Climate Control: Move Towards Sustainability and HVAC system

Climate Control

Climate is the average range of weather experienced at a place or in a region over a long period of time, for example, rainfall averaged over 30 years in Reading or in the UK. Commonly used climate measurements include temperature, rainfall, snow and wind averaged over seasons, years, decades, centuries or more.

Our climate is powered by the Sun and modified by our atmosphere, which is made up of various gases. Some of the gases in the atmosphere allow sunlight to pass through, and prevent the heat from escaping back out into space, similar to glass in a greenhouse. This is called the natural greenhouse effect (Figure 1). The gases such as water vapour, carbon dioxide and methane are responsible for this effect and are called greenhouse gases. The Earth’s climate is a result of complex processes and interactions between the atmosphere (including the greenhouse effect), oceans, land, ice, plants and animals (including humans).

The change

Climate change is an identifiable change in the climate that persists for an extended period, typically decades or longer.

Climate can vary naturally in response to natural processes such as variations in the Sun’s radiation, the Earth’s orbit around the Sun, or the composition of the atmosphere due to volcanic eruptions.

Climate can also vary naturally because of interactions between the atmosphere and ocean. The El Nino/La Nina warming and cooling cycles in the tropical Pacific ocean are one of the best known examples of natural climate variability.

However, we know that human activities are also affecting global climate.

In the early 1900s, our climate started changing due to a persistent increase in the amount of greenhouse gases in the atmosphere. This change has been particularly rapid in the last few decades. For example, the amount of carbon dioxide in the atmosphere has increased by about 35% in the industrial era, and this increase is known to be due to human activities, primarily the combustion of fossil fuels and changes in land use by removal of forests and agriculture.

Humans have altered the chemical composition of the global atmosphere with substantial implications for climate, which is known as man-made climate change. The warming of the planet due to the increased greenhouse effect is known as global warming.

Climate change affects the environment, natural resources, economy and other aspects of life in all nations of the world. In 1988, an international body of climate scientists, the Intergovernmental Panel on Climate Change (IPCC), was established by the United Nations Environment Programme (UNEP) and World Meteorological Organisation (WMO).

The IPCC produces regular reports on the state of climate change research. Members of the panel study all the published research on climate change, and based on all the available evidence, make assessments of how the climate is changing and will change in the future. In their sixth assessment report, the IPCC stated that human activities are estimated to have caused 1°C of global warming above pre-industrial levels.

The devastation

Thousands of studies conducted by researchers around the world have documented increases in temperature at Earth’s surface, as well as in the atmosphere and oceans. Many other aspects of global climate are changing as well. High temperature extremes and heavy precipitation events are increasing, glaciers and snow cover are shrinking, and sea ice is retreating. Seas are warming, rising, and becoming more acidic, and flooding is become more frequent along the U.S. coastline. Growing seasons are longer, and large wildfires occur more frequently. Many species are moving to new locations, and changes in the seasonal timing of important biological events are occurring in response to climate change.

These trends are all consistent with a warming world and are expected to continue.

Many lines of evidence demonstrate that human activities, especially emissions of heat-trapping greenhouse gases from fossil fuel combustion, deforestation, and land-use change, are primarily responsible for the climate changes observed in the industrial era, especially over the last six decades. The atmospheric concentration of carbon dioxide, the largest contributor to human-caused warming, has increased by about 40% over the industrial era. This change has intensified the natural greenhouse effect, driving an increase in global surface temperatures and other widespread changes in Earth’s climate that are unprecedented in the history of modern civilization.

Greenhouse gas emissions from human activities will continue to affect Earth’s climate for decades and even centuries. Humans are adding carbon dioxide to the atmosphere at a rate far greater than it is removed by natural processes, creating a long-lived reservoir of the gas in the atmosphere and oceans that is driving the climate to a warmer and warmer state.

Beyond the next few decades, how much the climate changes will depend primarily on the amount of greenhouse gases emitted into the atmosphere; how much of those greenhouse gases are absorbed by the ocean, the biosphere, and other sinks; and how sensitive Earth’s climate is to those emissions.


Impacts on Society

Climate change is affecting the American people in far-reaching ways. Impacts related to climate change are evident across regions and in many sectors important to society-such as human health, agriculture and food security, water supply, transportation, energy, ecosystems, and others-and are expected to become increasingly disruptive throughout this century and beyond.

Climate change affects human health and wellbeing through more extreme weather events and wildfires, decreased air quality, and diseases transmitted by insects, food, and water. Climate disruptions to agriculture have been increasing and are projected to become more severe over this century, a trend that would diminish the security of America’s food supply. Surface and groundwater supplies in some regions are already stressed, and water quality is diminishing in many areas, in part due to increasing sediment and contaminant concentrations after heavy downpours.

In some regions, prolonged periods of high temperatures associated with droughts contribute to conditions that lead to larger wildfires and longer fire seasons. For coastal communities, sea level rise, combined with coastal storms, has increased the risk of erosion, storm surge damage, and flooding. Extreme heat, sea level rise, and heavy downpours are affecting infrastructure like roads, rail lines, airports, port facilities, energy infrastructure, and military bases.

