembly Weight 70,000 Lb #VALUE!Ceiling Assembly Weight 2,100 Lb #VALUE!Partition Weight 6,600 Lb #VALUE!Live Load Weight 8,800 Lb #VALUE!Dead Load Weight 88,300 Lb #VALUE!Total Load 97,100 Lb #VALUE!PSF Live Load 13 Lb/SF #VALUE!PSF Dead Load 126 Lb/SF #VALUE!PSF Total Load 139 Lb/SF #VALUE!Total Load/CF 12 Lb/CF #VALUE!

Tributary Area Load Estimates

Input Value Units Calculation Trib Length Beam 24 FtTrib Width to Next Beam on Right 8 FtTrib Width to Next Beam on Left 10 FtTrib Floor Thickness Estimated 6 inTrib Beam Width Estimated 10 inTrib Beam Depth Estimated 18 in #VALUE!Trib Uniform Floor Live Load 50 Lb/SFTrib Wall Height over Beam 11.5 FtTrib Wall Material Thickness over Be 8.5 InTrib Density Floor Material 135 Lb/CFTrib Density Wall Material 90 Lb/CF

Trib Width Tributary Area 9 Ft #VALUE!Trib Floor Slab Volume 108 CF #VALUE!

Trib Wall Volume Resting on Beam 195.5 CF #VALUE!

Trib Beam Volume 30 CF #VALUE!

Trib Floor Slab Load per Foot Beam 608 Lbs/LF #VALUE!Trib Beam Load per foot 169 Lbs/LF #VALUE!Trib Wall Over Beam Load per foot 730 Lbs/LF #VALUE!

The most basic task in structural analysis is to find out how much load is applied to a building. This calculates the "gravity" load for a given area - typically a building "bay" bounded by four columns or a "tributary area" spanning from the midpoint of one bay to the midpoint of the next and the full length of the bay.

A basic distinction is between "live" and "dead" load. It's much easier to predict the "dead" than the live load because the designer has control over it whereas they have to guess at the worst case for live load.

This calculation is a good approximation - but should not be used for a real design. It does NOT take into account factors of safety, code requirements and other important ingredients. Take the structures class first.

Note how very much bigger the dead load is than the live load in most cases.

B9

This is the thickness of the floor slab assembly, not the full ceiling plenum. It's typically 4-10" of concrete. You can estimate an average thickness.

B10

The default estimate is for 12 pieces at 200# per piece.

B11

The default estimate is for four pieces of 600#. This means equipment that the owner/tenant moves in and that is not built-in.

B12

The default estimate is for 20 people weighing 200#. You always want to think of the "worst case" - e.g. a party with lots of people close together.

B13

This is the "casework" which is hung on walls or permanently attached to the floor. It's often estimated by the linear foot which is how it's show in the default of 400#/ft * 20ft.

B14

As with cabinets, this is equipment that's hung from the ceiling - Lighting fixutres, HVAC units, piping etc. The example here is for 4 units of 400#. This takes into account the connecting ductwork, conduit, piping etc.

B15

The density of the floor slab. Concrete weighs about 150#/CF and is the most common ingredient in floor slabs.

B16

This addresses the weight of a "hung ceiling" of acoustic tile. They're typically in the 2-4#/SF range. A plaster ceiling could be more in the range of 15-20#SF.

B17

You need to estimate the weight of the walls surrounding the space. The default show here is assumes 2 pieces of drywall on steel studs. I've estimated 2 pieces of drywall 4'x8' weighing 60# each plus 4 studs weighing 10# each. To calculate the entire building weight one would share this weight with the adjoining space, but I've included it all here for simplicity - the conservative approach.

B28

This is the weight to be transferred to the vertical elements must carry the load down to the ground. The load the foundations must carry is the sum of these for each floor plus the weight of the vertical load bearing elements and the foundations themselves.

B30

Most Codes would never allow less than about 30#/SF as a design load. For public spaces its often 100#/SF and for storage spaces up to 300#/SF. You can see that the code builds in a factor of safety.

B33

This number isn't often used, but can be very interesting when comparing different designs for high volume structures such as stadiums or warehouses

B40

This is the typically also the long dimension of a "bay" to the centerline of the column supporting it. Note that we do not include the column weight because it is self-supported. Ideally we should leave out its area in the calculations, but that's over-refining our estimate.

B41

For many beams the distance to the next beam to the right and to the left is equal, but not always. Note that the definition of "right" and "left" is up to you in your specific case.

B43

This is the structural floor thickness. In the case of composite systems such as corrugated steel with concrete make your best estimate of the average depth. It won't be far wrong - remember this is only an estimate.

B44

As with the floor thickness you'll estimate a width - probably conservatively. The default of 10" is reasonably common for floor bays.

B45

This is the depth of the beam projecting beneath the floor slab. A reasonable estimate is 3/4 of the length of the beam in inches. That's how this default is arrived at, but you can change it.

