AN ASSIGNMENT

ON

CONDENSATION PROBLEMS IN TYPICAL BUNGALOW IN AKURE

Submitted by:

AKINYOSOYE OLUFEMI

(ARC/04/3178)

Course:

APPLIED CLIMATOLOGY [ARC 810]

To

The Department Of Architecture, Federal University of Technology, Akure

In Partial Fulfillment of M. Tech Degree in Architecture

Lecturer in Charge: Prof. Ogunsote

AUGUST, 2011

OUTLINE

1.0 Introduction

2.0 Definition of Condensation

3.0 Causes Identified In Typical Bungalows in Akure

4.0 Where Condensation Could Be Found In Typical Bungalows in Akure

5.0 Effects of Condensation in Buildings

6.0 How Condensation Can Be Controlled or Reduced

6.1 How to Prevent Mould

6.2 What Can Be Done To Reduce Risk Of Condensation?

7.0 Recommendation

8.0 Conclusion

References

1.0 Introduction

Man’s needs for housing cannot be overemphasized however there is the need for a qualitative

housing which seeks to reduce the problems associated with creating a shelter. One of such

problems is the issue of condensation. Problems do occur because of the way in which buildings

are built today or have been converted, however many people just do not make sure the property

is properly ventilated. All air contains a certain amount of invisible water vapour and warm air

can carry more water vapour. If warm air comes in contact with a cold surface, the air gives up

its water as droplets on the surface through a process called condensation. The effect of moisture

generation is increased by keeping the moist air in the property and it is possible to avoid

condensation by adequate ventilation. Certain parts of the building, like the bathroom and

kitchen will have much more warm air that contain a lot of moisture so it spreads to cooler part

of the building.

Condensation is one of the most common problems in houses. Condensation occurs when warm

air meets a cold surface. The water in the air then either settles as water droplets on the surface

(as it does on windows for example), or, if the surface is absorbent, it soaks into the surface. In

the latter case condensation is often not noticed unless or until moulds appears. Moulds tend to

appear on surfaces where condensation takes place regularly, because the external walls of a

room are usually the coldest. They tend to be most affected by condensation (and as a result of

mould) particularly at the corners of the room. Mould is often found in cupboards and behind

furniture which is pushed close up against a cold wall; this is because there is poor ventilation in

cupboards and behind furniture so that any condensation there gets little chance to dry off.

Components that are more effectively sealed keeping any moisture produced within the property

provide better conditions for condensation.

The moisture can come from cooking, bathing, washing, drying clothes and even breathing

produces condensation. However, there are ways of controlling condensation. One way is to

reduce the amount of moisture in the air (the humidity), or another is to increase the warmth of

the surface of the walls or other areas affected. Reducing condensation is the best way of

controlling mould but it is possible to use fungicidal washes and paints also.

2.0 Definition of Condensation

All air contains a certain amount of invisible water vapour and warm air can carry more water

vapour. If warm air comes in contact with a cold surface, the air gives up its water as droplets on

the surface. If you wear glasses you will know what happens when you come into a warm house

from the cold outside. The same effect can be seen on a bathroom mirror when you have a hot

bath, warm moisture-laden air chills on contact with the cold surface. This process is can occur

anywhere in the home. The amount of vapour air can hold depends on the air temperature. Warm

air can hold more vapour than air at the lowest temperature. When air is cooled therefore, there

comes a time when the vapour in the air is sufficient to saturate the air mass. The vapour

pressure at this temperature is called the saturation vapour pressure while the temperature is the

dew point of air for the given vapour content. When the air is cooled further, it will no longer be

able to hold some of the vapour and this excess vapour is converted to a liquid in a process called

condensation. There are two types of condensation, surface and interstitial condensation. Surface

condensation occurs when air comes in contact with a surface at a temperature below its dew

point. A layer of moisture is formed on the surface of the wall or roofs as may be observed in

some kitchens, bathrooms or rooms, this leads to damp interiors and mould growth. Interstitial

condensation is condensation within walls or roofs. This is a result of temperature and vapour

pressure gradient across the wall it may also be caused by surface condensation being absorbed

into the wall. This may cause damage to organic building materials and increase heat loss

through a reduction in resistance of the building materials.

3.0 Causes Identified In Typical Bungalows In Akure

It is a fact that warm air can hold more water as vapour than cool air. Condensation is caused

when moisture-laden air comes into contact with a cold surface, the air is cooled to the point

where it can no longer holds its burden of water. At this point the dew point water begins to

release out of the air and is seen as condensation on impervious surfaces such as glass and gloss

paint, beads of a film of water collect on permeable surface such as wall paper and porous

plaster, the condensing water is absorbed with the material therefore the problem is not initially

obvious

Condensation affects millions of homes in Nigeria. it is closely related to how well the home is

heated, ventilated, insulated and draught proofed and remedies often include improvements in

heating and insulation, although there e are simple things which can be done to help cut down the

problem.

