What is rainwater harvesting?
It simply means catching and holding rain where it falls and using it. You can store it in tanks or you can use it to recharge groundwater.
Does it work?
Yes. Our ancestors harvested rain just as naturally as they tilled the ground to grow crops. We lost touch with these local solutions. But now, as the taps dry up, more and more people are reviving this age-old system and practicing it very successfully.
Can I harvest rain in my own house?
Yes you can. Structures to harvest rain require little space. A dried bore well, a row of soak pits or a tank--concealed below the ground- are all that you need. The open spaces -- rooftops and ground - can be used as your catchment (surface to catch rain).
How much will it cost?
It varies, depending on the area of your roof and other structures that you will use to harvest rain. But rainwater harvesting does not require major construction work, so the expenses suit most of our pockets
Who will build it and how long will it take?
You need someone who understands rainwater harvesting. It is simple but it still needs someone who has experience in the principles of rainwater harvesting. Then a skilled mason or a plumber can do the job for you within 10 days.
Who will it benefit?
You. Your groundwater will be recharged. But as groundwater moves, your neighbourhood will gain too. So for best results, get all your neighbours to become rainwater harvesters as well.
What will be the quality of water?
You are putting rain water into the ground, which once contaminated, cannot be cleaned easily. Please do not let water with sewage or other dirt flow into your recharge pits. This is why the cleanest rainwater is from our rooftops. There are also filters to keep some dirt out.
Does it require a lot of maintenance?
Once or twice a year, at very little cost. Remember rainwater harvesting means that you have to get involved. This is about making water all our business. This is about building our relationship with water. With the environment. Harvest rain. Learn the value of each raindrop.
How do solar water heaters work?
Solar water-heating systems can be used in any climate, and the fuel they use-sunshine- is free. These systems include storage tanks and solar collectors. There are two types of solar water-heating systems: active, which have circulating pumps and controls, and passive, which don't.
Most solar water heaters require a well-insulated storage tank. Solar storage tanks have an additional outlet and inlet connected to and from the collector. In two-tank systems, the solar water heater preheats water before it enters the conventional water heater. In one-tank systems, the back-up heater is combined with the solar storage in one tank.
What types of systems are suitable for homes?
Three types of solar collectors are used for residential applications:
• Flat-plate collector
Glazed flat-plate collectors are insulated, weatherproofed boxes that contain a dark absorber plate under one or more glass or plastic (polymer) covers. Unglazed flat- plate collectors-typically used for solar pool heating - have a dark absorber plate, made of metal or polymer, without a cover or enclosure.
• Integral collector-storage systems
Also known as ICS or batch systems, integral collector-storage systems feature one or more black tanks or tubes in an insulated, glazed box. Cold water first passes through the solar collector, which preheats the water. The water then continues on to the conventional backup water heater, providing a reliable source of hot water. They should be installed only in mild-freeze climates because the outdoor pipes could freeze in severe, cold weather.
• Evacuated-tube solar collectors
Evacuated-tube solar collectors feature parallel rows of transparent glass tubes. Each tube contains a glass outer tube and metal absorber tube attached to a fin. The fin's coating absorbs solar energy but inhibits radiative heat loss. These collectors are used more frequently for U.S. commercial applications.
What types of active solar-water heating systems are available?
There are two types of active solar-water heating systems:
• Direct circulation systems
Pumps circulate household water through the collectors and into the home. They work well in climates where it rarely freezes.
• Indirect circulation systems
Pumps circulate a non-freezing, heat-transfer fluid through the collectors and a heat exchanger. This heats the water that then flows into the home. They are popular in climates prone to freezing temperatures.
What type of passive solar water heating systems are available?
Passive solar water heating systems are typically less expensive than active systems, but they're usually not as efficient. However, passive systems can be more reliable and may last longer. There are two basic types of passive systems:
Integral collector-storage passive systems
These work best in areas where temperatures rarely fall below freezing. They also work well in households with significant daytime and evening hot-water needs.
Thermosyphon systems
Water flows through the system when warm water rises as cooler water sinks. The collector must be installed below the storage tank so that warm water will rise into the tank. These systems are reliable, but contractors must pay careful attention to the roof design because of the heavy storage tank. They are usually more expensive than integral collector-storage passive systems.
