Green, green home, green building, going green, sustainability and LEED are all catch phrases that seem to be catching steam and quickly building momentum these days. What does go green and green building specifically mean? Green building is the philosophy, design and implementation of the most efficient use of resources, that are both environmentally responsible and positively affect our health throughout the building's entire life cycle. The building's life cycle starts with siting, includes design, construction, operation, maintenance, renovation and then finally demolition. The total long term environmental cost of all building components is calculated and factors into green building design. Green building extends traditional building's short term concerns of economy, utility, durability and comfort with long term goals of sustainability, high performance, human health and environmental impact. The environment is impacted by the production and consumption of materials, natural resources, energy, water and land. Our environment is adversely altered by the building's inhabitants generation of waste products, water pollution, air pollution, heat and noise. Ultimate effects may include harm to human health, degradation of the environment including the atmosphere and loss of natural resources. Green building's goal is to reduce or eliminate any adverse health and environmental impact for every kind of building including residential, public, governmental, religious and commercial.

Ductwork in commercial and residential forced air heating and air conditioning systems circulate air throughout your building in the process of heating and cooling. Any biological pollutants, contaminants, pathogens, bacteria, microbes and viruses present in the air circulating around the HVAC system are breathed in and also settle on surfaces in all the rooms. Exasperating this problem in newer buildings is the fact that most are constructed to be more sealed or tighter for energy efficiency which in turn reduces fresh air exchange or ventilation. The same pollutants and disease causing organisms become concentrated and readily multiply. Also typically air duct work is a friendly, hospitable place for fungi, bacteria and mold to grow and spread. Like most living organisms, they require temperatures between 40-120 degrees F, food and moisture, conditions which are present in commercial and residential heating and A/C duct work. This can result in poor IAQ or indoor air quality, some times referred to as sick building syndrome, not only having possibility of making us sick but understandably promoting allergic reactions and exasperating asthma conditions.

To reduce our exposure to such biological pollutants and contaminants at home, at work and in public places, we need to attack this increasing problem on several fronts. Increasing or providing adequate fresh air ventilation can help reduce the concentration and trapping of these bacteria and pollutants. Reducing humidity or moisture levels to less than 50% or even 30% will help prevent condensation and disrupt growth of microbes, bacteria and mold. Of course reducing the sources of biological pollutants and even destroying or eliminating those present is paramount. Methods tried to reduce and eliminate circulating biological pollutants include cleaning of air ducts and decontamination of air ducts using chemicals, biocides, fungicides and ozone. Unfortunately duct work cleaning has not been proven to be effective. The EPA (Environmental Protection Agency) in fact not only has stated that air duct cleaning has never been shown to actually prevent health problems but EPA also does not recommend that air ducts be cleaned except on a as needed basis. Regarding decontaminating heating and A/C systems including duct work, the EPA has stated that there is an unresolved controversy over the necessity and wisdom of introducing chemical biocides and ozone into duct work. The American Conference of Governmental Industrial Hygienists made an even stronger statement saying that application of chemical biocides as opposed to removing microbial growth and settled biological material is considered unacceptable. Still the fact remains that unhealthy biological pollutants and microbial growth are circulating around and residing in our duct work and it is imperative that something be done to reduce and eliminate it.

Beyond increasing fresh air ventilation and reducing moisture or humidity levels to help control biological pollutants and growth, there is considerable growing interest in deploying copper material for use as duct work. Copper has already been well documented and proven to destroy harmful bacteria, germs, microbes, pathogens, molds, fungi and viruses which come in contact with copper surfaces. Copper is also EPA approved as an antimicrobial agent after exhaustive tests confirmed it's effectiveness. Plus copper is inherently much safer than widespread use of ozone and chemical biocides - germicides whether liquids, sprays or aerosols. Copper and strong copper alloy materials are already proving effective in reducing the existence of biological pollutants, biological growths and bioaerosol contaminants in A/C duct work. Copper is quite an order of magnitude better than materials historically and  commonly used for duct work such as galvanized steel, aluminum and stainless steel. While copper will not cure all IAQ problems and continuing studies will quantify it's measurable improvement in indoor air quality, it is known that usage of copper duct work will improve IAQ and is a positive step in the right direction. While we are waiting on definitive EPA approval for performance and health claims of copper duct work, builders and remodelers might also consider copper for it's elegance, beauty, richness, longevity, durability and corrosion resistance which are all much greater than any other material. Not coincidentally, these are the same reasons we have seen copper's ageless popularity for use in building architectural features and also increasingly in copper kitchens and copper home decor.

