ARID ZONE JOURNAL OF ENGINEERING, TECHNOLOGY & ENVIRONMENT
AZOJETE - Centre for Satellite Technology Development Special Issue:

Space Science and Technology for Sustainable Development
AZOJETE, June, 2019. Vol. 15(SP.i2):35-45

Published by the Faculty of Engineering, University of Maidiguri, Maidiguri, Nigeria.

Print ISSN: 1596-2490, Electronic ISSN: 2545-5818
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35

ORIGINAL RESEARCH ARTICLE
IMPACT OF CLIMATE CHANGE ON THE DESIGN PARAMETERS OF HEATING,
VENTILATION AND AIR CONDITIONING SYSTEMS FOR MANNED SPACECRAFT

K. O. Adeyemi, I. I. Ozigis*, M. T. Zarmai and S. I. Ishola

Department of Mechanical Engineering, University of Abuja, Kilometre 23, Airport Road, Abuja, Nigeria

ARTICLE INFORMATION

Submitted: 14/10/2018
Revised: 16/11/2018
Accepted: 18/03/2019

Keywords:
Air-Conditioning,
Dry-bulb Temperature,
Humidity,
Spacecraft,
Statistics,
Pressure.

ABSTRACT
Climatic design information has been published for several locations
in the world by American Society of Heating, Refrigerating and Air-
Conditioning Engineers (ASHRAE) but there has not been data for
Nigerian cities in these publications. Therefore, this study was
embarked upon to bridge the gap in knowledge. The study of
impact of climate change on the design parameters of Heating,
Ventilation and Air Conditioning (HVAC) systems for spacecraft
cabin environment is presented with particular focus on Ikeja-Lagos,
Nigeria. Firstly, the characteristics climate parameters such as
outdoor dry-bulb temperature, coincident wet-bulb temperature,
relative humidity, pressures, air composition, among others as it
affects manned spacecraft were discussed. The data for climatic
parameters for Ikeja-Lagos, Nigeria, for a period of fifteen years
(1995-2009) were obtained from Nigerian Meteorological Agency
(NIMET), Oshodi-Lagos. Statistical data and Microsoft excel were
used for evaluation of variation trends of the climate parameters for
departure city. This is very important in determining thermal human
comfort in spacecrafts on ascent. Results obtained from this study
are hereby presented. The Ikeja-Lagos dry-bulb temperature
average results obtained were 33.81°C, 32.98°C, 32.3°C, 22.1°C,
21.19°C, 20.43°C, 23.84°C and 31.65°C.at 0.4%, 1.0%, 2.0%, 97.5%,
99.0%, 99.6%, median of extreme lows and median of extreme highs,
respectively. The Ikeja-Lagos relative humidity average results were
116.3, 112.65, 109.14, 99.83 and 49.42 at 0.4%, 1% and 2.0%
occurrence as well as at median of extreme highs and median of
extreme lows, respectively. Ikeja-Lagos had mean coincident dry
bulb temperature of 33.81°C and 32.98°C at 0.4% and 1% percentile
respectively. The dry bulb temperature for Ikeja-Lagos was
determined to be an average range from 20.43°C to 22.1°C between
January to December, in the period of 1995-2009, at 97.5% 99% and
99.6% percentile respectively. These results provide values of design
parameters which are useful in the design of HVAC for space crafts
with climate change adequately taken into consideration as it
applies to Ikeja-Lagos, Nigeria

© 2019 Faculty of Engineering, University of Maiduguri, Nigeria. All rights reserved.

1.0 Introduction
There is robust evidence that extreme weather conditions are happening with greater frequency
and intensity than what was experienced few decades ago. Mitigation measures needs to be put

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Adeyemi, et al, Impact of Climate Change on the Design Parameters of Heating, Ventilation and Air Conditioning
Systems for Manned Spacecraft. AZOJETE, 15(sp.i2):35-45. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: idris.ozigi@uniabuja.edu.ng 36