How do I select a solar water heater?
Before you purchase and install a solar water heating system, you want to do the following:
• Consider the economics of a solar water-heating system
• Evaluate your site's solar resource
• Determine the correct system size
• Determine the system's energy efficiency
• Estimate and compare system costs
• Investigate local codes, covenants, and regulations
How do I install and maintain a solar water-heating system?
The proper installation of solar water heaters depends on many factors. These factors include solar resource, climate, local building code requirements, and safety issues; therefore, it's best to have a qualified, solar thermal systems contractor install your system.
After installation, properly maintaining your system will keep it running smoothly. Passive systems don't require much maintenance. For active systems, discuss the maintenance requirements with your system provider, and consult the system's owner's manual. Plumbing and other conventional water heating components require the same maintenance as conventional systems. Glazing may need to be cleaned in dry climates where rainwater doesn't provide a natural rinse.
Regular maintenance on simple systems can be as infrequent as every 3-5 years, preferably by a solar contractor. Systems with electrical components usually require a replacement part after or two after 10 years. For more information about system maintenance, see the following
Solar Water Heating System Maintenance and Repair
Solar Water Heating System Freeze Protection
Scaling and Corrosion in Solar Water Heating Systems
When screening potential contractors for installation and/or maintenance, ask the following questions:
• Does your company have experience installing and maintaining solar water heating systems? Choose a company that has experience installing the type of system you want and servicing the applications you select.
• How many years of experience does your company have with solar heating installation and maintenance? The more experience the better. Request a list of past customers who can provide references.
• Is your company licensed or certified?
Having a valid plumber's and/or solar contractor's license is required in some states. Contact your city and county for more information. Confirm licensing with your state's contractor licensing board. The licensing board can also tell you about any complaints against state-licensed contractors.
What other ways can I improve water heating energy efficiency?
After your water heater is properly installed and maintained, try some additional energy- saving strategies to help lower your water heating bills, especially if you require a back-up system. Some energy-saving devices and systems are more cost-effective to install with the water heater.
How can I protect a solar water heater from freezing?
Solar water heating systems, which use liquids as heat-transfer fluids, need protection from freezing in climates where temperatures fall below 42ºF (6ºC).
Don't rely on a collector's and the piping's (collector loop's) insulation to keep them from freezing. The main purpose of the insulation is to reduce heat loss and increase performance. For protecting the collector and piping from damage due to freezing temperatures, you basically have two options:
• Use an antifreeze solution as the heat-transfer fluid.
• Drain the collector(s) and piping (collector loop), either manually or automatically, when there's a chance the temperature might drop below the liquid's freezing point.
Using an Antifreeze Solution
Solar water heating systems that use an antifreeze solution (propylene glycol or ethylene glycol) as a heat-transfer fluid have effective freeze protection as long as the proper antifreeze concentration is maintained. Antifreeze fluids degrade over time and normally should be changed every 3-5 years. Since these systems are pressurized, it is not practical for the average homeowner to check the condition of the antifreeze solution. If you own this type of system, have a solar heating professional check it periodically.
Draining the Collector and Piping
Solar water-heating systems that use only water as a heat-transfer fluid are the most vulnerable to freeze damage. "Draindown" or "drainback" systems typically use a controller to drain the collector loop automatically. Sensors on the collector and storage tank tell the controller when to shut off the circulation pump, to drain the collector loop, and when to start the pump again.
Improper placement or the use of low-quality sensors can lead to their failure to detect freezing conditions. The controller may not drain the system, and expensive freeze damage may occur. Make sure that the sensor(s) have been installed according to the manufacturer's recommendations, and check the controller at least once a year to be sure that it is operating correctly.
To ensure that the collector loop drains completely, there should also be a means to prevent a vacuum from forming inside the collector loop as the liquid drains out. Usually an air vent is installed at the highest point in the collector loop. It is a good practice to insulate air vents so that they do not freeze. Also make sure that nothing blocks the airflow into the system when the drain cycle is active.
