HVAC Design for Humid Climates

Blog for HVAC system Humid climates commonly come with the challenge of moisture standards. When HVAC (heating, ventilations, and air-conditioning) systems do not maintain proper moisture conditions/humidity control, it causes damages and defects to the building.

A humid climate is defined as a condition where the average monthly latent load (energy required to remove moisture from the air) of environment’s air is the same or higher than the average monthly energy needed to cool the air during the cooling season. Using air with high latent load easily brings moisture in and accumulates it in building materials.

Maintaining humidity control isn’t an easy task. The HVAC unit has to be able to support a proper pressurization system using dehumidified air to entire the building. In order to provide the right dehumidification, a HVAC system must be able to dehumidify the air that flows across the cooling oil (which means the precise sizing of cooling coil must be selected to meet the load of both outside and return air). That is not the only criteria that an HVAC system needs to fulfill though. The system must also meet the sufficient run time to remove moisture from the interior air. In a humid condition, temperature control is not enough. Moisture control comes second on the priority list ( though this has to be fulfilled without scarifying the main goal of giving comfortable temperature to users).

In geographical areas with humid weather, such as in the southeast, public housing generally uses chilled water and direct expansion for the cooling system. This requires an outdoor condenser unit to exchange heat to the outdoor air.



What’s the Biggest Problem in the HVAC Industry?

HVAC in the Sky with DiamondsWhen asked about problems rising in the HVAC industry, people typically point to the availability of trained workers or labor force. The growth of the HVAC industry brings more open jobs into the market. According to a report by U.S Department of Labor, by 2020, this particular market should bring about 90,000 new jobs in the industry. With that being said, the spike in work doesn’t necessarily align with quantities of qualified workers. Even with strong job security and above average pay, HVAC doesn’t seem to attract too much young potential. In the past year, the HVAC industry has lost thousands of workers, not only from the lagging economy, but also due to the work force available. Currently, the average age of the entire 7.5 million HVAC workforce is around 55 years old, which is much older than the normal workforce.

With the rate of how quickly technology in the HVAC industry is currently growing, the pool of talent in the market can’t quite seem to catch up. Day by day due to increasing demand and competition, leading companies in this industry is required to come up with new design and new technology with better efficiency, easier operation, and better control is needed. Demanding increase in technology does not meet with the current available skill pool. As a result, the hiring process for skilled labor takes considerably longer. Finally, once you take into account calculation of training and orientation, the entire hiring process requires a lot of investment both in time and money.

Technology companies seems to spend most of their available budget on research and development activities. It’s important to pay attention into this particular trend since a high bleed could really impact on the cost of production. During this difficult time of short talents, it makes sense for companies to source out their research and development activities. Our R&D engineering team consists of consulting experts who have completed extensive projects on the subject. We’d be more than happy to assist you with any project needs.



Outlook for the Future HVAC Market

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According to the new market research report, the industry of heating, ventilation and air conditioning (HVAC) is predicted to rise at a solid, stable compounding annual growth rate of 5.9% up to the year 2022. With the growing trend of smart homes and changing weather conditions, cooling equipment is expected to remain the largest major share of the entire HVAC market taking around 70% of the entire market totaling to a prediction of 24.28 Billion USD  – including coolers and room air conditioners.

With global warming and increased temperatures taking effect, demand for cooling systems continues to rise in geographical areas where weather is a significant factor, such as Asia Pacific. Countries such as China, Japan and India are significantly driving the growth of this market, as the automotive air conditioning sector plays an important role in these geographical areas as they are still the leaders of the automotive manufacturers by volume.  Rise in middle income (and improvement of environmental standard) in developing countries also push the construction boom and replacement of older technology in air conditioning.

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Though it’s a positive outlook on the market, increasing demand also leads to tougher competitions. Many new technologies have been introduced in the market, from thermally-driven chiller that provides lower cost alternative to electrical air conditioning units, better sensor control, new software for energy monitoring and improved insulation technologies.  The main factors which influence air conditioning efficiency and economic feasibility are still the refrigeration cycle and compressor component itself. With improvements of compressor mechanisms for less noise and less energy consumption, a slight improvement on blade design or incorporation of more compressor stages to save energy could go along the way.


  1. http://www.grandviewresearch.com/industry-analysis/hvac-equipment-industry 
  2. https://www.thisoldhouse.com/ideas/air-conditioners-really-are-getting-better

The Future of Nuclear Power Plants

With the blast of the French nuclear power plant a few weeks ago, safety of nuclear power plant designs has fallen under more scrutiny. Although according to sources the blast took place in the turbine hall and no nuclear leak was found, this event has brought more attention to improved design and operation standards.