Galvanic Corrosion is an electrochemical process which occurs when dissimilar metals are in contact with each other in the presence of an electrolyte, most commonly being moisture and oxygen. For example rain water and salt water make especially good electrolytes. An electrolyte could be any non-metal matter that will conduct an electric current and are predominantly liquids or moisture. Every metal has been rated for nobility and then placed on galvanic scales according to nobility. Basically nobility is a measurement of the resistance to corrosion, especially of one metal contacting another metal. Metals that are the least noble means they are very anodic, electropositive or high potential and will corrode most easily. Whereas metals that are the most noble, means they are highly cathodic, electronegative or low potential and will be the most resistant to corrosion. The most corrosive effects will occur between metals from the opposite ends of the galvanic scale or ranking of nobility. This difference in electrical potential between two or more metals causes galvanic corrosion. Dissimilar metals in contact with each other in the presence of an electrolyte causes current to flow through their points of contact at the expense of the metal with the higher potential or less nobility. The much less noble metal is gradually consumed in the Electro-chemical reaction and will deteriorate or wear away as the metal ions migrate away from the very anodic metal to the more noble cathodic one. The more noble metal's corrosion resistance actually increases from this transfer of ions to it from the less noble metal, while the other metal is gradually getting consumed. Below is an abbreviated galvanic scale showing ranking of the most common construction metals from the least noble up to the most noble in a normal construction setting where both moisture and oxygen are present.

Galvanic Scale (Nobility of Common Metals)*
Least Noble
Aluminum
Zinc
Galvanized Steel
Iron
Stainless Steel – Active
Tin
Lead
Brass, Bronze
Copper
Stainless Steel – Passive
Titanium
Most Noble

Electropotential of Various Metals
High
Aluminum     +1.30
Zinc            +0.76
Chromium     +0.60
Iron            +0.44
Nickel          +0.22
Tin              +0.13
Lead            +0.12
Copper         -0.34
Silver           -0.80
Platinum       -0.86
Gold            -1.10
Low

Since dissimilar metals in contact with each other in the presence of oxygen and moisture will result in the less noble metal being corroded or eaten away the more noble one, contact between dissimilar metals should be avoided. For example, copper as one of the most noble of metals should be kept separated from less noble metal such as aluminum and galvanized steel. If contact between dissimilar metals cannot be avoided, their surfaces should be insulated as much as possible at the least with a non-metallic, non-conductive coating, such as bituminous or zinc chromate primers or paint. Separating the dissimilar metals with tape, gaskets, waterproof membrane, sealants or other non-conductive material that does not absorb and hold moisture can be used effectively. Care must also be taken to avoid the liquid wash run off or discharge from the drains from noble metals to less noble ones. For example rain water run off from a copper roof going into aluminum gutters and downspouts will result in traces of copper salts in the run off wash accelerating corrosion of the aluminum. Additionally, the use of galvanized nails, screws, flashing or drip edge on copper roofing or copper gutters should likewise be avoided as such less noble fasteners and metals will corrode rapidly. While rain water is a good electrolyte so too is high humidity or moisture laden air especially when it contains a high concentration of corrosive acids as is typically found in larger cities or near industry. In industrial or heavily populated areas, harmful electrolytes are formed by the absorption of gases by rain and fog to form acids and salts, while in coastal areas a saline electrolyte is formed by the combination of salt with the moisture laden air.
 
As copper has one of the highest galvanic numbers or nobility of construction metals, copper will not be harmed by contact with any of the common metals. However, copper will promote corrosion of other less noble metals if placed in direct contact with them. Copper can be used most appropriately with lead, tin, lead-tin solder or stainless steel under almost any circumstance. The primary metals of concern in terms of galvanic corrosion contact with copper are aluminum and zinc. Large differences in the thermal expansion rate between copper and these metals may cause additional problems. Also avoid using copper and some brass fasteners with aluminum, zinc and most ferrous metal. Paints or coatings that are used for isolation must be compatible with both of the dissimilar metals. The bituminous or zinc chromate primers and paints can be used between copper and aluminum surfaces. These same coatings or a red lead primer can also be effective in separating copper from iron and the other ferrous metals such as galvanized steel or mild steels.

Another type of corrosion called erosion corrosion is caused by the flow of acidic water concentrated into a very small area. While especially true for the least noble and most corrosive of metals, but capable of affecting all metals, acidic water allowed to concentrate on a small area, for example rain water from a large area like a roof diverted towards a flashing, valley or gutter can cause erosion corrosion. Also acidic water or liquids pooling on metal surfaces or trapped without air circulation between roofing or sheathing can quickly corrode the metal. Solution is to eliminate such pooling, maintain air circulation underneath metal roofs or between inert roofing material and drip edge, valleys and flashing. Another solution is to use replaceable reinforcing insulative strips between the inert materials and metal. Raw zinc and aluminum especially are susceptible to prolonged contact with acidic moisture, as for example the underside of a zinc roof. But care should be taken even with copper and stainless steel. Copper and zinc possess a superior property in that both will gradually develop a long term protective patina that helps guard against such corrosive effects for a very long period of time providing initial safeguards are exercised such as drying out provisions or temporary coatings.