The capacity of ecosystems like forests, barrier beaches, and wetlands to buffer the impacts of extreme events like fires, floods, and severe storms is being overwhelmed. The rising temperature and changing chemistry of ocean water is combining with other stresses, such as overfishing and pollution, to alter marine-based food production and harm fishing communities.

Some climate changes currently have beneficial effects for specific sectors or regions. For example, current benefits of warming include longer growing seasons for agriculture and longer ice-free seasons for shipping on the Great Lakes. At the same time, however, longer growing seasons, along with higher temperatures and carbon dioxide levels, can increase pollen production, intensifying and lengthening the allergy season. Longer ice-free periods on the Great Lakes can result in more lake-effect snowfalls.

Today, these and other aspects of climate change are having increasingly complex and important impacts on the American economy and quality of life.

Climate models

Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface and ice. They are used for a variety of purposes; from the study of the dynamics of the weather and climate system, to projections of future climate. All climate models balance, or very nearly balance, incoming energy as short wave (including visible) electromagnetic radiation to the earth with outgoing energy as long wave (infrared) electromagnetic radiation from the earth. Any imbalance results in a change in the average temperature of the earth.

The most talked-about applications of these models in recent years have been their use to infer the consequences of increasing greenhouse gases in the atmosphere, primarily carbon dioxide (see greenhouse gas). These models predict an upward trend in the global mean surface temperature, with the most rapid increase in temperature being projected for the higher latitudes of the Northern Hemisphere.

Models can range from relatively simple to quite complex:

  • Simple radiant heat transfer model that treats the earth as a single point and averages outgoing energy
  • this can be expanded vertically (radiative-convective models), or horizontally
  • finally, (coupled) atmosphere–ocean–sea ice global climate models discretise and solve the full equations for mass and energy transfer and radiant exchange.

Climate forecasting is used by some scientists to predict climate change. In 1997 the prediction division of the International Research Institute for Climate and Society at Columbia University began generating seasonal climate forecasts on a real-time basis. To produce these forecasts an extensive suite of forecasting tools was developed, including a multimodel ensemble approach that required thorough validation of each model’s accuracy level in simulating interannual climate variability.

Climate control for in construction of buildings

Today’s professional construction contractor is becoming more proactive in dealing with moisture issues during the construction process. A new level of knowledge is needed by the rental professionals to provide the right equipment and information to the contractor. The rental companies who embrace the new technologies and provide the equipment and information will develop a profitable new revenue source to help grow their business. A contractor can improve the reputation of their company, reduce chargebacks, and add a new source of revenue by utilizing climate control. When a contractor defines true climate control and all of its benefits, it is very easy to validate the importance.

If you are a Contractor, moisture can your worst enemy, especially when you are up against a tight deadline. By implementing tailored temporary climate control solutions and construction drying services, construction sites can mitigate problems caused by high moisture levels and experience greater flexibility with a better quality of workmanship.

Buildings can be vulnerable to climate change. In the future there may be an increase in the risk of collapse, declining health and significant loss of value as a result of more storms, snow or subsidence damage, water encroachment, deteriorating indoor climate and reduced building lifetime. In the short term stronger storms are the greatest challenge. Storms will constitute a safety risk in those parts of existing buildings that do not meet the building code’s safety requirements. In the longer term, more and longer-lasting heat waves could have health-related consequences. Powerful cyclonic storm named Fani is one such recent example.

Move towards sustainability

The definition of “Sustainable Construction” is a living concept and varies in different scenarios based on peoples’ needs. Taken as the starting point, the definition above has been reinterpreted and expanded based on different approaches and priorities from country to country. In a study led by the International Council for Research and Innovation in Building and Construction (CIB) and carried out with the collaboration of experts from countries around the world, different definitions were given.

According to United Nations Environment Programme (UNEP), “the increased construction activities and urbanization will increase waste which will eventually destroy natural resources and wild life habitats over 70% of land surface from now up to 2032. ” Moreover, construction uses around half of natural resources that humans consume. Production and transport of building materials consumes 25 – 50 percent of all energy used (depending on the country considered).By implementing sustainable construction, benefits such as lower cost, environmental protection, sustainability promotion, and expansion of the market may be achieved during the construction phase.

By adopting sustainable construction, contractors would make the construction plan or sustainable site plan to minimize the environmental impact of the project. According to a study took place in Sri Lanka, considerations of sustainability may influence the contractor to choose more sustainable, locally sourced products and materials, and to minimize the amount of waste and water pollution.  Another example is from a case study in Singapore,the construction team implemented rainwater recycling and wastewater treatment systems that help achieve a lower environmental impact.

