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EN/nnTENTAL ^SIGN AURARIA I IRRARY
MASTER DEGREE IN ARCHITECTURE AT THE
UNIVERSITY OF COLORADO, DENVER CAMPUS DENVER, COLORADO
OFFICE/TEACHING LABORATORY BUILDING I FOR THE
UNIVERSITY OF COLORADO, COLORADO SPRINGS CAMPUS
BEGINNING 1 FEBRUARY 1978 THROUGH 17 APRIL 1978 BY
LARRY DIMINYATZ, ARCHITECTURAL STUDENT'
3 1204 00270 7603
RESEARCH & ANALYSIS
Site Information 4
Construction Considerations 10
Heating & Cooling Loads 11
Design Conclusions 12
Statement of Intentions 1
Response to Client Needs 2
Energy Concepts 5
1st Floor Plan 8a
2ncj Floor Plan 8b
Cross/Longitudinal Sections 8C
HVAC, Lighting & Structure Integration 9
Passive Solar Items 10
Lighting System 13
VAV Double Duct HVAC System 14
HVAC System 18
Thermal Gain/Loss Calculations 19
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This report/project is the result of my desire to better understand the use of passive solar principles in building design. In the process I have attempted to demonstrate that energy efficient design can result in usable, buildable structures. I agree with the concept that "our goal as designers should be the creation of habitats that enhance the quality of human life without degrading the natural environment. However, this goal will only be reached when our designs begin to integrate human needs, energy, environment and economic concerns into new forms which reflect both the aspirations and limitations of our society.
Rick Cowlishaw, University of Colorado, Colorado Springs Architect
advisor, materials and sources
Y/ally Leiper, Manager of Utilities and Engineering Division, University of Colorado, Boulder
Gary Long, University of Colorado, Denver, Faculty, College of Architecture
G. K. Vetter, University of Colorado, Denver, Faculty, College of Architecture
Introduction 1 Construction Considerations 1 10
Data 3 1. Physical Environment Requirements
1. Client Needs 2. Foundation Design i
' 2. Code Requirements Heating & Cooling Loads 11
3. Soil Conditions
it. Utilities Design Conclusions 12
1. Passive Solar / Energy Conservation Responses
Site Information k 2. Mechanical & HVAC System Responses
1. Campus Plan 3. Client / Functional Needs Response
2. Major Site Determinants Plan Bibliography 14
1. Regional Map
2. Sun Path Diagram
3. Temperature Range Clear and Cloudy Days
6. Relative Humidity
This project is the design of an Office/Teaching Laboratory building for the University of Colorado at the Colorado Springs Campus. The research and design were based upon the "Program Plan"3 drawn up by Rick Cowlishaw, UCCS Architect, which accompanies this booklet. My intentions were to study and apply passive solor and energy conservation principles into the building design in relation with the user needs. (A more detailed list of the user needs are given under the title of DATA and in the accompanying "Program Plan.
The University and it's consultants will carry out detailed computer simulation studies for the economic feasibility and performance of each passive solar principle used. My design based upon research (readings, interviews and basic calculations) will use those principles which I feel are practicle.
In light of the recent energy shortages projected cost studies and future availability of conventional energy resources it is clear these sources are limited and will be depleted within the next ^0 years. Based upon research, cost effectiveness and feasibility studies the University has decided to implement a Passive Solar System in the building design. "It is possible today to develop a passive solar system which can provide between 70$ to 80$ of a building's needs for heating and cooling. The investigation and results of this first building (o/T Lab building) will make it possible to further refine passive solar techniques. It may well be possible to develop a building which is 100$ passively heated and cooled in the near
ESTIMATED ECONOMIC RESULTS (as computed by the University)
"Based on a UO-year life cycle of the proposed building utilizing the combination of passive heating and cooling techniques, and heat pumps and heat recovery systems, the calculated utility cost savings for the proposed new building are $3^67,693. The pay back for that period would be years. This calculation is made as-
suming an escalation of 10$ of the price of natural gas per year, and 6$ of the cost of electricity per year... The above calculations make it quite apparent that a relatively small investment in a building constructed today that pays greater attention to energy saving techniques and conservation, is an investment that will readily pay for itself in a very short period of time, through reduced energy costs." (Feasibility Study prepared by Everett/ Zeigel Associates, Boulder, Colorado.)
The construction of this building is to provide needed space for the Biology, Chemestry and Psychology departments, office and classrooms. Generally:
1. Supply needed office, teaching laboratories, and classroom space.
2. To organize separated departments into integrated units in one building.
3. To bring the individual departments in closer proximity to those groups with which they have common interests.
4. To bring the departments closer to the planned academic core of the campus as detailed in the UCCS Master Plan.
(A more detailed description of specific needs and requirements is given in the "Program Plan.")