B46

As always, this is the greater of: - The code requirement - The owner's requirement - Your professional judgement

B47

This assumes that a signficant wall/partition is constructed directly over the wall (actually it doesn't have to be exactly over it) running the full length of your beam. The height is the constructed height of the wall - often the floor-to-floor height minus the thickness of the slab on the next floor. The default shown of 11.5' is based on a typical office building Floor-to-Floor of 12'.

B48

Use the actual thickness of the material minus any void spaces. The 8.5 inches shown assumes a typical concrete block wall faced with gypsum (drywall) board on both sides. Again, remember that this is only an estimate.

B49

The default of 135 lb/CF is based on standard weight concrete

B50

The default of 90 lb/CF is based on Concrete Masonry Units (CMU)


Trib Live Load per foot 450 Lbs/LF #VALUE!Trib Subtotal Dead Load per foot 1,510 Lbs/LF #VALUE!

Trib Total Dead Load for Beam 36,200 Lbs #VALUE!Trib Total Live Load for Beam 10,800 Lbs #VALUE!Trib Total Load for Beam 47,000 Lbs #VALUE!

Trib Symmetrical Reaction Load 23,500 Lbs #VALUE!

Beam Stress & Deflection

Input Value Units Calculation Case

Bm Beam Shape BBeam Geometry

Bm Beam Depth -"d" 20.00 inchesBm Flange thickness 0.00 inchesBm Flange width 2.63 inchesBm Web Thickness 0.00 inches

Material PropertiesBm Modulus of Elasticity 1,600,000 psiBm Density 32 lbs/ft3Bm Max Tension/Compression Stress 1,800 psi

Loading GeometryBm Beam Length - "L" 20.00 ftBm Beam Spacing - "s" 18.00 inBm Point Load1 X coord. - "Px1" 5.00 ftBm Point Load2 X coord.. - "Px2" 10.00 ft

Live LoadingBm Uniform Load - "w" 80 lb/SFBm Point Load 1 - "P1" 500 lbBm Point Load 2 - "P2" 500 lbBm X Position Evaluated - "x" 10.00 ft

Beam Unit Properties - CalculatedBm Web Height (calc) 20.00 inches #VALUE!

Bm Area 53 in2 #VALUE!

Bm Moment of Inertia 1,750 in4 #VALUE!

Bm Weight/Foot of Length 12 lbs/linear-ft #VALUE!Bm Section Modulus 175 in3 #VALUE!

Beam Total PropertiesBm Beam Weight 233 Lbs #VALUE!Bm Live Load Carried 2,400 Lbs #VALUE!Bm Total Load Carried 2,633 Lbs #VALUE!Bm Total Load/Ft 132 Lbs/Ft #VALUE!

MomentsBm Moment UDL 6,583 ft-lbs #VALUE!

When designing a beam (or girder) it's essential to find how much load is applied to it. To do so one must define the "tributary area" that the beam is supporting. A conservative approach (neglecting the fact that girders at the end may carry some load too) defines the tributary area as the length of the beam times the tributary width. The tributary width is best estimated as the distance from halfway to the beam on the left TO halfway to the beam on the right. (Note that where the widths are constant then this is just the distance from one beam to the next - edges are where life usually gets more interesting.)

In this case we've also assumed a wall resting on the beam - a fairly typical situation in buildings, especially for fire separation.

We've shown the load per linear foot (Lbs/LF) as well as total loads because that is often used in beam calculations.

This calculation is a good approximation - but should not be used for a real design. It does NOT take into account factors of safety, code requirements and other important ingredients. Take the structures class first.

Note how very much bigger the dead load is than the live load in most cases.

B87

Enter either I or B - note use of logic in formulas

B88

To be realistic you may wish to take values from manufacturer's information. Note that for real I-Beams the rounded corners make small changes from what is calculated here.

B94

Modulus of Elasticity for Various Materials Steel - 30,000,000 PSI Fir - 1,600,00 PSI Basswood - 1,460,000 PSI

B95

Density for Various Materials: Steel - 515 Lb/Ft3 Fir - 32 Lb/Ft3 Basswood - 24.9 Lb/Ft3

B96

Max Tension/Compression: Steel - 18,000 PSI Fir - 1,800 PSI Basswood - 1,640 PSI

C111

Using the theorem that Ix' = Ixc + a^2*A


Bm Moment P1 1,250 ft-lbs #VALUE!

Bm Moment P2 2,500 ft-lbs #VALUE!

Bm Total Moment at X 124,000 In-lbs #VALUE!Stress Calculation

Bm Maximum Fiber Stress at X 709 psi #VALUE!Bm Less Than Allowable OK #VALUE!

Deflection CalculationsBm Deflection due to UDL 0.169 in #VALUE!

Bm Deflection due to P1 0.035 in #VALUE!