According to SUSTAINABLE CONSTRUCTION: REDUCING THE IMPACT OF CREATING A BUILDING, the contractor in collaboration with the owner, would deliver the project in a sustainable way. More importantly, the contractor would have known this was a key performance indicator for the client from day one, allowing them the opportunity to not tender for the work, should this not appeal to them. Moreover, “It also sends a clear message to the industry, ‘sustainability is important to us’ and this, especially within the government and public sectors can significantly drive change in the way projects are undertaken, as well as up-skilling the industry to meet this growing demand.

By promoting sustainable methods and products in daily work, the good result directly shows the public the positive effect of sustainable construction. Consequently, there would be potential to expand the market of sustainable concepts or products. According to a report published by USGBC, “The global green building market grew in 2013 to $260 billion, including an estimated 20 percent of all new U.S. commercial real estate construction.”

Currently, sustainable construction has become mainstream in the construction industry. The increasing drive to adopt a better way of construction, the more strict the industrial standard and the improvement of technologies have driven the cost of applying the concept, according to Business Case For Green Building Report, the cost of sustainable construction nowadays might even be 0.4% lower than normal one.

The growth of HVAC system

Heating, ventilation, and air conditioning (HVAC) is the technology of indoor and vehicular environmental comfort. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics and heat transfer. “Refrigeration” is sometimes added to the field’s abbreviation, as HVAC&R or HVACR or “ventilation” is dropped, as in HACR (as in the designation of HACR-rated circuit breakers).

HVAC (Heating, Ventilation and Air Conditioning) equipment needs a control system to regulate the operation of a heating and/or air conditioning system. Usually a sensing device is used to compare the actual state (e.g. temperature) with a target state. Then the control system draws a conclusion what action has to be taken (e.g. start the blower).Short for heating, ventilation, and air conditioning. The system is used to provide heating and cooling services to buildings. HVAC systems have become the required industry standard for construction of new buildings. Before the creation of this system, the three elements were usually split between three or more devices.

Working module of HVAC system

The main parts of the HVAC system are a heating, a ventilation, and an air-conditioning unit. … Heating is most often done by a furnace or a boiler in residential buildings. It also includes a pipe system for the fluid delivering the heat, or a duct work for forced air systems.

HVAC is an important part of structures such as single family homes, apartment buildings, hotels and senior living facilities, medium to large industrial and office buildings such as skyscrapers and hospitals, vehicles such as cars, trains, airplanes, ships and submarines, and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fresh air from outdoors.

Ventilating or ventilation (the V in HVAC) is the process of exchanging or replacing air in any space to provide high indoor air quality which involves temperature control, oxygen replenishment, and removal of moisture, odors, smoke, heat, dust, airborne bacteria, carbon dioxide, and other gases. Ventilation removes unpleasant smells and excessive moisture, introduces outside air, keeps interior building air circulating, and prevents stagnation of the interior air.

Ventilation includes both the exchange of air to the outside as well as circulation of air within the building. It is one of the most important factors for maintaining acceptable indoor air quality in buildings. Methods for ventilating a building may be divided into mechanical/forced and natural types.

‘India Cooling Action Plan (ICAP)’ : Govt planning minimum indoor temperature settings for commercial buildings

India’s share in total room air conditioners being used worldwide may just be little over 2.2% at present, but it will rise to almost 25% of the global stock by 2050 posing a huge challenge in terms of finding adequate energy to feed cooling systems in future.

As one of the solutions, the government may look at making ‘minimum indoor temperature settings’ mandatory in commercial buildings.

Anticipating massive growth in future cooling demand, the government  released the ‘India Cooling Action Plan (ICAP)’ – the first such plan in the world – recommending ways and means to reduce cooling demand across sectors by 20-25% and cooling energy requirements by 25-40% in next 20 years from the 2017-18 level.

Its one of the key short-term (2019-24) recommendations is to make ‘minimum indoor temperature settings’ mandatory in commercial buildings across the country to reduce cooling requirement and energy consumption.

Analysis of the ICAP shows the country’s overall cooling requirement (building sector, transportation and refrigeration) will increase by eight times by 2037-38 with room air conditioners alone consuming more than half of the energy required for space (building sector) cooling in India by that time.

The ICAP flagged that the building sector cooling demand would show maximum growth at nearly 11 times in next 20 years as compared to 2017-18, followed by transport sector by five times and cold-chain and refrigeration sectors by four times.

According to International Energy Agency (IEA), refrigeration and air-conditioning currently cause 10% of the global carbon emissions.

The ICAP listed a number of recommendations in the form of short (2019-24), medium (2024-29) and long (2029-38) term strategies for all the sectors so that the cooling demand and energy requirement could be reduced.

Under the short-term recommendations, the plan also suggested “mandatory public procurement guidelines” where all public sector agencies will have to go for only highest star-rated energy efficient ACs, fans or chillers.

An earlier report, Solving the Global Cooling Challenge, released in November last year also pitched for concerted efforts to reduce energy requirement for cooling demand flagging the increase in room air conditioning units from 1.2 billion in 2016 to 4.5 billion in the world by 2050

Let’s hope we catch up with the damage already done the environment!

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