Collectors and piping must slope properly to allow the water to drain completely. All collectors and piping should have a minimum slope of 0.25 inches per foot (2.1 centimeters per meter).
In integral collector storage or "batch" systems, the collector is also the storage tank. Placing large amounts of insulation around the unglazed parts of the collector and covering the glazing at night or on cloudy days will help to protect the collector from cold temperatures. However, water in the collector can freeze over extended periods of very cold weather. The collector supply and return pipes are also susceptible to freezing, especially if they run through an unheated space or outside. This can happen even when the pipes are well insulated. It is best to drain the entire system before freezing temperatures occur to avoid any possible freeze damage.
See Heat-Transfer Fluids for Solar Water Heating Systems to learn more about the different types of heat-transfer fluids.
For more information about residential solar systems, see:
• Solar Water Heaters
• Solar Space Heating Systems
• Heat Exchangers for Solar Heating Systems
What heat transfer fluids are used in solar water-heating systems?
The following are some of the most commonly used heat-transfer fluids and their properties
Air
Air will not freeze or boil, and is non-corrosive. However, it has a very low heat capacity, and tends to leak out of collectors, ducts, and dampers.
Water
Water is nontoxic and inexpensive. With a high specific heat, and a very low viscosity, it's easy to pump. Unfortunately, water has a relatively low boiling point and a high freezing point. It can also be corrosive if the pH (acidity/alkalinity level) is not maintained at a neutral level. Water with a high mineral content (i.e., "hard" water) can cause mineral deposits to form in collector tubing and system plumbing.
Glycol/water mixtures
Glycol/water mixtures have a 50/50 or 60/40 glycol-to-water ratio. Ethylene and propylene glycol are "antifreezes." Ethylene glycol is extremely toxic and should only be used in a double-walled, closed-loop system. You can use food-grade propylene glycol/water mixtures in a single-walled heat exchanger, as long as the mixture has been certified as nontoxic. Make sure that no toxic dyes or inhibitors have been added to it. Most glycols deteriorate at very high temperatures. You must check the pH value, freezing point, and concentration of inhibitors annually to determine whether the mixture needs any adjustments or replacements to maintain its stability and effectiveness.
Hydrocarbon oils
Hydrocarbon oils have a higher viscosity and lower specific heat than water. They require more energy to pump. These oils are relatively inexpensive and have a low freezing point. The basic categories of hydrocarbon oils are synthetic hydrocarbons, paraffin hydrocarbons, and aromatic refined mineral oils. Synthetic hydrocarbons are relatively nontoxic and require little maintenance. Paraffin hydrocarbons have a wider temperature range between freezing and boiling points than water, but they are toxic and require a double-walled, closed-loop heat exchanger. Aromatic oils are the least viscous of the hydrocarbon oils.
Refrigerants/phase change fluids
These are commonly used as the heat transfer fluid in refrigerators, air conditioners, and heat pumps. They generally have a low boiling point and a high heat capacity. This enables a small amount of the refrigerant to transfer a large amount of heat very efficiently. Refrigerants respond quickly to solar heat, making them more effective on cloudy days than other transfer fluids. Heat absorption occurs when the refrigerant boils (changes phase from liquid to gas) in the solar collector. Release of the collected heat takes place when the now-gaseous refrigerant condenses to a liquid again in a heat exchanger or condenser.
For years chlorofluorocarbon (CFC) refrigerants, such as Freon, were the primary fluids used by refrigerator, air-conditioner, and heat pump manufacturers because they are nonflammable, low in toxicity, stable, noncorrosive, and do not freeze. However, due the negative effect that CFCs have on the earth's ozone layer, CFC production is being phased out, as is the production of hydrochlorofluorocarbons (HCFC). The few companies that produced refrigerant-charged solar systems have either stopped manufacturing the systems entirely, or are currently seeking alternative refrigerants. Some companies have investigated methyl alcohol as a replacement for refrigerants.
If you currently own a refrigerant-charged solar system and it needs servicing, you should contact your local solar or refrigeration service professional. Since July 1, 1992, intentional venting of CFCs and HCFCs during service and maintenance or disposal of the equipment containing these compounds is illegal and punishable by stiff fines. Although production of CFCs ceased in the U.S. 1996, a licensed refrigeration technician can still service your system. You may wish to contact your service professional to discuss the possible replacement of the CFC refrigerant with methyl alcohol or some other heat transfer fluid.
