«HUYS ADVIES Plastic Waste Insulation Re-Use of PET for High Altitude Houses Thermal Insulation for House Construction with used PET bottles Report ...»
Plastic Waste Insulation
Re-Use of PET for
High Altitude Houses
Thermal Insulation for House Construction with used PET bottles
Report by: Sjoerd Nienhuys
Edited by: Doreen Nienhuys
Report date: November 2004
Location: Kathmandu, Nepal
Plastic waste is increasingly becoming an eyesore and is polluting the environment, especially in high
mountain villages where no garbage collection system exists. A large amount of plastic is being
brought into the tourist trekking regions (PET and HDPE bottles, food wrappers, PVC and plastic bags used for transport and packing materials) and discarded or burned. This plastic waste can be perfectly reused as source material for thermal insulation. Empty PET and HDPE bottles are separated into “clean” and “less-clean”, and packed in PP fibre bags can be utilized as thermal insulation material inside housing. Designs are provided for floors, over ceilings and inside cavity walls. Used PVC shopping bags can be used to insulate water piping of solar water heaters and warm water piping inside houses. Common non-biodegradable waste products are re-used as high value thermal insulators, being extremely needed in the high altitudes to conserve warmth and reduce firewood consumption. A basic explanation on how thermal insulation works and a comparative table of insulation values is included.
FORWORD The first report about the re-use of wasted PET bottles (Polyethylene Terephthalate) was realised in May 2003 after a working visit to the foot mountains of the Himalayas in Nepal, a popular trekking area for tourists. Not only the tourists brought PET, HDPE (High Density Polyethylene) and PVC bags to the area, also the local population imported the materials for sale to tourists and own use. The result was an accumulation of non degradable waste, remaining for years polluting the environment.
The plastic is not only an eye-soar for the people who otherwise would come to the mountains to enjoy the scenery, but cattle and other animals would eat the material and with that kill themselves.
PET bottles are often finding a second use as container, but eventually end up as waste or being burned in the winter. With very large numbers of PET and HDPE bottles, recycling may become an option, but the transport from the high mountain regions back to recycling plant will be too costly, even if the PET bottles are shredded first. Direct re-use therefore is preferred above re-cycling.
Using the empty PET and HDPE bottles as thermal insulation in the building construction saves firewood and firewood collection time, thus being an additional benefit to the environment. One year after this report the first house was thermally insulated in Kathmandu, using the empty bottles in the cavity wall and in the ceiling under the roof.
Sjoerd Nienhuys Renewable Energy Advisor E-mail: firstname.lastname@example.org Website: www.nienhuys.info Photos and sketches: Sjoerd Nienhuys Photo front page: Plastic waste of a few weeks of one household.
Plastic Waste Insulation (Year 2004)
TABLE OF CONTENTS
Availability of Raw Biomass Material
Prohibition and Provision
Heating Equipment Versus Thermal Insulation
2. PLASTIC WASTE USUABLE FOR INSULATION
2.1 TYPES OF PLASTIC
2.2 USEABLE AND NON-USEABLE WASTE MATERIAL
3. HOW DOES INSULATION WORK?
4. MAKING PLASTIC INSULATION
Types of Plastic Insulation
Organisation of Collection
5. DOMESTIC APPLICATION
6. SWH APPLICATION
Plastic Waste Insulation (Year 2004)
1. INTRODUCTION This report provides information about the use of plastic waste materials in mountain areas for thermal insulation in houses. In houses the insulation can be placed under the floor, inside cavity walls and under the roof. External and internal water piping of Solar Water Heaters (SWH) can also be insulated with used plastic bags, and mattresses can be stuffed with shredded EPS packaging, providing high quality and light weight insulation. Thermal insulation is very important in high altitude areas where the cold climate increases heating requirements. Improved insulation of houses therefore results in better comfort and a reduced consumption of firewood.
