The evaporative cooling system works on the principle of evaporating water by drawing air through a moistened media. The media is typically either fibers of aspen or pleated paper. It requires about 7,000 BTU’s to evaporate one gallon of water. The amount of cooling you can achieve depends on how much air you can put through the cooler and how much water you can add to the air as it moves through it. The air coming into it with a lower humidity is going to absorb more water and will be cooled more thoroughly, so the temperature of the air coming out of the cooler is going to be lower than if you are working with outside air with a higher relative humidity. Evaporative coolers are much more effective in places like the Southwestern United States. But they also have limited use even in more humid areas for industrial applications.

There are several ways to improve efficiency on an evaporative cooler – to move more air with the same amount of electricity or to add more moisture to the air that’s being moved through it. The more modern evaporative coolers, which are sometimes called a single-pad cooler, such as the Master Cool Unit, are much more effective than the older, three- or four-pad units. They have a single pad that’s 8- to 12-inches thick in comparison to the older coolers whose pads are typically only an inch and a half thick. The pad on the Master Cool Unit only have to be replaced once every three to ten years in comparison to once or even twice a year with the older style evaporative coolers.

Two ways to make the coolers more efficient by moving more air are by having larger ductwork or shorter ductwork. A third way is to have a higher efficiency motor. The motors that are typically used on evaporative coolers are very low efficiency, shaded pole motors. It’s possible to put a higher efficiency motor on there that will have up to three times the efficiency of the more typical motors. The fan speed should always be adjusted by means of changing the diameter of the pulleys. They typically have an adjustable pulley to optimize the efficiency of the motor. This is done by using an ammeter. The ammeter is connected to leads outside of the air conditioner, and the air conditioner is run in its normal condition with all panels closed, pads in place, and vents open. Then the pulley speed is adjusted if the amperage reading does not agree with the amperage rating on the motor rating plate.

A properly sized duct for the evaporative cooler should be at least as large as the outlet of the evaporative cooler. Most commonly, evaporative coolers are hooked up to duct works that are sized for refrigeration or forced air heating. Efficiency can be increased by a factor of two-fold. Combine that with an adjusted, high-efficiency motor, and it’s possible to move up to six-times as much air for the same amount of electricity. In addition, the high-efficiency motor has a much greater life expectancy and doesn’t require any maintenance. The payback period on the high-efficiency motor is less than two years.

Lots of ductwork is in the attic where it picks up a lot of heat, and it is often poorly sealed so there is a lot of leakage. If the duct is insulated and sealed, it will improve efficiency or if the ductwork is moved inside the house or just greatly reduced in scope, you can improve the efficiency a lot. Much of the air distribution in a house by an evaporative cooler should be done by opening the windows in the part of the house that requires the most cooling. You can usually tell when you have enough windows open in the house because a piece of paper held up against a screen by the air pressure inside the house should barely stay on the screen. If it falls off, you have too many windows open and it’s stuck on hard, you need to have some more windows open. You should open the windows in the part of the house that’s hottest. It is not unusual for the air in the ductwork to vary from 5 to ten degrees in temperature from one end to the other. That’s quite a bit when you’re talking about the relatively small comfort range that people tolerate.

Evaporative coolers should have a bleed-off system or a purging system that removes part of the water to remove excess salt from building up in the water, which will cause corrosion. It’s very easy to move part of this water to landscaping. With a typical bleed-off system, you need 50 feet of quarter-inch black plastic tubing and two or three drip emitters and then periodically move those drip emitters around. If there is supplemental irrigation applied periodically, you’re not likely to cause any damage from excess buildup in the soil around the plants.

At the end of each cooling season, it’s important that the coolers be maintained. The ductwork connected to the evaporative cooler needs to be closed off very tightly. It’s common practice to put a canvas cover over a cooler, but it’s much more effective to close off the ductwork. Some coolers will have their warranty voided if you put a canvas cover over it. The theory being that you will build up moisture there during the winter. With the single pad units, you should put a pint or so of vinegar in it and circulate it for a half hour and then drain it.

