The other side of the coin is the rapidly growing urban centers within the Himalayan belt being important tourist basins, both nationally and internationally. They have grown rapidly, often with very little attention to building by-laws and planning principles, which are almost non-existent at this point.

An energy code has been proposed as a means of controlling energy use in buildings in the post-occupation stage.

2. GEOGRAPHICAL DESCRIPTION

The Himalayan ranges stretch from east to west across the north-eastern border of India, in places falling within the political jurisdiction of Nepal and Bhutan in the central and eastern parts (fig. 1). The ranges can be classified very easily in terms of their varying altitudes and an idealized cross-section through them in the north-south direction is given in fig. 2.
 
 

The Foothills, or Sivaliks as they are known, are rounded, gently sloping hills that run between a height of approximately 2000’ and 4000’. The Lesser Himalayas abruptly rise from the foothills to a height of between 4000’ to 10000’. This is the region of complex microclimates and is called the Microthermal region. The Greater Himalayas are a region of permanent snow cover above 10000’, which house some tribal communities.

3. CLIMATIC ANALYSIS

3.1 Locations for analysis

We reviewed weather data for 11 stations in order to determine which areas to group together to define climatic zones.

TABLE I - STATIONS CHOSEN FOR ANALYSIS
 

Sr. #	Name of town	Elevation
1.	Leh	11593’
2.	Srinagar	5234’
3.	Dalhousie	6465’
4.	Simla	7267’
5.	Mussourie	6980’
6.	Dehradun	2250’
7.	Mukteswar	7636’
8.	Pokhara	2730’
9.	Katmandu	4412’
10.	Darjeeling	7475’
11.	Shillong	4950’

The location of the towns that appear in Table I is shown in fig. 1. The towns are marked in the number in which they are indicated in Table I.

The issues looked at in the climatic analysis of these towns were the degree days for heating, the degree days for cooling, if any, and the percentage of time the temperature floats within the comfort zone.

3.2 Calculation of climatic indicators

The median for calculating the degree days for heating was taken as 65° F, to be consistent with U.S. standards. The median for degree days of cooling was taken as 80° F.

Since an overwhelming majority of the population in the region are indigenous, the measure for percentage of time in the comfort zone had to be done using comfort indices that are applicable to the local population. In order to derive that, the Mahoney tables, developed by Sean Mahoney for the UN center for Housing, Building and Planning were used (6). These tables take into account the mean monthly maximum temperatures, the mean monthly minimum temperatures, the average temperature ranges, and the humidity levels to derive comfort indices which are higher during the daytime, or during "active" hours, and lower during nighttime, or "retired" hours.

10000 DD (F)

From the analysis of the climatic data (fig. 3 & 4), it was possible to classify the region into eight major climatic zones (table II).

TABLE II -THE DERIVED CLIMATIC ZONES WITH TYPICAL HEATING DEGREE DAYS
 

Zn	Name of Zone	H. Deg. Days	Elevations
1.	Sivaliks and Valleys	1000-1600° F	2000’-4000’
2.	Lower Microthermal	1700-2500° F	4000’-5500’
3.	Middle Microthermal	2500-3300° F	5500’-7000’
4.	High E. Microthermal	3500-4500° F	7000’-8500’
5.	High W. Microthermal	3500-4500° F	7000’-8500’
6.	South Kashmir	4000-5000° F	5000’-7000’
7.	Upper Outer Ranges	5000-7000° F	8500’-10000’
8.	High Desert	7000-10000° F	above 10000’

In spite of the High Eastern and High Western degree day ranges being similar, they are kept separate because the eastern region is very humid and has low diurnal and annual temperature swings. The South Kashmir valley has special climatic characteristics with high precipitation levels and higher heating degree days than other areas at similar elevations. The upper outer ranges (climate zone 8) have not been analyzed due to the non-availability of data.

4. THE CALIFORNIA ENERGY CODE AS A MODEL:

For a careful study of the issues involved in writing an energy code, and for strategies that can be adopted within a code, it was necessary to look for a prototype. The California Energy Code was one of the first to come up in the US (the 1992 version of the Energy Code is considered second generation standards) and it is on par with, if not more stringent than the national standards (ASHRAE 90.1).

It was also to our advantage that California is a microcosm of many different climates and terrain, which makes it easier for us to compare annual temperature ranges, heating or cooling degree days and building energy demands as a result of that.

The compliance methods in the California Energy Code are of interest because of the two completely different approaches to achieving energy efficiency.

4.1 Tests on model building

By looking at typical heating degree day ranges of the foothill towns, some California climate zones were chosen to act as Equivalent Climate Zones (zones 1, 3, 5, 7 or 8, and 16) for computer testing of building components and for studying the prescribed values in the California Energy Code.

