# HVAC Calculations and Duct Sizing

Size: px
Start display at page:

Transcription

1 PDH Course M199 HVAC Calculations and Duct Sizing Gary D. Beckfeld, M.S.E., P.E PDH Center 2410 Dakota Lakes Drive Herndon, VA Phone: Fax: An Approved Continuing Education Provider

2 HVAC Calculations and Duct Sizing Gary D. Beckfeld, M.S.E., P.E. COURSE CONTENT 1. Heat Conduction and Thermal Resistance For steady state conditions and one dimensional heat transfer, the heat q conducted through a plane wall is given by: q = ka(t 1 - t 2 L Btu hr (Eq.1 Where: L = the thickness of the wall in inches A = the area of the wall in square feet (t 1 - t 2 = temperature difference across the wall in degrees Fahrenheit k = thermal conductivity of the wall material Btu-in hr-ft 2 -F Equation 1 can be put in terms of a unit thermal resistance, R = L/k, or an overall heat transfer coefficient, U = 1/R, to give A(t 1 - t 2 q = R = UA(t 1 - t 2 (Eq.2 Note that the R in equation 2 is the factor often found on blanket insulation and other building products. Equations 1 and 2 are for a single material so the resistance R must be modified for building walls of several materials. 2. Building Walls Walls of buildings are constructed of several layers of different thickness, material, and area. Figure No. 1 shows a typical 2x4 framed house wall and a concrete wall with polystyrene insulation on both the interior and exterior surfaces. For the concrete wall, with the vinyl siding and drywall, there are Gary D. Beckfeld Page 2 of 21

3 five thermal resistance layers. In addition there are thermal resistances on the inside and outside surfaces of a building wall due to convective air currents and radiation. These resistances are accounted for with film coefficients, f, given by f i = 6.0 Btu/ (hr-ft 2 -F = 1/R i inside surface with still air (Eq.3 f o = 1.63 Btu/ (hr-ft 2 -F = 1/Ro outside surface with moving air (Eq.4 Then for the whole concrete wall, the thermal resistance to be used in the conduction equation 2 becomes R = R o +R 1 +R 2 +R 3 +R 4 +R 5 +R i (Eq.5 For the framed wall, similar thermal resistance equations would be written for the heat path through the studs and through the insulation path between the studs as indicated in Figure 1. q q q SIDING INSULATION CONCRETE INSULATION DRYWALL FRAMED WALL CONCRETE WALL FIGURE 1 In addition to the heat conducted through the walls, given by equation 2, a building can have heat gains or losses from the attic and basement. Gary D. Beckfeld Page 3 of 21

4 3. Building Attic and Basement At equilibrium conditions, the heat loss or gain from the attic or basement, as indicated in Figure 2, is equal to the heat loss or gain to the building through the ceiling or floor. For an attic, equation 2 gives U r A r (t o - t a = U c A c (t a - t i (Eq.6 Where r = roof properties, c = ceiling properties, a = attic properties a = attic temperature, o = outside temperature, and i = inside temperature. Solving equation 6 for the attic temperature gives t a = (U r A r t o +U c A c t i / (U r A r + U c A c (Eq.7 After the attic temperature is found from equation 7, the heat conducted to the building through the ceiling can be found from equation 6. This procedure can also be used to estimate a basement (or attached garage temperature and heat loss or gain to a building through the floor or wall. q q FIGURE 2 Gary D. Beckfeld Page 4 of 21

5 4. Building Heat Loads The total cooling or heating load of a building consists of two parts, the sensible heat, Q s, and the latent heat, Q l. The sensible heat load comes from the following sources: 1. Heat conducted through the building (walls, ceiling, floor, windows. 2. Internal heat from lights, computers, ovens, and other appliances. 3. Infiltration of outside air through cracks around windows and doors. 4. People in the building. 5. Sun radiation through windows. The latent heat load to a building comes from the following sources: 1. People in the building. 2. Infiltration through cracks, chimneys. 3. Gas appliances, range, ovens. 4. Dishwasher, other appliances. The sensible heat load results in an air temperature rise in the building. To maintain temperature requirements, the air in the building is circulated over a cooling coil at a certain rate determined from the equation Q s = 1.1 (w (t s -t i (Eq.8 Where w = cubic foot per minute of air circulation flow i = denotes inside air temperature s = denotes supply temperature of the air The latent heat load determines the amount of moisture that is added to the air in the building and must be removed from the air by the cooling coil to maintain humidity requirements. This is found from the equation Q l = 4840 (w (G s - G i (Eq.9 Where G i = pounds of moisture per pound of air in conditioned space G s = pounds of moisture per pound of a supply air Gary D. Beckfeld Page 5 of 21

6 Once the sensible heat, Q s, and latent heat, Q l, are known, a sensible heat ratio, SHR, can be found from SHR = Q s / (Q s + Q l (Eq.10 The sensible heat ratio is useful in finding G, the moisture content of air, at different conditions using a psychrometric chart. 5. Psychrometric Chart A psychrometric chart is a graphical representation of the properties of moist air and is a useful tool in air conditioning calculations. This chart can be viewed online and a copy can be printed out from the following website: Figure 3 is a sketch of an air conditioning cycle plotted on a psychrometric chart. The numbered points on the diagram correspond to the numbered points in Figure 4, a sketch of a building air conditioning system. These points are determined in the air conditioning calculations % RH 25.8 ENTHALPY 5 TEMP DP G MOISTURE SHR TEMPERATURE DB FIGURE 3 Gary D. Beckfeld Page 6 of 21

7 BUILDING 35 X 73 80DB, 50%RH 2 1 REHEATER 5 COIL 4 COMPRESSOR 15% MAKEUP 3 95DB,75DP 15% EXHAUST FIGURE 4 6. Air Conditioning Calculations Example A building, 35 feet wide and 73 feet long, is constructed with the type of concrete wall indicated in Figure 1. The concrete is 4 inches thick and the polystyrene insulation is 2 inches thick on each side. The east and west walls each have two windows. The north wall has 6 windows and the south wall has 9 windows. All windows are 2.5 feet by 4 feet. The roof and ceiling are frame construction. The conditions inside are to be maintained at 80 F db (dry bulb temperature and 50% relative humidity. The outside conditions are 95 F db and 75 F dp (dew point temperature. The cooling load in tons is be found for selecting cooling and air handling units. For ventilation, it is assumed the air handler will take 15% of the required flow from the outside conditions. Supply air in the building is to be 65 F db. Some thermal conductivities, k, and thermal resistances, R, of building materials for this problem are shown in Table 1. Where the overall heat transfer coefficient, U, is given, it is assumed to include film coefficients. More extensive lists of these values are found in References 1 and 2. Gary D. Beckfeld Page 7 of 21

