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The Energy Hog
Amount of Wasted Energy
The nation’s 113.4-million homes, having nearly 89-million heating-A/C (HVAC) systems, consumed close to 624-billion kWh, or about 44.5 percent of all electricity used in homes as of the end of 2007. That number comes from operating the air conditioner, electric fan and/or heat pump or electric furnace. But considering all types of energy sources, the 89-million units with oil/gas furnaces use 56 percent of all household energy.
Although the HVAC usage is high as a percentage, the amount of energy consumed is not the biggest issue, but rather the quantity of wasted energy represented in that figure. The fact is these millions of units operate at approximately 34 percent below their efficiency standards, wasting some 212-billion kWh of electrical energy - enough waste to power 17.2-million homes for one year. If we eliminated this waste, these millions of systems would operate at 412-billion kWh rather than 624.
On a per home basis, the wasted energy is at least five-times, and in some cases, up to twenty-times more than the combined use of all other home devices. In addition, the HVAC systems is responsible for generating up to six-times more indoor pollution (toxins, germs, molds, allergens, house dust) than any other source.
The underlying reason for such waste by HVAC systems is very simple. It has to do with something called “starved airflow.” To operate effectively, HVAC units need 400 cubic feet of air per minute (CFM) per ton. Yet, the nation’s 89-million systems function with an average of 265-270 CFM/ton - a scarcity that accounts for most of the lost billions of kWh.
The mechanical causes for such shortages are multiple but primarily associated with three system chokepoints. They are:
(a) Airflow filter,
(b) Uncared for evaporative coil
(c) Undersized return air ducts.
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| Typical HVAC System |
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The inclusion of these, and other, chokepoints by the HVAC industry represent a misunderstanding of real-world ergonomics, dynamic air movement, and the methods microorganisms grow and spread debris.
There are other problems, chokepoints, that could affect system efficiency, but they tend to be the minor reasons (in some cases, they can become major):
1. Restrictive air grills and registers.
2. Excessively long ducts, “L” bends and severe pinching of ducts.
3. Ribbed flex-duct.
4. Gas/oil furnaces choking airflow to A/C e-coils.
Fundamental Reasons for HVAC Energy Waste
Over all, the airflow, energy and pollution problems are a consequence of serious issues that can be boiled down to five main factors: (1) old-line, unbending mindset and philosophy by HVAC’s institutions not adapting to new conditions; (2) misdirected approach to HVAC by government regulations; (3) lack of skills, knowledge and standards of on-site assemblers; (4) traditional, commonly accepted built-in parts that starve and pollute airflow, and (5) lack of simple owner maintenance of dirty filters and A/C coils.
And then there is a direct connection between energy consumption and indoor debris and pollution
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An operating HVAC system is not a self-contained appliance, but, rather a system made up of different components – filters, grills, ducts, registers, and the like. A HVAC system is much greater than a single furnace or air conditioner. It’s an integrated part of a larger system – a building or a home. The HVAC system is the environmental equivalent of a heartbeat -- forcing air through arteries of ducts into the larger body. However, being part of a larger complex means that the system will inevitably meet counter forces that make the HVAC unit susceptible to the dynamic influences of the building itself.
House Produces Contamination
The indoor environment of America’s homes is more polluted than ever. The indoor air contains some 6-7 times more toxins, germs and house dust than even fifty years ago.
The EPA now lists indoor pollution in the top four pollution problems in the nation. Risk studies by the Science Advisory Board consistently rank indoor air pollution among the top four environmental risks to public health – ranked in order of environmental risks:
1. Nuclear Waste
2. Outdoor Pollutants and Green House Gases
3. Super Toxic Dump Sites
4. Indoor Air Quality (IAQ)
The hazard of indoor pollution has increased over the decades to be ranked with the notorious, top tier of environmental risks. There are many causes for the increased levels of indoor pollution. These are:
1. Modern building by-products
2. Higher indoor moisture content
3. Higher use of cleaning and other chemical products for personal and household use
4. Higher indoor microbial growth and debris
5. More concentrated human by-products (such as hair, dander, dead skin, etc) caused by people living/working indoors at a much higher percentage than in former years
6. Higher presence of insect, cockroach and dust mite feces and debris
7. Bio-nesting growth within the HVAC unit (possibly the largest source of indoor pollutants)
The outer walls of the home and the HVAC system are irrevocably tied together with a common element -- indoor air. What affects one area will affect the other. It is due to this common connection, that airborne pollution and higher particle counts are finding their way into our modern homes and the HVAC system. This indoor pollution, in turn, blocks airflow, causing a drop in operating efficiency – raising energy costs and waste. But this is only part of the story…
HVAC Produces Heavy Contaminates
The HVAC system produces much of its own pollution and debris that affects operations. And the contamination generated by the HVAC system is then distributed back to the home, where people live. It seems that the HVAC system is the biggest culprit of indoor pollution. This generally occurs in two ways:
1. When the HVAC system operates, it can pull through the system (from the building’s air space) a volume of air equal to 100-percent of the building’s air volume about every 8-12 minutes. Hence, pollution and debris generated within the home is dragged by the HVAC fan into the system and back out again, redistributed to every nook and cranny of the building - spaces not previously contaminated become such.
The “Venturi Effect”, a scenario where air velocity speeds up as it passes through progressively smaller holes, drag high volumes of debris with it. Debris that was stationary and affixed in home spaces becomes airborne as it is pulled into the small opening of the HVAC return air entry. Furthermore, a certain percentage of this circulating debris collects within the system filter and A/C e-coil, starving airflow and increasing energy consumption.
2. The HVAC is perhaps the largest single source of contamination in the home based upon the biological nesting that occurs within the system. Simply stated, the system filter and the e-coil are perhaps the largest growth source of bacteria and mold in a typical home. It is estimated that the HVAC system produces up to 6-times more indoor pollution (toxins, germs, molds, allergens, house dust) than any other source. The by-products of this growth are airborne versions of:
a) Pathogenic organisms
b) Toxic metabolic gases (formaldehyde and benzene) from the microbial growth
c) Aggressive allergens, such as mold spores and mycelium enzymes particles
d) Microbial debris, dust and body parts.
Extreme levels of pollutants and toxins come from this growth, circulated by the system fan into the breathable air space. Thus, the HVAC system not only grows the pollutants, but also becomes the mechanism by which they are propelled back into the space where people live. In addition, this HVAC growth also loads up the filter and e-coil, choking off airflow.
In conclusion, there is a direct relationship between system collection and growth of pollutants and debris and energy consumption. Furthermore, what is generated within the house as a whole has a direct bearing upon the efficiency of the system.
For in-depth discussion on HVAC energy waste and indoor pollution, go to “Reports & Information” section of website and pull-up the report: “Wasted Thinking, How Faulty Paradigms Waste Billions In Nation’s Heating-A/C”
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