Thursday, 24 July 2014

Renewable Energy Resources for HVAC

HVAC is an absolute necessity in almost every building in San Jose. Whether it is for heating, cooling, or ventilating, energy is required for the systems to do the job effectively, efficiently, and comfortably. But, there's not one system that will do the job for every facility.

Traditionally, electricity is generated from fossil fuels - coal, natural gas, and petroleum. As the demand for energy increases, the supply for it is decreasing and depleting rapidly all over the world. Plus, this energy is also responsible for the green house gases that have adverse effect on the environment and are the cause for the global warming that is melting glaciers and causing tsunamis.

All this has led to increased environmental awareness and the need to source energy for electricity from alternate sources and renewable sources such as wind, sun, biomass fossils. According to the reports, renewable energy is one of the most vital recently discovered resources. A report from the National Renewable Energy Laboratory (NREL), quotes, "Renewable energy resources—such as wind and solar energy are constantly replenished and will never run out."

Renewable Energy for HVAC

For HVAC/R (heating, ventilation, air conditioning and refrigeration), solar and geo-thermal energy is most suited for heating and cooling in the residential scenarios. While a majority of energy in the United States comes from fossil fuels, there is also tremendous growth in alternative and renewable energy technologies.

Solar Energy

A solar energy system produces electricity from the sun’s rays. This electricity is then used to power a building’s HVAC system. This system is made up of photovoltaic (PV) cells. The solar modules in the system harvest the energy from the sun and convert it into electricity. This is how you can use solar energy to run your HVAC units, lights, other electrical devices.

Basically, there are two types of solar power systems. These are stand-alone and grid-connected systems. The stand-alone systems are designed in such as way that they operate independently and do not need an electric utility grid and supply certain DC or AC loads. In many such solar power systems, energy storage needs to be done through batteries.

The other type, the grid-connected power systems need an electric utility grid. These systems are designed in such a way that they are interconnected with the grid and operate parallel to the grid. These systems also use photovoltaic cells to generate energy from the sun’s rays and this energy is stored in a grid as AC power. The electricity from this grid is supplied into the building or the household.

Geothermal HVAC

Geothermal HVAC is said to bring a household or building in harmony with the earth beneath. It takes advantage of subterranean temperatures to generate heat in winter and cool air in summer.

The temperature at the bottom of the earth's crust is constant, typically over 1000°F. In some locations, the temperatures are so high and so close to the earth’s surface that they result in hot springs, geysers, and volcanic activity. Such places have high potential opportunity for geothermal electricity generation. Through geothermal plants, the steam is tapped and used to operate turbines which generate electricity.

A geothermal system typically consists of an indoor handling unit and a system of pipes that is buried in the earth. These pipes are called an earth loop and connected to a pump to reinjection well from where the steam is tapped. The constant temperatures provide the “free” energy.

In winter, the fluid that circulates through the system’s earth loop or well absorbs the heat stored and carries it indoors. The indoor unit then compresses this heat to a higher temperature and t releases it into the building, working as a heater. In summer, the geothermal system pulls out the heat from the building and transports it through the earth loop/pump to reinjection well. Here it deposits this heat into the cooler earth/aquifer. Geothermal systems do not need periodic maintenance. Once installed properly, the buried loop lasts for generations. However, filter changes and annual coil cleaning are required.

The United States Environmental Protection Agency (EPA) is expecting that some states in the US will switch to natural gas for electricity generation, according to senior agency officials on a media briefing. There are attractive discounts also available for new constructions and upgradation projects.

Thursday, 17 July 2014

Save Energy - Go Green

It is a known fact that HVAC units are the biggest energy hogs. A report from the Rocky Mountain Institute quotes, “Air conditioning accounts for nearly 50% of the energy use in the United States during peak summer months, and air conditioning is responsible for nearly 100 million tons of carbon dioxide emissions every year.”

The rising cost of energy, the residential and corporate boom has increased the energy requirements; it has also led to an increased awareness towards energy consumption and environmental issues. The government and environmentalists are pushing towards “green HVAC” systems. Building owners and contractors are being offered attractive incentive programs to build and maintain the construction and eco-friendly measures and substances.

If you are an existing owner or a tenant with an already installed and working HVAC system, you too contribute towards the going green revolution. You can adopt simple ways to reduce your energy consumption and your share of the carbon footprint.

Here are some ways you could make your existing HVAC system eco-friendly or ‘green’
    1. Keep the air filters clean and replace them every three months.
    2. Check out the duct work. Poor ducting can cause around 20% loss in the system efficiency.
    3. Install a programmable thermostat. Pre-programmed temperature settings for different times of the day can ensure zero energy wastage as energy will not be spent on cooling or heating an empty building. Reports say that adding a programmable thermostat help you save $180 in annual energy savings.
    4. If you are going for a new air conditioner, select an ENERGY STAR-certified HVAC system. These are based on efficient technology in comparison with traditional systems. They can help you save as much as 50% of your energy costs and are environmentally friendly too. There are attractive tax credit offers also available for such type of upgrades.
    5. In summer, consider investing in insulated, thermal-backed drapes. Install these drapes on your windows. They will help in keeping the indoors cooler in summer and warmer in winter.
    6. Consider installing an attic ventilator. Such a ventilator draws cool air upwards throughout the house. This type of air distribution can provide the same level of comfort as an air conditioner. The energy consumed is much lower than an air conditioner. Attic ventilation can also help reduce your winter heating bills too.
    7. Set the temperature on your thermostat at 77 degrees Fahrenheit on your air conditioner. For each degree set below 75 degrees, you use three to five percent more energy. For most comfort, set your thermostat to 77 degrees.
    8. Ceiling fans consume lesser electricity than furnaces or air conditioners. You can keep the temperature settings at 77 degrees and use the ceiling fan for air circulation. This will result in at least 30% savings in energy costs.  
    9. Consider upgrading your roof to a reflective one. A reflective roof prevents the heat from the sun’s rays from transferring inside the home or building. It can reduce the roof surface temperature by up to 60 degrees Fahrenheit.
    10. Ensure that your heating vents are not blocked by the furniture or the drapes in the room. Make sure that the dampers are open. Make a habit of vacuuming out dust and pet hair from the warm air registers and cold air returns. This will make the HVAC systems run more efficiently.