The Himalayan ranges and other high altitude areas in Nepal have suffered severe deforestation in the
last 20 years due to the increasing population and their demand for:
Firewood, to support the rise in population growth and tourist activities, and Timber, needed for the construction of housing and hotel accommodation.
As a measurement to reduce firewood collection for use in the tourist industry, travel organisations are now obliged to import kerosene into the region for heating fuel and to carry this kerosene to the mountain base camps. Cutting firewood has been recently prohibited in nature conservation areas.
The local population is allowed to use, to a very limited extent, deadwood (branches) for local firewood needs and to collect forest waste products. In addition they use cow-dung, this however will decrease the soil fertility and with that plant growth.
Availability of Raw Biomass Material High altitude areas have a rather slow regeneration of biomass. Tourist trekking areas often lie between 2000m and 4000m (6,000 ft. and 12,000 ft.) where a considerably slower wood and biomass regeneration exists than at lower altitudes; between five to ten times slower.
In the Terai at 500m (1500 ft.) young hardwood trees can produce about 100 kg wood/ year.
At 2000m (6,000 ft.) this is, compared to the Terai, about 20 kg wood per year, or one-fifth.
At 3000m (9,000 ft.) this is only about 10 kg wood per year, or one-tenth of the lowland.
Above 4000m (12,000 ft.) no more trees will grow.
Despite the prohibitive measurements to use firewood in the conservation and tourist trekking areas, the regeneration of biomass remains far below the demand for firewood. This is because tourists, who are unaccustomed to cold areas, have high demands for space heating, warm showers and cosy fires while on holidays. Sufficient alternatives must be provided to reduce the demand for firewood.
Prohibition and Provision Control of energy resources can be accomplished in two ways: prohibiting and providing. For example, it is prohibited to use firewood, so kerosene is provided as a substitute. Kerosene, however, is expensive and a non-renewable energy resource. The imbalance between consumption of firewood and supply of energy can only be adjusted by providing sufficient alternatives in renewable energy resources. There is little point of prohibiting without provision.
Heating Equipment Versus Thermal Insulation Although many people are seeking solutions by making better heating equipment, more than half of the energy resources (and cost) for space heating can be reduced by adequate thermal insulation. The application of thermal insulation techniques is a permanent measurement in directly displacing energy resources. Moreover, thermal insulation once installed functions for the lifetime of the building.
Collecting firewood consumes a substantial part of the annual workload for both men and women.
The women normally have the task of chopping the logs into small pieces that fit into the stoves.
The amount of firewood shown here is required for one winter season only.
This amount can be reduced by half with improved thermal insulation of the living quarters.
More firewood can be saved with solar water heating and some adaptation of cooking methods.
About 2 million Nepalese, or more than 300,000 families, live in high mountain areas (over 2000m) and are annually influenced by the winter cold, being severe at the very high altitudes (over 3000m).
This population is highly dependent on firewood for its energy needs (cooking, warm water and space heating). About 3-4 tons of firewood is consumed per family per year, an amount that annually is becoming more difficult and costly to collect due to the continuous deforestation. Per family more than a full month of hard labour is required to collect the firewood from the hills. Due to this large firewood consumption, forests at high altitudes are not exploited in a sustainable way.
In tourist and trekking areas where large amounts of food items and plastic drink bottles are imported, these waste materials can be seen littered about. It is becoming an eyesore and having an negative environmental impact on the area if not collected and properly disposed of by the local organisations.
In the two most popular trekking regions, Annapurna Conservation Area and the Sagarmatha Conservation Area, local organisations such as ACAP and SPCC (Sagarmatha Pollution Control Centre) are very much involved in organising the local population in waste collection.
This paper explains the main principles of thermal insulation and how plastic waste can serve perfectly as thermal insulation in houses and for external applications. Especially for external applications that are not exposed to the direct sunlight, the waste material can be reutilised as a very durable insulator solving five issues at the same time.