Bm Deflection due to P2 0.051 in #VALUE!

Bm Deflection Total 0.256 in #VALUE!

Bm Deflection Ratio 937 :1 #VALUE!

BEAM CALCULATIONSThis document is prepared as a starting point for beam design It is important to realize that it is simplified for the sake of education. In particular: - shear is ignored- buckling is ignored- all stresses are assumed in the plane of symmetry.- the beam is assumed to be simply supported- factors of safety are built into the allowable stress.

Warning: The calculation is only for point "x" along the beam. You must explore multiple "x" values to determine the 'worst case'. For symettrically loaded beams that is at the midpoint of the span, but for unsymettrical situations you must find the 'worst case' location. Excel's "solver" can be very handy for this.

Reference: The specific terms used in this spreadsheet were derived from Timoshenko & Young - Elements of strength of Materials - 4th Edition (1962).A more recent reference (used in Drexel's courses) is: Gere & Timoshenko - Mechanics of Materials. - 3rd Edition 1990. The relevant chapter in that book for fuller understanding of the equations used here is: Chapters 5 (Stresses) & 7 (Deflections).

B123

Note change to In-Lbs

B124

Note that E doesn't affect the stress calculation. It does, however, affect the deflection.

B126

A check that max stress is less than allowable.

B132

This deflection ratio is often used as a measure of stiffness. <240 is regarded as too flexible in almost all cases. <360 is often used <480 is regarded as reasonably stiff for most commercial buildings.

document.xls - HVAC - Printed 04/21/2023 16:58:17 - p.7 of 18

HVAC Calculations

Conductive Heat Transfer Through a Wall & Roof

Input Value Units Calculation User CommentTemperature Outside 14 DegFTemperature Inside 68 DegFCd Building Length 40 FtCd Building Wdith 30 FtCd Building Number of Floors 3Cd Floor-to-Floor Height 11 FtCd Window Spacing along Wall 12 FtSingle Window Ht 6 FtSingle Window Width 5 FtNumber of Windows 35 #VALUE!

Insulation Thickness 2.5 inR-Value Insulation 6 SF-DegF-Hr/BTU-inR-Value Construction and Air Gaps 2 SF-DegF-Hr/BTU-in #VALUE!R-Value Window 2 SF-DegF-Hr/BTU-in

Wall Length 140 Ft #VALUE!Wall Height 33 Ft #VALUE!Delta-T -54 DegF #VALUE!Area Wall with Windows 4,620 SF #VALUE!Area Windows 1,050 SF #VALUE!Area Roof 1,200 SF #VALUE!Cd Building Area 3,600 SF #VALUE!Area Wall & Roof without Windows 4,770 SF #VALUE!R-Insulation 15 SF-DegF-Hr/BTU #VALUE!R-Wall &Roof 17 SF-DegF-Hr/BTU #VALUE!Heat Flow Q Wall & Roof -15,152 BTU/Hr #VALUE!Heat Flow Q Windows -28,350 BTU/Hr #VALUE!Total Conductive Heat Flow -43,502 BTU/Hr #VALUE!

-12,750 Watts #VALUE!

Infiltration & Ventilation Heat Load

Input Value Units Calculation Inf T Outside 14 DegF #VALUE!Inf T Inside 68 DegF #VALUE!Inf Building Area 3,600 SF #VALUE!

Inf Floor Height Average 11 Ft #VALUE!

Inf Infiltration Air Changes / Hour 1.5 Air Change/Hour

Inf People In Building 9 #VALUE!

Inf CFM per Person 20 CFM/person

Inf Delta T -54 DegF #VALUE!Inf Building Volume 39,600 CF #VALUE!Inf Infiltration CF per Hour 59,400 CF/Hr #VALUE!Inf Ventilation per Hour 10,800 CF/Hr #VALUE!Inf Total Air Per Hour 70,200 CF/Hr #VALUE!Inf Heat Lost to Air Movement -68,519 BTU/Hr #VALUE!

In HVAC, as in structures, the most basic requirement is to calculate the "Loads" on a system. For HVAC the most important of these is the amount of Heat (Q) that the system must add to (heating) or remove from (cooling) a space.

In a real building you must take account of not only the heat flow through the windows, but also the air leakage and the amounts of heat added by the appliances, people and sunlight coming into the room. Once you understand the principles this is best done with a modeling program like Energy-10 or the commercial programs by Carrier or Trane.

Nonetheless this approximation is quite good, especially for a heating situation - in the middle of winter with no one in the building at night.

B15

The default calculates a window at the regular interval defined along the wall. You can put in your own value.

B17

The "R" is 1/U I use it because it's a lot easier to sense differences. It's directly analagous to Resistance in electrical circuits.

B18

To be precise we need to worry about the number of air gaps, winter vs. summer conditions etc., but a good rough approximation is 1 for air gaps and films and 1 for other construction.