Some test runs were made on a prescribed building (the form and organization of which is also a prototype rural dwelling in the Himalayan region) on CALRES and DOE2 programs, to get figures for typical space-conditioning budgets for the Equivalent climate zones. The figures were then compared with available figures for domestic energy consumption for space-heating in some foothill village clusters. The results are presented in table III.

TABLE III- COMPARISON OF ENERGY-USE FIGURES
 

CA City	budget for test house in MBtu	Himalayan Station	Annual space heating in Mbtu
El Toro	22 (source )	Fatehpur	8
Oakland	20 (source)	Khurpatal	17
Arcata	19 (source)	Mukteswar	28

 

Source energy (as opposed to site energy) factors the generating efficiency when including electrical energy. It is to be noted that the source energy figures for the space-conditioning budget in California cities include space-heating as well as space-cooling, whereas the figures for the foothill towns are only for space-heating.

5. FACTORS CONSIDERED IN CODE FORMULATION

Due to the patterns of energy usage in the region, two possible strategies were looked at. The first was efficiency controls for equipment in the manufacturing stage. The second was in formulating a building code to control the energy demand of the building by improving its thermal performance.

The main features that affect the thermal performance of the building that were considered are:

5.1 Infiltration:

In order to understand the full impact of infiltration on building performance, parametric runs were done on a simple building using the DOE2 program for the California climate zones equivalent to the Himalayan climate zones and results observed for increasing rates of infiltration, with an infiltration rate increase of 0.5 air changes per hour for each case.

A second set of tests were run for increasing building envelope resistivities. These tests were done to explore the possibility of improving the performance of leaky buildings by incorporating higher building envelope resistivities. Fig. 6 shows that infiltration losses continue to climb indefinitely. Fig. 7 shows that increases in resitivities produce very limited gain after about R-40. It is nearly impossible to keep up with the heat loss through infiltration by increased insulation after that point.

It is hoped, and for the purpose of this paper it is assumed that it will be possible in the future to identify the degree of air-tightness of different construction techniques, so as to make it easier to choose the applicable component resistivities. For the present, the code recognizes different commonly used construction techniques and materials that have different degrees of vulnerability to air-leakage, and classifies them as either higher or lower level constructions (called Grade A and Grade B constructions) with a corresponding set of applicable building envelope resistivities.

5.2 Interior Heat Capacities:

The Himalayan code also takes two main categories of interior heat capacities, one which is a certain multiple of the south glazing area (identified as package I) and the other with no heat capacity (package II). The intermediate interior heat capacity packages are ignored in the code because situations with disconnected floors are rare in the region yet.

5.3 Direct Gain Through Glazing:

A third set of simple simulation tests were run to check suitable glazing types for different orientations and different climate zones to check the cost-effectiveness vs. performance of single and double pane glazing for various climate zones. The two types of glazing used were single pane clear, with a U-value of approximately 1.14 and double pane clear, with a U-value of approximately 0.65 and run for the California climate zones which are equivalent to the Himalayan climate zones using the DOE2 program (fig. 8).

Fig. 8 - Heat loss and gain in Kbtu through glazing for different orientations in the Oakland climate (zone 3).

The conclusions from these tests for residential applications are:

6. GENERAL ORGANIZATION OF THE CODE

The code recognizes distinct development groups where the codes might be applied, with some areas of overlap. This differentiation occurs due to different degrees of development in terms of electrification, commercialization and commercial resources available, disposable income available and also the completely different approaches that may be applied to implementation and enforcement. The first category consists of regions where a regulatory environment exists. Here, one may have a target figure for energy efficiency, and both the performance and prescriptive approaches for compliance are applicable.

The other categories consist of regions where no regulatory environment exists, i.e., building permits are not required to carry out new construction, therefore there are no direct methods of enforcement. This would include most of the underdeveloped, remote rural areas of the region. This code would have to be in the form of a handbook, with instructions and recommendations on various issues and strategies for achieving them.

The overlapping categories are areas that may have a regulatory environment, but still have widespread use of non-commercial fuels, which makes the control of their usage very difficult.

The categorization of development groups in the code is as follows.

Category 1: Where all lighting needs are met by electricity, space-conditioning needs are at least partly met by commercial fuels, water-heating and cooking needs are met by commercial fuel. Building permits are required by an authorizing body for new construction or additions/alterations of existing construction.

Category 2A: Where all lighting needs are met by electricity, space-heating utilizes non-commercial fuel (above 75%) and water-heating and cooking needs are met by non-commercial fuel. Building permits are required by an authorizing body for new construction or additions/alterations of existing construction.