The facility shall be designed and constructed a Type II, Group B, Division 2, Fire Zone 3, building in accordance with the Uniform Building Code, the University of Colorado Construction
"Based on the results of our field and laboratory investigation and our preliminary understanding of the proposed construction, the following tentative comments and recommendations are made: It is expected that the foundations will be supported by the natural strata consisting of medium dense to dense, slightly silty to clayey sands. These materials have moderate supporting capacities and are considered to be non-expansive in that they will not experience volume changes (swelling) if their moisture is increased."^
Water, sanitary and electrical power systems exist underground just east of the University Center and may be tapped for the o/t Lab building.
No central power plant exists on the campus, each building is independent in this respect and must provide its own heating and cooling.
1. Dwire Hall
2. Main Hall
3. Fine Arts
ho Cragmore Hall
6. Arts Cottage 7 South Hall
A, B, C Psychology Labs D Business An Annex
9. Library/Class-roorn Building
UNIVERSITY OF COLORADO AT COLORADO SPRINGS Site Plan
X 10. University
11. Temporary Classrooms (North & South)
12. Future Offic^ Teaching Lab Building
MAJOR SITE DETERMINANTS &
Latitude 38 ky' II Longitude 10^ 43' W Elevation 61^5 ft
SUN PATH DIAGRAM
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC YEAR
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC YEAR
CLEAR AND CLOUDY DAYS
cloudy .7-1.0 ptly cloudy .3-.7 clear 0-.2
131 123 ill
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC YEAR
MAR APR MAY
JUN JUL AUG
OCT NOV DEC YEAR
Certain criteria as stated by the "Program" should be considered:
PHYSICAL ENVIRONMENT REQUIREMENTS
1. The design of the building should reinforce and continue the architectural character as established by the Library/Classrocm building and in keeping with UCCS Master Plan.
2. The structure shall be a pre-cast concrete columnar design with spacing similar to the Library/Classroom building.
3. The exterior walls generally shall be non-bearing and of masonry construction. All exposed exterior walls shall be brick to match the Library/Classroom building. Some exposed concrete may be allowed.
U. The building will utilize a modular system with standard ceiling heights and standard location of electrical outlets and air conditioning drops, all to provide maximum flexibility.
- Source No. 3
1. "The proposed structure will be able to be supported by conventional spread footing foundations.
2. It will not be necessary for the foundations to carry a minimum dead load pressure."^
3. "The installation of a subsurface drain tile system will be recommended around all areas where the interior ground floors are located at elevations below finished exterior grades."^'
"According to educators, chronic overheating and uneven ventilation are the most commonly encountered deficiencies in the control of the classroom environment. More attention in every season is needed to cooling than to heating, regardless of geographical location. Population density in classrooms is about three times as heavy as in offices. The heat of occupants plus lighting which is usually a high level, plus sun effect through glass makes for large heat gain in all seasons. Figure a. indicates the heat gain in the typical 30 student, 800 sq ft classroom with glass facing east or west and under critical conditions. The lighting load is 3 watts per sq ft. It is seen that there is a net heat flow into rather than out of the room even at outdoor temperatures less than zero. Figure b. is a similar graph for an interior classroom. It also has a heat gain when outdoor temperatures are less than zero but, because of the exclusion of the sun, it has only about half the heat gain of the exterior room with glass when outdoor temperatures are in the 80 to 90 F range. Cooling can be effected by circulating outdoor air when this air is below 60 F.
Sensible Heat Load in Classrooms, No Scale --------Loss o Gain----*
-20 0 20 40 60 80 100
Outdoor DB Temperature-*F (a)
Fig. a. and b. Sensible heat gain or loss at various outdoor temperatures for a. typical exterior classroom and b. typical interior classroom. Both rooms fully occupied during normal daytime school hours.
When outdoor air at less than 60 F is not available for cooling, room temperatures will surely rise above 72 F in winter and 78 F in warm weather unless cooling by refrigeration is used." 8
From the criteria researched the o/T Lab building design should respond with the following general concepts:
passive solar/energy cohservatiqn responses
Passive solar system defined: Passive solar systems differ from active solar systems in that the techniques applied depend on the building itself acting as a collector, distributor, and a storage medium of solar energy. This should be accomplished with as few moving parts as possible. The advantages are little or no maintenance, low initial cost, no pollution, early payback within 3 to 7 years and little dependence on non-renewal resources.
1. Orientate to achieve exposure to the south for certain building zones and protection from northwestern wind for others.
2. Because of the large mass/square footage of this building (56,5^9 sf) use skylights and/or courtyards to allow lighting and ventilation into core areas.
3. Allow as much natural lighting as possible to avoid using artificial illumination thus cutting energy consumption and
excessive heat build up.
4. Structural mass and insulation should be increased compared to conventional amounts to increase thermal mass and reduce thermal transmission.