in place to avoid what can lead to decrease in performances of facilities in space technology due
to dramatic increase in the frequency and intensity of these extreme weather conditions. In the
aviation sector, infrastructures such as airports and aircrafts are designed with historical weather
conditions. Often, these infrastructures like air ports and aircrafts will need retrofitted facilities
to match changes in climatic conditions.
Therefore, aircraft and spacecraft designers will require a detailed and quantified information for
specific regions and locations with a focus on maximum and minimum temperatures as well as
associated humidity conditions. This then suggests a need for model-based climatic projections
for future climate using historical climatic data to identify priorities in mitigation measures.
Although the global environment is affected by climate change, this study is particularly
concerned about the impact of climate change on the cabin environment in spacecraft. In this
study the impact of climate change on design parameters of Heating, Ventilation and Air
Conditioning (HVAC) systems were analyzed to determine the proper parameters to be used for
design of the systems.
The HVAC systems are devices designed to control the climatic and environmental parameters
to provide thermal comfort at acceptable indoor air quality in terms of air composition,
temperature, humidity, pressure, wind speed and direction, amount of rainfall or water vapour in
any area of application such as in manned spacecrafts. The payload includes the living things, air
conditioners, fans, heaters and cargo carried by a spacecraft but excluding propulsion units.

The studies on effects of dry bulb temperature and relative humidity on performances of power
electronics, gas turbines, compressors, among others have been documented as reported by
Olorunmaiye and Awolola (2016). The load in a spacecraft can include gas turbines, compressors,
refrigerators, amongst others, which are directly linked to climatic conditions.
Furthermore, the control of cabin environment in spacecrafts has been a challenge especially for
flights across continents due to varying climate parameters. The relative humidity inside a
spacecraft cabin is generally much lower than the minimum for thermal comfort recommended
by ASHRAE (2013a), Wyon et al. (2006) and Uchiyama et al. (2007) for comfort standards. The
temperature is the only variable which can be controlled to its optimal level, but this optimal
control is only permitted in the cruise process, not during ascent and descent processes, as this
can affect the performance of the engine. Therefore, in order to monitor the performance,
reliability and control of HVAC systems in spacecrafts, the study of the climatic conditions of the
departure city as recommended by ASHRAE in the design of HVAC systems is of key importance
as reported by ASHRAE (2013a).
It is appropriate to determine the main climate input parameters in a location for when there is
desire to launch and operate a space craft. Climatic design information had been published for
several locations in the world but Nigeria did not feature as published by ASHRAE (2013a). Some
West Africa countries such as Mali and Niger republic had climatic data stations at Bamako and
Niamey, respectively, in which climate data had been recorded for over 15 years according to
ASHRAE (2013a). In the design of comfort in space craft, complete knowledge of temperature,
humidity, purity of air, motion of air and thermal load are required.
This study aimed to discuss climatic design parameters as it applied to Ikeja-Lagos, Nigeria. The
objectives include data gathering and computation to provide information on dry bulb
temperature and wet bulb temperature at several percentiles, median of extreme lows and

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Arid Zone Journal of Engineering, Technology and Environment, June, 2019; Vol. 15(sp.i2):35-45. ISSN 1596-2490;
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Corresponding author’s e-mail address: idris.ozigi@uniabuja.edu.ng

37

median of extreme highs, as well as at mean daily temperature range essential in climatic design
information for spacecraft technology.

2 Climatic Design Parameters for Human Comfort in Manned Spacecraft
2.1 Air Composition and Air velocity
The space craft cabin is a confined space with varying pressure from one atmospheric pressure
to one-third atmospheric pressure in some extreme cases as reported by Liping et al. (2017).
Similarly, air composition also varies between oxygen and nitrogen, with 20.95% oxygen like in
the earth’s environment or 40% oxygen and 60% nitrogen in some situations. When pressure in
the cabin is high, oxygen has to be provided as well as disposal of cabin carbon-dioxide
produced by human being. ASHRAE (2013a), Standard 62 recommends a certain volume of fresh
air to be supplied to various areas in a space craft and is dependent on the number of people
present and the nature of the activity taking place. Design condition for any habitable space is to
guarantee an air flow of 10 litres/second (10 l/s) as reported by Ballaney (2003). Similarly, it is
recommended that air supply speed should be within 2-5 m/s, to prevent air noise in built
environment. ASHRAE (2013a) as well as Khurmi and Gupta (2003) reported that all spaces in
spacecraft should receive minimum of air velocity of 0.3 m/s, that contains enough oxygen for
breathing and also sweep away odours, microorganisms, and heat release.