8 TABLE 1 Material k Btu-in/(hr-ft 2 -F R (hr-ft 2 F/Btu U Btu/(hr-ft 2 F Siding 1.0 Polystyrene.17 Concrete 10 Drywall.45 Pine 2x4.8 Insulation.28 Sheathing.5 in.8 Glass 1.13 Framed Ceiling.23 Framed Roof.22 Using Equation 5, the thermal resistance of the 4 inch concrete wall with 2 inch insulation is R = = 26 (hr-ft2 F/Btu Equation 2 gives the heat conducted through the wall area minus the window area assuming 8 foot high walls. East wall West wall North wall South wall q = ((8x35-2(2.5x4 (95-80 / 26 = 150 Btu/hr q = ((8x35-2(2.5x4 (95-80 / 26 = 150 Btu/hr q = ((8x73-6(2.5x4 (95-80 / 26 = 302 Btu/hr q = ((8x73-9(2.5x4 (95-80 / 26 = 285 Btu/hr There are 19 windows with 10 ft 2 each for a total glass area of 190 ft 2. The heat conducted through the glass is given by equation 2 as q = 1.13 (190 (95-80 = 3220 Btu/hr Also for single sheet of unshaded glass, the radiation heat gain can be significant. This heat gain can be found from the equation q = A (SC (SCL Btu/hr (Eq.11 Gary D. Beckfeld Page 8 of 21

9 Where A = glass area in ft 2 SCL = solar cooling load in Btu/ (hr-ft 2 SC = shading coefficient assumed 1.0 for no shading Reference 1 indicates that for south facing windows, depending on the latitude, the solar cooling load can be nearly 100 Btu per hr per sq ft and nearly twice that for glass facing east or west. Then the radiation heat gains for this building are, from equation 11 East facing glass West facing glass South facing glass q = 20 (200 = 4000 Btu/hr q = 20 (200 = 4000 Btu/hr q = 90 (100 = 9000 Btu/hr For heat conducted through the ceiling from the attic, the attic temperature is found from equation 7. Assume the roof pitch is 30 degrees and using data from Table 1 gives t a =.23(2555(80+.22(2950(95.23( (2950 = 88 F Then from equation 6 the heat from the attic is q =.23 (2555 (88 80 = 4701 Btu/hr To account for infiltration of outside air through cracks around windows and doors, a leakage rate of 20 cubic foot per minute assumed. The resulting sensible heat gain inside is given by equation 8 as q = 1.1 (20 (95-80 = 330 Btu/hr For the heat gain from electrical appliances and lights, Reference 2 gives the equation q = 3.42 (Wattage (Eq.12 For the medium size building considered here, Reference 1 gives an average electrical usage of 1.0 watts/ sq ft. This gives a heat gain of q = 3.42 (1.0 (2555 = 8738 Btu/hr Gary D. Beckfeld Page 9 of 21

10 Human occupants of the building contribute sensible heat according to their activity. From Reference 1, 200 Btu/hr per person is estimated for light activity. For two people in the building, this gives a heat gain of q = 2 (200 = 400 Btu/hr Adding all the heat gains from conduction and internal sources gives Total sensible load Q s = Btu/hr Human occupants also contribute to the latent heat gain in the building. For light activity people produce a latent gain of about 180 Btu/hr per person so this heat is q = 2 (180 = 360 Btu/hr The assumed infiltration of 20 cubic foot per minute of outside air brings latent heat into the building which is given by equation 9 as q = 4840 (20 (G 3 - G 2 where the quantities G 3 and G 2 are the moisture content of the outside and inside air respectively. Referring to a copy of a psychrometric chart or to Figure 3, locate point 2 representing the inside design conditions of 80F db and 50% relative humidity. From point 2, project a horizontal line to the right to the moister content scale and read and read G 2 =.011 lb moisture per lb dry air. Similarly locate point 3 for the outside conditions of 95 F db and 75F dew point. From the chart obtain G 3 =.019 lb moisture per lb dry air. Then the latent heat from the infiltration is q = 4840 (20 ( = 774 Btu/hr Appliances such gas ovens, ranges, and dishwashers add to the latent heat load in a building. These contributions are estimated from the data of Reference 2 as follows: Dishwasher Gas oven Gas range q = 420 Btu/hr q = 1200 Btu/hr q = 5600 Btu/hr Gary D. Beckfeld Page 10 of 21

11 Adding the latent heat gains gives Total latent load Q l = 8354 Btu/hr With the sensible and latent heat loads determined, equations 8 and 9 become = 1.1 (w (t 2 -t = 4840 (w (G 2 -G 1 The first of these equations determines the flow rate, w, required of the air handler. The temperature t 2 is the inside design condition 80F and t 1 is the desired supply of 65F air at the outlet of the air handler. The flow rate is w = / ((1.1 (80-65 = 2137 ft 3 /min The second equation determines G 1, the moisture content of the air at the air handler outlet. G 2 =.011, the moisture content of the 80F and 50% RH air in the space. The moister content is G 1 = / (4840x2137 =.0102 lb/lb dry air With this value, the point 1 shown in Figure 4 can be located on the psychrometric chart. From.0102 on the moisture scale extend a horizontal line to intersect with a vertical line at 65F. This point 1 can also be located or checked using the sensible heat ratio given by Equation 10 SHR = 35274/ ( =.81 From.81 on the SHR scale draw a line through point 2 and extend it to intersect the 65F line to again define point 1. Extending the horizontal line from this point to the 100% relative humidity curve locates point 5 shown in Figures 3 and 4. This gives the dew point temperature of 59F. This is the required cooling coil temperature of the air conditioning unit. Point 4 shown in Figures 3 and 4 is the condition of the air entering the cooling coil. This point can be found from the following equation: Gary D. Beckfeld Page 11 of 21

