ENERGY SITE MANAGEMENT EQUATION & A PROPOSED PROCESS TO ESTABLISH ENERGY BALANCES ON SITE

Solar energy is the source of life and the principal factor of evolution and its interaction with site massing remains inevitable. As we transform the natural environment to our needs, we introduce hard surfaces such as roads, walls, widows and roof; they all absorb energy by radiation which transfer the heat at different rate and different time by conduction as well as release heat by convection. Also the structure requires energy for heating and cooling system to function thus a bigger quantity of energy or heat is produced and transferred back to the living site.

It is essential to reveal how the footprint and massing of a site manage the quantity of solar energy at pre-development state and compare them to the quantity of energy that the same site is going to produce after development. By subtracting the comparative results, we will discover the additional quantity of energy that site must manage therefore taking necessary measures to establish the natural balance of energy management on site.

The following study has been pursuit to explore energy site management equation prior and after development. The focus will be only on what quantity of solar energy that site and exterior envelop attract and as designer what measures we need to take to regulate the energy balance as it was at pre-development state. The energy required for basic function of the envelope and its production on site is subject to a separate study and it would not be included in the calculation because the necessary energy to be produced is equivalent to the energy that the envelope will consume independently.

For study case I have chosen a typical existing single family residence in phoenix area:

Lot size 7,000 sf, building footprint 1,500 sf, east west oriented, climate zone 2,July 31st at 12PM, sun altitude 80^o south. The warmest day in summer is chosen as the base for calculation,the radiation effect on various sides of a building is expressed in KBtu / ft²/ Day per below chart.

 

Orientation – Phoenix Area	KBtu / ft 2 Day
East wall	1.207
South wall	0.563
West wall	1.207
North wall	0.452
East wall	1.207
Roof & horizontal surface	2.596

*Reference: Design with Climate, Victor Olgyay

Step 1 – Inventory of energy on site at pre-development state:

   a) Research historic data, referring to title and survey plan, we may find out waht site used to be at natural state.

   b) Calculate the surface area considering the amount of solar energy that site is receiving,reflecting and absorbing at natural state.

Since the solar reflectance energy is reflected and not retained on site, we should focus on the portion that site absorbs and releases with lag time. We should also consider the amount of energy that is not reflected therefore is absorbed.

Material	Surface area SF	SRI in. %	Absorpt. %	Calcs    KBtu / Day
Site horz. surface Light colored soil	70’x100’ = 7,000 – 226 = 6,774 Site – tree shade area	45	55	2.596 x 6,774x 0.55 = 9,672
2 Exist. Deciduous trees 12’ Dia	2 x 113 = 226	18	82	2.596 x 226 x 0.82 = 481
Total energy attracted on site @ pre-development state				Inventory   10,153

***Approximate albedo of light colored soil surface = 0.4 – 0.5

Within pre-existing Macroclimate, we have just discovered the amount of energy that site was generating and processing. As we modify a site, we create a Microclimate at the scale of site attracting more energy means producing more heat and enforcing Heat Island Affect.

The challenge will be to balance the total amount of energy on site with implementation of measures and strategies for proposed site and envelope therefore 10,153 KBtu / Day remains as a reference.

Step 2 – Survey of Existing Condition:

  To survey and calculate the surface area of existing condition considering the amount of solar energy that is attract by site surface, site features and the existing envelope to reveal the total amount of attracted energy on site.