4.0 Where Condensation could be Found in Typical Bungalows in Akure

Cold surfaces such as mirrors, single-glazed windows and metal-framed windows

Kitchen and bathrooms (where moist air is produced through washing, cooking e.t.c )

Walls of unheated rooms

Cold corners of rooms

Wardrobes, cupboards (particularly built-in cupboards and behind furniture against an

outside wall

5.0 Effects of Condensation

Condensation is by far the most common cause of dampness in building. Probably accruing for the

majority of damp problem noticed. It affects both old and new buildings. Condensation is directly

associated with mould growth. The obvious places for condensation to occur are on cold walls and

floors. Condensation can cause staining and mould growth, and can severely damage wall surfaces

and window frames as well as furniture and clothes. The black mould that is a familiar sight when

there are several condensation problems can also be a health risk. Condensation, like all other forms

of dampness, is a particular problem because damp homes are harder to heat. Condensation, like all

other forms of dampness, makes houses difficult to keep warm. the reason being wet building

materials lose heat more quickly than dry ones and also some of the heat input is being used to dry

out the house. It is important to realise that condensation can occur in rooms some distance away

from the source of moisture production. Warm moist air naturally moves to colder areas and will

condense on cold surfaces. For example, a common problem in homes that are not centrally heated is

that moisture-laden air moves to unheated rooms (often bedrooms) and cause condensation.

Plate 1: Shows wall paint being damaged due to the effect of condensation.

Plate 2: Shows black mould at the window frame of a kitchen.

Plate 3: Shows black mould at the entrance of a bathroom due to the effect of condensation

Plate 4: Shows the effect of condensation on a wall that is not exposed to sunlight

Plate 5: Shows destruction to the wall surface caused by condensation.

Plate 6: Shows the effect of condensation on a wall that is not exposed to sunlight.

6.0 How Condensation Can Be Controlled or Reduced?

The most effective ways to reduce condensation is to see that rooms are always warm and

properly ventilated. Too much ventilation in rooms can carry away too much heat and thus can

cause wall surface to get so cold. It will actually encourage condensation rather than reduce it.

Steps which can be adopted include;

When cooking keep kitchen door shut and window open

When using a bath or shower or washing clothes, keep the room door shut and the

window open. if it is an internal bathroom, make sure that the extractor fan is kept

switched on

Drying clothes; tumble dryer produce a great deal of moist air and this should, ideally

ducted directly to the outside of the house if condensation is very bad in the house

then one should consider drying clothes outside or in a cool area inside. it will take

longer, however there will be less moisture when you dry clothes inside a room that is

ventilated

When anyone comes into the building in wet clothes, hang them outside the living

area to dry, if you have a porch use it.

In cold weather, keep some heating on all the time, i.e. for 24hours a day. The

warmer the house the less condensation will occur provided that the level of humidity

is controlled too

Do not fill cupboards to busting point particularly if there are clothes in them, let the

air flow into the cupboards

Increasing warmth, heating and ventilation; a property can be made warmer inside by

increasing the level of heating or by increasing the insulation. it must be remembered

however, that if there is no heating at all in the house then improving the ventilation won’t

make it any warmer.

6.1 How to prevent mould

General- the most important action to take against mould is to try and reduce the

condensation in the ways described above. In particular, if moulds are found behind

furniture or in cupboards, then move them away from the cold outside walls. if

possible and put ventilation holes in the top and bottom of cupboard if necessary.

Cleaning- cleaning away mould is best done using an anti-mould solution or wash

and there are a number of different brands. A little while after using them the surface

should be scrubbed cleaned with stiff brush. these washes kills the mould and its

spores and does provide some short term protection against the re-appearance of

moulds

Paints and mould inhibitors- longer term protection against the re-appearance of

mould can be gained by re-decorating the area affected with a mould inhibiting paint.

For some people the microscopic spores produced by the black mould are a health risk. Remove

mould using household bleach or a fungicide solution. If the mould is particularly bad, wear a

facemask. The cleaned area may be over painted with fungicide paint or covered with special wall

paper paste before redecoration, but unless the cause of the problem is treated, the mould will return

in due course. The most effective way to eradicate mould in the long term is to eliminate the source

of the water to reduce the risk of condensation on surfaces

Fungicidal washes; Cleaning with fungicidal washes can be effective. They can also be

considered as a temporary measure pending lasting improvements.

Fungicidal paints; some fungicidal paint now available may be capable of giving

prolonged control and can be of value for redecoration. Indeed where damp conditions

are slightly, intermittent fungicide paints may give adequate period of protection.

Fungicide paint differ in effectiveness especially if conditions have not been improved to

reduce dampness

Fungicidal wall paper pastes; pastes cannot be relied on to protect the wall covering

itself from growth of moulds. The fungicide is present solely to protect the paste during

use and during the sometimes prolonged drying which can occur with various types of

wall covering. For example vinyl paper. Fungicide pastes can be sprayed on to wall paper

surface to prevent mould growth

Anti condensation paint; these are not fungicidal paints and not intend to prevent mould

growth directly, they work by forming a barrier to prevent moisture being absorbed on a

paint surface or material, so avoid or reduce conditions suitable for mould growth. They

may be considered as part of the overall strategy for reducing condensation mould

growth.