12 G 4 = G 2 + f (G 3 - G 2 (Eq.13 Where the G s are the moisture contents at the various points and f is the fraction of the air flow taken from the outside. Here f =.15 so at point 4 G 4 = (.15 ( =.012 lb/lb dry air First draw a line between points 2 and 3 on the psychrometric chart. Then intersect a horizontal line draw from.o12 on the moisture scale to define point 4. The points of the air conditioning cycle on the psychrometric chart are now used to read the enthalpy of the air at points 1, 4, and 5. These are h 1 = 27.2 Btu/lb h 4 = 33.2 Btu/lb h 5 = 25.8 Btu/lb These values are used in calculating the refrigeration load and reheater load. The refrigeration load is given by Re = w (Den (h 4 - h 5 Btu/hr (Eq.14 Where Then Or w = (2137 ft 3 /min (60 min/hr = 128,220 ft 3 /hr, air flow Den =.075 lb/ft 3, air density Re = 128,220 (.075 ( = Btu/hr Tons of refrigeration = / = 5.9 tons The re-heater load is RL = w (Den (h 1 - h 5 / 3412 kilowatt (Eq.15 RL = 128,220 (.075 ( / 3412 RL = 3.9 kilowatt Gary D. Beckfeld Page 12 of 21

13 A review of manufacturer s data on air handlers, shows that for each ton of cooling capacity, the unit will give about 400 cubic foot per minute of air flow at.2 inch of water static pressure. Then a 6 ton unit would give an acceptable air flow of 2400 cubic foot per minute. The.2 inch static pressure is the pressure available for designing the ducts for distributing the air to the rooms of the building. 7. Duct Sizing Figure 5 shows an air supply duct arrangement to distribute the 2137 cubic foot per minute air flow to the rooms of the building in proportion to the heat gain in each room. The flow quantities are shown at each outlet diffuser. Since the pressure available is.2 inches of water and the pressure loss at each outlet diffuser is assumed.04 inches, there is.16 inches of water pressure for the ducts. The ducts will be sized to make the total pressure loss equal in each run. Lengths of each duct segment are shown in feet. Additional length must be added to each run to account for losses in elbows and the entrance at the air handler. From Reference 2 the entrance is found to be equal to 10 feet of straight duct and the elbows equal to 35 feet. Duct sizes will be found for round and rectangular shapes. Equivalent round and rectangular ducts can be found in Reference 1 or online at the website Air friction charts are in References 1 and 2 and pages 5 and 6 of website These charts relate duct friction, duct size, air flow in cubic foot per minute and flow velocity. Reference 2 indicates that duct velocities should be about 900 ft/min or less. Entering an air friction chart at 2137 ft 3 /min flow quantity and a velocity of 900 ft/ min at the air handler outlet, gives a friction loss of.05 inches of water per 100 feet and an outlet duct of 21 inches diameter. To get the maximum pressure loss in the system, determine the longest run of duct. Inspection of Figure 5 shows that the longest run consists of duct sections A+C+D+F+H+J. Including the entrance and elbow equivalent lengths, this run length is L = 10ft entrance ft elbow ft elbow +17 = 141 ft The total pressure loss is P =.05 (141/ in. diffuser loss =.1105 in. of water Gary D. Beckfeld Page 13 of 21

14 371 CFM N 8 8 L 22 AIR HANDLER A 2137 CFM 6 15 B C 6 D 198 CFM 10 F 198 CFM 17 G 2 20 H 19 K 604 CFM M E J CFM 247 CFM 148 CFM FIGURE 5 Since the total loss of.11 in. in the longest run is less than the.2 in. expected to be available from the air handler, all the sections of the longest run will be sized using the.05 in. /100ft loss factor. Table 2 illustrates the procedure. The size of duct section A has been found. For the other sections, the flow quantities for a section are found by deducting all branch quantities head of it. The flow in duct section C is = Lengths of each section plus applicable entrance and elbow equivalent lengths are listed. Then for section C, enter an air friction chart at 1939cfm and.05 in. /100 ft friction factor. Read the duct velocity, 880 ft/min, and 20 inch duct diameter directly from the chart. The remaining sections of this run are sized similarly. Losses in each section are found from the lengths and friction factor. The round duct sizes can be converted to equivalent rectangular sections from available charts. The remaining branches, K, G, E, L, M, N, and B, are now sized to balance each branch with the same total pressure loss. For equal pressure loss in branch K, this branch must have the same loss as branch J. From Table 2, the loss must be.026 in. of water. Since the K Branch is 19 feet long, the pressure loss is.026(100/19 =.1368 in. /100 ft. Entering an air friction chart at.1368 and 604cfm gives the duct velocity as 950 fpm and the duct diameter as 11 inches. Gary D. Beckfeld Page 14 of 21

15 TABLE 2 Duct c f m L V Friction Total D w x h Ft ft/sec in/100 in in A x25 C x23 D x16 F x15 H x14 J x7 Diffuser.04 Total Similarly, branch E must have the same pressure loss as the sum of losses in branches J, H, and F. From Table 2 this loss is =.037 in. of water. Branch E has an equivalent length of 17 ft + 35 ft (elbow = 52 ft. The loss per 100 ft then is.037(100/52 =.071 in. /100 ft. Locate the point.071 and 247cfm in an air friction chart. From this point read the duct velocity to be 650 fpm and the duct size to be 8.5 inches in diameter. The remaining branches are sized using the same procedure. This results in all branches having the same total pressure loss while having the required amount of flow in each branch. 8. Ventilation The ventilation for this study was assumed to enter through an outside duct into the air handler. If instead the fresh air is brought directly into the premises, the ventilation contributes to the sensible and latent heat loads of the interior space. Assuming 320 cfm satisfies code requirements, the sensible load from the ventilation is given by equation 8 q = 1.1 (320 (95 80 = 5280 Bt/hr The total internal sensible load is = Btu/hr and the new flow rate required from the air handler is w = 40554/ ((1.1 (95-80 = 2457 ft 3 /min Gary D. Beckfeld Page 15 of 21

