denver_evaporative_coolerThe 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 (Public Domain)
Evaporative cooler cut-away diagram courtesy of Wikipedia, released under a CC BY-SA 3.0 license


denver-swamp-cooler-installation-repair-replacementWhat determines how much air flow I get to the rooms in my home?

Your duct-work system and furnace blower are the most important factors that affect air flow for both heating and air conditioning.

Duct work: Inadequate duct-work is an unfortunate but common problem for Colorado homeowners, especially in newer homes. As air moves through your duct system, friction between the air and the duct slows the airflow’s velocity. By the time air reaches your upper floors it has lost the necessary force to properly cool down a room. Also, small duct diameters restrict airflow, for much the same reason, for example, that it is difficult to drink a can of soda through a coffee straw. It is oftentimes impractical to overhaul your system’s duct-work because the majority of it is between your walls. However we can make a significant difference in your airflow by adjusting the exposed ducts in your basement.

Furnace Blower: Your furnace’s blower is what creates air movement through your ducts. It is important that the blower be powerful enough to push the cold air to your upper floors. More force is necessary to push cold air up through your ducts than warm air—adding to the difficulty of effectively cooling a second floor. While air conditioning can usually be added onto an existing furnace, keep in mind that a marginal or old furnace (15 years or older) may have lost substantial effectiveness or efficiency due to its age. Our licensed air conditioning technicians can give you a recommendation that will suit your needs.

How can I make sure that my new system will actually cool my home?

When it comes to heating and air conditioning, bigger is not always better. An oversized air conditioning system can freeze the coil due to overcooling. On the other hand, an undersized system will fail to cool your home on the hottest days when you need it most. Properly sizing the outdoor condenser, and air conditioning coil, is an essential step in ensuring that your home is cooled effectively. We determine the right-sized air conditioner for your home by performing a whole house heating and cooling analysis that conforms to the standards set out by the American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE). Additionally, it is important to do a survey of your home’s duct-work system. Your home’s duct-work is an important factor in the effectiveness of your entire air conditioning system. It is possible to cool your home at 12,000 Btu’s (1 Ton) for every 400 cubic feet per minute of the airflow that your duct-work can deliver. If too much cooling is applied to a small amount of airflow, then the air conditioning coil will freeze over, compromising the system’s capacity to move air past the ice above your furnace. Frozen air conditioning coils are a frequent problem in Colorado because so many homes have undersized duct-work. If the ducts in your home are inadequate for cooling we can make duct modifications to maximize your home’s cooling capacity. In rare cases a smaller condenser is needed in order to accommodate that particular duct system. Accordingly, we can make recommendations for how you can decrease the cooling load of your house. It is better to have the properly sized system for your individual home’s need rather than experience unexpected problems after the installation.

How can I know if the technician coming out to my home knows what he is doing?

Believe it or not there is no license requirement in the State of Colorado to be a heating or air conditioning installer! Unlike many of the appliances in your home, such as a washer or dryer, your heating and air conditioning requires a lot of assembly. Consumer reports have indicated, from equipment testing, that the most important factor on an air conditioning system’s longevity and performance is the competency the installers rather than the manufacturer of the equipment. All of Chaput Rootmaster’s air conditioning installers are N.A.T.E. (North American Technician Excellence) certified, the highest industry designation that an HVAC installer can acheive. N.A.T.E certification is endorsed by every major manufacturer, yet less than 10% of technicians nationwide are N.A.T.E. certified.

What will the outdoor unit look like in my yard?

Your new system will sit on the side of your house or in your back yard. Trane’s outdoor condensers are all manufactured with steel louvered panels that protect the coil inside and look very attractive on the outside. Here are representative examples of Trane’s two product lines:

Trane XLi Series:


Trane XR Series:


How much will it cost to run air conditioning?

The outdoor air temperature and the temperature setting on your actual thermostat both factor into your cooling bill. The following chart shows a clear presentation of the savings between higher and lower efficiency systems.


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.