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Needed not just to save time, but also to get “the right look”, pet grooming dryers are some of the most important pieces of equipment in a pet grooming salon. The decision of which to buy can be complicated. The type of dryer, available utilities, length of hose, intended location of the dryer, tolerance for sound, performance, and budget—along with a host of other factors—need to be considered.

Drying pet hair requires more time than drying human hair because pets have so much more of it. Showing consideration for hair density and diameter, a typical Golden Retriever has 30 times the surface area of hair than a person with a nominal length of 10” hair.

Most humans have a scalp size in the range of 120 to 150 square inches with about 700 hairs per square inch. Most people with a full head of hair have between 70,000 and 125,000 strands of hair. Based on a 10” hair length and 0.0027” hair shaft diameter, the surface area of a human’s hair is about 70 square feet. This is about the surface area of one side (inside or out) of both halves of a sliding patio door.

Dogs, depending on the coat type, have from 1,000 to 6,000 hairs per square inch. A typical Standard Poodle has 20 times the surface area of a human’s hair, and a Golden Retriever has about 30 times the surface area of a human’s hair. So, referring back to the sliding patio door example, while the surface area of a woman’s hair is equal to one set of patio doors, the Poodle and the Golden have hair surface areas of 20 or 30 sets of sliding doors, respectively. All this hair holds water primarily as a function of surface area. The water must be removed at the right time in the grooming process in order to obtain “the right look”.

Before examining details of the three dryer types, it is important to review the technical terminology in order to understand the buzzwords that apply to all dryers. This nomenclature includes:

? c.f.m. is cubic feet per minute. It is the volume, in cubic feet, of air that is moved in a minute. This attribute is important for cage dryers, where large volumes of air need to be moved but not necessarily at a high velocity.

? f.p.m. relates to air velocityin units of the feet per minute. This performance attribute is important with the high velocity dryers that rely upon air speed to mechanically push water from the coat.

? Amps is the amount of electrical current in amperes. Most newer wall circuits are 20 amperes. Some older circuits are only 15 amperes. Many of the larger double motor high velocity dryers draw at or near 20 amps, necessitating a dedicated circuit, as 20 amps is the limit of conventional residential and commercial circuits.

? Volts or voltage is typically 115/120 for common appliances in the USA. 240v circuits are typical for electric clothes dryers. Europe and Asia primarily have 240 volt circuits.

? H.P. and Watt are related in that they both represent energy. Watts = Volts x Amps and there are 746 Watts in 1 Horsepower (H.P.). Electrical efficiency and power factor are ignored, as they are negligible with the small motor size.

Electric Heating Element:

To take advantage of the evaporation effect, many cage, stand, and a few of the high velocity dryers have electric elements to elevate ambient air temperature. Timers and dryer location are very important for pet safety with dryers that have heat. Adding a heating element to a dryer dramatically improves air’s ability to carry moisture as the temperature increases.

There is a six-fold increase in the ability of air to carry water as it is heated from 70 F (21 C) to 140 F (60 C). The 140 F value is of interest with humans, as it is commonly accepted as the “threshold of pain” value. Most dryers will deliver air at or near this crucial 140 F (60 C) temperature. Unfortunately a dog body temperature above 106 F, for even a short period of time, is very dangerous, resulting in heat stroke and possible death.

Of course the dryer’s warm air is mixed with cooler ambient air and can be very effective in removing moisture. However, prolonged exposure in closed areas with high starting ambient temperatures is fertile grounds for disaster. On the flip side, due to the cooling effect of evaporation, in cool ambient air, the pet can be chilled without heat. This makes the timer feature of high interest, as it can provide a balance.

Speed Control:

Variable speed control is an excellent feature on most of the dryer types. It does add cost to a dryer, so it is sometimes offered as an option. The speed control board controls the rotation speed of the blower motor. This is done with an electronic device called a Triac. In a variable resistance circuit, this device acts just like a dimmer for lights in a home.

A speed control potentiometer controls the point in each cycle that the triac is triggered on. With the speed control turned all the way up, the triac is turned on at the beginning of each cycle. As the speed control is turned down, the trigger point is delayed more and more. This reduces the average power fed to the motor and thus reduces speed.

Cage Dryers

Some grooming shops boast being “cage free” and have no use for the cage dryer while others have as many as ten units in use during a busy day. Cage dryers commonly have three key features: heat control, timer control and speed control.

These types of dryers are commonly placed on the floor or hung on the side of the cage in such a way that the air flow is below the dog’s eyes to avoid drying of the eyes. The dryers require very little intervention and allow the groomer to tend to other tasks while the animal is being dried.

A typical cage dryer may have from 1,000 to 4,000 f.p.m. The cage dryer is designed such to replenish the air within the cage with new warm air. As this warm air enters the cage, it picks up moisture via evaporation. These dryers take advantage of the six-fold increase in the ability of air to carry water as it is heated from 70 F (21 C) to 140 F (60 C).