All coolers should be hosed down at the end of the season and drained and the belt that drives the pulley should be loosened or taken off for the winter. In the springtime, the pads need to be cleaned and replaced
as needed, and all the bearings need to be lubricated. If there is any accumulated debris in the pans, they need to be washed out and the ductwork opened again. The air that comes out of the evaporative cooler eventually comes out of the house. It retains the entire cool that has been generated by evaporating the water. Ductwork registers cause a lot of airflow restriction, and substantial improvements can be made by using more and larger ducts, or by just eliminating them.

In contrast, a refrigeration system works by pumping heat from the inside of the building to the outside. A refrigeration system’s efficiency is based on how many BTU’s it can remove per watt of electricity uses. A typical refrigeration system has an efficiency rating of ten. The highest available right now is about sixteen. They are requiring an efficiency rating of twelve on new construction now. The maximum by how highly you can compress the cages that are used in it, and that is going to be limited by how high a temperature your systems can tolerate. I think we are probably reaching the limits of our efficiency already. The higher efficiency units are quite a bit more expensive than the standard units.

A substantial amount of energy that goes into a refrigeration-cooling unit is used to remove moisture from the air. The evaporator coils in a refrigeration unit are typically -20 to -40 degrees; so even in an arid climate, much of the moisture from the air will be precipitated out. This will increase the operating cost because you will have the same 7,000 BTU per gallon of water, but in this case, there is energy that has to be supplied to the unit to remove water from the air even though typically our air is dryer than we want it to be.

In a more humid climate, the de-humidification is a useful thing, but around here, it usually isn’t. In addition, this moisture will remain on the capillary coils when the unit is shut off, which encourages air-borne fungus, which releases spores, which causes health problems. The water that is extracted from the air is put into the sanitary drain where it has to be disposed of by the city sewer system. It causes an
incremental cost there before it goes into a septic system. The water that is being used in an evaporative cooling system actually cools off the immediate environment, whereas the refrigeration system heats and
dries the environment.

Commercial electric generation stations only deliver about one-third of the power that they consume as electricity to the end user. Most of the rest of it is waste heat. Most of the waste heat has to be eliminated
by evaporation of water, so electricity that is being used by refrigeration units requires the evaporation of a large amount of water be electrical generating units. It requires a gallon of water to generate one-kilowatt
hour. For the typical generating station that makes up most of our power supply, (here we will insert some figures about how much water is required for each unit of cooling the building requires, and how much power is in how many units of fossil fuel required for each cooling unit in the building.

Beating the Heat

From the El Paso Solar Energy Association:

The simplest way to keep cool is to first design and build your home for our unique climate, but that’s another article. For now we’ll concentrate on cooling an existing home.

If your goal is to keep a home cool in our desert climate, turning on the air conditioner or evaporative cooler is the LAST thing you should do. They’re expensive to operate, they use water and they’re noisy. There is no single answer to being comfortable but taking the shotgun approach is easier, and less expensive.

The three major sources of unwanted heat in your house during the summer are heat that conducts through your walls and ceiling from the outside, heat that is given off inside your house by lights and appliances, and sunlight that shines through windows.

Keeping the sun out of your home is obviously a major goal. Closing curtains and drapes makes your home darker but doesn’t effectively stop the heat. Stopping the sun’s energy from entering your home is best done on the outside of the window. Solar screens or shade cloth can stop as much as 80% of the sun’s heat before it enters your home. These materials are available at most home centers and window and screen suppliers. Windows on the west side are typically the biggest problem followed by the east and north facing windows. South facing windows are often protected by your roof overhang, which shades the glass when the sun is at its highest point. High-performance windows with “low-emissive” coatings (Low-E) and low “shading coefficients” will stop heat from the sun while allowing visible light to pass through the glass. These same windows help keep heat on the home during the winter.