16 Similarly, the latent load from the ventilation can be calculated and a new total latent heat load and new sensible heat ratio, SHR, found. Entering the new SHR on the psychrometric chart locates a new point 1, new coil temperature, and new enthalpy values for resizing the required cooling tonnage. 9. Cooling Load Temperature Difference and Heating Degree Days In the heat conduction equation 2, the difference between the maximum outside temperature and desired inside temperature was used. Equation 2 can also be used as q = U A (CLTD q = U A (DD for cooling for heating Reference 1 gives cooling load temperature differences (CLTD for several latitudes, months, time of day, and building wall orientations. These CLTD values are based on 78F indoors and 95F maximum outdoor temperatures. In the heating degree day (DD method, a no load outside temperature (65F is used as a base at which no heating or cooling is required. At any outside temperature below 65F, a building will need heating and the number of degree days is the difference between 65F and the outside temperature. For example, in November, if the outside average temperature is 50F, there are 15 degree days for that day. For 30 days at 50F, there 450 DD. The DD for the entire heating season September through May are given for various cities in Reference 4. Course Summary This course has presented the basic methods of evaluating building heat gains or losses for air conditioning or heating. Heat conductivity and thermal resistance were reviewed. A numerical example of heat loads to a building was described including external and internal heat sources. Both sensible heat and latent heat loads were discussed. The air conditioning process including ventilation was presented in a diagram of a psychrometric chart. Cooling load tonnage was found and air handler flow and pressures discussed. An air distribution duct sizing method was detailed. Finally, the methods of cooling load temperature difference and heating degree days were reviewed. Gary D. Beckfeld Page 16 of 21

17 References 1. ASHRAE Pocket Guide for Air Conditioning, Heating, Ventilation and Refrigeration, Heating, Ventilating, and Air Conditioning Analysis and Design, Faye C. McQuiston and Jerald D. Parker, Wiley & sons, Building Construction Handbook, Frederick S. Merritt, McGraw-Hill, Principles of Solar Engineering, Frank Kreith and Jan F. Kreider, McGraw-Hill, Gary D. Beckfeld Page 17 of 21

18 APPENDIX Duct Size Equivalents Duct Diameter Inches Rough Equivalent Rectangular, Inches 6 4 x 7, 5 x x 9, 5 x 7, 6 x x x 12, 6 x 10, 7 x x 9, 8 x x 12, 9 x x 14, 9 x 12, 10 x x 13, 11 x x 15, 12 x x x 22, 14 x x 19, 14 x x 17, 16 x x 20, 15 x x 26, 16 x x 30, 14 x x 34, 15 x x 25, 20 x x 30, 20 x 24 Gary D. Beckfeld Page 18 of 21

19 Gary D. Beckfeld PDH Course M199 Page 19 of 21

20 Air Friction Chart 1 Friction loss, inches of water per 100 ft Gary D. Beckfeld Page 20 of 21

21 Air Friction Chart 2 Gary D. Beckfeld Page 21 of 21

### Air Conditioning Contractors of America

Air Conditioning Contractors of America WHO IS ACCA???? Industry Manuals Residential D, J, S, H, RS, T, P A manual J load calculation is a measurement of how much heating and cooling capacity a home will

### THE PSYCHROMETRIC CHART AND ITS USE

Service Application Manual SAM Chapter 630-16 Section 3A THE PSYCHROMETRIC CHART AND ITS USE Psychrometry is an impressive word which is defined as the measurement of the moisture content of air. In broader

### Characteristics of Evaporators

Characteristics of Evaporators Roger D. Holder, CM, MSME 10-28-2003 Heat or Energy In this paper, we will discuss the characteristics of an evaporator coil. The variance of the operational condenses of

Heating Load Calculation ME 425 Air Conditioning System Design Keith E. Elder, P.E. Heating Load Calculation The heating load calculation begins with the determination of heat loss through a variety of

### Refrigeration Manual. Part 3 - The Refrigeration Load

Refrigeration Manual Part 3 - The Refrigeration Load FOREWORD The practice of refrigeration undoubtedly goes back as far as the history of mankind, but for thousands of years the only cooling mediums were

### Cooling Load Calculations and Principles

Cooling Load Calculations and Principles Course No: M06-004 Credit: 6 PDH A. Bhatia Continuing Education and Development, Inc. 9 Greyridge Farm Court Stony Point, NY 10980 P: (877) 322-5800 F: (877) 322-4774

### Comparing Air Cooler Ratings Part 1: Not All Rating Methods are Created Equal

Technical Bulletin By Bruce I. Nelson, P.E., President, Colmac Coil Manufacturing, Inc. Comparing Air Cooler Ratings Part 1: Not All Rating Methods are Created Equal SUMMARY Refrigeration air coolers (evaporators)

### WORKSHEET FOR RESIDENTIAL AIR SYSTEM DESIGN page 1

WORKSHEET FOR RESIDENTIAL AIR SYSTEM DESIGN page 1 Wallet card photocopy Inspection Authority: Signature: Date: / / Submitted For: ( Owner ) Name Address City Prov Postal code Phone ( ) Fax ( ) Designer/Signature:

### Glossary of Heating, Ventilation and Air Conditioning Terms

Glossary of Heating, Ventilation and Air Conditioning Terms Air Change: Unlike re-circulated air, this is the total air required to completely replace the air in a room or building. Air Conditioner: Equipment

### Residential HVAC System Sizing

Residential HVAC System Sizing William P. Goss University of Massachusetts, Amherst, Massachusetts, USA Corresponding email: goss@acad.umass.edu SUMMARY Heating, ventilating and air-conditioning (HVAC)

### Residential HVAC Load Sizing Training October 14, 2015. David Kaiser Green Code Plan Reviewer

Residential HVAC Load Sizing Training October 14, 2015 David Kaiser Green Code Plan Reviewer DCRA - Green Building Division Regulations of green codes including: Green Building Act Green Construction Code

### Energy Efficient Building Design College of Architecture Illinois Institute of Technology, Chicago. Relative Humidities RH% 49.4. 0.

Psychrometrics Psychrometric Chart Relative Humidities RH% 49.4 100% 80% 0.030 Enthalpies 70% H btu/lb 46.5 0.028 85 Not to Scale 0.026 Humidity Numbers and Values 43.7 60% Ratios are approximate 0.024

### Below are detailed instructions for using the EMS load calculator.

Introduction The EMS load calculator is designed to make load calculating as painless as possible. For sizing the equipment, only the first three tabs (Steps 1, 2 & 3) need to be completed. This process

### UNDERSTANDING AND USING THE HVAC DESIGN REVIEW FORM

Page 1 UNDERSTANDING AND USING THE HVAC DESIGN REVIEW FORM Each of the 38 points of requested information is discussed, and references to the supporting manual are given to substantiate the requirement.

