THE POTENTIAL OF GEOTHERMAL ENERGY FOR SPACE HEATING IN INSTITUTIONAL BUILDINGS A CASE OF GILGIL

1. 1 Introduction

Areas within the tropics arguably have the most favourable climatic conditions for building design. This is mainly due to the minimal or lack of extreme climatic conditions in majority of the habited areas. Kenya is located in this region between latitudes 5 ° N and 4 ° S with the altitude ranging from 0m to 5000m above sea level. The habitable areas fall between 0m at the Kenyan coast to 2750m in the highland region of Mt. Kenya. Very few people reside above 2750m.

Malindi at an altitude of about 20m above sea level has an annual mean temperature of 26.5 ° C while Kapenguria at an altitude of 2143m has an annual mean temperature of 18.8 ° C. This is a result of positive lapse rate which holds that for every 1000m rise in altitude there is a 4 ° C drop in temperature.

However, several factors including topography play an important part in creation of localised climatic conditions. Case in point is the e ect of the topography of the Eastern Rift Valley highlands on the local climatic conditions. Towns like Gilgil, Nakuru and Naivasha located on the leeward side of the Aberdare Ranges experience cool to cold night temperatures due to a resultant localized climatic condition known as temperature inversion. Night temperatures in Gilgil for example, could drop to as low as 7 ° C thus potentially pos- ing a human thermal comfort problem.

Various space heating strategies have been adopted by residents in these areas including charcoal burners, electric space heaters, air conditioners and rewood hearths. Charcoal burners and rewood hearths promote deforestation activities while electric space heaters and air conditioning units increase the electricity load for buildings while contributing to the production of greenhouse gases into the atmosphere.

A potential solution to averting thermal discomfort in these areas would be the use of geothermal energy space heating systems. Currently untapped for this purpose in Kenya, geothermal energy from the earth’s mass, underground or surface hot water bodies can be harnessed for space heating and hot water supply in buildings. These systems are expensive therefore would be economically and technically feasible for institutions where activities run in the night and early morning. These could include but are not limited to hospitals, boarding learning institutions and research facilities.

This thesis research is therefore focused on studying how geothermal technology can be used to harness the earth’s heat energy and use it to for space heating in areas a ected by temperature inversion.

Calendar

M T W T F S S
 
 
 
 
1
 
2
 
3
 
4
 
5
 
6
 
7
 
8
 
9
 
10
 
11
 
12
 
13
 
14
 
15
 
16
 
17
 
18
 
19
 
20
 
21
 
22
 
23
 
24
 
25
 
26
 
27
 
28
 
29
 
30
 
31