Using Insulation in China’s Buildings: Potential for Significant Energy Savings and Carbon Emission Reductions

doi:10.4236/lce.2011.24027

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Low Carbon Economy, 2011, 2, 220-223

doi:10.4236/lce.2011.24027 Published Online December 2011 (http://www.SciRP.org/journal/lce)

Using Insulation in China’s Buildings: Potential

for Significant Energy Savings and Carbon

Emission Reductions

Guoliang Liu1, Hans Liu2

1Institute of Applied Forest Ecology, Chinese Academy of Science, Shenyang, China; 2The Biomedical Research Centre, University

of British Columbia, Vancouver, Canada.

Email: [email protected]

Received September 29th, 2011; revised October 30th, 2011; accepted November 8th, 2011.

ABSTRACT

Most old residential and commercial build ings in China are not insulated or not to new standard s. This is true even in

regions with very cold winters or regions with very hot summers. The insulation in new buildings is very poor relative

to North American standar ds . However, insulating the exterior walls, attic roofs, and foundation walls to new standards

of building s in China would red uce the n eed for h eating a nd air cond itioning, and thus would save roughly 200 million

tons of coal each year. This in turn would lead to a reduction in CO2 emissions of about 510 million tons per year,

which is equal to about 8.4% of China’s total carbon emissions in 2006. The use of insulation in buildings will help

homeowners save money, help China save energy and help th e environmen t all at the same time. In sulatio n will provid e

a continued payback to the homeowner, not only in dollars and cents, but also by providing a more enjoyable and com-

fortable living environment for many years.

Keywords: China Building Insulation, Air Pollution, Energy and Coal Saving

1. Introduction

China burns about 6 million tons of coal every day [1].

According to the World Bank, of the world’s top 20 cit-

ies with the worst air, 16 are in China [1]. According to

Chinese government sources, about one-fifth of urban

Chinese breathe heavily polluted air. Many Chinese cit-

ies smell like high-sulfur coal and leaded gasoline in the

winter. Of the 340 Chinese cities that are monitored for

pollution, only one-third meet China’s own standards [1].

Coal is the number one source of air pollution in China

[1]. “The pollution is worst during the winter,” said Ji

Youping, a former coal miner who now works with a

local environmental protection agency. “Datong gets

very black. Even during the daytime, people drive with

their lights on”. Pollution is a major public health con-

cern of the government. The Asian Development Bank

says it is financing pollution control programs in Shanxi

because the number of people suffering from lung cancer

and other respiratory diseases in the province has soared

in the past 20 years [2].

China obtains 80% of its electricity and 70% of its to-

tal energy from coal, much of which is high-sulfur coal.

The sulfur dioxide produced in coal combustion poses an

immediate threat to the health of China’s citizens, and

contributes to about 400 ,000 pr emature deaths a year [2].

It also causes acid rain that poisons lakes, rivers, forests,

and crops [2]. During winter, emissions from coal-fired

central heating facilities are the primary cause of the se-

rious air pollution that is prevalent in northern China’s

cities. However, due to the major cost advantage of co al,

and to a lack of alternatives, coal is expected to remain

the dominant fuel for central heating systems in China

for the foreseeable future [3].

Officially, residential and commercial energy use ac-

count for 19% of China’s total consumption. This meas-

ure, though, omits many commercial and residential

buildings that belong to units that are categorized under

the industrial, agricultural, construction or other sectors

of the economy. Chinese academics estimate that the

buildings sector actually accounts for 23% of total en-

ergy use and will exceed 30% by 2010 [4].

Roughly half of China’s population lives in northern

regions where temperatures fall below 10˚C for more

than 90 days of the year. In terms of energy per square

Using Insulation in China’s Buildings: Potential for Significant Energy Savings and Carbon Emission Reductions 221

meter of living space, air conditioning uses more energy

in areas with hot climates, and heating uses more energy

in areas with cold climates. The total energ y required for

air conditioning and heating combined is the most per

square meter in regions with very cold winters and in

regions with very hot summers [5]. In regions with only a

moderate difference between summer and winter cli-

mates, such as in Beijing, the energy required for air

conditioning is about the same as that required for heat-

ing [5].