Landscaping can play a large role in achieving comfort. Trees located on the west, east and north can not only put windows in shade, but also shade the walls of the home as well as the ground area. This shaded
area keeps the home cooler and cools breezes as the reach the home. On the south side, you should choose low growing shrubs and plants so as not to block the winter sun from entering south facing windows. This
vegetation will reduce the amount of solar energy, which is reflected
into windows by lighter colors.

The colors of various materials around your home can have a dramatic effect on your comfort and wallet. A dark colored roof can reach temperature 40 degrees hotter than a light colored reflective roof. This heat not only increases the cooling load of your home but also decreases the life of your shingles. Ventilate your attic space to reduce heat build-up during the summer, which finds its way into your home. Darker colored
walls especially brick and stone will actually absorb solar energy, which increases cooling problems and slows the nighttime cooling process. To reduce heat gains through walls and your ceiling, you can add insulation
and seal up cracks to reduce air infiltration.

You can reduce heat from lights and appliances by purchasing energy-efficient products. A conventional, incandescent light bulb uses only 10% of its input energy to produce light and the other 90% is wasted heat. Compact Fluorescent lights can produce the same amount of light as an incandescent lamp but use about one-fifth the energy and produce about one-fifth the heat. Check out the EPA’s Energy Star web site (www.energystar.gov) for energy smart options for your home.

Natural ventilation by opening windows is only effective when outdoor temperatures are lower than interior temperatures. An indoor/outdoor thermometer is a useful tool to determine the optimum time to open your windows. Open your windows when this temperature difference is reached in the evening and then close your windows in the morning. Opening windows more on the downwind side will increase airflow.

Evaporative Cooling

Opening windows is very important when operating an evaporative cooler. A common mistake in the El Paso area is not opening windows enough. If we think of an evaporative cooler as providing a nice breeze, then the best way to kill that breeze and its cooling effect is to close windows. You can increase the amount of cooling in one particular room simply by opening those windows more. The amount of force from an evaporative cooler is limited and can’t compete with a strong summer breeze/wind. If you have a 100-degree breeze coming from the west, then close those windows. When checking the operation of your cooler, make sure that the entire pad(s) is wet. Hot, outside air will flow freely through dry openings and dry pads drastically reducing the cooler’s effectiveness.

It’s very important to supply fresh water to an evaporative cooler and flush out the salts etc. left behind in the evaporation process. Typically this is accomplished with a bleed-off line but there is better, water saving method available at most home centers. Sometimes referred to as a “power dump” this new pump is installed in addition to your regular pump. This new pump operates on a timer and is designed to flush all the water in the pan once every 8 to 12 hours of operation.

The more attention you pay to the sun’s impact and the way you operate your home, the less you’ll spend while being more comfortable.

Don’t Forget your Ducts!

From the US Department of Energy:

Identify any leaks with diagnostic equipment. Seal your ducts with mastic, metal-backed tape, or aerosol sealant. Duct tape should not be used; it cannot withstand high temperatures and will not last. Test airflow after ducts are sealed. Your new or existing cooling and heating equipment is only as good as the system that carries its heated or cooled air. Central air conditioners, heat pumps and forced air furnaces rely on a system of ducts to circulate air throughout your home. To maintain comfort and good indoor air quality, it is important to have the proper balance between the air being supplied to each room and the air returning to your cooling and heating equipment. Leaky ducts can cause an unbalanced system that wastes energy. Sealing your ducts improves your system’s ability to consistently cool and heat every room in your home.

Duct Improvment Checklist

To improve your ducts, make sure to have your contractor:

• Insulate your ducts where it counts to keep the air at its desired temperature as it moves through the system.
• The contractor should use duct insulation material rated at R-6 to insulate ducts located in unconditioned spaces such as the attic.
• Conduct a combustion safety test after ducts are sealed to be sure all gas or oil-burning appliances are working properly.

Radiant heating systems convert a floor into a large-area, low-temperature radiator. In most modern systems, warm water is circulated through closely spaced plastic tubing that is embedded in the floor slab or attached to the underside of wooden sub-flooring. Under-floor insulation is a critical component.Zoning depends on advanced manifolds that regulate flow or modulate the water temperature in different tubing runs. Sophisticated controls regulate all this – often with temperature sensors in the slab – in the rooms being heated and outdoors.