### Fan Applications & System Guide

Fan Applications & System Guide Airflow for general ventilation can be calculated by; Area Method Air Change Method Occupancy Method Ventilation Calculation Methods Area Method Derives the ventilation

Calculations -1- AIRCONDITIONING Cooling s Calculations Employer : 4M SA Project Location : ASHRAE Office Room : Example from ASHRAE 2013 Handbook - Fundamentals : Chapter 18, Single Room Example (p. 18.37)

2008 Desert Aire and USA Swimming. Used by permission. Desert Aire & USA Swimming - Aquatics Webinar - Answers to Your Questions Answers to Your Questions from the Webinar Thank you for your interest in

### Software Development for Cooling Load Estimation by CLTD Method

IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) ISSN: 2278-1684Volume 3, Issue 6 (Nov. - Dec. 2012), PP 01-06 Software Development for Cooling Load Estimation by CLTD Method Tousif Ahmed Department

### CHAPTER 3. BUILDING THERMAL LOAD ESTIMATION

CHAPTER 3. BUILDING THERMAL LOAD ESTIMATION 3.1 Purpose of Thermal Load Estimation 3.2 Heating Load versus Cooling Load 3.3 Critical Conditions for Design 3.4 Manual versus Computer Calculations 3.5 Heating

### EFFECTS OF INDOOR RELATIVE HUMIDITY ON REFRIGERATED DISPLAY CASE PERFORMANCE

P (5, EFFECTS OF INDOOR RELATIVE HUMIDITY ON REFRIGERATED DISPLAY CASE PERFORMANCE Ronald H. Howell, Professor Luis Rosario, Graduate Student Antonio Bula, Graduate Student Department of Mechanical Engineering

### 1/9/2013. Terminology Calculating Heat Transfer Code Requirements Design Examples and Sustainability

1/9/13 By Brett T. Fagan, P.E. Presented by Marie Horan, P.E. Building Diagnostics, Inc. Building Diagnostics Terminology Calculating Heat Transfer Code Requirements Design Examples and Sustainability

### Innovent LASER Packaged Fresh Air Conditioning Units

LASER Latent And Sensible Energy Reduction Latent And Sensible Energy Reduction For Outside Air Innovent LASER Packaged Fresh Air Conditioning Units Innovent LASER units provide both sensible and latent

### APPLICATION GUIDE. Comparison of Latent Cooling Performance of Various HVAC systems in a Classroom Application

APPLICATION GUIDE Comparison of Latent Cooling Performance of Various HVAC systems in a Classroom Application Section Comparison of Latent Cooling Performance of Introduction Most commercial HVAC systems

### Air Conditioning Clinic

Air Conditioning Clinic Cooling and Heating Load Estimation One of the Fundamental Series April 2011 TRG-TRC002-EN Cooling and Heating Load Estimation One of the Fundamental Series A publication of Trane,

### Low Cost. Lower Energy Costs. Higher Efficiency.

HI-E DRY dehumidifiers remove two to three times more water per kilowatt hour of electricity than conventional dehumidifiers. Low Cost. Lower Energy Costs. Higher Efficiency. Therma-Stor designed an efficient,

### DESIGN OF A SINGLE-ZONE HVAC SYSTEM FOR A PUBLIC LIBRARY IN DALLAS, TEXAS

DESIGN OF A SINGLE-ZONE HVAC SYSTEM FOR A PUBLIC LIBRARY IN DALLAS, TEXAS ME 260 - Heating, Ventilation and Air Conditioning George Washington University Spring Semester 1999 Submitted to: Professor A.

### Home Energy Evaluation Report

Home Energy Evaluation Report Nate Begeman, 1550 Saint Francis Dr San Jose, CA 95125 Air Infiltration Current Air Leakage 2,852 Current Air Changes Per Hour 0.91 Recommended Air Changes Per Hour 0.35 Percent

### Cooling Load Estimation and Air Conditioning Unit Selection for Hibir Boat

The International Journal Of Engineering And Science (IJES) Volume 3 Issue 5 Pages 63-72 2014 ISSN (e): 2319 1813 ISSN (p): 2319 1805 Cooling Load Estimation and Air Conditioning Unit Selection for Hibir

### Total Heat Versus Sensible Heat Evaporator Selection Methods & Application

Total Heat Versus Sensible Heat Evaporator Selection Methods & Application Scope The purpose of this paper is to provide specifying engineers, purchasers and users of evaporators in industrial refrigeration

### HVAC FORMULAS. TON OF REFRIGERATION - The amount of heat required to melt a ton (2000 lbs.) of ice at 32 F. 288,000 BTU/24 hr. 12,000 BTU/hr.

HVAC FORMULAS TON OF REFRIGERATION - The amount of heat required to melt a ton (2000 lbs.) of ice at 32 F 288,000 BTU/24 hr. 12,000 BTU/hr. APPROXIMATELY 2 inches in Hg. (mercury) = 1 psi WORK = Force

### Optimum Solar Orientation: Miami, Florida

Optimum Solar Orientation: Miami, Florida The orientation of architecture in relation to the sun is likely the most significant connection that we can make to place in regards to energy efficiency. In

### Moisture Control. It s The Dew Point. Stupid! Its not the humidity.

Moisture Control Its not the humidity. It s The Dew Point Stupid! Mike Schell EpiphanyTec Inc. Santa Barbara, CA mschell@epiphanytec.com 805 687-3175 Matching great technology to market need! Topics SHR

### By Tom Brooke PE, CEM

Air conditioning applications can be broadly categorized as either standard or critical. The former, often called comfort cooling, traditionally just controlled to maintain a zone setpoint dry bulb temperature

### HVAC Basic Science - System Capacity

HVAC Basic Science - System Capacity Btu/hour, btu/h, b/h, btuh. btu?? 1 MBH = 1000 btu/hour 1 KBH = 1000 btu/hour 1 ton of cooling= 12,000 btu/hour 1 watt = 3.414 btu/hour 1 kilowatt = 1000 watts = 3,414