Site	Surface area  SF		SRI. %	Absorpt. %	Calcs                           KBtu / Day
Conc. Fence  E.	6’ x 90’= 540		25	75	1.207 x 540 x 0.75 = 489
Conc. Fence  S.	6’ x 20’ = 320		25	75	0.563 x 320 x 0.75 = 135
Conc. Fence W.	6’ x 90’= 540		25	75	1.207 x 540 x 0.75 = 489
Conc. Fence  N.	6’ x 20’= 120		25	75	0.452 x 120 x 0.75  =  41
Conc. pads	625+125+600=1,350 Minus 290 shaded Area on North of bldg.		20	80	2.596 x 1,060 x 0.80 = 2, 201
4 Exist. Trees 25’ Dia.	4 x 113 = 452		15	85	2.596 x 452 x 0.85 = 997
Remaining Site Surface	7,000–1,740-1,350-1,963-1,350-390 = Site–roof area-tree’s area-conc. pads-shades areas		45	55	2.596 x 1,557 x 0.55 = 2,223
Building	Surface area  SF		SRI. %	Absorpt. %	Calcs
Medium dark paint / stucco – East	420 sf wall. 24 sf window		20 –	80 71SHGC trans.	1.207x420x 0.80  =  552 1.207 x 24 x 0.71 =    20
Medium dark paint / stucco South	632 sf wall. 80% of south wall shaded by overhang includ.  windows Count 50% of SHGC 144 sf window		20 –	80     71SHGC trans.	0.563x420x 0.80 x 0.80 = 324     0.563 x 144x 0.80 x 0.50 =32
Medium dark paint /. stucco  West	420 sf wall. 24 sf window		20 –	80 71SHGC trans.	1.207x420x 0.80  =  552 1.207 x 24 x 0.71 =    20
Medium dark paint / stucco – North	632 sf wall. 144 sf window		20 –	80   71SHGC trans.	0.452 x 632 x 0.80 = 229   0.452 x 144 x 0.71 =   46
Roof w. gray asphalt singles	58 x 30 including Overhang		13	87	2.596 x 1,740 x .87 = 3,930
Total					11, 626 KBtu / Day
Total energy surplus on site @ existing condition					11,626 -10,153=1,109 KBtu/Day

*Reference: Mechanical and Electrical Equipment for Buildings, Benjamin Stein, John S. Reynolds @ other sources

Step 3 – Comparing inventory with survey of existing conditions

: By subtraction the results reveals we have an excess of 11,626 -10,153 =1,473 KBtu /Day

At this point we should consider regulating site energy balance by surface improvement, landscape area and body of water, we should also revise the material of the exterior envelop for a better site energy balance.

Step 4 – Design Concept:

Selecting material with high albedo meaning less absorption; providing trees and shading, green cover, replacing aged concrete with new light color pavers and so on.

Site	Surface area  SF		SRI. %	Absorpt. %	Calcs                           KBtu / Day
Conc. Fence  E. White acrylic paint	6’ x 90’= 540		80	20	1.207 x 540 x 0.75 = 489
Conc. Fence  S.	6’ x 20’ = 320		80	20	0.563 x 320 x 0.75 = 135
Conc. Fence W.	6’ x 90’= 540		80	20	1.207 x 540 x 0.75 = 489
Conc. Fence  N.	6’ x 20’= 120		80	20	0.452 x 120 x 0.75  =  41
Conc. Pads Replaced w. clear conc. pavers	625+125+600-285 –290 =775   Minus 290 shaded Area on North of bldg. Minus 285 tree shade		70	30	2.596 x 775 x 0.80 = 604
4 Exist. Trees. Added 15 new Trees, 4 +15=19	19 x 113 = 2,147		18	82	2.596 x 2,147 x0.82 = 4,570
Green ground cover	850 – 500 = 350 Ground cover – tree shade area		20	80	2.596 x 350x 0.80  = 727
Pool clear background	35 x 20 = 700		8	92	2.596 x 700x 0.92  = 1,672
Decomposed white granite cover	2,120 – 1,465 = 651 DG’s Cover – tree shade area		60	40	2.596 x 651x 0.40  = 676
Building	Surface area  SF		SRI. %	Absorpt. %	Calcs
clear paint / stucco – South	632 sf wall. 100% of south wall shaded by overhang & 50% of the wall is shaded by trees – Count 50% only for radiant energy for South wall Windows Count 50% of SHGC 144 sf window		80 –	20           39 SHGC trans.	0.563x632x0.20×0.50=36           0.563 x 144x 0.39 x 0.50 =16
clear paint / stucco – West	420 sf wall. 24 sf window Minus 50%  shaded wall		85 –	15 27SHGC trans.	1.207x420x 0.15x 0.50 = 38 1.207 x 24 x 0.27 =    8
clear paint / stucco – North	632 sf wall. 144 sf window 100% of North wall shaded by overhang & 30% of the wall is shaded by trees – Count 50% only for radiant energy for Notrh wall Windows Count 50% of SHGC		80 –	20 71SHGC trans.	0.452x632x0.20×0.50 = 29 0.452x144x0.71×0.50 = 23
Cool Roof	58 x 35 = 2,030 Include. Extended Overhang 50% of roof is shaded by trees		80	20	2.596x2030x0.20×0.50= 527
Total					10,126 KBtu / Day
Total energy surplus on site @ existing condition					Study Case Result: 14,031 -9,995 = 4,036 KBtu /Day