2.2. Thermal Load
Radiations from warm surfaces of the load in spacecraft are important factor that can affect
comfort reaction of human being. Radiations from occupants to room surfaces and structures as
well as between occupants, has an important bearing on the feeling of warmth and can alter the
optimum. The heat liberation from crew and passengers as well as heat liberation from machines
and transformers in the spacecraft contributes to thermal load. Similarly, solar radiation around
spacecraft and oxidation processes of materials of construction of spacecraft contributes to heat
load. Air-conditioner is one of devices that contributes to human comfort in spacecraft. Some
researchers reported that energy consumption for running air conditioning system depends on
the climate of location along with the location solar radiation as reported by Olorunmaiye et al.
(2012). The researchers also recommended use of economizers on air conditioner, orientation of
buildings and planting of trees to positively influence climatic conditions to minimize global
warming. Space technology is well suited to benefit from above particularly in location and
environment of lunch of spacecraft and ascent.

2.3 Air Temperatures
Air temperatures in spacecrafts are evaluated based on dry-bulb temperature, wet-bulb
temperature, and mean daily temperature ranges. The likelihood of temperature changes with
height also affects design of spacecraft as stated in Liping et al. (2017). Spacecrafts are designed
with temperatures that are not expected to exceed 27°C for wet bulb, 35°C for dry bulb while
effective temperature, should not exceed 27°C, according to ASHRAE (2013a) Standard 55. In
evaluation of climate changes, dry-bulb temperature is presented in percentile corresponding to
0.4%, 1.0%, and 2.0% cumulative frequency of occurrence and the mean coincident wet-bulb
temperature, according to ASHRAE (2013a). Similarly, wet-bulb temperature is presented in
percentile corresponding to 0.4%, 1.0%, and 2.0% cumulative frequency of occurrence and the

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Adeyemi, et al, Impact of Climate Change on the Design Parameters of Heating, Ventilation and Air Conditioning
Systems for Manned Spacecraft. AZOJETE, 15(sp.i2):35-45. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: idris.ozigi@uniabuja.edu.ng 38

mean coincident dry bulb temperature, according to procedures recommended for evaluation of
climatic conditions in a location or region by ASHRAE (2013a). Dew-point temperature
corresponding to 0.4%, 1.0%, and 2.0% annual cumulative frequency of occurrence, mean
coincident dry-bulb temperature and humidity ratio are also parameters for climate study
according to ASHRAE (2013a). The 0.4%, 1.0%, and 2.0% dry-bulb temperatures and mean
coincident wet bulb temperatures indicates severity of conditions on hot, mostly sunny days as
reported by ASHRAE (2013a). In summary, mean daily temperature range is mean of the
difference between daily maximum and minimum dry-bulb temperatures for hottest months as
reported by Anekwe and Onuchukwu (2017). Similarly, dry-bulb temperatures are calculated
from extremes of the hourly temperature observations. It is important to note that dry and wet
bulb temperatures is more convenient than the partial vapour pressure and temperatures in
climatic characteristics evaluation of manned spacecraft.

2.4 Relative Humidity of Air
Human comfort demands relative humidity (RH) in the range of 50 to 70%, but this is not
maintained aboard spacecraft to avoid condensation problems on cold walls and equipment,
which tends to corrode metals and boost micro-organism growth as reported by Ballaney (2003)
as well as Olorunmaiye and Awolola (2016). Therefore, relative humidity is kept in a low range of
10 to 20%, with some discomfort of evapotranspiration and electrostatic build up if human
beings are among the payload in spacecraft as reported by Liping et al. (2017). At cruise
altitudes there is practically no water vapor in the air, so it is natural to have dry cabin air. On
ground and during ascent, the air conditioning system must dehumidify fresh air introduced into
the cabin, particularly in tropical climates when doors are still open. Outside humidity is very
small at high altitudes and is kept low inside spacecraft to minimize problems of condensation
and frost on the cold structure. Some researchers undertook determination of energy
requirements in a building with particular focus on provision of cooling by air conditioner, which
is also relevant in provision of human comfort in spacecraft as reported by Ariyo and
Olorunmaiye (2017a). Therefore, design values of relative humidity of departure city enable
designers to size HVAC system to achieve an acceptable level of comfort. In some spacecrafts,
cabin temperature can range between 18-24°C, while its relative humidity ranges between 50-
70% as reported by Liping et al. (2017).

2.5 Minimum and Maximum Pressures
Climatic characteristics involves sum of all inlet pressures and pressure losses in the main lines
and ducts as linked to air conditioners and fans in the manned spacecraft, called the system. The
system constant is obtained at minimum and maximum pressures in relation to the air required
delivery flow rate, which are in turn used to determine the system characteristics at minimum
and maximum pressures. Worthy of note is effect of gravity compression of air in the spacecraft,
that arose from the pressure difference at the surrounding surfaces and in the spacecraft on
ascent and descend. The average of air pressures in different months of the year 2011 was
determined for Calabar to have minimum of 1001.5 Pa and maximum of 1008.1 Pa, while Port
Harcourt had minimum of 1003.5 Pa and maximum of 1012.0 Pa, according to some researchers
such as Anekwe and Onuchukwu (2017). Researchers such as Liping et al. (2017) reported that
spacecraft cabin pressure can range between 90-100 kPa.