(1) Getting rid of plastic waste;
(2) Thermally insulating houses and installations;
(3) Avoiding the importation of insulation materials;
(4) Reducing firewood consumption because of increased thermal comfort; and (5) No waste burning.
• Thermal insulation of a house or hotel is a good method to increase the comfort level during the winter and at the same time considerably reduce firewood consumption for space heating. It saves energy by maintaining the warmth inside the rooms so that constantly maintaining the (wood burning) fire is not necessary. Insulating the ceilings and under the roof of houses are the most effective energy savers.
• Solar Water Heaters (SWH) are very effective in high altitudes for warming shower water and pre-warming kitchen water. The piping system between the SWH and the tap point needs to be well insulated to avoid cooling down, causing a reduction in the efficiency of the system. Plastic waste can be used for this insulation, covered with (thin) HDPE pipes having a large diameter.
No More Burning
• Burying and burning are two practices being used to get rid of waste material. However, these practices destroy the possible use of a technically valuable insulation material. In very large cities facilities often exist to recycle most of the different types of plastic. In Nepal this is rather limited and the cost of bringing the plastic back to Kathmandu is prohibitive to any reprocessing.
However, in remote areas the plastics can easily be recycled (reused) as thermal insulation.
The plastic waste material can consist of empty PET water and soft drink bottles, empty wrappers of instant noodles, flimsy plastic shopping bags and used transport bags, among others. This report provides some details of various applications of plastic waste as thermal insulation.
Some figures are quoted from the Sagarmatha Pollution Control Centre (SPCC), but similar quantities may also be the case in the Annapurna Conservation Area Project (ACAP) supported region. Because of the large quantities of waste material already collected by SPCC, immediate application of thermal insulation from plastic waste can be easily realized. In other areas, however, it may take some time for community organisations to organise the collection of the material and will therefore need to begin with a limited application of the thermal waste insulation, for example, use in greenhouses only.
During the 2001/2002 season about 30 tons of non-degradable waste was collected in the Sagarmatha-Khumbu region by SPCC. About 10% of the solid waste consists of plastics which can be used as insulation material.
2.1 TYPES OF PLASTIC Two main forms of plastic wastage are present in the mountain areas, plastic bottles and foil-type plastics, such as grocery bags and large fibre bags. Bottles without residues can be used directly as insulation because they contain air. It is the air that provides the insulation.
PET Bottles The transparent Polyethylene Terephthalate (PET) bottles have become increasingly common and are used for mineral water, soda waters and soft drinks. In some areas (Khumbu) empty bottles are imported and bottled with clean spring water. Most containers are glossy, clear transparent, while some are green in colour. In some high mountain areas bringing in these bottles is now being prohibited because of their pollutant aspects. With a collection system prohibition is not necessary.
LDPE Bags and Wraps Plastic grocery bags are often made from lowdensity polyethylene (LPDE). LPDE is also found in cookie wrappers, noodle packages, etc.
Polyethylene plastic has a density of 0.91-0.96 kg/dm3 and will float in water. Although the plastic does not emit poisonous gasses when burned, it is better to use the plastic as an insulator. When used for thermal insulation it must first be washed, sun-dried and crumpled up for packing between the plastic bottles.
PVC Foil and Bottles Polyvinyl chloride is semi-rigid and glossy. It is used in bottles (shampoo and soap) and in transparent foils used for a wide variety of purposes. PVC transparent foils come in a variety of thickness (0.08mm = 200 gauge) but are not resistant to extended exposure to UV light, having a high intensity at high altitudes.
Incinerating PVC causes poisonous gasses to be released into the atmosphere. The PVC plastic has a density of 1.2-1.55 kg/dm3 and therefore sinks in water. This aspect can be used in both cleaning and separating the PVC from other plastics. When not extremely soiled, PVC is excellent for use in thermal insulation, but it should be kept out of the sunlight.