*Note: Galvanic chart rankings involving sea water immersion and low oxygen conditions will vary somewhat - the more typical nobility given here is for land based construction.

Re-using old guttering or buying cheap aluminum or plastic guttering are tempting options but may perhaps not be the best option. It is recommended you stay away from any kind of painted, rusted guttering or lead coated guttering for obvious health reasons if you are growing produce. Many plastics have unhealthy emissions and plastic gutters can also break down from the weight, UV sunlight and trowel work. It is best to use a gutter made from a pure metal that does not have any chemicals or paint applied, does not corrode or rust over time, is durable, long lasting, naturally weathers well, is aesthetically pleasing and is a genuinely attractive feature of your home. Steel and aluminum are relatively low priced but most varieties require some type of coating to resist rust and corrosion and coatings oxidize, scratch, are not durable, long lasting and mostly unhealthy too for a gutter garden. Galvalume is a zinc-aluminum coated steel that is a better candidate than either steel or aluminum alone, combining the corrosion and rust resistance of zinc and aluminum with the strength of steel but with an industrial looking gray metallic appearance and you would probably be tempted to paint this material. Three even better choices for your gutter garden are zinc, stainless steel and copper. Everyone is familiar with the appearance and attributes of stainless steel and it is a viable option. Stainless steel does not rust providing it's surface is not damaged and it is generally considered a healthy, sanitary material. Stainless steel's shiny appearance may be attractive or it may not blend in or complement your home's exterior. Pure zinc is a viable, healthy option that is durable, weathers well and zinc develops an attractive protective, grey patina that is somewhat pewter like though zinc is priced higher than galvalume and stainless steel. Then we have pure copper which may be the best choice for a multitude of reasons: copper has proven itself for centuries to be the most durable and longest lasting metal; copper weathers extremely well, forming a protective attractive patina; requires little to no maintenance; copper is attractive, aesthetically pleasing, elegant and complements most home decor well; copper is EPA approved antimicrobial, germicidal, antibacterial and fungicidal; copper is a key nutrient for plant life; copper is considered eco-friendly and is a green building material. These are all attractive and most desirable traits for use in your gutter garden. Copper although being our highest rated choice also has the highest initial cost of all the metals and metal alloys mentioned above. Copper's many and unique advantages, help justify it's premium cost, especially considering the relatively short lengths required for most gutter gardens, which put copper gutters' premium price within reach and affordability.


Once you have decided on the material for your gutter, you will then likely choose between three common styles of gutter: K-style gutter, half-round gutter and box gutter. A box gutter will give you the most volume with which to garden with, and as it's name suggests, it has a rectangular box appearance or if you like a plain box planter. K-style gutters are probably the most common residential gutters used in the U.S. and are somewhat boxy as well, though with a angled stepped front for a little more pizzazz. Half round gutters do look just like they sound, like half of a round cylinder or pipe and half-round gutters also have the most elegant appearance of all the various gutter types. There are also quarter round gutters which also are very attractive with their curved front. Quarter round and K-style gutters are generally available from 5 inches to 8 inches wide, half round gutters usually from 5 inches to 10 inches wide and box gutters are usually manufactured to size. Custom widths are also available through Rutland Gutter Supply.  Compare the different appearances of K-style, box gutters, half-round, quarter round and embossed gutters, all pictured below.

For the framework we will be using aluminum tubing, plywood sheathing and waterproof membrane. We begin by precisely cutting square aluminum tubing to size and bending the tubes using a roll forming machine to form the base and the many vertical support cross members. A partially completed aluminum frame is shown below.


After all the plywood sheathing panels have been securely fastened in place with self-tapping screws, we then apply to the partially completed dome a self-sealing waterproof membrane, taking care to completely seal the dome. After the membrane is in place, we draw guidelines and begin carefully attaching the hand-cut copper tile to the dome and to each other. The copper tile have been designed to interlock securely with each other and we use copper ring shank nails to fasten them to the plywood.

The custom copper leader head (also known as conductor head, hopper head, rain collector box) in video below is a recreation of a cast iron leader head that adorned a church in England for centuries. Rutland Gutter Supply specializes in the highest quality of custom architectural copper work and copper gutter systems. There are over sixty-five different leader head designs now in Rutland's growing collection. View some of these custom copper leader heads and other custom copperwork, such as copper domes, copper cupolas, copper finials, copper chimney caps, copper spires, copper gutters, etc at Rutland Gutter Supply & Architectural Copper Work. Leader heads are mounted inline on the downspouts being fed from a building's gutters. Leader heads mix air in with the water flowing down through the downspouts, eliminating the back pressure or vacuum. See picture below of an installed copper leader head and copper guttering.