B19

R values for windows can range between about 1-6. 1 = Single Pane Window 2= Typical insulation glass - Now standard 3= Special extra film 4-6 = Fancy gases and films $$

B22

The default value here is based on a 4 story building with sides 60x80'

B23

The default is a 4 story building with a floor to floor of 11'

B31

Note that the roof often has more insulation, but for this calculation this is a reasonable approximation. We are also leaving out basement losses and assuming doors are treated like windows.

B34

Note the Sign - Means flowing OUT + Means flowing IN

B35

It may be easier to comrehend the number in watts - think of the number of light bulbs.

B43

The default is taken from the conduction calculation above. You can change it.

B44

The default is taken from the conduction calculation above. You can change it.

B45

Again, the default is taken from the conduction calculation, but you can change it.

B46

Again, the default is taken from the conduction calculation, but you can change it.

B47

This changes markedly between buildings - and is not the standard way of calcuating, but is useful here: For Small buildings <5,000SF New Construction Average -1.5 changes/hr New Construction - Energy Efficient with heat recovery -0.5 changes/hr Old Construction - 3-5changes/hr For Larger buildings >5000SF Ventilation requirements dominate - use a small number for infiltration Large buildings 0.1 changes/hr

B48

The default takes the area from the conduction calculation and uses the SF/Occupant number for an office building.

B49

For all buildings there should be a minimum of about 20CFM/person. For smoking or spaces creating odors or fumes the number can be much higher, more like 50CFM/person


-68234.4

Duct Sizing to Transfer Required Heat

Input Value Units Calculation QNeed -112,020 BTU/hr #VALUE!TDuct 120 DegFTRoom 68 DegFAir Velocity In Duct 1,200 fpmAspectRatio 1.5

DeltaT Delivery 52 DegF #VALUE!Coeff - BTU per CFM Deg 1.08 BTU/(CFM Hr DegF) #VALUE!Air Flow CFM 1,990 CFM #VALUE!Area Needed 239 in2 #VALUE!DiamRound 18 in #VALUE!Rectangle ShortSide 14 in #VALUE!

Rectangle LongSide 21 in #VALUE!AreaRect 294 in2 #VALUE!

Seasonal Fuel Usage and Cost

Input Value Units Calculation HDd Building Area 1,200 SFHDd T Interior 68 DegHDd T Exterior Min 5 DegHDd Max Hourly Building Heat Transfer 19,288 BTU/HrHDd DDhAnnual 3,749 Deg-Day

Fuel EfficienciesHDd Oil Efficiency 80%HDd Gas Efficiency 85%HDd Elect Resistance Efficiency 100%HDd Heat Pump Coefficient 262%

Fuel PricesHDd Cost Oil Per Gallon $ 1.10 $/GalHDd Cost Gas per CCF $ 0.88 $/CCFHDd Cost Elect per KWH $ 0.130 $/KWH

HDd Building Constant 306 BTU/Hr-deg #VALUE!

HDd Season Heat Transfer 27,532,656 BTU/Yr #VALUE!HDd Season Heat Transfer Per Sq Ft 22,944 BTU/SF-Season #VALUE!

Fuel ConsumptionHdd Gallons Oil 240 Gallons #VALUE!

HDd CCFGas 310 CCF #VALUE!

HDd KW Resistance 8,070 KWH #VALUE!

Once you know how much heat is required to be transferred you want to know how big the duct is that carries the air (the usual fluid) carrying the heat. This is a straightforward calculation that uses the velocity, density, and specific heat of the air to determine how much must flow to carry the required amount of heat. Once you know how much (CFM), the velocity then allows you to calculate the size of the duct necessary to conduct it.

Note that the velocities in ducts are limited by two things - the noise the air makes in the duct and the friction of the air in the duct - the slower the flow the less energy is lost in friction. In practical terms, that limits low velocity ducts to about 1,200FPM - which is about13 MPH. High velocity ducts operate about 3,000FPM (34MPH), but require special construction and more fan energy.

Note that the defaults tie this calculation to the conductive loss calculation above and the ventilation/infiltration calculation, but you can change it to suit your own needs.

Heat is lost through movement of air in and out of a building, both intentional (ventilation) and unintentional (infilitration). When calculating the heating or cooling load one must include this heat loss or gain as well.

This estimate is crude, but gives an approximation, better for small buildings than large ones, but a reasonable start for both.

Note that the defaults tie this calculation to the conductive loss calculation above, but you can change it to suit your own needs.

B66

Heat transfer needed The default is taken from the conduction and ventilation/infiltration calculations above but you can overwrite it with your own value.

B67

Temperature of the Source of air - the duct as it leaves the duct into the room. For Heating usually about 120Deg For Cooling about 50

B68

Temperature of the Room

B69

Average velocity in the duct in feet per minute Low Speed ducts are about 1,200fpm = 13mph approx High speed ducts are about 3,00fpm = 34 mph approx

B70

Ratio of Long side of duct to short side If = 1, then duct is square

B72

Temperature Difference - Source to Delivery Typically have 20degF for Cooling, 60DegF for htg.

