By Daniel J. Williams & Ellen Kominars
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”.
Three primary types of pet grooming dryers include the cage dryer, the stand dryer, and the high velocity dryer. This article focuses on understanding the differences, benefits and uses of these three dryer types.
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.
The c.f.m. and f.p.m. attributes are determined by the blower motor manufacturer and are different from one product design to the next. These performance variables include configuration, air inlet and outlet aperture size, hose diameter and length.
• 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.
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.
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).
The “off delay” timer circuit is excellent on this dryer type. The unit automatically shuts off after timing out. The frequently distracted pet groomer has the peace of mind that the unit will shut off automatically without any further effort, thereby protecting the animal from overheating.
An alternative to moving the dryer from one cage to another is enabled with a single dryer with multiple air outlets. The hose ends can be relocated from one cage to another as needed. There are apertures that can be closed on this cage dryer allowing airflow at one, two or three locations. With the two apertures closed the airflow is directed out of a single outlet allowing the unit to be used with a hose to act as a high velocity dryer.
Stand dryers are used at the grooming table and are often referred to as “fluff dryers.” This type of dryer enables “hands free” use, allowing the groomer to use both hands on the animal.
These dryers are versatile in that they can be moved easily within the shop. They can also be used as cage dryers if they are placed in the right position in front of a cage. The dryer can then be easily moved near a grooming table to dry the dog during a brush out. A shortcoming of the stand dryer is that it does not have a flexible, hand-held hose. In order for a groomer to reach tight spots and to blow out tangles and mats, a high velocity dryer is usually needed.
Some dryer makers offer adaptor kits complete with special stands that allow high velocity dryers to be used as stand dryers.
High Velocity Dryers
Many high velocity dryers do not have heat, as they rely on air impingement force to mechanically remove the water from the pet’s skin and coat. In other words, they “force” or “blast” the water off the animal’s skin and coat. Due to air friction, these dryers add 8-15 F to incoming ambient air. Motor arrangement, be it a series or parallel arrangement, affects both temperature and air speed. The “series configuration” adds more temperature than does the parallel.
The number of motors inside the dryer is important, though not always published by the dryer maker. Generally, the most powerful high velocity dryers have more than one motor and often consume the bulk of available current on a conventional 20-amp circuit.
The lightest weight and lowest cost units are generally single motor dryers. They typically draw between 6-15 amps. Arranged in a “series” circuit, the dual motor dryers deliver between 1.3-1.5 times the amps of a single motor unit. This configuration is excellent with long hoses (over 33 feet), as air volume and velocity drop only minimally.
Dual motor dryers arranged in “parallel” deliver almost twice the volume or about 190% of the single motor. However, this arrangement is prone to performance loss if the hose runs over 33 feet.
The two configurations above deliver the same airflow with a hose length of about 33 feet. Therefore if the hose run is less than about 30 feet, the parallel configuration will outperform the series. Single vs. two motor dryers can be distinguished by their size and shape. The long single canister has two motors in series airflow and the large “twin” canister or wider box dyer has two motors in parallel.
A large double coated Golden that would take 3 hours to dry with a hand blow dryer might take 42 minutes with a single motor high velocity dryer and only 22 minutes with the two motor configuration. This dryer type is of interest to the large volume grooming shop where there are never enough minutes in the day.
With so much said on reducing blow dry time with different dryer types, it is important to acknowledge that there are also liquid products available that dramatically reduce dry time. These products improve slip between hair strands with quaterniums that smooth and coat the individual strands. Such spray-on detangling and dematting products can be used before and after the bathing process. Such products, if well formulated, also contain conditioning agents that repair much of the damage caused by brushing and drying.
This type of product will accelerate both the mechanical removal and evaporation processes by getting the water to sheet on the hair shaft. The sheeting is accomplished by reducing the surface tension of water remaining in the coat. Such “spray on–leave in” products have been proven to reduce blow dry time by as much as 50%. Some large volume pet grooming shop owners mandate that their bathers use such products for the purpose of reducing blow dry time.
Deciding which dryer to purchase is made easier by understanding each of the available products. Shop owners will show consideration for their unique environment and budget. For example, a mobile groomer generally looks for the highest performance high velocity dryer that generates the least noise and draws the least amount of current. A large facility with many cages, on the other hand, will become experts at taking advantage of the “crossover” units that can act as both cage and high velocity dyers. Budget, shop type (cage free shop vs. with cages and mobile vs. salon), available utilities, and shop layout all influence which dryer is best to purchase for each application. ✂
1. A.L. Hunting (1985). Encyclopedia of Shampoo Ingredients. New Jersey: Micelle Press, Inc.
2. Williams, Daniel. “A comparison of air velocity with increased hose length in three motor arrangements.” EZ-Groom Internal Publication June 12, 2009.
3. Cosmetic Bench Reference, Allured Publishing Company, Abbott Park, IL 1998
4. Meisler, Elizer. “Independent variables studies by percentage separately and together for synergistic reduction of water’s surface tension” EZ-Groom Internal Publication July 12, 2007.
Daniel J. Williams is the managing director of EZ-Groom Pet Products Inc. in Oak Park, Michigan, U.S.A. He holds an undergraduate degree in electrical engineering from Lawrence Technological University and has completed advanced studies in metallurgy and thermodynamics. Dan earned a master’s degree in business administration from Baker College and has completed the University of Chicago Advanced Leadership program. He has authored numerous articles on cosmetics, and metallurgy as it relates to pet grooming shears. Dan has designed and engineered a number of manufacturing projects at metal-making factories in the Americas, Europe and Asia. Over the past 22 years, Dan has served as president and CEO of three small closely held organizations where he managed a number of mergers and acquisitions. Dan has worked with EZ-Groom since 2002.