### UNIVERSITY OF MISSOURI 23 0000 - Heating Ventilating and Air-Conditioning (HVAC) March 2015.01

GENERAL: This section provides general standards for overall sizing and design of Heating, Ventilating, and Air Conditioning (HVAC) systems. Other sections contain specific standards for each system per

### Energy Efficient Homes: Air Conditioning

Energy Efficient Homes: Air Conditioning Quick Facts The average energy bill for a typical single family home in the U.S. is \$2,200. Roughly 46 percent of the bill, or \$1,012, is spent on heating, ventilation,

### Technical Information

Determining Energy Requirements - & Gas Heating & Gas Heating and gas heating applications can be divided into two conditions, air or gas at normal atmospheric pressure and air or gas under low to high

### DEVELOPMENT OF AN OPEN SOURCE HOURLY BUILDING ENERGY MODELING SOFTWARE TOOL

DEVELOPMENT OF AN OPEN SOURCE HOURLY BUILDING ENERGY MODELING SOFTWARE TOOL Brittany Hanam, MASc, EIT RDH Building Engineering Ltd. Vancouver, BC John Straube, PhD, P.Eng. Building Engineering Group, Civil

### ) and air spaces (R a

5.3.3 Thermal Resistance (R-value) Common thermal properties of materials and air spaces are based on steady state tests, which measure the heat that passes from the warm side to the cool side of the test

### New Homes EPS Modeling Frequently Asked Questions. Developed by Energy Trust of Oregon

New Homes EPS Modeling Frequently Asked Questions Developed by Energy Trust of Oregon 1 General Questions 3 REM/Rate questions 4 -Creating custom entries 4 -Modeling Heat Pumps 5 -Modeling HRV/ERV 7 -Modeling

### Climate and Energy Responsive Housing in Continental Climates. The Suitability of Passive Houses for Iran's Dry and Cold Climate. Farshad Nasrollahi

Climate and Energy Responsive Housing in Continental Climates The Suitability of Passive Houses for Iran's Dry and Cold Climate Farshad Nasrollahi Table of Contents Abstract German Abstract Introduction

### HVAC Made Easy - Overview of Psychrometrics

PDHonline Course M135 (4 PDH) HVAC Made Easy - Overview of Psychrometrics Instructor: A. Bhatia, B.E. 2012 PDH Online PDH Center 5272 Meadow Estates Drive Fairfax, VA 22030-6658 Phone & Fax: 703-988-0088

### Presented By: WALTER E. JOHNSTON, PE CEM, CEA, CLEP, CDSM, CPE <walterjohnston@bellsouth.net

Presented By: WALTER E. JOHNSTON, PE CEM, CEA, CLEP, CDSM, CPE

### Presentation Outline. Common Terms / Concepts HVAC Building Blocks. Links. Plant Level Building Blocks. Air Distribution Building Blocks

Presentation Outline Common Terms / Concepts HVAC Building Blocks Plant Level Building Blocks Description / Application Data Green opportunities Selection Criteria Air Distribution Building Blocks same

### HVAC and REFRIGERATION

This is a preview. Some pages have been omitted. PE principles and practice prracticce of engineering mechanical: HVAC and REFRIGERATION sample questions + solutions Copyright 2011 by NCEES. All rights

### Element D Services Heating, Ventilating, and Air Conditioning

Load Calculation Criteria PART 1 - GENERAL 1.01 OVERVIEW A. This section includes requirements for calculating HVAC cooling and heating loads. B. Load calculations must be performed in accordance with

### Greenhouse Cooling. Why is Cooling Needed?

Greenhouse Cooling Why is Cooling Needed? Solar radiation is the heat input for the earth can radiate as much as 277 Btu/ft 2 /hr onto the surface of the earth on summer s day in coastal and industrial

### VAV Laboratory Room Airflow The Lowdown on Turndown

Technology Report March, 2003 VAV Laboratory The Lowdown on Turndown Turndown comparison of these two turndown ratios. Note the small actual airflow difference between them. control ranges are normally

### Building Performance Solutions HVAC Design Guide, 2007

Building Performance Solutions HVAC Design Guide, 2007 HVAC sizing, system design, layout, and installation shall be sized according to (Air Conditioning Contractor of America), ACCA manual J8, 8 th edition,

### Dr. Michael K. West, PE 1 Dr. Richard S. Combes, PE 2 Advantek Consulting / Melbourne, Florida

Optimizing 100% Outside Air Systems with Heat Pipes Dr. Michael K. West, PE 1 Dr. Richard S. Combes, PE 2 Advantek Consulting / Melbourne, Florida Introduction To meet increasingly rigorous building codes

### DUCT SYSTEM DESIGN CONSIDERATIONS Part 1

Refrigeration Service Engineers Society 1666 Rand Road Des Plaines, Illinois 60016 DUCT SYSTEM DESIGN CONSIDERATIONS Part 1 by Roger M Hensley, CMS TYPES OF SUPPLY DUCT SYSTEMS There are several basic

Dehumidification Basics Why do you want to keep indoor Rh between 30-60%? ASHRAE recommends keeping the relative humidity in a home between 30-60% to limit the effects of many unwanted conditions and harmful

### Pool Dehumidification Basics

Copyright 2009 Wescor. All rights reserved. Permission granted to reproduce for personal and educational use only. When energy costs were low, many pool owners considered only first cost when choosing

### FLORIDA SOLAR ENERGY CENTER

FLORIDA SOLAR ENERGY CENTER Creating Energy Independence Since 1975 Impact of Energy-Efficiency Parameters on Home Humidity Rob Vieira Florida Solar Energy Center A Research Institute of the University

### CHAPTER 4 VENTILATION

CHAPTER 4 VENTILATION SECTION 401 GENERAL 401.1 Scope. This chapter, in conjunction with the building code, shall govern the ventilation of spaces within a building intended to be occupied. Mechanical

### Exhaust Calculation Booklet

Exhaust Calculation Booklet American Dryer Corporation 88 Currant Road Fall River MA 02720-4781 Telephone: (508) 678-9000 / Fax: (508) 678-9447 e-mail: techsupport@amdry.com ADC Part No. 450450 Exhaust

