The state of Colorado is attractive to many people because of its mountainous wilderness and good weather. Those who have lived here many years take advantage of the 300 days of sunshine per year, moderate fluctuations in temperature, semi-arid climate, and generally short winter storms (especially in Denver and along the front range). But many Colorado homeowners are still using conventional air conditioners rather than evaporative coolers, despite the substantial savings to an energy bill and ease of maintenance that the latter provides. Let’s take some time to discuss the basic differences between these two systems, what the advantages of an evaporative cooler are, and why an evaporative cooler is such a smart choice, given the climate.

While there are many different types of air conditioners (e.g., dehumidifiers, window units, split systems, etc.), the basic air conditioner works like a refrigerator but without the insulated box like the one in a kitchen. In a basic unit there are two coils: one condensing coil for heating, and one evaporative coil for cooling. The heart of a conventional A/C system is the compressor, inside which freon is heated or cooled and sent into the coils, so that the air, blown over the coils by a fan or blower, has the desired temperature. This is also why A/C systems are described as ‘blowing warm air out in order to bring cool air in’, otherwise called cycling. In effect, this constant vapor compression regulates the temperature of the air in a home, and is very common in humid areas of hot or moderature temperature (such as in the southwest), and in humid areas of cold and extremely cold areas (such as in the northeast). The bulk of the cost of these systems, which can range anywhere from $3,000 to $7,000, comes from the brand (such as a Trane, for example), the compressor within, and the labor to install them (sometimes half of the total cost). The number of kilowatts per hour for such a unit, a common measurement used to weigh the cost of A/C units, is anywhere from 3 to 8 kilowatts per hour for the average U.S. household (5 to 20 kilowattsfor bigger units used in larger residential homes, often found in suburban areas). Of course, they are very effective, and have cooled millions of homes for decades. However, the bill for its use during peak season can cost a Colorado homeowner up to $500 a month (presuming the kilowatt cost will continue to increase dramatically, as it has been in the past few years).

However, Colorado homeowners have a large advantage over homeowners in other states: Colorado’s dry climate means that evaporative cooling systems are a fantastic and economical alternative to expensive air conditioning. At the same time, XCel Energy and other utilities are increasingly offering incentives for switching to, or adding, evaporative cooling to one’s home (such as rebates or discounts if an evaporative cooler is installed). Even as effective as modern conventional A/C units are, the cost per month, and the cost to service these units (as much as $75 an hour), is becoming a major budget consideration for Colorado homeowners, and evaporative coolers provide an attractive alternative.

An evaporative cooler is essentially an air-cooling device. Rather than using compression and condensation (meaning, using freon to heat the condenser coil and blow out hot air), it uses evaporation in tandem with a fan, which is then used to pull air through a medium inside the device, a medium that is constantly kept wet by water that is sprayed onto it, or dripped onto it. Consequently, this action puts humidity, or moisture, into the air (unsuitable for humid climates such as Houston, Tx, but great for dry climates like Denver). They have been around for about sixty years, and are still sometimes referred to as ‘swamp coolers’, the name probably arising from the mold once common in older systems that did not have the built-in monitors and self-cleaning systems that modern evaporative coolers have today. The unit basically consists of an up-duct system leading into the cooler, evaporative water pads, water distribution lines, a blower motor, a recirculating water pump, and a grill cover. Up-ducts are, essentially, airflow channels that have to be installed for the cooler (i.e., if existing ducts are incompatible). Air comes in from the duct, the evaporated water cools the air, and the air then blows out into the room. A cooler of this nature can cool the air to about 20 degrees lower than the current ambient air temperature (e.g., if it is 90 degrees, the EC can cool it to 70 degrees). If the airflow throughout the house is used wisely, the unit can oftentimes cool a room much faster than a conventional air conditioner.

There was once a time when all evaporative coolers were virtually the same, and thus suffered from the same problems. Only one type of media was used for the water pads, meaning that they had to be cleaned, and changed out, often and were not all that effective. The water reservoirs were a pain to clean, and the blower motor, especially for larger units, was disturbingly loud. The blower motors had only one or two settings, and thus could not take advantage of electronic thermostat controls (now available), which allow for the blower speed to be changed but the motor to remain at a more constant speed. Additionally, and most importantly, old swamp coolers typically ran at 3 to 4 kilowatts per hour, which in some cases was not that much better than medium-sized, conventional air conditioners in use at the time. Today things are quite different, and the advantages of modern swamp coolers are impressive.

The process of cooling air all comes down to speed. The hotter a room is, the more cold air you need to circulate per second in order to cool down the room. Since reduced power is at the core of modern evaporative cooling technology, advances in this area have yielded some very smart machinery inside modern coolers. For the homeowner, this translates into reduced costs, about ⅓ of what it would cost to install even a modern, advanced air conditioner. Even better, this modern evaporative coolers in Colorado often lead to about a 75% reduction of one’s energy bill, particularly during peak seasons. Some of the new features are as follows:

• Newer models from high-performance brands such as OASys and Breezair can run as low as 60 watts per hour and cool a room at the same rate as, or better than, a previous model.
• High-performance media for water pads can maximize the moisture exchange (a key measurement of the effectiveness of all swamp coolers today).
• Modern coolers will have completely encased housing, which allows for easier assembly, and thus, a lower cost at the point of sale.
• Electronic thermostat controls manage all the components, particularly the blower motor, and automatically respond as the ambient air temperature changes.
• Instead of only 70% of the circulated water being used to cool the air like their older counterparts, newer evaporative cooling units use 95% of the circulated water to cool the air, even after filtration.

There’s really no doubt about it: evaporative coolers have come a long way, bringing significant cost advantages to the Colorado homeowner looking to cut home energy costs. Every year the components in newer models are optimized to deliver the same rate of cooling at a lower rate of power. They also run quieter, cool air more quickly, filter and manage the water and air more effectively within the unit, and provide sleeker and more compact designs that are easier to install, use, and maintain. If it’s time to replace your old air conditioning, consider the cost benefits of switching to evaporative cooling — it just might be the perfect cooling system for your Colorado home.

Call 303-421-2161 to reach YOUR Denver Plumbing Company: Blue Sky Plumbing.

We service Applewood, Cherry Hills, Arvada, Golden, Evergreen and the entire Metro Denver area.

Evaporative cooler illustration from www.Energy.gov (Public Domain)
Evaporative cooler cut-away diagram courtesy of Wikipedia, released under a CC BY-SA 3.0 license