The noise level is higher when the whole length of a blade overlaps/passes a shroud strut and if all the blades pass all the struts of a shroud at the same time, noise is at its worst. Performance cooling products for the automotive market. Fan blades are curved for optimum air circulation which is determined by solidity ratio. Each blade on curved blade fan pulls air at slightly differing times and the air impulses overlap, cancelling the airwaves each creates while … Fan blades have gone through a number of evolutionary steps. The next fan uses an. The angle is designed to almost cut or curve its way through the air. I changed a curved blade SPAL for a straight blade SPAL and the difference in noise level was significant. As shown in the performance curves below, Davies Craig Thermatic Fan outperforms a competitor’s curved blade product across the full pressure range: The fan pulled about 7A, was straight blade and appeared to drive air well enough. If you desire a more quiet fan then the curved is the way to go but if you need all airflow possible, go for the straight blades. Please visit our buy online section to view our Thermatic Electric Fan range. The straight blade fans provide maximum cooling for their size. All three electric fans shown use a 16-inch fan blade. Very easy to fab some brackets and install. Solidity ratio is the ratio of area of the blades to the area of the disc swept by them. While the purpose of a ring is to reduce losses from air passing from the high-pressure side of the blade to the low-pressure side as shown, Davies Craig managed to achieve this by adding winglets to the blade tips without energy loss. This reduced depth helps the fan fit in tighter spaces. As shown in the performance curves below, Davies Craig Thermatic Fan outperforms a competitor’s curved blade product across the full pressure range: Noise Control: Most fan noise is generated from a blade passing a shroud strut. If you ever look closely at a fan, the first thing you will notice is that the blades are set at an angle. But if it's drawing the fan blades into the surface of the radiator.... then it could eventually wear a hole or two into the very thin aluminum fins of the Rad. I was riding this summer in some pretty hot climate during a road trip. If a fan moves less air, then simply, you can expect less noise. The loss in performance is caused by the fact that curved blades stall at a lower static pressure than straight blades. Some manufacturers have chosen to curve the blades and keep the struts straight. This is a popular choice for many owners because it offers slightly better total airflow performance than the straight blade, but it is noticeably quieter. Tue Jul 01, 2008 9:09 pm. All shot blasting machines require blades to propel media towards workpieces. As a result of the extensive research program, Davies Craig were able to ascertain that curved blades generated less noise, however, this was achieved at the expense of a significant loss in performance. I went on to try and explain that just saying curved blade is not enough, as there are foward facing curved blades as well as backward or reverse facing curved blades. A. Will the electric fans help keep my car cooler at highway speeds? It fits very nice and pulls a ton of air through the radiator. The full product line now includes the patented Flex-a-fit aluminum radiators, electric fans, belt-driven fans, oil coolers, Mojave heaters and Flexite windows. The loss in performance is caused by the fact that curved blades stall at a lower static pressure than straight blades. This electric cooling fan can draw 6.6 amp of current and produces 1550 CFM. Our investigations also found that when air flowed in layers (laminar flow), it breaks up into counter rotating airflow vortices (whirlwinds): These vortices consume energy and therefore reduce the airflow. The curved blade fans sacrifice a small amount of performance in return for a much quieter fan. It measures 3.39 inches in total depth. Features curved blades which are much quieter than straight bladed fans; Available in 10, 12, 13, 14 or 16-inch sizes; Blades are made from durable plastic and have a natural finish; 12V motor uses a total of 14.2 amps; Fan assembly has a depth of 3.5" The thread was in regard to comparing straight blades versus curved blade cooling fans. The straight blades move more air but they are louder. Cooling Fans - … Included with each fan is a fan mounting kit with 4 plastic through radiator core rods and clips, 4 … Straight vs. Curved Fan Blades - Dispelling the Myth! This unit is spec'd at 2780 cfm, which has been more than adequate to cool my 9.2:1 468 in 105 ambient temperature in heavy traffic. CFM — cubic feet per minute — is the rating given to every fan, signifying how much air a fan … Blade Technology: Straight vs. Curved Blades Explained. It moves 590 CFM at 0 static pressure, drawing only 5.3 amps. Our fans come in many different sizes and styles, ranging from 6.5” to 16” in diameter. The idea of a ring around the blade tips was also researched and rejected since the performance suffered due to the increased energy required to propel the blade with extra weight at the tips. SINGLE FAN MOUNTING HARDWARE KIT (12V) (1000) SINGLE FAN MOUNTING HARDWARE KIT (24V) (1001) DUAL FAN MOUNTING KIT - UNIVERSAL 12V (1002) DUAL FAN MOUNTING KIT - UNIVERSAL 24V (1003) FAN & TRANS OIL COOLER MOUNTING HARDWARE (UNIVERSAL) (0578) The Davies, Craig Universal Fan Fitting Kit includes all parts necessary for mounting and wiring any 12- and 24-volt electric fans – all Davies, Craig Thermatic®Fans and other electric fan models. 02-10-09 07:02 AM - Post# 1626775 In response to Jim.Biron I am running a Be-Cool p/n 75007 dual 11" paddle fan setup. If a fan has a lot of blades but the pitch of those blades is flat… you will get the riverboat paddle wheel affect where the fan will make a lot of noise but not move much air, like a riverboat paddle wheel. Davies Craig conducted a thorough research program to formulate the design of fans in which several design types including straight blades and curved blades with and without a ring were considered. Some manufacturers have chosen to curve the blades and keep the struts straight. In addition to that, it has a fan diameter of 11.73 inches and depth 2.56 inches. Initially I used a small (1" thick) radiator fan and constantly over heated. The idea of a ring around the blade tips was also researched and rejected since the performance suffered due to the increased energy required to propel the blade with extra weight at the tips. Our investigations also found that when air flowed in layers (laminar flow), it breaks up into counter rotating airflow vortices (whirlwinds): These vortices consume energy and therefore reduce the airflow. As a result of the extensive research program, Davies Craig were able to ascertain that curved blades generated less noise, however, this was achieved at the expense of a significant loss in performance. 61-67 Taras Avenue, P O Box 363Altona NorthVictoria  3025Australia, Phone: All in an effort to seek more fan efficiency. If ultimate performance is the objective, use the straight blade fans. They are quieter than a straight blade fan but are also less efficient. 7-blade plastic fan correctly orientated, with the deep dish facing away from the engine, and the slightly curved leading edge of the blades for clock-wise rotation. Besides, it is excellent for an upgrade from factory parts and a replacement. If installing one into a high-performance engine, the straight blade is the way to go. I'm writing this review for using this 12" high output SPAL fan on a kit car based on the ford focus 2.0L engine rear mounted with a front mount honda b16 triple core radiator. Spal VA08-AP71/LL-53S 14" Blower fan, vs an eBay fan advertised as 220W... but after testing only drew 85W. The relative merits and technology of curved vs. straight fan blades have been debated for some time. im thinking of replacing my 10" puller fan to a 12" as there seems to be a good amount of room for a bigger fan. Q. +61 3 9369 1234, Follow us on your favourite social media sites, FAN & EWP CONTROLLERS / SWITCHES-Testimonials. It was found that by inserting triangular protrusions near the leading edge of the blade, the air is tripped into going into vortices earlier. The loss in performance is caused by the fact that curved blades stall at a lower static pressure than straight blades.