B73

This takes into account the specific heat of air and its density and the fact that velocity is in feet per minute, but heat flow is in BTU/Hr. It's a constant that adjusts the units properly in the equation which says if I need 'so many' BTU/Hr, how much air does that take with a given density and specific heat.

B74

CFM = Cubic Feet Per Minute This is the industry standard volume flow measurment in the USA

B75

Area of round duct needed to carry this much flow - assuming uniform flow - not a good assumption, but a reasonable approximation.

B77

This is one of the few equations that I ask you to take on faith. It comes from ASHRAE Fundamentals 32.25. It essentially takes into account the irregularities due to a rectangular duct having more air resistance than a round one. I include it just to show how complex the calculations are to be accurate in practice. The rest of these examples do NOT include similar precision corrections

B89

The gross SF of the building

B93

The Degree Days for the season. This number is calculated by the weather bureau and published. For Philadelphia its about 3,500 DD In the midwest in may be up to 7,000DD In Florida it may be only a few hundred DD

B95

Efficiency of oil combustion Usually 80-95% Obtain from manufacturer or text

B96

Efficiency of natural gas combustion Usually 85-98% Obtain from manufacturer or text

B97

The conversion efficiency of electricity to heat in a resistance device. It's essentially 100%

C98

The efficiency of a "heat pump" moving heat from one location to another. A number greater than 100% means that more heat is moved than it takes to operate the motor. The default is a typical number for room air conditioners/heat-pumps. Efficiencies for larger units can be signficantly better. Note that efficiency decreases as the outside temperature decreases.

B104

This is essentially the number of BTU per hour that will be lost for each degree the temperature departs from the inside temperature

B109

Note that gas is solid in units of CCF = Hundred Cubic Feet


HDd KW Heat Pump 3,080 KWH #VALUE!

Fuel Consumption Per SFHdd Gallons Oil Per SF 0.20 Gallons/SF-Season #VALUE!HDd CCFGas Per SF 0.26 CCF/SF-Season #VALUE!HDd KW Resistance Per SF 6.73 KWH/SF-Season #VALUE!HDd KW Heat Pump Per SF 2.57 KWH/SF-Season #VALUE!

Season CostHDd Oil Season Cost $ 264 #VALUE!HDd Gas Season Cost $ 273 #VALUE!HDd Elect Resistance Season Cost $ 1,053 #VALUE!HDd Elect Heat Pump Season Cost $ 402 #VALUE!

Season Cost Per SFHDd Oil Season Cost per SF $ 0.22 $/SF #VALUE!HDd Gas Season Cost per SF $ 0.23 $/SF #VALUE!HDd Elect Resistance Season Cost per SF $ 0.88 $/SF #VALUE!HDd Elect Heat Pump Season Cost per SF $ 0.33 $/SF #VALUE!

When developing an HVAC system the designer is interested in two things.- How big does the equipment have to be to take care of the worst case?- How much is it going to cost to operate for the year (or season of heating or cooling)?

The worst case situation is estimated by calculating the loads on the house.- For heating it is the "conduction load" of heat lost through walls, windows, roof and to a small extent the floor. One must include as well the "infiltration load" - the heat necessary to warm air that enters from the outside either through intended ventilation or through cracks.- For cooling it is the "conduction load" plus the solar energy, plus the infiltration, plus the heat from people, equipment and lights.

The "right" way to calculate the energy consumption is by a simulation using standard weather on an hour-by-hour basis. This requires a complex program

For small buildings the Degree-Day method uses the Degree-Day number produced by the weather service and the "worst case" calculation the designer has already performed to estimate the operating costs.

The weather bureau publishes both heating degree-day records and cooling degree day records. Both can be used to calculate the energy cost for the heating and cooling season respectively.

document.xls - Lighting - Printed 04/21/2023 16:58:26 - p.10 of 18

Lighting Calculations

Lighting Fixture Requirements Estimate


Lighting Calculations

Lt1 Room Area 500 SFLt1 Lighting Level 50 FootcandlesLt1 Lamp Type Semi-Direct FluorescentLt1 Number of Lamps Per Luminaire 4Lt1 Lumens Per Lamp 3,200 ManufacturerLt1 Watts Per Lamp 46 ManufacturerLt1 Watts Per Transformer 10 AverageLt1 Maintenance Factor 0.67Lt1 Coeff of Util 0.47 From Chart

Lt1 Efficacy - Lumens/Watt 70 Lumens/Watt #VALUE!Lt1 Area/Luminaire 81 SF/Luminaire #VALUE!

Lt1 Number of Luminaires (rounded 7 #VALUE!Lt1 Watts/Luminaire 194 Watts/Lumina #VALUE!