Following the incident earlier this month Toshiba, a Japanese multinational company, announced the resignation of its chairman following a $6.3 billion loss in their nuclear sector –also withdrawing from the nuclear business. The two back to back events have highlighted the main two problems of nuclear power: high cost and environmental/safety concerns. Said to be a green technology, nuclear power raises concerns with potential nuclear meltdown and risk of safety from toxic waste, accompanying the fact that building a new plant cost around $5,000.00 per kilowatt of capacity with around 6 years of lead time. Each dollar invested on a nuclear power plant has about 2-10 less carbon savings and is 20-40 times slower compared to other alternatives. Yes, evidently nuclear power is found to be very reliable, enabling consistent baseload energy production at any time of day and night. Though, it has been questioned whether this reliability is worth the high cost of nuclear production, in fact all nuclear plants are still operating with 100% subsidized.

Transatomic power, a company started by two MIT PhD candidates, came up with a new approach to safer and cheaper nuclear reactors. Utilizing molten salt reactors, which has not really been used commercially and so far is only existed in paper, the technology is promised to cut initial cost and increase safety. Today’s conventional nuclear reactor is cooled by water, due to the high operating temperature, failure to do so will open the risk of radiation leak as well as hydrogen explosion. The high boiling point of salt helps solve some of the problems associated with the technology. The new design also incorporates ways of producing faster neutrons, enabling the reactor to burn most waste materials, thus keep waste to minimum. The ability of this smaller unit to be made in a factory (and not onsite) as well as cost reduction on the safety side makes this attractive economically as well. That being said, this generation 4 nuclear reactor is still in design and development will take years and high capital cost.




Double Flash System Application in Geothermal Power

Geothermal power market has been showing sustainable growth globally, with many installations in developing countries. As people turn to renewable sources while demand for energy is experiencing rapid growth, geothermal is found to be a reliable energy source and current development is calculated to increase global capacity by over 25%. Geothermal power plants can usually be divided into several types of cycles, including binary, flash, double flash and more. Flash power plants are found to be the most common forms of geothermal power plant and specifically, we are going to talk about the double flash cycle.

A flash system produces high pressure dry steam to move the turbine, generating electricity after going through a flash separator. A double flash system uses two flashes separating systems in order to generate more steam from the geothermal liquid and increase cycle output. The cycle starts with high temperature fluid extracted from a geothermal source to a high pressure separator (HPS) for flashing. The HPS produces a saturated steam that enters the high pressure turbine and the remaining brine is directed into a secondary low pressure separator (LPS). Reducing the flashing pressure increases the mixture quality in the LPS, which results in higher steam production. Low pressure saturated steam is mixed with the steam flow exhausted from the high pressure turbine and the resulting steam flow is directed to the low pressure turbine and produces more electricity. Steam that is exhausted from the low pressure turbine will then be compressed and injected back to the ground. In a flash system, separator pressure has a significant effect on the amount of power generated from the system – and the flashing pressures also influence double flash cycle significantly. In order to optimize one design, the value of parameters versus cost of operations should be taken into account.

A double flash system is able to achieve better energy utilization than a single flash cycle, which means that the application has a higher efficiency. At the same geofluid conditions, double flash systems are able to give you a higher capacity. That being said, since this is a more complex system the application of such technology would not be economically feasible for some applications.





The Feasibility of Bringing Back Coal

Power generation and energy sectors happen to be very politically volatile. With our new leader in the USA taking control, we are expecting a shift in technology trends. The topic of bringing more coal fired power plants back to the equation has been brought up quite often, coming after Trump’s skeptical statement regarding global warming and climate-change. To follow that statement, Donald Trump pledged to lift restriction on US agencies funding new coal plants in other parts of the world. In addition, Australia’s minister also has been arguing regarding adding new coal power plants into the mix. As world’s largest coal exporter, it should economically make sense for Australia to forego with the plan.

There are three major categories that typically determine whether a technology would be suitable to be implemented: cost to public, reliability of supply and environmental impact. The old coal power generator is found to be less reliable as well as less environmentally friendly. Consequently, a new technology must be used to provide “cleaner” energy from coal. Southern Company has become one of the first private sectors using new technology to produce energy from coal.  The technology is said to be generating electricity while at the same time capturing carbon dioxide from coal. Maybe if this technology is implemented, we will come back to coal.Power Plant

That being said, what is clean coal technology? Coal is currently known to be the biggest enemy to environment, however clean coal seeks to reduce emission. Before burning the coal, some technology purifies the coal to remove unwanted minerals. Then control the burning to minimize the harsh emission, installing wet scrubbers or desulfurization systems, electrostatic precipitators and Low NOx burners among many other processes.

