MAHONEYS TABLE.pptx

Presented By. ASSISTANT PROFESSOR. Rajini
Chandra Waker

CLIMATOLOGY is a study of climate, scientifically defined of time. this modern
field of study is regarded as a branch of the atmospheric sciences and a subfield
of physical geography, which is one of the earth sciences. climatology now
includes aspects of oceanography and biogeochemistry
MAHONEY’S TABLE
 When the climatic pattern emerging form the data clearly corresponds to warm
humid or hot-dry climate types. It is relatively easy to arrive performance
specifications
 A weighting system must be used to assess the relative importance of
confliction requirements.
 The system must take into account the duration and severity of the various
climatic factors.
By. Assistant Professor.
Rajini Chandra Waker

MAHONEY’S TABLE
In composite climates, the seasonal requirements may be contradictory. For
simple passive buildings, not assisted by mechanical means of heating or
cooling, Mahoney worked out a weighing system to assess the relative
importance of conflicting requirements. The system takes into account the
duration and severity of the various climatic factors. The Mahoney tables
classify precisely the nocturnal and diurnal thermal stress in centigrade
scale of temperature. The comfortable hot and cold periods are clearly
outlined.
Based on such a system. A series of tables have been derived by C
Mahoney.
TABLE1 – To record the most essential climatic data
TABLE2 – Facilities a diagnosis of the climate.
TABLE3 – Translates into performance specifications or sketch design
recommendations.

With the help of MAHONEY’S TABLE we can access the climate at a particular
place or location.
AIR TEMPERATURES. The max, min and mean temperature for each month are
entered into this table.
HUMIDITY, PRECIPITATION AND WIND. The max, min and mean figures for
each month are entered into this table and the conditions for each month
classified into a humidity group.
COMPARISON OF COMFORT CONDITIONS AND CLIMATE. The desired
max/min temperatures are entered, and compared to the climatic values from
table1:
A note is made if the conditions create heat stress or cold stress (i.e the building
will be too hot or cold).
INDICATORS( OF HUMID OR ARID CONDITIONS). Rules are provided for
combining the stress (table 3) and humidity groups (table 2) to check a box
classifying the humidity and aridity for each month. For each of six possible
indicators, the number of months where that indicator was checked are added
up, giving a yearly total.

SCHEMATIC DESIGN RECOMMENDATIONS: The yearly total in table 4
correspond to rows in this table, listing schematic design commendations, e.g.
Buildings oriented on east-west axis to reduce sun exposure, medium-sized
opening 20%-40% of wall area.
DESIGN DEVELOPMENT RECOMMENDATIONS : Again the yearly totals from
table 4 are used to read off recommendations, e.g. 'roofs should be high-
mass and well insulated'.
• choose the location and then according the location find Longitude,
Latitude and Altitude.
TABLE:1 ( First Part)

They are a set of reference tables which are used inn architectural and they help
us in designing a climate responsive building.
The parameters which we consider here are air temperature, humidity
precipitation and wind and using these we compare the comfort conditions and
accessing climate, on the basis of this the indicators are decided the climate in
assessed as humid or arid and a schematic design recommendation is provided.
Let us look at these Mooney's table some time during your early courses. For
Assessing any of the climate, we have to enter the values for location, longitude,
latitude, altitude along with that for air temperature, we need the monthly mean
maximum and monthly mean minimum and from that we can calculate the range.
Let us look at the climate data of Jaipur the climatic data of Jaipur.
So, if you look at the climatic data of Jaipur. Where the average hourly driver
temperature for each month is given. We can find out maximum temperture which
for January is 22.1 and the minimum is say 11.
We can enter these values. So, monthly mean maximum was 22.1 and 11.
So, for each month like that we fill up these monthly mean maximum and monthly
mean minimum. We would know the monthly range which is the difference of
these two.
So, we would have 11.1 here which is the monthly mean range, we can have the
highest temperature and the lowest temperatures the highest of all monthly mean
maximum. So, it will come some where in many, June, July and monthly mean
low.

The data of JAIPUR the temperature of every month which are been recorded
as per ASHRAE-55

and monthly mean low. So, the lowest of all the monthly mean minimum
which will be here, we will have an average annual mean temperature which
Will be here, we will have an average annual mean temperature which will be
the average of each and there will be an average monthly range which will be
the average of all the monthly mean ranges which we will get here
TABLE -1 PART ONE

From metrological records enter the monthly mean maximum and mean minimum
air temperature values in the first two line.
All values should be rounded to the 0.5ºĆ.
Find the mean range for each month by deducting the mean minimum from the
mean maximum value and enter these in third line.
In the separate box on the right enter the highest of the twelve maxima and the
lowest of the twelve similar respectively.
By adding these two values and dividing it by two find the annual mean
temperature and enter this in the box marked AMT.
By finding the difference between these two values get the annual mean range and
enter it in the box marked AMR.