China currently consumes about 200 million tons of

raw coal per year for space heating of urban, residential,

and commercial buildings in its cold and severely cold

regions [5]. The amount of energy used for air condi-

tioning is estimated to be about the same as for space

heating [5], so China currently consumes about 400 mil-

lion tons of raw coal per year for the purposes of space

heating and air conditioning combined.

Energy use per unit floor area in China is at least dou-

ble that of buildings in similar cold climates in Western

Europe or North America [5], yet far lower levels of

comfort are achieved, largely because insulation is not

widely used in China’s buildings. In Canada, detailed

building codes have been in place for decades, and all

buildings in all regions are required to be insulated to a

certain standard. In Canada, fiberglass is the most com-

mon insulation material.

The cost of insulating with fiberglass is very low, ev en

when the framing lumber, vapor barrier, and drywall

components are included. The space waste associated

with the installation of insulation is very low because

only the exterior walls and roof need to be insulated. All

electrical wires, network cables, vacuum ducts, ventila-

tion ducts, and telephone lines can easily be installed

inside the wall, i.e., between the outer and inner walls,

with no need to alter the concrete walls or foundation.

The consumption of heating energy is starting to be

metered in many of China’s cities, which is causing resi-

dents to pay more attention to th eir heating bills. The use

of insulation in buildings will help homeowners save money

and help the environment all at the same time. Insulation

will provide a continued payback to the homeowner, not

only in dollars and cents, but also by providing a more en-

joyable and comfortable living environment for many years,

and by reducing greenhouse gases and air pollution.

The purpose of this paper is to discuss the effective-

ness of installing insulation in buildings in China in

terms of saving energy and in terms of reducing carbon

emissions by reducing coal consumption. We compared

the energy required to maintain the same temperature

conditions for insulated and non-insulated buildings in

China, based on the research presented in the US De-

partment of Energy’s report “Insulation Comparison De-

monstration” [6], and we calculated the energy savings

and carbon emission reductions associated with imple-

menting the use of insulation .

2. Effectiveness of Insulation

Canada’s detailed building cod es require that the exterior

walls, attic roofs, and foundation walls of buildings in all

regions be insulated to a certain standard. Fiberglass is

the most common insulation material installed inside of

concrete walls in Canada. Most old residential and com-

mercial buildings in China, even in the severe weather

regions where the winter is cold and the summer is hot,

are not insulated. The newer buildings in China are insu-

lated using Styrofoam that is in stalled outside of the con -

crete walls. Styrofoam is difficult to install, and the ef-

fectiveness of Styrofoam insulation is low, especially

after a few of years of moisture building up between the

Styrofoam and the concrete wall. Most Styrofoam is not

fire resistant, and if a fire does start in a building it fa-

cilitates the spread.

Unlike Canada and the United States, China has no

clear standards for measuring insulation effectiveness.

Every city or region of Canada has a detailed building

code that includes clear insulation standards as measured

by R-value.1 The use of insulation material and tech-

nologies has to be standardized in China in order to avoid

the mistakes associated with the application of Styrofoam.

Much can be learned from countries that have established

standards for using insulation, especially fibreglass in

buildings.

According to a report by the US Department of Energy

[3], a building with fiberglass insulation in the mild re-

gion can reduce its energy use by 50% compared with an

uninsulated building. Accordingly, China could reduce

its annual coal consumption by abou t 200 million to ns by

introducing the u se of insulation to Can adian stand ards in

buildings. A calculation th at considers the population, the

average living space per person, and the space heating

energy required per square meter [2,6] reveals that coal

consumption would be reduced by 6 million tons per year

in Harbin city alone, by 7 million tons per year in Shen-

yang city alone, and by 15 million tons per year in Bei-

jing city alone, simply by insulating buildings to Cana-

dian standards. According to the basic combustion reac-

tion, C + O2 to CO2 + H2O, an incomplete combustion

will yield CO instead of CO2. But, assuming the coal is

between 46% and 98% carbon , burning 1 ton of co al will

1R-value is a measure of thermal resistance used in the building and

construction industry. Under uniform conditions it is the ratio of the

temperature difference across an insulator and the heat flow per unit

area. The typical per-inch R-values for building insulation materials are

R40 for vacuum-insulated panels, R3.7 for fiberglass, R2.5 for wood

anels, and R0.08 for poured concrete. i.e., 1 inch of fiberglass insula-

tion is as effective as 46 inches (3.7/0.08 = 46) of poured concrete [6].