Adding up the Pluses

Radiant floor heating systems offer a wide range of benefits.

Comfort

The large floor area warms people by direct radiation instead of heated air currents. Homeowners can walk around barefoot, even in the dead of winter – a very popular feature. Until you have lived with this form of heat it is hard to understand how comfortable it is.

Energy Savings

The floor’s radiant shine boosts the mean radiant temperature of a space and prevents temperature stratification. Proponents claim this allows homeowners to keep their thermostats lower. Someone normally comfortable at 72F would be comfortable at 68F without the usual hot and cool spots, offering significant energy savings. Another potential source of savings: boiler temperatures can be kept lower, trimming heat loss from the boiler and pipes. In addition, hydronic systems do not affect house air pressures; forced air heat, by contrast, can pull heat-wasting drafts through walls and ceilings when the supply and return pressures are not in balance.

Potential for Use of Solar Energy

The relatively low temperature of water required for radiant floor heating systems is well suited to solar water heating. In addition, the concrete slab can store daytime solar gains for nighttime use.

Quiet Operation

Radiant floor heating is very quiet, with no fan or duct noise and little of the gurgle and creaking sometimes heard in hydronic baseboard systems.

Flexible Room Layout

With no baseboard radiators and no floor registers, radiant floors do not restrict furniture placement or interior design.

Improved Air Quality

Radiant floors do not blow dust around as some ducted heating systems do. In addition, unlike electric baseboard systems, they do not use heating surfaces hot enough to burn dust particles, which can cause
respiratory irritation.

“The in-floor radiant heating system is much less drying than forced air during the winter months.”

Green building construction refers to those practices that promote occupant health and comfort while minimizing negative impacts on the environment. There are different degrees of “greenness.” Often it is necessary to strike a balance between many different sometimes conflicting “green” options based on the particular conditions of a given project. For example, proper strategy for a sustainable retrofit
project may differ from that of new construction design.

Green building practices offer an opportunity to create environmentally sound and resource-efficient buildings by using an integrated approach to design. Green buildings promote resource conservation by including design features, such as: energy efficiency, use of renewable energy, and water conservation.

By promoting resource conservation, green building design creates healthy and comfortable environments, reduces operation and maintenance costs, considers environmental impact of building construction and retrofit, and concentrates on waste minimization.

In the interim, green building design addresses such issues as historical preservation and access to public transportation and other community infrastructure systems. The entire life cycle of the building and its components is considered, as well as the economic and environmental impact and performance.

In building construction, post-tensioning allows longer clear spans, thinner slabs, fewer beams and more slender, dramatic elements. Thinner slabs mean less concrete is required. In addition, it means a lower overall building height for the same floor-to-floor height.

Post-tensioning can thus allow a significant reduction in building weight versus a conventional concrete building with the same number of floors. This reduces the foundation load and can be a major advantage in seismic areas.

A lower building height can also translate to considerable savings in mechanical systems and façade costs.

Another advantage of post-tensioning is that beams and slabs can be continuous, i.e. a single beam can run continuously from one end of the building to the other. Structurally, this is much more efficient than having a beam that just goes from one column to the next.

“Fly Ash is a pozzolan: a silica, alumina, and calcium based material which, in the presence of water, will chemically combine with the free lime contained in the fly ash and produces a cementitious material with excellent structural properties.

“Fly Ash can be used as a direct replacement for Portland cement in making concrete, in addition to many other applications.”

Benefits of using fly ash in concrete:

• Pozzolanic properties reduce need for cement
• Spheres act like ball bearings, increasing workability
• Fills in voids with cementitious material and acts as filler, reducing
  total surface area to be covered with cement
• Increased strength with age

In predominantly warm climates, the high solar reflectance and high infrared emittance roof drops the building’s air conditioning load and reduces peak energy demands on the utility. In North American climates, being predominantly cold, a more moderate reflectance and a low emittance result in a warmer exterior roof temperature, which reduces heat loss from the building.