 

Step 5 –  Design comparasion at different stages:

• At pre-existingstate within natural environment site was generating:

10,153 KBtu / Day

 

• At existing condition with envelope & other features site was generating:

11,626 KBtu / Day

 

• At design case with material revision and site improvement site in generating:

10,126 KBtu / Day

 

Conclusion: At the design case calculations indicate that site s less than once it used to be part of natural environment despite we have built-in an envelope on. We can conclude the energy site management equation and the proposed process works.

 

Si Djahedi,

November 3, 2011

Slideshow

Site Analysis Down Town Gilbert Arizona : Perception and visual interpretation

On the arterial road of Gilbert road, downtown is visually defined between two penetrable edges: Rail road crossing on south side and Gilbert Road Crossing Trail or irrigation canal on the north side. Within this visual limit of downtown perception, Gilbert Road remains the major path of cars and pedestrians simultaneously. As we drive through downtown, from observer’s point of view, the short path does not allow enough time to take sufficient mental pictures in order to be motivated and having the desire of exploring the downtown. The small scale of downtown gives the impression of semi private rather than a public place in the past, giving the impression that in this small town everybody knows each other, the feeling of being strangers after all or the presence of a cult or a specific group of people working and living there particularly the scent of barbeque is associated with that section.

As we approach downtown Gilbert from any directions, the presence of Water Tower as a historic landmark feature evokes us a strong image of an agricultural community in transformation towards an early industrial town. The passage of train occasionally changes entirely the perception of downtown giving an image of industrial city connecting to other places.

Recent Liberty Market on the intersection of West Page Avenue and Gilbert Road draw our attention to explore Water Tower at eye level discovering more the history of the town; surprisingly we discover Hale Theater Center which used to be imperceptible as well as the discovery of an empty Farmer Market in which an event takes place occasionally. All these discoveries make us aware of an existing District in evolution in which people perceive as having some common identifying character. Oregano, a recent commercial development at 2nd Street and Gilbert Road has expanded downtown to the north adding vitality to the urban environment.

With the recent improvements, downtown Gilbert has reached a base for a greater expansion and developments, and in order to increase expansion, the equation of 3-E sustainability could apply to bring Equity, meaning people, which create forces to generate Economy providing a sustainable Environment for downtown and ultimately the 3-E equation impacts positively the entire municipality.

The potential of downtown Gilbert is enormous; the abundance of industrial unused sites next to railroad suggests we are able to reuse these sites for a Mix-Used building within the limit of downtown rather to build another commercial structure such as Santan Village with a single use in no man’s land. One’s could imagine what would have been the outcome if a sustainable Santan Village was built in downtown Gilbert?

How do green building programs and policies promote the three E-s of sustainability?

As we have evolved throughout the history of human kind, we have needed more room and infrastructures to accommodate a large number of people, therefore the creation of city was the result of that need; transforming the natural habitat into an environment in which we can live and
work.

Industrial revolution and early capitalism have largely over abused the natural resources and people to increase production and to pollute the environment at large scale for long time. The traditional design has been responding to the need of modern cities with some aesthetic flavors for buildings. While the focus of traditional design was mostly response to a need and the opportunity to make an architectural statement the focus of green architecture programs remain on Environment, Economy and Equity which are the three fundamental and interrelated aspects of a sustainable design.

The focus of sustainable design is people as the capital, respect for people as well as respect for the place will naturally encourage a healthy production, generates a healthy economy and finally a healthy happy life which we all dream for.