Using Insulation in China’s Buildings: Potential for Significant Energy Savings and Carbon Emission Reductions

222

generate 1543 to 3560 k g of CO 2. On average, a 200 mil-

lion ton reductio n in coal for the purposes of heating and

air conditioning for the whole of China will mean an

overall reduction of 510 million tons of CO2 emissions

each year.

Implementing the use of insulation to Canadian stan-

dards in China’s buildings would reduce annual CO2

emissions by 15 million tons in Harbin alone, by 18 mil-

lion tons in Shenyang alone, and by 38 million tons in

Beijing alone. China’s population in 2009 was 1300 mil-

lion [7], and its per-capita carbon dioxide emissions were

4.65 tons [1], for a total of 6045 million tons of CO2 emi-

ssions per year. Therefore, a 510 million ton reduction

per year in CO2 emissions as a result of reducing the

need for heating and cooling would be equal to about

8.5% of China’s 2006 total CO2 emissions (510/6045 =

8.5%).

As per the results of the US Department of Energy’s

study (Table 1) [6], and based on China’s housing de-

velopment from 2008 to 2010 [7], theoretically China

could reduce its annual coal consumption for the pur-

poses of heating and cooling from the current 400 million

tons per year to 200 million tons per year by introducing

the use of insulation in bu ildings.

The installation of insu lation in b uild ings req uires only

a one-time invest ment on the part of the builder or own er,

yet the positive effects on the environment are long term.

A one-time insulation investment will provide a 50-year

payback. China would save a total of 10,000 million tons

of coal during the next 50 years if Canadian standard

insulation was introduced to China’s buildings today (50

years  200 million tons per year). At the same time, 25

500 million tons of reduced CO2 emissions would be

achieved (50 years  510 millions tons of CO2 emissions

per year). These achievements would make significant

inroads in managing China’s energy supply and air pol-

lution problems, and in providing comfortable living

space to the people in China. Also, because of the effec-

tiveness of insulation, the use of other heating options,

such as electricity or solar energy, become possible.

Table 1. Energy consumed to heat or cool a fiberglass-in-

sulated building and an uninsulated building, for one week

of each season.

Season

Building type Autumn

(kW) Winter

(kW) Spring

(kW) Summer

(kW)

Fiberglass-insulated 90 350 48 100

Uninsulated 159 685 100 210

From “Insulation Comparison Demonstration” report by B. Justice, Louisi-

ana Department of Natural Res ou r ces [6].

3. Conclusions

Fiberglass is a common insulation material in Canada

and the United States because of its effectiveness, low

cost, and user friendliness. A 1-inch thickness of fiber-

glass (R-value 3.7) is as effective an insulator as a 46-

inch-thick concrete wall. Good insulation not only helps

create comfortable living spaces but it also reduces the

need to use air conditioning and heating, which in turn

significantly reduces greenhouse gas emissions and air

pollution because there is less need to burn coal.

It is important for China to spend more effort on re-

searching and promoting the use of energy-efficient

technology and equ ipment, but it is also important to pay

more attention to the benefits of insulating buildings.

Insulating existing buildings to the proper standard is a

very cost-effective method of saving energy. China can

reduce its coal consumption by about 200 million tons

each year by introducing the use of fibreglass insulation

to urban residential and commercial buildings in regions

with severe climates. The CO2 emissions can be reduced

by 510 million tons each year, which is about 8.5% of

China’s 2006 total carbon emissions.

Although the installation of insulation in buildings re-

quires only a one-time investment on the part of the

builder or owner, the positive effects on the env ironment

and the payback are long term. If the broad use of insula-

tion in buildings was introduced today, over the next 50

years China would save a total of 10,000 million tons of

coal and reduce CO2 emissions by 25,500 million tons.

Our conclusion is conservative comparing with Dena’s

report “by applying new standards, the country could cut

energy consumption for new buildings by up to 80 per-

cent” [8] because we did not include other factors. Our

analysis result is similar to Lei’s research “Comparison

of Building Codes and Insulation in China and Iceland”

[9].

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Using Insulation in China’s Buildings: Potential for Significant Energy Savings and Carbon Emission Reductions

223

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