5. Possible use of rock storage for heat in the winter and "coolness" in the summer.
6. Use shading devices that allow winter sun to enter building but shade summer sun.
7. Lighting system
a. Use a flexible lighting system that can be manipulated for various uses.
b. Cool or exhaust air around luminaires to capture heat and prolong fixture life.
c. Use a photocell to control lighting with possibility of manual override.
Miscellaneous Passive Solar Items
1. Stairs as a glass and masonry plenum.
2. Interior fountains or pools for humidity control.
3. Northern/cool side of building HVAC intake.
U. Reflection of ground light into building for diffused light.
5. Operable windows for selective natural ventilation.
6. Low water consumption air vacuum toilet system.
7. Berm or bury building.
MECHANICAL AND HVAC SYSTEM RESPONSES
1. Decentralized HVAC system building divided into zones to be served.
2. A HVAC system that allows flexibility/control down to the individual classroom or laboratory level.
3. A system that can be "tuned" for various loads, seasons and will be integrated with the passive solar and structural aspects of the building.
client/functional NEEDS RESPONSE
1. Orientate spaces/departments within the building as stated in the "Program."
2. Facilitate inter- and intro-departmental relationships as shown in RELATIONSHIP DIAGRAMS under "Design Development."
3. Use as much natural light within the building as possible, especially in those spaces where required (i.e, faculty offices).
4. Consider building as part of the planned academic core of the campus, making an appropriate design statement.
5. Fulfill the circulation requirements as stated in the "Program."
6. Respond to the views, plaza, access points, etc., as shown on the SITE DETERMINATES map, page 5.
ASHRAE Guide and Data Book and Applications, American Society of
Heating, Refrigeration, and Air Conditioning Engineers, New York,
2. Competition For an Energy Efficient Office Building, sponsored by, The California Energy Resources Conservation and Development Commission, and The Office of the State Architect, 1977
3. Cowlishaw, Rick (UCCS Architect), Program Plan Office/Teaching Laboratory Building I, University of Colorado at Colorado Springs, February 1978
Crowther, Richard L., Sun Earth, "How to Use Solar and Climactic Energies Today," The A. B. Hirschfield Press, Inc., Denver, Colorado, 1977
5. Davis/Schubert, Alternative Natural Energy Sources, Van Nostrand Reinhold Company, New York, 1976
6. Ferguson, W. R., Practical Laboratory Planning, Applied Science Publishers, Ltd., Essex, England, 1973
7. Caseu, Paul, Graijhic Problem Solving For Architects and Builders,
A Division of Cahners Publishing Co., Inc., Boston, Massachusetts,
. Me Guinness, W. J., Mechanical and Electrical Equipment For Buildings, John Wiley and Sons, Inc., New York, 1971
9. New Spaces For Learning, Report of a Research Project Conducted by the School of Architecture, Rensselaer Polytechnic Institute, Troy, New York, 1966
10. Olgyay, Victor, Design with Climate, Princeton University Press,
11. Olgyay, Victor, Solar Control and Shading Devices, Princeton University Press, 1957
12. Schmert>z, M. F., Campus Planning and Design, Architectural Record, McGraw-Hill, Inc., 1972
13. Summerlee, Thomas E., Soil and Foundation Engineering Report, Colorado Springs, Colorado, 1978
1^. 10 Designs of Colleges, A Publication of the Department of
Architecture, Rice University, Houston, Texas, 1962
DEVELOP ENERGY CONSERVATION AND PASSIVE SOLAR PRINCIPLES INTERGRATED WITH THE STRUCTURE AND MECHANICAL SYSTEMS.
CREATE AN ENJOYABLE LEARNING ENVIRONMENT FULFILLING THE CLIENT NEEDS.
BE IN HARMONY WITH THE SURROUNDING CAMPUS AND REINFORCE THE CHARACTER OF THE IMMEDIATE AREA AS THE CAMPUS CENTER.
The new Office/Teaching Laboratory building should respond to the stated major requirements. The first aspect held primary impor-
tance in this project due to my goal of becoming better acquainted with Passive Solar principles, and will be discussed in the major portion of the report.
Secondarily, but of equal importance outside of this report, are the client needs. The siting of the building was a given by the program. It will house three major departments, Psychology, Biology and Chemistry, in addition to classrooms and research laboratories. The layout of these spaces and the inter and intra relationships of the departments was developed in conjunction with the design of the Passive Solar principles.
The building consists of two levels; Chemistry and Biology on the second, with Psychology, the lecture hall and office spaces on the first. The main entrance to the building is on the first level of the southwestern corner. This was in response to the entry statement that has been generated by the entryway of the
Library/Classroom building and by the stairway to the Plaza and the future Commons building. This area seems to be the main entry for students using the adjacent parking lot. Three other entrance points are located around the building to facilitate pedestrian circulation from the plaza and the rest of the campus.