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39

3.0 Methodology
The hourly weather data for climatic design for Ikeja (Lagos, Nigeria), for a period of fifteen years
(1995-2009) were obtained from Nigerian Meteorological Agency, Oshodi-Lagos (NIMET, 2011).
The NIMET laboratories are equipped with facilities to obtain weather data. The NIMET
procedures include hourly measurement of wet-bulb and dry-bulb temperatures at synchronized
controls and stabilized power supply. The initial and final dry-bulb temperatures and wet-bulb
temperatures, respectively, were recorded as well as the inlet and outlet of the forced air
passage as well as the suction and discharge pressures including air velocity within the weather
station (NIMET, 2011). Ikeja-Lagos, Nigeria, is located at latitude 6.59°N and longitude 3.34°E on
an altitude of 9 m. Ikeja-Lagos, Nigeria, was hypothetically chosen to determine the climate
parameters due to its heavy traffic of airplanes with large weather data generation.

This work involves use of statistical data and Microsoft Excel spreadsheet 2015 version with
normal distribution table. The evaluation of variation trend of the climate parameters for
departure cities, are very important in determining thermal comfort in spacecrafts on ascent. The
high values of dry-bulb and wet-bulb temperatures were computed on criteria of 0.4%, 1.0% and
2.0% percentiles. Furthermore, the low values were also computed on percentiles of 97.5, 99.0%
and 99.6% frequencies of occurrence for all twelve months of the year under consideration. The
mean daily temperature range, median of extreme lows and highs for Ikeja-Lagos were
computed.

4.0 Results and Discussion
This section presents results in Tables and Figures along with the discussion of them all.

4.1 Average Temperature of Ikeja-Lagos as at 1995 and 2015
The evidence of increase in temperature over the years can be observed as shown in Table 1.
The average temperature for Ikeja-Lagos in 1995, was obtained from NIMET (2011) while
average temperature for Ikeja-Lagos in 2015, was a weather forecast as predicted by Ojeh et al.
(2016). In Table 1, the average temperature for the year 1995 in Ikeja-Lagos was 26.66°C while
the average temperature for the year 2015 in Ikeja-Lagos was 26.81oC. The increase in average
temperature in Ikeja-Lagos from 1995 to 2015 was 0.15°C, which agrees to convincing evidence
to global warming. The temperature trends during the year 1995 and 2015 are as shown in
Figure 1. Researchers have reported that there is gradual increase in average temperature of the
earth surface which has been predicted to rise between 1.4°C and 5.8°C by year 2100 as
reported by Trenberth, et al. (2007). The increase in average temperature in locations of
spacecraft ascent and descent will have to be factor in during design stage to minimize
retrofitting thermal comfort facilities.

Table 1: Average Temperature of Ikeja-Lagos as at 1995 and 2015
Year/Months Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec
Temperature,
1995

26.9 28.2 28.5 28.3 27.3 25.9 24.8 24.9 25.2 26.0 27.0 26.7

Temperature,
2015

27.3 28.5 28.5 28.0 27.1 25.6 25.3 25.1 25.5 26.4 27.2 27.2

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Adeyemi, et al, Impact of Climate Change on the Design Parameters of Heating, Ventilation and Air Conditioning
Systems for Manned Spacecraft. AZOJETE, 15(sp.i2):35-45. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: idris.ozigi@uniabuja.edu.ng 40

All these measurements are in degree Celsius (oC).

Figure 1: Average Temperature of Ikeja-Lagos as at 1995 and 2015

4.2 The Design Dry-Bulb Temperatures for Ikeja-Lagos from 1995-2009
The design dry bulb temperature for Ikeja-Lagos, are presented for all the months from 1995-
2009 at various frequencies of occurrence obtained using normal statistical table is as shown in
Table 2. Normal statistical estimates for average dry bulb temperature were made at 0.4%, 1.0%
and 2.0% for Ikeja-Lagos. The corresponding highest mean maximum temperature occurs from
February to May for years studied. These months of highest mean maximum temperature
becomes the design month for consideration in planning and operation of spacecrafts.
Furthermore, Figure 2, shows the mean coincident dry bulb temperature at 0.4% and 1%
percentile and were computed as 33.8°C and 32.98°C for Ikeja-Lagos respectively. Similarly, the
dry bulb temperature at 99% and 99.6% percentile respectively were at an average of 21.19°C
and 20.43°C from January to December for Ikeja-Lagos, respectively, were as shown in Figure 3.
These data are useful for cooling applications, especially air-conditioning in spacecraft
technology.