Temperature, heat flow, reflectance, and emittance field data have been catalogued for a full 3 years for 12 different painted and unpainted metal roofs exposed to weathering on an outdoor test facility. Habitat homes were tested unoccupied for a full summer in Ft. Myers, Florida.

Measurements showed that the white reflective roofs reduced cooling energy consumption by 18-26% and peak demand by 28-35%. The houses were side-by-side, and had different roofing systems designed to reduce the
attic heat gain.

Results show that a judicious selection of the roof surface properties of reflectance and emittance represent the most significant energy and cost saving options available to homeowners and builders.

Superior Durability

Metal roofing is a proven product, more durable than most available roofing systems. Metal roofs simply last longer, and is often the roofing choice for many government, school and industrial buildings.

Excellent performance

Metal roofs rate high in wind, fire, and hail resistance.

Energy Efficient

Not only will a metal roof keep your house comfortable, regardless of the weather outside, it may actually lower your air conditioning and heating bills.

Environmentally Friendly

According to the National Association of Homebuilders Research Center, 20 billion pounds of asphalt shingles are dumped into US landfills every year. The recycled content of the steel in a metal roof is far superior to asphalt. Metal roofs also have a low per unit area weight, making it possible in most cases to install directly over existing roofs, saving removal and disposal costs.

Buildings designed for passive solar heating with natural sunlight to light a building’s interior incorporate large south-facing windows, skylights, and building materials that absorb and slowly release the sun’s heat. Incorporating passive solar designs can reduce heating bills as much as 50 percent. Passive solar designs can also include natural ventilation for cooling. Windows are an important aspect of passive solar design. In cold climates, south-facing windows designed to let the sun’s heat in while insulating against the cold are ideal. In hot and moderate climates, the strategy is to admit light while rejecting heat. Interior spaces requiring the most light, heat, and cooling are located along the south face of the building, with less used space to the north. Open floor plans allow more sun inside.

Active Solar Heating

Active solar heating systems consist of collectors that collect and absorb solar radiation and electric fans or pumps to transfer and distribute the solar heat in a fluid (liquid or air) from the collectors. They may have a storage system to provide heat when the sun is not shining.

An active system may offer more flexibility than a passive system in terms of siting and installation.

Heating your home with an active solar energy system can significantly reduce your fuel bills in the winter.

A solar heating system will also reduce the amount of air pollution and greenhouse gases that result from your use of fossil fuels such as oil, propane, and natural gas for heating or that may be used to generate the electricity that you use.

To learn more about Active Solar Systems, click here.

Combined Passive/Active Solar Heating

We have learned to combine passive and active solar elements in our designs because they both have advantages. Passive heating allows us to use building elements (walls, floors, etc.) as heat storage, reducing the requirements for water storage while leaving the advantages of active solar systems.

A cubic foot of water will transport or store 3800 times the amount of heat the same volume of air will. Active solar systems allow the use of water to collect, store and transport heat.

For more information visit our Radiant Floor Overview page

While some of our houses have been completely passive, actually able to meet their heating loads with the elegant simplicity of passive heating, we believe that a combined system is most effective because the increased area of glass amplifies total heating and cooling load, and active systems allow the greatest flexibility of site design, landscaping, and room layout.

One advantage to using the sun to heat your building in New Mexico is that it allows you to use the unique ”solar right of way” law preventing neighbors from shading your collecting surface, and preserving
the open spaces to the south of your building.

The answer in all cases is to insure a decent, secure, healthy life for all species on this planet.

As consumers, we are frequently confronted with lifestyle decisions that can impact our environment.

There are choices in this life that can make a big difference in what the quality of life will be for those who follow us.

Going with the flow of our culture is hard to avoid, and unfortunately the flow is not in the right direction for evolving a sustainable future.

One of the most momentous choices that any of us will make is the kind of house we live in.