The major circulation within the building is centrally biaxial, dividing the building into 4 major portions per level. Major classrooms and office spaces opening directly onto this pathway have recessed doorways so as not to constrict circulation. From this major pathway minor circulation routes serve the various departments and laboratories. Vertical circulation is provided by stairways at each entrance and supplimented by an elevator at the main entryway. Service elevators are provided for the mechanical and storage areas.
Consideration has been given to the location and intra relationships of the departments. Each department is arranged around a courtyard with the faculty offices adjacent to this space. The laboratories and classrooms are located around the perimeter of the building, with instructor offices and service areas (equipment rooms, storage) in the center. The
chairman of each department is adjacent to the centrally located
secretary yet has a potentially secluded office position. The
majority of the faculty offices are located on the departmental
circulation loop to facilitate student contact. The majority of
spaces are naturally lit due to the building form in relation
with architectural features. The courtyards have operable sky-
lights, and are faced with glass. Partitions within the building have a 3 foot glass strip above them to further facilitate natural light diffusion.
To facilitate inter departmental relations considerations such as Biology and Chemistry departments being positioned next to each other so they may share certain facilities; and the Statistic Lab is being located within the Psychology department so that it is accessible by the other departments.
The courtyards have been developed to bring light and natural ventilation into the core of the building, and to provide an "outdoor" space as lobby and informal meeting place. The
courtyard adjacent to the Biology department is used as a potentially controlled greenhouse. The other is designed with stepped seating, a fountain and landscaping to be used as a lounge or an informal classroom
The third and last requirement was to reinforce the character of the immediate area as the planned Cantus Center and relate to the surrounding cairqpus; in specific the Library Classroom building.
I interpreted the entry area for the L/C building and the plaza space as being an appropriate "center" for the complex of buildings planned for this area. In response to this I felt that the Office/Teaching Lab building should reinforce this by allowing the plaza area to expand, thus providing more space between buildings. This would act as a buffer between the buildings defining each as separate elements of the whole, yet provi.de a circulation link for the complex.
To separate the Office/Teaching Lab building from the parking lot a landscaped and seating area has been developed. This will act as a
visual screen and envelope an outdoor amphitheater to be used for concerts, plays, or classes.
One important change of an existing situation would be to relocate the service access under the plaza stairway to possibly the northwest face of the Student Center. As of now, service trucks frequent this area which causes interference with circulation end demeans the entry statement. If left where it is it would only doubly complicate matters when the Office/Teaching Lab building is constructed. With this change the existing winding stair case should be dismantled and be replaced by a straight rim stair onto the plaza. The would provide a grandeur entry to the plaza and the Complex Center as viewed when arriving by automobile and in walking through this space.
The service area to this project is on the southeast building face in order that this activity may be isolated from the major portion of pedestrian circulation.
In reinforcing the character of the Library/Classroom building I felt that the Office/Teaching building should be a separate entity but not in severe contrast. Using the same exterior brick, reflecting some of the forms and angles would be adequate.
BUILDING MASS INSULATION DOUBLE GLASS WINDOWS "COURTYARDS WITH MOVEABLE SKYLIGHTS
* DAYLIGHT INTEGRATION
REFLECTION OF DIFFUSE GROUND LIGHT INTO BUILDING SUNSIIADING rock STORAGE 'GLASS STAIR PLENUM BURIED BUILDING
use of landscaping/vegatation protection
FLEXIBLE,IIVAC RETURN AIR COOLED, PHOTOCELL CONTROLLED LIGHTING "SIMPLE ENERGY EFFICIENT MECHANICAL SYSTEMS
* MULTIFUNCTIONAL DESIGN ELEMENTS
BUILDING DESIGN/ENERGY CONSERVATION
The building design has been generated by the need for conserving energy in relationship with user needs. The response uses energy efficient features that are simple and multifunctional, e.g., the courtyards serve as informal meeting spaces, as light wells to the core of the building and provide a preheat zone for outside air in winter months. The response to user requirements was developed in conjuntion with these features to enhance the quality and use ability of the buildings.
ORIENTATION, BUILDING MATERIAL AND LANDSCAPING A primary factor is orientation. The predominant orientation of the building is northwest-southwest, minimizing solar radiation gains on the east and west facades. Though the optimum orientation is north-south this orientation has only a slight increase in SHGF.
The openings on the facades are either set at an angle to the north or are designed with an overhang to shade direct sun during warmer months. The material of the building provides both an insulating boundry and thermal storage. The use of adequate insulation and double glazed windows lessens the impact of external temperature variations on the interior of the building. Landscaping/deciduous vegetation is used to protect the building from solar radiation during warmer months. This is specifically important around the glass stair cases at the northwest and southeast entrances. These glass plenums, if needed, are used to capture solar radiation to be used for heating purposes. During summer months vents at the top will exhaust air from the building increasing ventilation.