This is how we will fill up the data for air temperature. The same thing we do
for relative humidity. So, monthly mean maximum or monthly mean minimum
for each month. The average and then on the basis of this average that we
get here. So say for Jaipur which we were looking at, we have a humidity
which is around 100% and 20%. So, we have a monthly humidity of maximum
of around 100% and minimum of around 100% and 20%. So, this 60% of
average the humidity ground is 50% to 70% which is the humidity groups. So,
we fill up these two tables, this is the key to fill up the humidity group here.
Again, we have this data for rainfall and the total rainfall, the annual total
rainfall prevailing wind which is the primary direction and these secondary
directions for each of these months.
Now in table 2, we can write the monthly mean maximum as what we have in
the table 1, and we can write the monthly mean minimum which we have in
table 1, again, once we have that, we can write for the given humidity group.
So, suppose and we also have the annual mean, temperature, so suppose
the annual mean temperature in case of Jaipur comes out to be say 24.6
degrees.
So, I have an annual mean temperture of 24.6 degrees which we can
calculate if we have the entire year data.

So, looking at the annual mean temperature 24.6 which is above 20 degrees
and we have the humidity group which we identified as group 3 here. So, we
can look at the day and night comfort range. So, we can look at the day and
night range, so, in January the upper limit would be 29 the lower would be 23 for
the day and for night it would be 23 and 11here. So, from this table, we can
calculate fill up for each of the month and when we have to calculate the thermal
stress during the day, what we have to see is if mean monthly maximum which
is 22.1, if it is we wil compare it with the thermal stress of the day. If it is lying
between the comfort limits for the day up between the upper and lower this then
we write cold. So, here we see that 22.1 is less than 23. So, we write cold same
we do for monthly mean minimum which is 11 and we compare ith with this
range of night temperature. So, if it lies between these two, it is zero if it is
higher than 23 which is the upper limit it is H and if it is lesser than this it is C.
So, we see that for a place of hot dry climate like Jaipur also January is actually
a cold month. Then we look at the indicators based upon this key. So, this key
has to be used to fill up this one.
Now we are looking at the January data in January we have thermal stress of C
we have humidity in Group 3. so, if we look at this, we have thermal stress
during the day as C and which implies that, we have the indicator as AS.

So, we have , if we have C it automatically comes to A3. for other months
suppose we have H so, we place the groups. So, we have the rainfall, we have the
thermal stress during day and night and we have the humidity group, we also have
the monthly mean range.
Together, we can find out which indicators are applicable. Once we have done
that, we move on and we total up.
How many H is are there, how many H1 are there, H3 and A1, A2 and A3 and like
that will have these total number of indicators once we have those indicators we
can go about finding out the strategy. So there are given suppose it can be very
conveniently read suppose, we have A1, 3 indicators are there, in case we have 3
indicators we are looking at this, so if A1 is 3.0 or 1, we are looking at large
openings of around 40 to 80%.
This is what is the proposed strategy, we are also looking at 0 to 2 for A1 light
walls. Short time lag is the strategy for walls. I have just filled up these numbers,
but you would get proper numbers, if you properly fill up the Mononey’s table and
Mohoney’s table are the first reference where you would actually get what kind of
design strategy you can use for your buildings, developed design. So, they are
talking about layout, the spacing between the buildings, air movement, openings,
wall roofs out door sleeping whether it is advisable or not. Protecting against rain,
the size of opening position of openings, protection of openings walls and floors.

What should be the thermal capacity of walls and floors, the roofs what kind of
reflective surfaces should be there and external features. So, Mohoneys Table
are first referance. Where on the basis of an initial analysis of very quick
analysis of the weathers data file, you can actually known, what kind of design
starategies can be employed into your design.

TABLE-1 (SECOND PART)
From metrological records enter the monthly mean maximum and minimum of
relative humidity in the first two lines.
Finding the average humidity for each month by adding the above two values and
dividing it by two values and dividing it by two. Enter these average in third line.
Establish the humidity group for each month according to the following categories.

TABLE-1 (SECOND PART)
Enter the monthly average rainfall value in the fifth line. Adding these twelve values
find the annual total rainfall and enter this in the separate box at the end of the line.
In the last two lines enter the prevailing and secondary wind direction for each
month, on the basis of first and second peak in published wind frequency tables
or figures.