Some of these products may be effective in keeping moulds at bay for a time, but in most cases the

mould will grow back unless the condensation dampness which caused it is dealt with effectively.

6.2 What can be done to reduce risk of condensation?

To reduce condensation one or more of the following factors should be considered

Reducing moisture production

Ventilation

Heating

Insulation

Reducing moisture production; Moisture is produced in the course of day-to-day activities, but there

are still a number of steps that can be taken to reduce moisture production.

Keep lids on sauce pans when cooking

Clothes should not be left to soak for longer than necessary

Tumble dryers should be vented to the outside

Bottle gas and paraffin heaters should be avoided

If producing steam in the kitchen or bathroom, open the window and close the door to

stop moisture spreading through the house (draught strip bathroom and kitchen interior

doors)

Cupboards and wardrobes will be less prone to considered if doors are left open from

time-to-time or if louver doors are fitted

Clothes should always be thoroughly dried before being put in wardrobe.

Ventilation; if there is not enough ventilation; moist air will not be able to escape. However, too

much ventilation makes a house draughty. Getting the balance right can be difficult. Background

ventilation can be given by air bricks and ventilators, (some of these are adjustable but they should

never be blocked) or by trickle ventilators fitted to window frames. if condensation is occurring

against furniture (commonly a bed, if pushed against an outside wall, or a sofa in a bay window,

move the furniture away from the wall and make sure air can circulate around the cold area.

In kitchens and bathrooms, extractor fans are very good idea. Humidistat fans switch themselves on

and off according to the dampness of the air. Ventilators which can recover the heat from the air

before expelling it are also available. Other measures for kitchen and bathroom include opening

windows when moisture is being produced and closing internal doors which should be draught

proofed to prevent the moisture spreading to the rest of the house.

If condensation is a problem, care must be taken when draught-proofing the home. too much

ventilation (as draught) can make condensation worse by making homes harder to heat, but if you

seal off all the draughts, then the moist air cannot escape. If condensation is a problem and you want

to draught proof your home then it is worthwhile seeking further professional advice.

Heating; condensation is most likely to be a problem in the home that is under heated. The home

may be under heated due to an inadequate heating system or not having enough money to heat the

home.

Insulation; Insulation is important in the treatment of condensation in three ways

It warms up the surface walls, ceilings and windows; removing cold surfaces for vapour

to condense onto

It generally warms up the building

It can reduce heating bills, enabling people to heat their homes to a higher standard

Dehumidifiers; a dehumidifier is an electrical device designed to help condensation problems by

removing moisture from the air. These should be used in areas where there is a risk of condensation.

In general, they are not an ideal solution, but they can help in some cases. In cases of severe

condensation they are a useful temporary measure. A dehumidifier draws in warm moist air from the

room and passes it over cold coils, which causes water to collect in a moisture collector. The air that

has been taken in is drier and cooler. The dehumidifier will then warm up this air and return it to the

room. Dehumidifiers are less effective in poorly heated rooms. Moisture collectors may fill up

quickly and need to be regularly emptied. Expensive to buy and cost money to run and they can be

noisy.

7.0 Recommendation

There is the need for proper ventilation of rooms and such spaces prone to

condensation.

There is the need to adopt some life style which reduces the risk of condensation. For

example, drying clothes inside a living space should be avoided.

By orienting the building well enough to allow for fresh air from the windward side,

to enhance ventilation and air flow around the building.

Cupboards and wardrobes should adequately be exposed to fresh airs or rays of

natural light.

If black moulds eventually occur, the wall surfaces should be properly treated.

8.0 Conclusion

Today, there is a paradigm shift from a reckless abandonment of the ecosystem towards a

more conscious effort to salvage the environment; therefore, there is the need to take issues

of the environment seriously. Condensation is a phenomenon which by conscious thought

can be controlled, reduced or avoided. There is a need for the environmentalist especially the

architect to be abreast of issues concerning the climate and the factors affecting the weather

and climate change, so as to forestall the aftermaths, one of which is condensation, a major

cause of black moulds in buildings.

References

Burberry, p. (1971). “Methods for determining condensation Risk”. In: architects’ journal, 26 may

1971 and 2nd June 1971. PP 1201-1208 and 1265-1269.

Daniel J. Lemieux, AIA and Paul .E. Totten.(1976). Building envelope design guide-wall system

Ogunsote O.O. (1991). Introduction to building climatology: A basic course for architecture

students. Ahmadu Bello University Press, Zaria.

Garratt’s Damp and Timber (www.dampproofing-london.co.uk).

www.highland.gov.uk/livinghere/housing/councilhousetenancies/councilhouserepairs/

condensatio.htm

www.jmlproperty.co.uk/condensation.htm

www.heritage-house.org