Global warming, depletion of ozone layer and recent natural disaster in Japan and the spread of nuclear pollution in the ocean the major part of the planet, are proofs that the planning, design and the policies of builder generation after 2nd World War were fundamentally wrong and certainly not sustainable, not green nor clean, instead we have been offered the colorful dream of having the utopia of modern society with an advanced technology in which we do not need to work; a naïve model for happiness which in reality is laziness and unhealthy.

The remedy is through the education of people, spreading awareness of being citizens of planet,respecting our planet means respecting ourselves. We need to revise our habits, adjust our needs,the way that we produce and consume. We need to understand even further to comprehend deeply people and their environment together; the change is more philosophic rather than the way of doing thing differently. We need to get the essence of sustainability and green way of
living inside of us as we breathe. Simply, it must become part of our life our culture, to share on
daily basis, to inform and to be informed constantly.

The recent event in Egypt thought us that people have a tremendous power of changing a regime by saying no to undesirable therefore, we must be able to do the same for enforcing policies,promoting green way of living, a collective effort at large scale. After all, we are all are coming from nature and we will go back to be recycled. Our mission is to be able to have a dialogue the nature, renew our friendship with wilderness as a place of refuges, and a place to learn.

NATURE AND INDOOR ENVIRONMENT QUALITY

Contrary to the most species humankind is borne in an indoor enclosed space and spends most of his life living and working at indoor environment. By openings through walls natural light was introduced, by burning wood, necessary heat for warming was provided and yet the desire for comfort remains as a continuous effort.With precision and control through advanced technology mankind reached the thermal comfort level of interior environment today and yet as we evolve toward, our living space also should respond to our needs and comfort level. Comparing living conditions of caveman to the living condition of man in technology information era, we realize indeed we have evolved, we have made mistakes and we need to correct them to reach the next level of evolution.

Comfort level to human living condition is extremely complex and depends on many variables such as thermal, acoustic, visual and ergonomic comfort. The quantity of air is essential to living human but when it is consumed the byproduct become a contaminated gas therefore the replacement is necessary to assure a healthy living condition. Air is a known as a composite gas and transports particles, humidity and it is the vehicle of solar energy. Not only we need a large quantity of air to live, we also need to consume the quality of it, indeed pure air is rare to find where the human population is concentrated. Industrialization has introduced pollution and noise into the environment, production of unimaginable industrial products disturbs the comfort level of human kind, materials off gas and affects our physical wellbeing, mental health and our productivity as well as the present and future generation survival, as result we have been disconnected with Mother Nature where all we come from, where we used freely clean air and clean water for thousands of years and now in contrast it has become a battle, even a law such as Clean Air Act, Clean water Act and ironically we have to struggle to gain back the rights that we used to have, it seems humankind is living in an environment in crisis.

The question remains what are alternatives to such a global tragedy;the free humankind is condemned to live in an unhealthy environment that he has created; is there another chance with Mother Nature? The answer is not simple to reach but surely lays in understanding natural laws, creation of primitive species, and the principal component of life, water coming from the heart of the Earth creating the atmosphere like a transparent enclosed envelope. Air was produced by interaction of solar energy and diluted chemical within water creating divers early vegetation species consuming carbon to produce oxygen and interestingly air remained within the atmosphere by gravity supporting life and evolution, therefore a solid base for creation of life was founded.As Mother Nature teaches us air and water are strongly related since they are basic component of life. Although the solution for air and water pollution is reduction and elimination of the pollution source, natural filters such as trees and vegetations play major role to restore healthy conditions for living creatures, also existence of water to support vegetation and trees is necessary to create an ecosystem in which water, air vegetation and sunlight all work together to create more of natural environment as it has been at the beginning of creation.

Since we have not been able to come up with an urgent solution to mitigate pollution crisis, mimicking nature would be would be one of the best alternative,connecting human to its roots, bringing nature to indoor environment and letting human to evolve but this time with nature. We should be aware that the air we breathe in is a precious gift of nature; we are privileged to drink water and fortunate to sit under the shade of a tree having blessing of sunlight.