### Energy Efficiency. Energy Efficient Home Cooling:

Energy Efficiency Energy Efficient Home Cooling: Choosing an air conditioning system is an important decision. A poor choice may be costly to purchase and operate and yet fail to provide the desired cooling

### Cooling Strategies for IT Wiring Closets and Small Rooms

Cooling Strategies for IT Wiring Closets and Small Rooms By Neil Rasmussen Brian Standley White Paper #68 Executive Summary Cooling for IT wiring closets is rarely planned and typically only implemented

### Molds and mildew are fungi that grow

Appendix C: Moisture, Mold and Mildew Molds and mildew are fungi that grow on the surfaces of objects, within pores, and in deteriorated materials. They can cause discoloration and odor problems, deteriorate

### APPLICATION GUIDE. Moisture Management in Waterborne Climate Systems

APPLICATION GUIDE Moisture Management in Waterborne Climate Systems Contents Introduction 3 WBCS Concept 3 Condensation 4 Moisture Sources in the Space 4 Impact of a High Moisture Load 5 Designing to Manage

### Strategy Guideline: Accurate Heating and Cooling Load Calculations

Strategy Guideline: Accurate Heating and Cooling Load Calculations Arlan Burdick IBACOS, Inc. June 2011 NOTICE This report was prepared as an account of work sponsored by an agency of the United States

### Preventing Ice Dams on Roofs

Preventing Ice Dams on Roofs Facility Manager November/December 2005 When a roof leaks, facility managers inevitably receive complaints from building occupants. If it is winter, ice dams are often the

### Measuring The Right Thing For Humidity Control It s the Dew Point Stupid!

Page 1 of 6 Measuring The Right Thing For Humidity Control It s the Dew Point Stupid! By Mike Schell, AirTest Technologies Corp. A version of this article appeared in the June 2004 edition of Indoor Air

### NADCA White Paper: Restoring Energy Efficiency Through HVAC Air Distribution System Cleaning

NADCA White Paper: Restoring Energy Efficiency Through HVAC Air Distribution System Cleaning Contributors: Mike White, Chairman, Education Committee, Dan Stradford, Chairman, White Paper Subcommittee,

### Energy Efficient Process Heating: Insulation and Thermal Mass

Energy Efficient Process Heating: Insulation and Thermal Mass Kevin Carpenter and Kelly Kissock Department of Mechanical and Aerospace Engineering University of Dayton 300 College Park Dayton, OH 45469-0210

### LOW-RISE RESIDENTIAL BUILDINGS ADDITIONS AND ALTERATIONS IN EXISTING LOW-RISE RESIDENTIAL BUILDINGS

SUBCHAPTER 9 LOW-RISE RESIDENTIAL BUILDINGS ADDITIONS AND ALTERATIONS IN EXISTING LOW-RISE RESIDENTIAL BUILDINGS SECTION 150.2 ENERGY EFFICIENCY STANDARDS FOR ADDITIONS AND ALTERATIONS IN EXISTING BUILDINGS

### Preliminary Final Proposal

1 Butler Memorial Hospital New Inpatient Tower Senior Capstone Project Mechanical Option Preliminary Final Proposal Mechanical System Re-design and Breadth Topics Butler Memorial Hospital New Inpatient

### Calculating Heat Loss by Mark Crombie, Chromalox

Calculating Heat Loss by Mark Crombie, Chromalox Posted: January 30, 2006 This article deals with the basic principles of heat transfer and the calculations used for pipes and vessels. By understanding

### KITCHEN AND BATH REMODELING BUILDING PERMIT REQUIREMENTS

St. Louis County Department of Public Works Division of Code Enforcement KITCHEN AND BATH REMODELING BUILDING PERMIT REQUIREMENTS This guideline is intended to provide the homeowner/contractor with the

### Energy Use in Residential Housing: A Comparison of Insulating Concrete Form and Wood Frame Walls

PCA R&D Serial No. 415 Energy Use in Residential Housing: A Comparison of Insulating Concrete Form and Wood Frame Walls by John Gajda and Martha VanGeem 000 Portland Cement Association KEYWORDS Concrete,

### Defining Quality. Building Comfort. Precision. Air Conditioning

Defining Quality. Building Comfort. Precision Air Conditioning Today s technology rooms require precise, stable environments in order for sensitive electronics to operate optimally. Standard comfort air

### Fuel and Energy Conversion and Equivalence Chart

Fuel and Energy Conversion and Equivalence Chart Please note, the fuel economy estimates within this document are examples only. Maine Public Service does not consult with customers regarding fuel source

### Energy Efficient Building Design College of Architecture Illinois Institute of Technology, Chicago. Ceiling/Airspace

HEAT GAINS and LOSSES : ROOFS and WALLS Wall Roof Ts To Ts To Ti Ceiling/Airspace Ti Roof and wall are analyzed in the same way. In winter the heat loss is simple transmission based on the inside and outside

for A Probabilistic Approach Taperit Tongshoob 1 Chirdpun Vitooraporn 2 Cooling Load Calculation Abstract 1 Ph.D Student 2 Lecturer at Building Technology Environment Laboratory, Mechanical Engineering

### Saving Heating Costs In Warehouses

2005, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www.ashrae.org). Reprinted by permission from ASHRAE Journal, (Vol. 47, No. 12, December 2005). This article may not

### Safety-Related Air Conditioning, Heating, Cooling, and Ventilation Systems Calculations

US-APWR Safety-Related Air Conditioning, Heating, Non-Proprietary Version March 2013 C2013 Mitsubishi Heavy Industries, Ltd. All Rights Reserved Mitsubishi Heavy Industries, LTD. Revision History (Sheet

### UNDERSTANDING REFRIGERANT TABLES

Refrigeration Service Engineers Society 1666 Rand Road Des Plaines, Illinois 60016 UNDERSTANDING REFRIGERANT TABLES INTRODUCTION A Mollier diagram is a graphical representation of the properties of a refrigerant,

### 85 F 80 F 50% 75 F 70 F 73.0/61.8 45 F 10% Figure 1

Feb. 07 INTRODUCTION: Wrap around heat pipes are air-to-air heat exchangers that are installed in the airstream upstream and downstream of a cooling coil to deliberately reduce the Sensible Heat Ratio