A sustainable building can be defined as any building that is sited, designed, constructed, operated, and maintained for the health and well-being of the occupants, while minimizing impact on the environment.

Sustainable building practices offer an opportunity to create environmentally sound and resource-efficient buildings by using an integrated approach to design. Sustainable buildings promote resource conservation by including design features, such as: energy efficiency, use of renewable energy, and encouragement of water conservation.

By promoting resource conservation, sustainable building design creates healthy and comfortable environments, reduces operation and maintenance costs, considers environmental impacts of building construction and retrofit, and concentrates on waste minimization.

Sustainable building design also addresses such issues as historical preservation and access to public transportation and other community infrastructure systems. The entire life cycle of the building and its components is considered, as well as economic concerns, environmental impact and over-all performance.

We offer post tensioned concrete, using fly ash as an additive material to concrete.

• Find out more about Post Tensioning Concrete.
• Find out more about Fly Ash as an additive material to concrete.

The advantages of metal as a roofing material are efficiency and sustainability. We combine these attributes and integrate this roofing into the heating and cooling system. To learn more please go our Solar Systems page.

Radiant Floor Overview

Radiant heating systems convert a floor into a large area, low temperature radiator. Warm water is circulated through closely spaced plastic tubing that is embedded in the floor slab or attached to the underside of wooden subflooring. Underfloor insulation is a critical component. Zoning depends on advanced manifolds that regulate flow or modulate the water temperature in different tubing runs. Sophisticated controls regulate the system using temperature sensors in the slab in each room being heated as well as outdoors. [Read more]

“Generally the house has not required heavy maintenance sue to the quality of materials and workmanship. However, the solar water system does require more attention than a conventional system.”

The wholesale price of propane increased at 3.8% per year from 1990 – 1999. That is the lowest annual increase we are likely to see given:

• propane is tied to the price of petroleum and natural gas
• petroleum prices have increased and are likely to be unstable, and storage facilities for petroleum, and especially propane are limited

Natural gas prices have increased sharply in the 1st part of this millennium because:

• natural gas is difficult and expensive to transport, especially overseas
• the United States has over invested in natural gas as a fuel for power generation.

The embodied energy (that is the energy used to make the building) can equal 5- 20 years of the energy consumption of a building. That one reason is why we prefer to use fly ash. It is a waste product that replaces part of the Portland cement in concrete. Portland cement production requires strip mining limestone, crushing the limestone, and enormous amounts of energy to convert the limestone to cement. Fossil fumes are consumed and carbon dioxide is produced both by fuel combustion and limestone conversion.

Buildings are a major source of the pollution that causes urban air quality problems, and the pollutants that contribute to climate change. They account for 49 percent of sulfur dioxide emissions, 25 percent of nitrous oxide emissions, and 10 percent of particulate emissions, all of which damage urban air quality. Buildings produce 35 percent of the country’s carbon dioxide emissions the chief pollutant blamed for climate change.

There are many opportunities to make buildings cleaner. As just one example, if only 10 percent of homes in the U.S. used solar water-heating systems, we would avoid 8.4 million metric tons of carbon emissions each year.

Sun & Earth Inc. uses quality materials with low embodied energy, while caring about the environment around us and building cost efficient home.

Reasons for Choosing Energy-Efficient Design

• Tangibles
  • Economics – the short term returns to building owner
    • immediate reduction in utility bills
    • decreased household maintenance, especially cleaning
    • increased appraisal without increase in property tax assessment
    • qualification for energy efficient mortgage programs
  • Economics – long term returns to building owner
    • energy costs increase more rapidly than inflation, so energy efficient upgrades increase their cost effectiveness. They appreciate more rapidly than other building amenities, which may even depreciate
    • energy efficient upgrades will be saving money at the same time they are appreciating. Similar to rental property except that they are a passive investment.
• Intangibles
  • Human rights and political self determination
  • Sustaining the environment

“We are very pleased. The house has exceeded our expectations in terms of aesthetics, quality, and energy efficiency.”