#VALUE!Lt1 Watt/SF 2.7 Watts/SF #VALUE!

Calculating the exact number of fixtures is a complex process best accomplished with a method called the "Zonal Cavity Method" or even better with a simulation program. Nonetheless it's possible to get an approximation at the beginning of a project using a cruder calculation such as the one given here.

Note that in the lighting worldA "fixture" is what the layperson would call a lamp - it's the device that holds the lamps.A "lamp" is what the layperson would call a bulb - it's the device that actually produces the light.

Examples are given here for several different types of lamps The number of lamps possible is very great as is the number of different fixtures. These are only representative.

Source Mechanical and Electrical Equipment for Buildings - 5th ed -P.760

B9

Design Goal - Typical Values: Intense Work - 150 FC Bright Office - 100FC Classroom - 75FC Standard Office - 50FC Quiet Waiting Room - 20FC General level Emergency Exit Lighting - 2FC

B12

Lumens per Lamp: How much light a single lamp puts out when new. It's provided by the manufacturer. Typical Values are: 48" Standard Fluorescent - 3,200 lumens - 46 watts 48" Good Color Fluorescent - 2200 lumens - 46 watts Incandescent Standard - 1750 - 100 watts Halogen - 2800 - 150 watts Mercury (poor color, slow start) - 3400 lumens - 113 watts

B14

Average Transformer watts/fixture Incandenscent = 0 - not necessary Fluorescent = 10

B15

Maintenance Factor: A multiplier that recognizes that the lamp degrades over time and that one wants to achieve that desired level not at the beginning, but during the life of the lamp. Fluorescents & Incandescents = 0.67 Halogen & Mercury = 0.9

B16

Coefficient of Utilization: A complex factor depending on the room, the fixture type and the light absorption of the walls. Average values for fluorescent fixtures are shown in the chart at the right.

document.xls - Electrical - Printed 04/21/2023 16:58:28 - p.11 of 18

Electrical Calculations

Estimating Building Watts Required

Input Value Units Calculation User CommentLighting - Area Requiring "Service" 2,000 SFLighting - Area Requiring Standard 10,000 SFLighting - Area Requiring "Intense" 2,000 SFLighting - Area Requring "Spotlight" 1,000 SFAppliances - Area Requiring Minimal 500 SFAppliances - Area Requiring Residential 300 SFAppliances - Area Requiring Office 15,000 SFAppliances - Area Requiring Intense 1,000 SFHVAC - Area Requiring Ventilation Only 1,000 SFHVAC - Area Requiring Heating Only - NonElectric Hea 1,000 SFHVAC - Area Requiring Full Conditioning 15,000 SFLighting Watts/SF Service 0.5 WSFLighting Watts/SF Standard 1.25 WSFLighting Watts/SF Intense 2 WSFLighting Watts/SF Spotlight 4 WSFAppliances Watts/SF Minimal 1 WSFAppliances Watts/SF Residential 2.5 WSFAppliances Watts/SF Office 5 WSFAppliances Watts/SF Intense 15 WSFHVAC Watts/SF Ventilation Only 0.4 WSFHVAC Watts/SF Heating Only - NonElectric Heat 0.6 WSFHVAC Watts/SF Full Conditioning 1.7 WSF

Lighting - Subtotal Area 15,000 SF #VALUE!Appliances - Subtotal Area 16,800 SF #VALUE!HVAC - Subtotal Area 17,000 SF #VALUE!Max Area - Use for PSF 17,000 SF #VALUE!

#VALUE!Lighting - Service Watts 1,000 Watts #VALUE!Lighting - Standard Watts 12,500 Watts #VALUE!Lighting - "Intense" Watts 4,000 Watts #VALUE!Lighting - Area Requring "Spotlight" Watts 4,000 Watts #VALUE!Appliances - Minimal Watts 250 Watts #VALUE!Appliances - Residential Watts 750 Watts #VALUE!Appliances - Office Watts 75,000 Watts #VALUE!Appliances - Intense Watts 15,000 Watts #VALUE!HVAC - Ventilation Only Watts 400 Watts #VALUE!

HVAC - Heating Only - NonElectric Heat Watts 600 Watts #VALUE!

HVAC - Full Conditioning Watts 25,500 Watts #VALUE!

#VALUE!Subtotal - Lighting Watts 21,500 Watts #VALUE!Subtotal - Appliance Watts 91,000 Watts #VALUE!Subtotal - HVAC Watts 26,500 Watts #VALUE!Total Estimated Watts 139,000 Watts #VALUE!

#VALUE!Lighting WSF Average 1.3 WSF #VALUE!Appliance WSF Average 5.4 WSF #VALUE!HVAC WSF Average 1.6 WSF #VALUE!Overall WSF Average 8.2 WSF #VALUE!