There are two main problems with clean coal: unproven and expensive. Operating cost for Southern company quadrupled to about $1 billion from the original estimate according to a report. Not only that, the initial cost of investment of this power plant is also two times over budget. Not to say that the same case would be applied to other clean coal power plant, but at the time being, installation of this technology is expensive. Until this could be studied further, seems like cost would be hovering well above standard normal. Another downside is that coal plants are inflexible. While they do give a very constant supply of power, they can’t easily increase or decrease supply –and when they do, it’s economically unreliable. This doesn’t eliminate the chances of coal making a comeback in the future, however, for the time being coming back to coal seems unreasonable since the renewables seems to be making a very positive growth towards the future.




The Future of Combined Cycle

In modern days, power generation planners are faced with the challenge of pushing out the most energy from fuel while at the same time minimizing cost and emission.However, finite fuel also generates mass concerns regarding the reserve left to be used in nature. Consequently, people are continuously looking for an economical and highly efficient solution.

To this date, combined cycle gas turbine applications are found to be the best solution to the problem. The application is known to be highly efficient, have favorable energy conversion rates, comparatively lower start up time compared to conventional steam cycles and able to squeeze more power from the same amount of fuel.

countriesOver the past decade, the use of combined cycles has taken over most of the power generation industry. Triggered in the 1990s by the higher costs and environmental concerns of coal power plants, people starting to look for an alternative to cover demands in energy. At the time natural gas seems to be the most logical substitute.

With the increase of renewable energy application, the demand for combined cycles also increases and helps offset the fluctuations of renewable technology. Combined cycle power plants are also found to emit significantly fewer greenhouse gasses compared to most traditional power plants. With this in mind, the use of combined cycle power plants has substantially reduced the amount of emission.

Due to all of the advantages of CCGT mentioned above and more–not to mention the low installed cost, fuel flexibility, flexible duty cycle, and short installation cycle,  investors find combined cycle implementation to be attractive. According to Black & Veatch, natural gas-fired generation is projected to add 348,000MW to U.S grid, where most (if not all) of it will be supplied by a combined cycle generation.

Interested in optimizing your combined cycle plant? AxCYCLE  should do the trick!






Concentrated Solar Power

As time goes by, the demand for energy rises while finite resources gradually diminish. The concept of going ‘green’ or using infinite resources has become more and more common in the marketplace. With this in mind, the abundance and reliability of solar energy makes for an attractive alternative. This is because solar power is different. This statement, of course, begs the question of HOW solar power differs.

Common traditional power plants still utilizes finite fuel. Steam power plants, for example, use the fuel as an energy source to boil water which, in turn, allows the the steam to turn the turbine and drive the generator to produce electricity. Concentrated solar power systems, however, use heat energy from the sun as a heat source – which is renewable. This system works by using utilizing mirrors or mirror-like materials to concentrate energy from the sun and then takes that energy to produce steam. The system can also store the energy that is absorbed during the day, to be used at night when the sun is not present. There are a few different types of concentrated solar power systems which one can choose from.

  1. Parabolic Trough: This type of solar power uses a curved mirror to focus the sun’s energy to a receiver tube with high temperature heat transfer fluid which absorbs the sun’s energy and passes it through  a heat exchanger to heat water which produces steam.
  2. Compact Linear Fresnel Reflector: The working principle of this solar power type is rather similar to parabolic trough, though instead of using a curved mirror, this application utilizes flat mirrors which are more economical. These mirrors act as reflectors to focus the solar energy into the tubes to generate high-pressure steam.
  3. Power Tower: The power tower uses heliostats to track the sun movement and focus the solar energy to a receiver in the middle which is installed into an elevated tower. This application has been found to have better efficiencies compared to other types of solar power and can run on a higher temperature. The use of molten salt as a transfer fluid for the power tower applications is relatively common and helps improve efficiency.
  4. Dish-Engine: This type of solar power utilizes mirrors that are designed to be distributed over a dish surface to concentrate solar power to a receiver in the middle. The application runs on a very high temperature and uses transfer fluid with a very high boiling point to power a high requirement engine.


Newer applications tend to lead to the installation and use of power tower design, since this design allows technology storage implementation which can be seen as a reliable option for the future of concentrated solar power application, not to mention the economic benefit it has compared to other technology storage implementation.