The courtyards are a means of "tuning the building for various seasons and requirements. During winter months the skylights would be closed
and would provide a "pre-heat" zone for the HVAC system. This space would also provide a comforable "outdoor" space for informal classes during inclement weather. During summer and temperate months the skylights would be opened for fresh air ventilation.
The courtyards have been so positioned that there is no more than 2k feet to an exterior wall with operable windows. This is to insure that natural ventilation will occur and in addition allow natural light in to the building core. It is assumed that this light through a 10 foot high window will reach 30 feet into the structure before artificial lighting is required. Partitions within the building in most cases have a 3 foot glass strip above them to allow natural light dispersion. The courtyard nearest the Biology department could be used as a controlled green house.
The other having landscaping and a fountain to enhance the character of the space.
Separate HVAC systems for building zones allows for flexibility in serving various requirements. If for example a certain area needs to remain open
at night or on weekends it may do so without putting an unnecessary load on the other systems; it is independent. With a "tighter" fitting system
energy consumption will be reduced. -With the complex re-
auirements of this building it utilizes the help of a small computer to monitor the building and mechanical systems thus insuring maximum energy consumption efficiency.
Lecture Hal I Classroom Learning Lab General Lab Statistics Lab Elementary Exp't Animal Storage Equipment Rm.
Experiment Rm Faculty Office Secretary Morphology Ecolog y Microbiology Live Organism
W E L L
31 ^ n;
t l l
15 I 28 \
\ I A V /
16 Prep / Store Rm.
17 Dark Rm.
19 Gen. Chemistry
20 Analytical Chem.
21 Organic Chem.
22 Physical Chem
23 Stock / Balance Rm.
24 Instrument Rm.
25 LAS Dean
26 Associate Dean
28 Sponsored Research
29 Language Lab
30 Mechanical / Store Rm.
31 HVAC Duct
CHEMISTRY CIRCULATION -BIOLOGY cmc' N
DOUBLE GLAZED WINDOWS
THE WINTER SEASON building is tuned to the climatic changes to minimize heat losses and to efficiently utilize available solar energy. The windows are designed to allow direct winter sun
infiltration. The closed courtyard skylights act as solar collectors and provide tempered supply air and also decrease the building perimeter thus minimizing losses.
SKYLIGHT OPENED TO TAKE
THE INTERMEDIATE SEASON building is basically an outdoor building taking advantage of the comfortable climactic conditions while still having the flexibility to handle extreme conditions
that may occur. The ability to respond to these conditions is obtained by the moveable skylight as well as the high insulation and building mass which tend to buffer climatic variations.
THE SUMMER SEASON building as in all cases focuses on minimizing loads. All windows are shaded in the summer season to eliminate direct solar gains and the high mass, insulated shell reduces conductive gains providing a thermal lag. The interior surfaces are light colored to enhance natural lighting. Seasonal landscaping
is located to shade the exterior facade and courtyards. Supply air is taken from the north side of the building or courtyard to, take advantage of the pre-cooling effect and the humidity from vegetation and the fountain.
One of the major form determinants for this building is the efficient UGe of daylight for interior spaces# The building is planned on a x 2h foot module. The courtyards and rear skylight have been so positioned that there is no more than this distance (2^ feet) to a window. It is assumed that with a 10 foot high window natural light will reach 3 feet into a space before artificial lighting is required# This capability is a compensation for interior partitions that will be erected. Interior partitions in the majority of cases have a 3 foot glass strip at the top to allow light dispersion.
Natural light levels are Increased by the light reflection from the concrete seating area at the front of the building, from the light colored concrete panel at the base of the windows, and from the curved sections of suspended ceiling adjacent to the courtyards# Light colored materials are used throughout the building. Natural light levels within individual spaces are controlled by interior window shades. To balance the com-
bination of artifical and day lighting the fluorescent luminares are placed parallel to the windows.
Control of the luminaires incorporates two major components to insure energy efficiency. The first is a jjhotocell that turns the system on or off according to required light levels. This aspect has a manual override for special occasions. The second component is the use of variable ballast which allows reduction of luminaire output in response again to individual requirements.
The luminaires are a fixture that is currently manufactured that allows return air for the IIVAC system to flow around the lamps drawing generated heat away, thus increasing lamp life, and reducing heat build up within the space. This heat may be circulated to a cooler zone, stored, or exhausted .
COOL AIR TEMPERATE AIR WARM AIR
WINTER OPERATING MODE
Perimeter heating utilizes solar tempered air from enclosed courtyard, heat recovery from core zone, and when needed from the rock storage and furnace.
Heat is recovered utilizing heat-of-light return air system. Control is by means of a mixing box using supply air via VAV Double Duct System.