Ammonia can also be used as a refrigerant. It's commonly used in industrial applications. Due to safety considerations it's not used in residential systems. The refrigerants can be aqueous ammonia or a calcium chloride ammonia mixture.
Silicones
Silicones have a very low freezing point, and a very high boiling point. They are noncorrosive and long-lasting. Because silicones have a high viscosity and low heat capacities, they require more energy to pump. Silicones also leak easily, even through microscopic holes in a solar loop.
See Solar Water Heating System Freeze Protection for more information about liquid heat- transfer fluids.
Are there any disadvantages to using solar energy?
The energy in sunlight can be used for many purposes, including heating water for a building or swimming pool. And using solar energy has many environmental and life-cycle economic benefits. However, solar energy heating or solar electric products often have higher first costs than other, similar products do. This means it will probably cost more initially to purchase and install a solar system than it will to purchase and install another kind of heating or electric system. Still, in nearly all cases, you will recover your initial costs through substantial fuel savings (as shown in lower utility bills) over the life of the product. Many solar systems last 15 to 30 years.
Do solar water-heating systems require a backup system?
Solar water heating systems almost always require a backup system for cloudy days and times of increased demand.Conventional storage water heaters usually provide backup and may already be part of the solar system package. A backup system may also be part of the solar collector, such as rooftop tanks with thermosyphon systems. Since an integral- collector storage system already stores hot water in addition to collecting solar heat, it may be packaged with ademand (tankless or instantaneous) water heater for backup.
How do I size a water purifier?
Our units are based on peak flow rate. Most single-family dwellings use 6, 9, req or 12gpm units.
What is the recommended temperature of the water?
Normal operating range is 40 - 105 degrees F – if operating outside this range please contact our engineering staff.
What is the recommended pH level of the water?
6.5 –9.5.
How can I insure that my flow rate does not exceed the rated flow of my ultraviolet water purifier?
We have flow control valves available that will restrict the flow of your water to the rated flow of the water purifier.
Do I need a special 220v 60Hz line?
No. All of our units come standard in 120v 60 Hz (please specify if you require a different voltage).
Do I need a pre filter before the water enters the ultraviolet unit?
Particulates can shield microorganisms from the ultraviolet rays. Therefore, we recommend a 5-micron pre-filter to remove particles that could hinder the operation of the ultraviolet unit.
My water looks clear. Do I still need a pre-filter?
Virtually all applications will benefit from filtering. Even if little is being filtered out of your water at this time – this will act as another layer of protection in case of any changes in your water supply.
Can I install my filter after the water purifier?
Filtering prior to the ultraviolet water purifier removes contaminants and particulates that may interfere with the ultraviolet process. Also, ultraviolet does not have a residual effect; therefore, it is beneficial to put the water purifier as close as possible to the point of use. Installing the filter prior to the ultraviolet water purifier eliminates the possibility of recontamination of the water in the filter.
Does it matter which connection on the unit is the inlet or outlet (for the Sanitron™, Mighty-Pure™ and Minipure™)?
No, this does not effect the operation of the unit.
Should I mount the water purifier horizontally or vertically?
Horizontal installation is recommended on Sanitron™, Mighty-Pure™, MiniPure™ and Bio-Logic™. Be aware that if mounting vertically, room should be allocated to allow the removal of the lamp or quartz sleeve or to utilize the wiper mechanism of the Sanitron™ model. Extra care is required when removing the lamp and/or quartz sleeve – there is the additional hazard of the lamp or quartz sleeve falling out of the unit. If you require a Guardian™ monitor (available for Sanitron™ or Mighty-Pure™) on a vertical installation you must get the remote version –a wall mount kit for the monitor is available for purchase.
I had to turn my unit off for service or a problem; can I just turn it back on again? How do I disinfect the downstream piping?