Custom leader heads are typically manufactured from pure copper, zinc, mill finish aluminum or lead coated copper on the finest commercial and residential gutter systems. Copper guttering and copper leader heads particularly, can last 80-100 years, require little to no maintenance, are aesthetically pleasing, they can be recycled nearly 100% and contribute to green building objectives. Leader heads add both a decorative (as seen in picture) and functional touch. Watch video below of a custom leader head that has been recreated from a centuries old one.



 

With a solid body of evidence showing copper's broad spectrum of antimicrobial efficacy and copper's ability to inhibit the most important pathogens challenging public health today, including MRSA, Clostridium difficile, Escherichia coli (E.coli), Legionella pneumophila (Legionnaire's disease bactera) and Influenza A viruses. Clinical trials examining copper's antimicrobial potential and role in fighting pathogens, transmissions of germs and Influenza A viruses such the bird flu and swine flu epidemics are being undertaken in the U.S., U.K., Germany, Japan and South Africa.

The EPA, the U.S. Environmental Protection Agency, has approved the registration of copper as an antimicrobial agent to reduce harmful bacteria linked to potentially deadly microbial infections, following a year of comprehensive testing in an independent US laboratory. The tests showed that 99.9% of bacteria on a copper surface were eliminated within 2 hours of exposure. Typically this type of registration has previously been granted to liquids and gases falling under the sanitizer and disinfectant categories. Copper's mechanical and aesthetic properties makes it an ideal choice for use in all products or surfaces offering us the benefits of copper's antimicrobial power.

A concise reference article to download is "Copper: essential for life" and a reference website page entitled "Antimicrobial Copper". Increased use of copper is indicated not just for commercial or public buildings and outside public fixtures but in the home copper's logical uses are plentiful including the bathrooms and in a copper kitchen. You can enjoy copper's aesthetic appearance throughout your home, while enjoying copper's natural health benefits with it's proven germicidal, antibacterial and antimicrobial power.

The need to prevent the spread of germs has always been a major concern. Research indicates that a copper surface is more effective at preventing the spread of germs than stainless steel. Copper has a 2000 year history of antimicrobial applications in a multitude of cultures. More recent research has sought to determine uncoated copper's effectiveness in stemming the proliferation of infectious disease. At the University of Southampton in the U.K. research studies have shown that many common disease causing microbes such as  E. coli, Aspergillus niger (black mold) and Influenza A, die within hours on copper surfaces. The Influenza A family of viruses includes the problematic Avian flu and swine flu strains and copper can help contain a flu. Even deadly antibiotic resistant bacteria associated with infections such as MRSA (Methicillin Resistant Staphylococcus Aureus) die within 1.5 hours on pure copper. On stainless steel and plastics, typically used for food-processing hardware, pathogens survived unabated for days, sometimes more than 30 days. There is enough solid evidence to put man’s oldest metal to work throughout the world to help protect us from infectious disease. Tested copper alloys, such as brass or bronze also offer increased protection over non-copper containing materials such as stainless steel, painted surfaces, wood and plastics, although not nearly as effective as pure copper surfaces.

Some fairly common and obvious uses in the home for elegant yet functional copper home decor include copper kitchen sinks, bathroom copper sinks, copper bar sinks, food prep sinks, copper basin, copper vanity sink, copper door knobs, copper handles, copper range hoods, copper planters, copper pot racks, copper bowls, copper sheets or copper tiles for making copper countertops and copper sink backsplashes, copper tabletops, copper chair arms, copper wall plates and switches, copper light canopies, copper ceiling fans, copper vents, copper louvers, copper cookware, etc. There are germ killing copper facades available for refrigerators, dishwashers, freezers, ice-makers, ovens and ranges. There are copper-plated kitchen appliances, copper vases, copper sculpture, copper accent pieces, copper planters, even copper flowers. Copper bathroom fixtures and copper kitchen appointments may be the most obvious places to most benefit from and utilize copper's antimicrobial power, yet manufacturers are now focusing in on all home furnishings and furniture as well as laptop, remote control and cell phone cases. The ceiling for new copper surfaced products is sky high, especially considering copper's aesthetic qualities, durability, long lifespan and green copper work as eco-friendly too.

For more detailed health information regarding the necessity of copper in the human diet and medicinal purposes, I will heartily recommend starting out with these two excellent articles: Copper and Human Health and Copper in Human Health.