Core comfort conditions are maintained using solar tempered air mixed with warmed heat-of-light return air.
System startup after an unoccupied period utilizes the furnace, and closing all exhaust and air intake dampers until the building is warmed.
When excess heat is present it is put into the rock storage or exhausted.
COOL Ain TEMPERATE AIR WARM AIR
FUME HOOD EXHAUST AND SUPPLY
INTERMEDIATE OPERATING MODE
Daytime cooling of perimeter and core zones using an economizer cycle; using untreated outside air in combination with solar tempered air/warmed return air for variable requirements.
* Night ventilation of building thermal mass (structure and building contents) will be used when daily maximum temperature exceeds comfort range.
COOL Ain _
TEMPERATE Am WARM AIR _
FUME HOOD EXHAUST AIMO SUPPLY
V r'.i-Mr.'li1--------- vfy.'.s------------------
Ps^jSq w\ 100
oW v $>Â¥?Â£ 0 Op 0noO
SUMMER DAYTIME OPERATING MODE
Space cooling for perimeter and core zones
Utilization of night purge cycle during the night.
Full untreated outside air from the north side is used during the morning and evening periods.
*As the day progresses and temperature increases, supply air is sent through the rock storage.
*In extreme conditions the supply air is further cooled by the evaporative cooler.
During this mode return air is exhausted when its temperature reaches a predetermined value.
COOL AIR TEMPERATE AIR WARM AIR
FUME HOOD EXHAUST AND SUPPLY
NIGHT VENTILATION OPERATING MODE
Thermal mass of exposed structure, building contents, and rock storage is recharged at night by removing the thermal build up with night ventilation.
This mode is used when the daily maximum temperature exceeds a predetermined value.
Outdoor night air temperature rarely exceeds a useful value, but in such a case the evaporative cooler may be used.
The Variable Air Volume Double Duct system was chosen primarily because it is a flexible system in that it can serve varying heating and cooling requirement. Throughout the year there will be some spaces that must be cooled (e.g., interior classrooms ) while concurrently there will be zones that will require heat in varying degrees. This system can respond to the needs of both spaces. (This will be further illustrated in the following diagrams.)
Because of ventilation requirements and the use of rock bed thermal storage an air* system was chosen. The laboratory and classroom functions have high ventilation requirements, while the rock bed operates best on heat transfer by air. This system also enables the lighting system to be cooled thus increasing the fixture life and drawing unneeded heat from the space.
The building is divided into 4 zones to be served by 4 HVAC systems accompanied by ^ rock storage beds located under the courtyards. The units are positioned on the roof between the
two courtyards so that l) they will not add a thermal load to the building, 2) so that they will be in close promimity to the courtyard for air intake/ exhaust, the rock bed, and the area they are serving. Being grouped together will allow the units to share certain machinery and facilitate monitoring and control. Supply air passes from the units through ducts suspended in the corridors to the spaces, returning through the luminaires and plenum to the courtyard or exhausted through the roof.
The following calculations were made to estimate the heating/ cooling loads that will effect the o/T building. Three seasonal periods are considered; l) a typical winter day, 2) a winter period of 2 days and 2 nights, and 3) a typical summer day.
Each of these periods are broken into divisions of day and night with varying occupancy and exterior temperature.
WINTER DAY (OCCUPIED 8 HRS)
Solar Radiation @ 1*0 N Lat
Glass area: SW @ 60$ glass of total wall SF - 1*320 SF;
SE @ 10$ 1*32 SF; NW @ 10$ 1*32 SF Assume a .5 shading coefficient for double glazed windows and a .7 shading coeff for cloud cover. From ASIIRAE take SHGF day totals for each orientation and divide by 8 for average hourly radiation.
Eq: Glass area x SHGFave x .55 shading coef x .7 clouds/ bldg area
Orientation SHGFave BTU/h/SF (January 21)
SE il*6 1
SW i)*6 7
NW 16 1
Load 49 BTU/H/SF
Note: Northeast wall no windows/bermed
Courtyards (horizontal glass) @ 230U SF & SHEF = 00
Gross floor area x SHGF x .7 x ,7/bldg area = +2
Roof Gains: Assuming 2 inches built up roofing; 3 inches rigid insulation; 6 inches concrete & 3/1* inch acoustical tile U = .0S6 Eq: U x daily average SHGF/bldg area = gain .056 x 00/56,51*9 = negligible Therefore, roof gains are negligible on a per SF basis (this includes summer periods)
People 50$ Lab; 50$ Offjce/Classroom
1 person/120 SF = 1*50 BTU/H/120 SF
Lights & Equipment (assume daylight)
50$ Lab; 35% Classroom; 15$ Office Lighting = .6 watt/SF
Equipment = 1.4 watt/SF
_______s 2 watt/SF
* 2 watt/SF x 3.4l BTU/watt = 7 BTU/H/SF @ 1 watt/SF
Shell Loss (@ Temp diff 30 outside exposure, temp diff 20 earth exposure)
Walls: glass U = .5; masonry U = .077 j concrete with insulation U = .05; roof = .056 (6 inch concrete slab roof with 3-4 inches insulation with built up roofing) Exposed to air: Assume approximately | roof and \ wall area; 30 foot zone of effectiveness, floor to floor 15 feet.