The Economic Optimization of Renewable Energy

clean-blog-postGlobal warming is a very popular topic at the present time. With the upwards trend of clean technology and the realization that strict climate policy should be implemented, demand of renewable energy has sky-rocketed while conservative plant popularity continues to fall. Additionally, the number of coal power plants have significantly dropped since its peak era, as they are now known as the largest pollutant contribution, producing nitrogen, sulfur oxide and carbon dioxides.

Renewable energy comes from many sources: hydropower, wind power, geothermal energy, bioenergy and many more. The ability to replenish and have no limit on usage and application makes renewable energy implementation attractive. To make this even better, it also produces low emission. Theoretically, with the usage of renewable energy, human-kind should be able to meet their energy needs with minimal environmental damage. With growth rates ranging from 10% to 60% annually, renewable energy is getting cheaper through the technological improvements as well as market competition. In the end, the main goal is to maximize profit while minimizing our carbon footprint.  Since the technology is relatively new, capital costs are still considerably higher compared to more traditional (–and naturally harmful) implementations. This begs the question of exactly how we maximize the economic potential of a renewable energy power generation plant.

Living up to the full potential of any power generation plant starts with the design process. Solar power plants are one environmentally friendly option.  During the design process, designers should take into consideration the type and quality of the solar panels as it is important to see the economic-efficiency tradeoff before jumping into an investment. Looking into the power conversion is also one of the most important steps one should take into consideration since it would be worthless to produce more energy than what is able to be transferred and put to use and low energy generation would mean less gross income.

Geothermal power plants are another option. Many studies have shown that boundary conditions on each component play a big role in determining the plant’s capacity and efficiency. High efficiency is definitely desired to optimize the potential of a power plant and minimized the energy loss. That being said, it is important to take into account the economic sacrifice. Regardless of how good the technology is, if it doesn’t make any profit, it would not make sense for one to invest in such technology. Low capital cost but high operating expenses would hurt the economic feasibility in the long run, whereas high capital cost and low operating expense could still be risky since that would mean a higher lump sum of investment upfront which may or may not breakeven or be profitable depending on the fluctuation of energy market.

Modern technology allows investors and the engineering team to make this prediction based on models developed by the experts. SoftInWay just recently launched our economic module, so check out AxCYCLE to optimize your power plant!

[1] http://scholarscompass.vcu.edu/cgi/viewcontent.cgi?article=4483&context=etd
[2] http://www.sciencedirect.com/science/article/pii/S0038092X12002022

What is an Integrated Coal Gasification Combined Cycle (IGCC) and What are the Advantages?

Source: http://www.slideshare.net/AbhijitPrasad4/integrated-gasification-combined-cycle-plant

Though fossil fueled power plants aren’t as commonly used anymore, coal fired power generation is still a major source of global electricity, making up about 25% of the market in total. Compared to other options in fossil fuel power generation, coal is found to be the most economical choice as well as a reliable option. Making demands that are heavily reliant on other fuels, such as oil-fired for example, slowly levers to coal power generation. The global reserve of coal can be found in abundance when compared to other energy sources (such as oil for example) as there is about 3 times more of it. Also, IGCC comes with an economic benefit as the price of coal has remained relatively constant, which results in a higher degree of confidence when relying on coal as an energy source in the future.

How Does an IGCC Work?

The system uses a high pressure gasifier to turn coal and other carbon based fuels such as high-sulfur coal, heavy petroleum residues and biomass into pressurized clean coal synthesis gas (also known as syngas). The solid coal is gas-fired to produce syngas by gasifying coal in a closed pressurized reactor with a shortage of oxygen to ensure that coal is broken down by the heat and pressure. Before going out of the system, the syngas runs through a pre-combustion separation process to remove impurities,  starting with water-gas-shift reaction to increase concentration of hydrogen and efficiency during combustion process, to a physical separation process (through variable methods). After that, a fairly pure syngas is used as a fuel in a combustion turbine that produces electricity. Waste heat contained in a gas turbine’s exhaust is used to produce steam from feed water that further turns a steam turbine to generate additional electricity.

What are the Advantages of IGCC?

IGCC is currently found to be the cleanest of coal technology with lower emission (especially for carbon dioxide by 10%) and is about 30-40 percent more efficient. Using syngas in gas turbines results in a higher output that is less dependent on temperature when compared with natural gas. Additionally, looking into the economic benefit of this technology, IGCC produces couple by-products, from chemicals to materials for industrial use that could be sold for side economic benefits.