This form is somewhat more detailed than is perhaps necessary, but it gives a reasonable sense of the variable loads for different conditions and allows a rapid overall estimate.

To use it all you need to do is put in the SF for each of your uses. You do NOT need to change the Watt/SF for each use, but they're left available if you have better information.

Note that normally the Area totals should be identical, but there may be some situations where differing is OK. I picked the maximum as the most reasonable for calculating overall WSF numbers.

Many building loads are quoted in KiloWatts (KW) - Just divide by 1,000 to determine the KWThe transformer for a building is usually in KVA - which is close to the total KW. It is usually sized with a growth factor of 20% or more.

Power Use In Building

Lighting WSF Average

Appliance WSF Average

HVAC WSF Average

B6

Supply

document.xls - Plumbing - Printed 04/21/2023 16:58:32 - p.12 of 18

Plumbing Calculations

Building Water Requirements


Wr Building Type OfficeWr Number Occupants 188 OccupantsWr Average Demand/Occupant 15 Gals/Day-OccWr Peak Water Demand/Occupant 0.09 Gals/Min-OccWr Summer Design Temp for Locatio 94 DegFWr Special Requirements Average 0 Gals/DayWr Special Requirements Peak Gals/Min

Wr Average Water Demand 2,880 Gals/Day #VALUE!

Wr Peak Water Demand 17 Gals/Min #VALUE!

One of the first tasks in defining a plumbing system is to determine the overall requirements, both on average and at a peak time. This is particularly important because one must check the service available to the building - either a water "main" or a well. If these are not sufficient for the need then there is likely to be significant additional expense to provide the necessary water.- If the average daily Demand is greater than the supply then a new "main" or well must be provided.- If the peak demand is greater than the "main" or well can supply, but the daily average is adequate, then a storage system will be necessary.

B6

The type of building your estimating - "school", "office" etc. See the comments for the different building types given. Not used in calculations, but helpful as a reminder.

B7

The number of people in the building. Note that there is estimation method in the Architecture section.

B8

The number of gallons per day an average occupant uses Assembly - 5 gal/day Hotels - 75 gal/day Offices - 10 gal/day Offices with food service - 15 gal/day Residences - 100 gal/day Restaurants - 20 gals/day for one meal + 15 gals/day for each additional meal Schools - 30 gal/day with food and showers Source - Standard Handbook of Architectural Engineering p. 584

B9

The maxium rate an individual occupant uses water in gallons per minute. The number of gallons per day an average occupant uses Assembly - 0.17 gal/min Hotels - 0.43 gal/min Offices - 0.09 gal/min Offices with food service - 0.09 gal/min Residences - 0.33 gal/min Restaurants - 0.15 gal/min Schools - 0.40 gal/min with food and showers (0.12 gal/min w/o food showers) Source - Standard Handbook of Architectural Engineering p. 584

B10

The outside maximum temperature during the summer. Obtainable from most HVAC books. E.g. Philadelphia = 94 approx

B11

Insert any special average load - e.g. that from a unique water fountain or cooling system.

B14

The average total water required for the building. A portion of this will be heated for hot water. Note that it does not take into account special situation such as a fire.

C14

Source - Standard Handbook of Architectural Engineering p. 584

C15

Source - Standard Handbook of Architectural Engineering p. 584

document.xls - Acoustic - Printed 04/21/2023 16:58:33 - p.13 of 18

Acoustic Calculations

Reverberation of Space

Input Value Units Calculation User CommentRoom Length Acoustic 150 FtRoom Width Acoustic 80 FtRoom Height Acoustic 50 FtAbsorption Wall Front 0.1Absorption Wall Sides 0.1Absorption Wall Rear 0.1Absorption Floor & Seats 0.9Absorption Ceiling 0.1

Volume of room Acoustic 600,000 CF #VALUE!Area Wall Front Acoustic 4,000 SF #VALUE!Area Wall Rear Acoustic 4,000 SF #VALUE!Area Wall Sides Acoustic 15,000 SF #VALUE!Area Ceiling Acoustic 12,000 SF #VALUE!Area Floor Acoustic 12,000 SF #VALUE!Absorption Front Sabins 400 Sabins #VALUE!Absorption Rear Sabins 400 Sabins #VALUE!Absorption Sides Sabins 1,500 Sabins #VALUE!Absorption Floor and Seats Sabins 10,800 Sabins #VALUE!Absorption Ceiling Sabins 1,200 Sabins #VALUE!Total Absorption Sabins 14,300 Sabins #VALUE!Reverberation Time 2.1 secs #VALUE!Suited for Music or Speech Music #VALUE!

Reverberation is the time for a sound (e.g. a hand clapping is a good test) to decrease by 60 decibels.

The reverberation time of larger spaces is an important characteristic because it strongly influences the type of use for which space is suited. Spaces in which understanding speech is important (a large classroom for instance) want minimal reverberation because it will confuse the audience's comprehension. For much music, on the other hand, a significant reverberation time (here defined as 1.2 seconds) causes the music to blend together in a pleasing manner.