The statistical values of median of extreme lows (MEL), median of extreme highs (MEH) and
mean daily temperature range (MDTR) were also calculated as shown in Table 2 while Figure 4
illustrate the trends of mean daily temperature range for the period. The probability of
occurrence of very extreme conditions can be required for the operational design of equipment
to ensure continuous operation and serviceability as stated in ASHRAE (2013b). These values
were calculated from extremes of the hourly temperature observations. The true maximum and
minimum temperatures for any day generally occur between hourly readings. The 95.7%, 99.0%
and 99.6% design conditions are often used in the sizing of heating equipment. Some
sophisticated electronics need a particular dry bulb temperature and relative humidity for its
proper design and operation as reported by Liping et al. (2017).

The design dry-bulb temperatures and mean daily dry bulb temperature for Ikeja can be
employed to calculate heating and cooling degree-days, which is further used in energy
estimation of HVAC systems as reported by Ariyo and Olorunmaiye (2017a). The design
conditions based on wet-bulb temperature represent extremes of the total sensible plus latent
heat of outdoor air, according to ASHRAE (2010). The dry and wet bulb temperatures together
with other climatic characteristics are useful for cooling towers, evaporative coolers, and fresh air
ventilation system design, which are adaptable for spacecraft technology. Generally, in design of

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41

HVAC systems, it is not economical to choose either the maximum or minimum prevailing
climate data of a location but highly recommended that the 0.4%,1%, 2%, 5%, 97.5%, 99.0%, and
99.6% values of occurrences be adhered to as suggested by some researchers such as Liping, et
al. (2017). However, no one knows what exactly the future climate is going to be but statistical
analysis of the climate of the past years can give a clue to the future as reported by Burdick
(2011).

Table 2: The Design Dry-Bulb Temperatures for Ikeja-Lagos from 1995-2009
Months Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Average
0.4% 35.6 36.6 36.4 35.8 34.6 33.0 30.4 30.0 31 32.6 34.5 35.3 33.81
1.0% 34.6 35.6 35.5 34.9 33.7 32.1 29.8 29.5 30.3 31.8 33.6 34.4 32.98
2.0% 33.7 34.8 34.7 34.2 33.0 31.4 29.3 29 29.8 31.2 32.9 33.6 32.3
97.5% 21.3 22.7 23.4 23.0 22.6 21.2 21.9 21.7 21.6 21.8 22.2 21.8 22.1
99.0% 20.2 21.6 22.3 21.2 21.6 20.3 21.2 21.1 20.9 20.9 22.0 21.0 21.19
99.6% 19.2 20.6 21.4 21.0 20.8 19.4 20.6 20.5 20.2 20.1 21.3 20.1 20.43
MEL 23.7 25.5 25.6 25.3 24.5 23.6 23.2 23.3 23.5 23.5 24.4 20.0 23.84
MEH 32.5 33.8 33.5 33.0 31.8 29.9 29.0 28.3 29.2 30.5 32.0 36.3 31.65
MDTR 4.9 4.4 4.2 3.9 3.6 3.1 2.9 2.6 2.9 3.3 3.9 4.3 3.67
All these measurements are in degree Celsius (°C)

Figure 2: The Mean Coincident Dry-Bulb Temperatures for Ikeja-Lagos from 1995-2009

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Adeyemi, et al, Impact of Climate Change on the Design Parameters of Heating, Ventilation and Air Conditioning
Systems for Manned Spacecraft. AZOJETE, 15(sp.i2):35-45. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: idris.ozigi@uniabuja.edu.ng 42