Although the unit will turn back on if properly connected, there may be some contamination of the downstream pipes (from the water purifier to point of use) if water flows through the system during shut down. It is a good practice to disinfect the downstream plumbing between the purifier and point of use whenever there is a chance that non-purified water has gotten into the pipes. This is done by introducing chlorine into the purifier chamber, a 100-ppm chlorine solution is suggested. With the chlorine in the purifier chamber, turn the ultraviolet purifier on. Open the downstream outlet until a chlorine odor is noticed. Close the outlet and allow the chlorine to remain in the plumbing for a minimum of three (3) hours. Flush the plumbing with ultraviolet purified water; allow the water to run for several minutes before use.
Where is the product serial number located on the Mighty-Pure™, Sanitron™ and Minipure™?
It is a five-digit number located on one-end cap of the unit.
Should the solenoid go on the inlet or outlet side of the water purifier?
Inlet side.
Do the units conform to the US Public Health Guidelines?
We recommend use of the following accessories with Sanitron™ Water Purifiers to conform to US Public Health Service Guidelines: monitor, solenoid, flow control valve, audio alarm and time delay mechanism.
What are some of the uses for purified water systems?
Farms and Ranches: Bacteria free animal drinking water increases production by eliminating losses due to water-borne infection. Improved sanitation promotes healthier stock and higher yields.
• Water Wells: Eliminates bacteria which may build up from time to time from seepage of surface water or sewage.
• Private Homes, Trailer Parks, Recreation Vehicles, Schools, Hotels, Airplanes: Provides safe, germ-free drinking water. Destroying bacteria, a serious problem for rural water supplies, prevents disease.
• Swimming Pools: Helps control bacteria, algae and slime formation. Ultraviolet water purification allows the user to substantially reduce the chlorine usage.
• Aquariums and Hatcheries: Bacteria-free water prevents disease organisms from growing or spreading without producing by-products toxic to marine life.
• Laboratories: Provides ultrapure water required for accurate testing and research.
• Hospitals: Insures ultrapure water for pathology labs, kidney dialysis and post disinfection rinses where bacteria-free water is essential.
• Swimming Pools: Helps control bacteria, algae and slime formation. Ultraviolet water purification allows the user to substantially reduce the chlorine usage.
What are Some Naturally Occurring Sources of Pollution?
Microorganisms: Bacteria, viruses, parasites and other microorganisms are sometimes found in water. Shallow wells — those with water close to ground level — are at most risk. Runoff, or water flowing over the land surface, may pick up these pollutants from wildlife and soils. This is often the case after flooding. Some of these organisms can cause a variety of illnesses. Symptoms include nausea and diarrhea. These can occur shortly after drinking contaminated water. The effects could be short-term yet severe (similar to food poisoning) or might recur frequently or develop slowly over a long time. Radionuclides: Radionuclides areradioactive elements such as uranium and radium. They may be present in underlying rock and ground water.
Radon — a gas that is a natural product of the breakdown of uranium in the soil — can also pose a threat. Radon is most dangerous when inhaled and contributes to lung cancer. Although soil is the primary source, using household water containing Radon contributes to elevated indoor Radon levels. Radon is less dangerous when consumed in water, but remains a risk to health.
Nitrates and Nitrites: Although high nitrate levels are usually due to human activities (see below), they may be found naturally in ground water. They come from the breakdown of nitrogen compounds in the soil. Flowing ground water picks them up from the soil. Drinking large amounts of nitrates and nitrites is particularly threatening to infants (for example, when mixed in formula). Heavy Metals: Underground rocks and soils may contain arsenic, cadmium, chromium, lead, and selenium. However, these contaminants are not often found in household wells at dangerous levels from natural sources.
Fluoride: Fluoride is helpful in dental health, so many water systems add small amounts to drinking water. However, excessive consumption of naturally occurring fluoride can damage bone tissue. High levels of fluoride occur naturally in some areas. It may discolor teeth, but this is not a health risk
What Human Activities Can Pollute Ground water?
Bacteria and Nitrates: These pollutants are found in human and animal wastes. Septic tanks can cause bacterial and nitrate pollution. So can large numbers of farm animals. Both septic systems and animal manures must be carefully managed to prevent pollution. Sanitary landfills and garbage dumps are also sources. Children and some adults are at extra risk when exposed to water-born bacteria. These include the elderly and people whose immune systems are weak due to AIDS or treatments for cancer.