For rooms in which electronic amplification is used the reverberation is important, but the amplification can often address shortcomings if well designed.

Remember that other factors determine the actual character of the sound - this is only an approximation. In particular the frequency composition of the sound and the specific shape of the space are extremely important and are not addressed here.

B3

Reverberation time is defined as the time for the sound level to drop 60db after the sound source has stopped producing sound.

B9

Measured in Sabins - a dimensionless ratio of Outgoing energy to incoming energy when sound is reflected. It is determined by experiment and varies with frequency. The range is from 0.01 for things like stone to 0.93 for heavy upholstery or an audience seated. Wood is about 0.1 for most frequencies

B12

This number can vary greatly. For a concert hall with lots of people this is a reasonable start for most frequencies.

B27

Reverberation time is defined as the time for the sound level to drop 60db after the sound source has stopped producing sound.

B28

This is not hard and fast, but generally one wants short reverberation times to make speech intelligible whereas much (but not all) music is enhanced by the blending produced by longer reverberation times. 1.2 seconds is an arbitrary number based on experience. As with all acoustic phenomena there should be much more careful consideration of all the factors, but this is a start.

document.xls - ConversionFactors - Printed 04/21/2023 16:58:36 - p.14 of 18

Conversion Factors Used in This Spreadsheet

Category ConverstionConversio Amt1 Units1 Eq Result1 Units1R Amt2 Units2 Eq Result2 Units2RArea SqIN/SF 144 1 SF = 144 SqIn 144 SqIn = 1 SF Square FootPower BTU/Wt-Hr 3.412 1 Watt = 3.412 BTU/Hr 3.412 BTU/Hr = 1 WattsPower Watt/HSP 745.7 1 HSP = 745.7 Watts 1000 Watts = 1.34 HspTime Min/Hr 60 1 Hr = 60 Min 60 Min = 1 HrVelocity FPM/MPH 0.011364 3000 FPM = 34.1 MPH 1 MPH = 88 FMP Feet Per Minute

Efunda = Excellent Reference

http://www.efunda.com/units/index.cfm

document.xls - Properties - Printed 04/21/2023 16:58:37 - p.15 of 18

Properties Used in Spreadsheet

Category Property Value Units CommentHVAC Air Density 0.075 Lb/CFHVAC Air Specific Heat 0.241 BTU/LbHVAC Oil Heat Value 141,000 BTU/Gal Heat value of #2 oil - often used in housesHVAC Natural Gas Heat Value 1050 BTU/ft3 Heat value of Natural Gas

Efunda = Excellent Reference

http://www.efunda.com/units/index.cfm

document.xls - Contributors - Printed 04/21/2023 16:58:38 - p.16 of 18

Contributors

Initial Name Email AffiliationJEM James E. Mitchell Drexel University - Civil & Architectural [email protected]

mailto:[email protected]

document.xls - FutureWork - Printed 04/21/2023 16:58:38 - p.17 of 18

Future WorkUpdate: 9/28/2002

Discipline Type Description Web Ref:Plumbing Load Fixture Units Ching 196-201Plumbing Load Hot Water Sizing Ching 196-201Plumbing Load Pipe Sizing from Fixture Units Ching 196-201

By

Here's where Additions to the calculations are proposed. When they're completed they'll be move to the main index page.

Users are urged to make corrections and additions and send the revised sheet back to J. Mitchell.

B5

Selection Triangles This sheet uses Excel's database capabilities. To see only those things of interest in a column click on the triangle and select what your interested in e.g "Structure" in the Discipline column

D5


F5

Ching = "A Visual Dictionary of Architecture" - Francis D.K. Ching - 1st Ed. - Wiley Butler = "Standard Handbook of Architectural Engineering" - Robert Brown Butler - 1st Ed - McGraw Hill

G5


document.xls - RevisionHistory - Printed 04/21/2023 16:58:38 - p.18 of 18

Revision History

Date Type Description Page10/21/2002 Calculation Structure JEM

10/21/2002 Format Workbook JEM

9/29/2002 Addition Added Future Work Future Work JEM9/29/2002 Addition Added Occupancy Calculation Architecture JEM9/29/2002 Addition Added Revision History Revision History JEM9/29/2002 Addition Infiltration Calculation & Degree Day Calc HVAC JEM9/29/2002 Calculation Added Plumbing Calculation Plumbing JEM9/29/2002 Format Revised Format to Make Printer Friendly Workbook JEM9/27/2002 Format Workbook JEM9/15/2002 Start Began Spreadsheet Workbook JEM

ByCorrected Error in Beam Calculation - Wrong reference to beam length

Made formulas display on Structures - Unprotected first sheet

Applied background and standardized format

Lists the revisions to this workbook with the page affected and th

D4


F4


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