Figure 3: The Design Dry- Bulb Temperatures for Ikeja-Lagos from 1995-2009

Figure 4: The Mean Daily Temperature Ranges for Ikeja-Lagos from 1995-2009

4.3 The Relative Humidity for Ikeja-Lagos from January-December of 1995-2009
The design relative humidity for Ikeja-Lagos from January to December of 1995-2009, is as
shown in Table 3 and Figure 5. The normal statistical estimates for the design relative humidity
were computed for 0.4%, 1.0% and 2.0%. The design relative humidity calculated for period
exceeded 100% as shown in Table 3. Since the design relative humidity exceeded 100%, it
implies that normal distribution statistical method cannot be used as stated by Ariyo and
Olorunmaiye (2017b) as well as Erbs (1984). Erbs (1984) suggested Weibull distribution for
design relative humidity to overcome defect of normal distribution statistical method. The
statistical values of median of extreme lows (MEL) and median of extreme highs (MEH) were also
calculated as shown in Table 3. Using the classification of ASHRAE (2013a), the relative humidity
for Ikeja, Lagos were computed to be an average of 116.3 and 112.6 at 0.4% and 1.0% percentile,
respectively, which is as shown in Table 3.
In the design and sizing simulation of HVAC systems for spacecrafts, design data based on dry
bulb temperature represent peak occurrences of sensible component of ambient outdoor
conditions. The design values based on wet-bulb temperature are related to enthalpy of the

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43

outdoor air while conditions based on dew point relates to peaks of the humidity ratio. The
design data for dry bulb, wet bulb and humidity ratio are optimized to obtain the most reliable
situation to adopt as stated in ASHRAE (2016). The foregone statement agrees to view on
decisions of conditions and probability of occurrence of climatic conditions to the design of
spacecraft as reported by Liping, et al. (2017).
Table 3: The Relative Humidity for Ikeja from January-December of 1995-2009.
Months Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ave.

0.4% 127.4 125.7 116.4 113.6 114.2 112.9 111.6 111.7 112.6 113.2 115.5 121.3 116.3
1.0% 121.3 119.9 110.6 109.7 110.6 109.2 108.8 108.7 109.7 110.1 111.9 121.3 112.65
2.0% 116.6 115 108.1 106.5 107.6 107.5 106.4 106.2 107.3 107.4 108.7 112.4 109.14
MEH 100 99 99 100 100 100 100 100 100 100 100 100 99.83
MEL 23 21 44 53 56 62 63 60 64 61 56 30 49.42

Figure 5: The Relative Humidity for Ikeja-Lagos from January-December in the Period of 1995-
2009

5.0 Conclusion
In this study, an investigation of the impact of climate change on the design parameters of
Heating, Ventilation and Air Conditioning (HVAC) systems for spacecraft was carried out. The
climate parameters investigated were outdoor dry-bulb temperature, coincident wet-bulb
temperature and relative humidity. These parameters are very important in determining thermal
comfort of payload in space crafts on ascent. Furthermore, the city of Lagos was used as a base
for potential launch of spacecraft. The values of climatic parameters were obtained with
adequate consideration of climate change. From the investigations carried out, the conclusions
drawn includes determination of mean coincident dry bulb temperature of 33.8oC and 32.98oC
at 0.4% and 1% percentile respectively at Ikeja, Lagos, on altitude 39 m with coordinates of
Latitude 6.59°N and longitude 3.34°E. The heat dry bulb temperature for Ikeja, Lagos, was
determined to range from 20.43oC to 22.1oC from January to December, in the period of 1995-
2009, at 97.5% 99% and 99.6% percentile respectively. The median of extreme lows (MEL) was at
an average of 49.42% for the period. The median of extreme highs (MEH) was at an average of
99.83% for the period. The Lagos relative humidity average results were 116.3, 112.65, 109.14,

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Adeyemi, et al, Impact of Climate Change on the Design Parameters of Heating, Ventilation and Air Conditioning
Systems for Manned Spacecraft. AZOJETE, 15(sp.i2):35-45. ISSN 1596-2490; e-ISSN 2545-5818, www.azojete.com.ng

Corresponding author’s e-mail address: idris.ozigi@uniabuja.edu.ng 44

99.83 and 49.42 at 0.4%, 1% and 2.0% occurrence as well as median of extreme highs and
median of extreme lows, respectively.
Acknowledgement
The authors wish to thank the Director and Chief Executive, Center for Satellite Technology
Development (CSTD) of the National Space Research and Development Agency (NASRDA), Abuja,
Nigeria, and Editorial Committee of CSTD for consideration of our paper for publication earlier
presented at 2017 CSTD conference.

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Arid Zone Journal of Engineering, Technology and Environment, June, 2019; Vol. 15(sp.i2):35-45. ISSN 1596-2490;
e-ISSN 2545-5818; www.azojete.com.ng

Corresponding author’s e-mail address: idris.ozigi@uniabuja.edu.ng

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