U for floor loading = .08
+ 7 btu/h/sf
Temp diff of 30.........08 x 65 = 2.4 BTU/h/SF
Ground Floor Exposure: Ground floor U = .066 (6 inch concrete; 3 inch insulation) .66 x 20 = 1.3 BTU/h/SF
Ventilating Assuming fume hoods will be used in the building (approximately 20 units); and allowing hoods to exhaust full inside air with HVAC system adding outside make up air.
Eq.......size of hood opening x Velocity (ASHRAE) x
number of units x Temp diff/GSF = BTU/h/SF 2* x 4' = 8 SF x 100 ft per minute x 20 units =
16,000 CFM x 30 = 1,040,000/56,549 GSF = -8 BTU/H/SF
For ventilation requirements assuming a general .25 CFM/SF ventilation rate (for office, classrooms and laboratory; figure kept low due to high exhaust rate of ventilation hoods).
Eq......BTU/H = CFM/SF x 60 x .018 x Temp diff for
- 5 btu/h/sf
.25 x 60 x .018 x 300 = 8 btu/h/sf
This figure balances with the exhaust of the ventilation hoods
8-8 = 0 8
Note: l) These calculations are based on full inside air exhaust; the ventilation hoods could be
WINTER NIGHT (OCCUPIED 6 HRS)
1 person/120 SF U50 BTU/h/120 SF or
BTU/li/SF Lights and Equipment
Assume 1+ watt/SF 4 watts/SF x 3.41 BTU/lI
designed to use 80$ O.A.; 20$ I.A. thus reducing heat loss to 1,6 BTU/h/SF which would make less of a load on the heat in the rock storage/building mass, especially on cloudy days. 2) The above calculations are based on an average day during the winter. Preceding and following this date the days become warmer thus reducing heat loss.
Load + 9 BTU/H/SF
(with 20$ exhaust +12)
Assume the same calculation as for Winter Day except with Temp diff = 40
Assume the same calculations as for Winter Day except with Temp diff 40 (& Temp diff 20 for earth exposure)
Note: With option of increasing to +12 by
dropping vent rate to a .15 CFM and reducing WINTER NIGHT (UNOCCUPIED 10 HRS)
exhaust. Lights and Equipment
Assume 1 watt/SF maintenance; 1 w/SF x 3.i+1 BTU/lI
+ 4 BTU/H/SF
+ 1.5 btu/h/sf
Assume ventilation system at a \/k of daytime use with Temp diff 50
Note: When the building is completely unoccupied the intake and exhaust could be shut down resulting in no loss.
Assume same calculations as for Winter Day with Temp diff 50 (Temp diff 20 for earth exposure)
This means a net BTU loss; therefore, during this time could draw on the rock storage and building mass to maintain a comfortable temperature.
.5 with no ventilating)
SUMMER DAY MODE (2h IIRS)
Summer Day (Oocupied l4 hrs)
Shell Gain: Assume that the transmission gains during the day will be balanced by the losses during the night; therefore, gains/losses =
Solar Radiation @ Uo N Lat: Assume a .55 shading coefficient for double glazed windows and a clear summer day. From ASHRAE take SHGF day totals for each orientation and divide by lA for average hourly radiation. For southwest and northwest exposures multiply figure by .2 for 80$ reduction due to shading.
Eq: Glass area x SHGFave x .55 shading coeff/bldg Glass areas: SW @ 60$ glass of total wall SF -U320 SF; SE @ 10$ U32 SF; NW @ 10$ 1*32 SF
Orientation SHGFave btu/h/sf (July 21)
SE 7^ o5
SW 74 1
NW 60 negligible
Note: Roof Gains are negligible on a total SF basis.
Courtyard: Eq........Glass area x SHGF x 7 x .2/
bldg area = 1^40 SF x 153 x .7 x .2/56,5^9 SF People: Same assumptions and calculations as for Winter Day.
Lights and Equipment: Same assumptions and calculations as for Winter Day with 1 watt/SF (1 x 3.*U) =
Ventilation: Assume during this l4 hr period that the losses are equal to the gains due to variations in morning and evening to midday hours.
This cooling load must be handled by natural ventilation, the rock bed, building mass and eventually the evaporative cooler. Gain
+ 1.5 btu/h/sf
Summer Night (Unoccupied 10 Hrs)
Assume during this period that there are no thermal gains from ventilation, solar radiation, nor people.