Category 2B: Where all lighting needs are met by electricity, space-heating and cooking utilizes non-commercial fuel (above 75%). No regulatory body exists for issuing permits for new construction.

Category 3: Where no electrical energy is available on site and cooking and space-heating utilizes at least 90% non-commercial fuels. No regulatory body exists for issuing permits for new construction.

It is assumed that when a lower category area is provided with the necessary infrastructure and attains the level of local government to be upgraded to a higher category of development, the code requirements for the higher category of development will be adopted.

However, any kind of non-residential construction, even in the underdeveloped areas would have to follow the standards set by the first section of the code.

The only differentiation made in occupancy types is in the method for compliance in the performance approach. All requirements within a climate zone for all occupancy types otherwise remain the same.

7. THE CODE

7.1 Building Envelope

Building envelope values for increased efficiency in terms of space conditioning (table IV).

TABLE IV - ALTERNATIVE COMPONENT PACKAGE FOR CLIMATE ZONE 3 (MIDDLE MICROTHERMAL)
 

Component	Package I	Package II
Building Envelope - Grade A:
Ceiling	R30	R30
Wall	R13	R19
"Heavy Walls"	(R4.5)	(R3.5)
"Light Mass" Walls	[R5.0]	[R5.0]
Slab floor perimeter	R7	R7
Raised floor insulation	R13	R19
High mass roof	R5.5	R5.5
Building Envelope - Grade B:
Ceiling	R38	R38
Wall	R24	R30
"Heavy Walls"	(R7.0)	(R5.5)
"Light Mass" Walls	[R8.0]	[R8.0]
Slab floor perimeter	R7	R7
Raised floor insulation	R24	R30
High mass roof	R5.5	R5.5
Glazing
Glass type for the entire building	Single [0.4]	Single [0.4]
North glass type	Double	Double
W, E and S glass type	Single	Single
(in case of rooms with single orientations)
Max. total area	NR	16%
Max. area on N orientations	2.4% W.A.	2.4% W.A.
Max. area on W orientations	4.8% W.A.	NR
Max. area on E orientation	2.4% W.A.	NR
Min. area on S orientation	6.4% W.A.	NR
Thermal Shutters	R1.0	R1.0
Shading Angle	NR	NR
Thermal Mass	REQ.	NR

7.2 Infiltration Minimization

Criteria for joints in building envelope, windows and doors for infiltration minimization.

7.3 Lighting

Energy efficiency in lighting by considering allowable L.P.D.s and zone control requirements.

7.4 Space Conditioning

Basic efficiency criteria for space conditioning equipment if using commercial fuel, equipment sizing conditions and thermostatic zone control requirements.

7.5 Instructional form

Since the code is written for a developing region, even in the higher category areas, it takes on the form of an instructive handbook in many places. For example, any kind of insulation requirement would be followed or preceded by a listing of the various forms of commonly available insulation materials and their conductivity values. These kinds of instructive lists are a dominant feature of the code as with other existing Indian codes.

7.6 Code for the lower development category

The second section is relevant to two parties, the first being the environmental groups and organizations involved with policy-making to improve conditions in the region, and the second being the local inhabitant for improving his living conditions. The complete methods of implementation are a planning issue, but it is possible to make suggestions such as to introduce it at the grass-roots government level ("gram panchayats" etc.). Therein various incentives like subsidized house loans for promoting the prescriptive code, or policing of new constructions for compliance with the code can be undertaken.

The main concerns in this category would be:

This code not only classifies climate zones, but also separates different development categories (1,2 and 3) and grades of construction methods (A and B) to accommodate disparities in development levels in different locations and a wide range of construction techniques practiced by the local populace. This is a model for possible codes in all developing countries.

9. REFERENCES

(1) Karan, Pradyumna P.- Nepal : A Cultural And Physical Geography, (Lexington : University Of Kentucky Press, 1960).

(2) Vinod Kumar, T. M. and Dilip R. Ahuja (eds.) - ICIMOD and TERI - Rural Energy Planning in The Indian Himalayas, (New Delhi : Wiley Eastern India Ltd., 1987).

(3) Minke, Gernot and R. K. Bansal - Climatic Zones and Rural Housing in India, (Julich : Zentralbibliothek, 1988).

(4) California Energy Commission - California Energy Code, (1992).

(5) ASHRAE - ASHRAE Handbook of Fundamentals - (1972, 1993).

(6) Koenigsberger, O. H. T. G. Ingersoll, Alan Mayhew and S. V. Szokolay - Manual of Tropical Housing And Building, Part 1, (Hyderabad : Orient Longman Ltd., 1973)

(7) Takahashi, K. and H. Arakawa (eds.) - World Survey Of Climatology : vol 8, (Amsterdam : Elsevier Scientific Publishing Co., 1981).