Table -2 (First part)
Table represents to relation between comfort limit (in term of temperature) and the
humidity group

Table -2 ( first part)
Enter the first and fourth lines the monthly mean minimum and maximum
temperature.
Find the upper and lower comfort limits for the day and night of each month,
on the basis of the above table, as defined by the annual mean temperature
and the humidity group for each month. Enter these values in 2, 3, 5 and 6
respectively.
Compare the day comfort limit with the mean maximum and the night comfort
limit with the mean minimum and establish the nature of thermal stress by
entering the following symbols in last two lines:

Enter the first and fourth lines the monthly mean minimum and maximum
temperature.
Find the upper and lower comfort limits for the day and night of each month,
on the basis of the above table, as defined by the annual mean temperature
and the humidity group for each month. Enter these values in 2, 3, 5 and 6
respectively.
Compare the day comfort limit with the mean maximum and the night
comfort limit with the mean minimum and establish the nature of thermal
stress by entering the following symbols in last two lines:
H (hot) - If mean is above limit
O (comfort) - If mean is within limits.
C (cold) – If mean is below the limit.

TABLE -2 (Second Part)
Certain group of symptoms ( nature of thermal stress, some climate characteristic
and the duration of both) indicate the remedial action and designer could take. The
method developed uses six indicators (three humid indicator H 1,2,3 and three arid
indicator A 1,2,3)

TABLE – 2 (Second Part)
The process to be followed is to check thermal stress indices (day and night) the
humidity group, the rainfall and the monthly mean range of temperature against
the definition of the indicators and place a trick in the appropriate indicator where
the month’s data corresponds to the definition.

Mahoney’s Table
Presented By. Ar. Rajini Chandra Waker

TABLE – 3 SPECIFIATIONS
BUILDING should be oriented on east or west axis, the long elevations facing
north and south, to reduce expose the sun.
Building should be planned around small courtyard if thermal storage required
of the most of the year, i.e when the hot dry season is dominant.

Building should be broadly spaced for breeze penetration.
If wind penetration is needed only for the part of the year, provision must be made
for protection from cold or dusty hot winds.
Compact planning is recommended if the air movement requirement is insignificant.

Room should be single baked with windows in the north and south walls, to endure
air movement by ample cross ventilation.
If air movement is never essential, and is desirable for not more than a month,
rooms can be double banked and there is not much need for cross ventilation.

Large, between 40% and 80% of the north and south walls. These need not be fully
glazed, but should be protected from the sun, sky glare and rain, preferably by
horizontal overhangs.
Very small, less than 20% of the wall.

External wall should be light with low thermal capacity.
Internal wall should also be light where hot dry condition prevail for a short time only
Internal walls should be heavy and massive, where any occurrence of hot and dry
conditions is combined with a large annual mean range of temperature (over 20ºĆ)
Both external and internal wall should be massive.

A light but well insulated roof, with low thermal capacity.
A heavy roof, with substantial thermal capacity, giving a time lag of at least 8 hours.

Special protective measures are needed if rain is frequent and heavy – such as
deep verandahs, wide overhang and covered passage are provided.
It should be provided on roof, balconies or in patios, so that sleepers are
exposed to the coldest part of the night sky in increase heat loss by out going
radiation.

Mohoney’s Table
They are a set of reference tables which are used in Architecture and they help us
in designing a climate responsive building.
The parameters which we consider here are air temperature, humidity,
precipitation and wind and using these, we compare the comfort conditions an
accessing climate, on the basis of this the indicators are decided the climate is
assessed as humid or arid and a schematic design recommendation is provided.
Let us look at these Mahoney's Table For assessing any of the climate, we have
to enter the values for the location,longitude,latitulde , altitude along with that for
air temperature, we need the monthly mean maximum and monthly mean
minimum and fro that we can calculate the range. Let us look at the climatic data
of Jaipur the climatic data of Jaipur. So, if your look at the climatic data of Jaipur,
where the average hourly driver temperature for each month is given with the help
of this we can find out the maximum temperture which for January is 22.1 and the
minimum is say 11 here. We can enter these values. So, monthly mean maximum
was 22.1 and 11 here. So, for each month like that we fill up these monthly mean
minimum we would know the monthly range which is the difference of these two
so, we would have 11.1 here which is the month mean range.

Mahoney’s Table
Presented By. ASSISTANT PROFESSOR. Rajini
Chandra Waker

MAHONEYS TABLE.pptx

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