Fertilizers can add to nitrate problems. Nitrates cause a health threat in very young infants called “blue baby” syndrome. This condition disrupts oxygen flow in the blood. Concentrated Animal Feeding Operations (CAFOs): The number of CAFOs, often called “factory farms,” is growing. On these farms thousands of animals are raised in a small space. The large amounts of animal wastes/manures from these farms can threaten water supplies. Strict and careful manure management is needed to prevent pathogen and nutrient problems. Salts from high levels of manures can also pollute groundwater. Heavy Metals: Activities such as mining and construction can release large amounts of heavy metals into nearby ground water sources. Some older fruit orchards may contain high levels of arsenic, once used as a pesticide. At high levels, these metals pose a health risk.
Fertilizers and Pesticides: Farmers use fertilizers and pesticides to promote growth and reduce insect damage. These products are also used on golf courses and suburban lawns and gardens. The chemicals in these products may end up in ground water. Such pollution depends on the types and amounts of chemicals used and how they are applied. Local environmental conditions (soil types, seasonal snow and rainfall) also affect this pollution. Many fertilizers contain forms of nitrogen that can break down into harmful nitrates. This could add to other sources of nitrates mentioned above. Some underground agricultural drainage systems collect fertilizers and pesticides. This polluted water can pose problems to ground water and local streams and rivers. In addition, chemicals used to treat buildings and homes for termites or other pests may also pose a threat. Again, the possibility of problems depends on the amount and kind of chemicals. The types of soil and the amount of water moving through the soil also play a role.
Industrial Products and Wastes: Many harmful chemicals are used widely in local business and industry. These can become drinking water pollutants if not well managed. The most common sources of such problems are:
• Local Businesses: These include nearby factories, industrial plants, and even small businesses such as gas stations and dry cleaners. All handle a variety of hazardous chemicals that need careful management. Spills and improper disposal of these chemicals or of industrial wastes can threaten ground water supplies.
• Leaking Underground Tanks & Piping: Petroleum products, chemicals, and wastes stored in underground storage tanks and pipes may end up in the ground water. Tanks and piping leak if they are constructed or installed improperly. Steel tanks and piping corrode with age. Tanks are often found on farms. The possibility of leaking tanks is great on old, abandoned farm sites. Farm tanks are exempt from the EPA rules for petroleum and chemical tanks.
• Landfills and Waste Dumps: Modern landfills are designed to contain any leaking liquids. But floods can carry them over the barriers. Older dumpsites may have a wide variety of pollutants that can seep into ground water. These and many other reasons are why water purification systems are essential for private wells and public utility sources
Why Use Water Filtration Systems At Home?
Just because you are on a municipal system, doesn't mean that you don't need a drinking water filtration system in your home. The Safe Drinking Water Act (SDWA) helps but it does not regulate all possible contaminants. The is even truer if you are on a private well. There are many factors that impact the quality of water that comes out of your household tap. The water treatment plant adds chemicals to the water through the process of treating the water, which may become contaminants with potential health risks. Some of these water treatment chemicals may not be eliminated and can be transported in the water to your home. Municipal water treatment plants can not remove every possible contaminant in water. The (SDWA) sets legal limits for certain contaminants that consider human health and the ability of municipal water treatment systems to achieve these levels based on available technology. Considering the average person uses 100 gallons per day, there is a tremendous load on a municipal treatment system to meet the SDWA standards. 90% of people that get their water from a community source are serviced from a medium to very large system (serve 3,301 to 100,000 people). Your local water filtration systems may be responsible for delivering 330,100 to 10,000,000 gallons per day. With this kind of demand, it may not be economically feasible for a municipal treatment facility to remove certain contaminants to a level that will have no health risk to humans. If you are bottling your own water in jugs at a local supply, you may be putting yourself at risk. Storage requires specific guidelines to prevent bacteria growth during storage. Containers should be sterilized prior to filling and contamination is easy during the filling process. Direct light has an impact on storage as well as the room temperature