### ENHANCED LABORATORY HVAC SYSTEM

ENHANCED LABORATORY HVAC SYSTEM INTRODUCTION Since the early 1980's the attention to more energy efficient laboratory designs has been on the rise due to the increase in energy cost and the emergence of

### CONDENSATION. Section Break (Next Page)

CONDENSATION Elimination of condensation on or within walls and floors is as important as reducing the heat loss through the wall or floor. In addition to the moisture damage caused to buildings by condensation,

### BPC Green Builders. Green building for new and existing homes. Health Comfort Energy

BPC Green Builders Green building for new and existing homes Health Comfort Energy Mechanical Systems Installed HVAC Systems Primary energy source large, roof mounted, solar thermal array (AET flat plate)

### Makeup Air For Exhaust Systems In Tight Houses. Tony Jellen Engineering Projects

Makeup Air For Exhaust Systems In Tight Houses Tony Jellen Engineering Projects PA Housing & Land Development Conference February 23, 2012 Effects of Kitchen Ventilation on Residential Dwellings Anthony

### HVAC Code Requirements

one and two family dwellings? Answer: SECTION 2001: GENERAL 2001.1 Air supply. Fuel-burning equipment shall be provided with a supply of air for fuel combustion, draft hood dilution and ventilation of

### Department of Mechanical and Materials Engineering Florida International University, Miami, FL. EML 4905 Senior Design Project

Department of Mechanical and Materials Engineering Florida International University, Miami, FL EML 4905 Senior Design Project HVAC Design for Green Building Miami Green Final Report Submitted By: James

### Kitchen Ventilation Systems: Part 2 Providing Adequate Makeup Air

The Pennsylvania Housing Research Center Kitchen Ventilation Systems: Part 2 Providing Adequate Makeup Air Builder Brief: April 2012 Anthony C. Jellen, PE & Brian M. Wolfgang, EIT, Michael A. Turns, MS

### Glossary of HVAC Terms

Glossary of HVAC Terms Heating, Ventilation and Air Conditioning (HVAC) is a major sub- discipline of mechanical engineering. The goal of HVAC design is to balance indoor environmental comfort with other

### Duct Design. Presented by Dave Janquart

Duct Design Presented by Dave Janquart Overview of Topics Duct design Duct insulation SMACNA Standards Factors Influencing Duct Design Equipment Losses Air Velocity Duct Material Duct Size & Shape Length

### > Executive summary. Explanation of Cooling and Air Conditioning Terminology for IT Professionals. White Paper 11 Revision 2. Contents.

Explanation of Cooling and Air Conditioning Terminology for IT Professionals White Paper 11 Revision 2 by Tony Evans Click on a section to jump to it > Executive summary As power densities continue to

### Whole House Dehumidification for Occupant Comfort and Energy Savings

Downloaded from www.rsrews.com. Since 1968, RS Andrews has proudly served Atlanta's Heating, Air Conditioning & Plumbing Needs. Whole House Dehumidification for Occupant Comfort Energy Savings June 2009

### A Glossary of HVAC Terms:

Since 1979 TACL A537C Doctor COOL & P rofessor HEA T The Team For All Seasons TM A Glossary of HVAC Terms: Confused by the many terms and acronyms surrounding your indoor comfort system? Don t be! This

### THE PSYCHROMETRIC CHART: Theory and Application. Perry Peralta NC State University

THE PSYCHROMETRIC CHART: Theory and Application Perry Peralta NC State University PSYCHROMETRIC CHART Identify parts of the chart Determine moist air properties Use chart to analyze processes involving

### Matching the Sensible Heat Ratio of Air Conditioning Equipment with the Building Load SHR

Matching the Sensible Heat Ratio of Air Conditioning Equipment with the Building Load SHR Final Report to: Airxchange November 12, 2003 Report prepared by: TIAX LLC Reference D5186 Notice: This report

### Venice Library Humidity Study. for Williams Building Diagnostics, LLC 305 15 th Street West Bradenton, FL 34205. Report April 13, 2015

for Williams Building Diagnostics, LLC 305 15 th Street West Bradenton, FL 34205 Report April 13, 2015 Moses & Associates, Inc. 2209 NW 40 th Terrace, Suite A Gainesville, FL 32605 FL License EB-0003097

### HOW TO CONDUCT ENERGY SAVINGS ANALYSIS IN A FACILITY VALUE ENGINEERING STUDY

HOW TO CONDUCT ENERGY SAVINGS ANALYSIS IN A FACILITY VALUE ENGINEERING STUDY Benson Kwong, CVS, PE, CEM, LEED AP, CCE envergie consulting, LLC Biography Benson Kwong is an independent consultant providing

### Cooling Strategies for IT Wiring Closets and Small Rooms

Cooling Strategies for IT Wiring Closets and Small Rooms White Paper 68 Revision 1 by Neil Rasmussen and Brian Standley > Executive summary Cooling for IT wiring closets is rarely planned and typically

### Components HVAC General Standards HVAC Guidelines HVAC System Selection Life Cycle Cost Analysis

Components HVAC General System Selection Life Cycle Cost Analysis Outdoor Air Design Values Indoor Air Design Values Outdoor Air Ventilation Welding Ventilation Temperature Control Systems Ductwork HVAC

### Roof insulations must perform the basic function of helping to control fluctuations in building interior temperature

Thermal Values Roof insulations must perform the basic function of helping to control fluctuations in building interior temperature relative to changing exterior temperatures. By reducing interior temperature

### Radiant Heating and Cooling Systems BY KWANG WOO KIM, ARCH.D., MEMBER ASHRAE; BJARNE W. OLESEN, PH.D., FELLOW ASHRAE

TECHNICAL FEATURE Fundamentals at Work This article was published in ASHRAE Journal, February 2015. Copyright 2015 ASHRAE. Posted at www.ashrae.org. This article may not be copied and/or distributed electronically

### Passive Solar Design and Concepts

Passive Solar Design and Concepts Daylighting 1 Passive Solar Heating Good architecture? The judicious use of south glazing coupled with appropriate shading and thermal mass. Summer Winter Passive solar

### HVAC Checklist - Long Form

HVAC Checklist - Long Form Page 1 of 14 Appendix B discusses HVAC system components in relation to indoor air quality. utside Air Intake Location pen during occupied hours? Unobstructed? Standing water,