Shell Loss; Same calculations used as for Winter Day, with Temp diff 10 and Temp diff = 20 for earth exposure
Lights and Equipment: Assume 1 watt/SF mainenance: 1 watt/SF x 3,lH BTU/H =
- 3 btu/h/sf + 3.5
4- .5 btu/h/sf
Winter Day (8 hrs) Winter Night - Occupied (6 hrs) Winter Night - Unoccupied (10 hrs)
Solar Radiation Courtyard People Lights/Equipment Shell Loss Ventilation + 9 btu/h/sf + 2 44 + 7 -5 People Lights/Equipment Ventilation @ Temp diff 40 Shell Loss 4 4 4 14 -11 (or -6 with 20$ exhaust) 5.5 Lights/Equipment Ventilation @ Temp diff 50 + 3.5 -3.5 (or 0 if ventilation rate cut to 0 and air just circulated)
@ Temp diff 30 -8 (or -5) Shell Loss -6
+10 (up to +13.0 btu/h/sf) + 1.3 (up to +6.5) 6 (or 2.5 if above is done)
(@ full inside air through hoods and 20$ I.A.)
Total with 100$ Exhaust
Total with 20$ I.A Exhaust & Nightime Shutdown
+ 10 BTU/H/SF x 0 hrs =+80 BTU/SF + 1.5 x 6 +15
-6 x 10 = -60
413 BTU/h/SF x 8 hrs = +10*1 BTU/SF
+ 6.5 x 6 a + 39
-2.5________x 10 -23_______
+ 35 BTU/SF
= +118 BTU/SF
Summer Day Occupied (]A hrs)
Summer Night Unoccupied (10 hrs)
Courtyard +1 BTU/h/SF
Solar Radiation +1.5 People __ + If
Light s/Equipment +3.5 Ventilation
Light s/Equipment +.5 BTlf/n/SF + .5
+ 10 BTU/h/SF X lU hrs =+l*fO BTU/SF + o5_________x 10 hrs = +5 ___
tl1! 5 BTll/SF
During the winter season there is a thermal excess in both building temperature exceeds a predetermined value. Night
operating modes which can be put into rock storage or ventilation would purge the building mass contents and rock
exhausted. As will be seen from the Worst V/inter Period storage of daily thermal build up.
calculations it is likely that heating will be needed, therefore thermal excess at other times should be stored.
The summer period calculations do not take into account natural ventilation, thermal mass, nor night ventilation cycle. A typical day: the building will not require cooling until late morning where upon natural ventilation or the rock storage may be utilized. As a back up measure the evaporative cooler would operate when
WORST WINTER PERIOD (COLDEST 2 DAYS 2 NIGHTS)
Day Occupied (8 hrs)
People Light/Equipment increased lighting + '4
@3.5 watt/SF Shell Loss -4-12
@ Temp diff 65 Ventilation @ Temp diff 65@ full exhaust thru -7
hoods @ 20$ exhaust thru hoods or .15 CFM -12
ventilation -5 -3 or f ll BTU/ll/SF
Might Occupied (6 hrs)
People + U
Light/Equipment + l!l Ventilation
Temp diff 65 -17 or -10
Shell Loss -8
-7 or 0
Total with 100'/ Exhaust
-3 BTU/ll/SF x 8 hrs -7 x 6
-65 x 10
= -130 DTU/SF x 2 =-260
Night Unoccupied (10 hrs)
Light/Equipment Ventilation Temp diff 650
Shell Shell Loss
-k or 0 (with
circulation only; no ventilation)
-6.5 or -2.5
Total with- 20/ I,A. Exhaust fc Might time Shutdown
+ U BTU/h/SF x 8 hrs 0 x 6
-2.5 x 10
= +7 BTU/SF x 2 = + llf
For Rock Storage
Eq........BTU = CF x Density x Sp Ht x Temp diff *
CF = BTU/Density x Sp Ht x Temp diff
ft3 = BTU/(lb/ft3)(BTU/lb)(deg)
= 1^.7 x 106/l00 x .2 x 10 = 73,500 ft3/lf = 18,000 CF
= 26* x 26' x 26*
During this period the control of the Fume Hood exhaust is important. If hoods are allowed to exhaust 100$ inside air the loss will he 260 BTU/SF which will require the use of the rock storage and likely the furnace. If the hoods are controlled so that exhaust is made up of no less than 20$ inside air (majority being outside air), then heat losses are reduced substantially; to the point where there may be
The calculation for rock storage is to show the amount that would be necessary to heat the building during this period (under 100$ exhaust operating mode). This amount would require approximately a 26' x 26' x 26' space, which may not be practicle in comx^arison with using the furnace. A smaller volume for storage as a partial back up source would be more feasible.