Tested: What is the best fan for indoor training?
Tested: What is the best fan for indoor training?
Indoor training has changed radically over the past decade. It’s not so long ago a blank wall was the most common form of trainer entertainment. Repeats of old races were about as interactive as indoor riding got. Nowadays we can enjoy smart trainers, virtual worlds, and even artificially intelligent training plans.
One thing that hasn’t changed is the sweating. Indoor training gets hot, quickly! Not only is the sweaty mess quite nasty, but the increased body temperature can be detrimental to training and even downright dangerous. So important is keeping cool that I put fans as the number one essential accessory in my perfect pain cave series. Most riders will agree that a good fan is an absolute must, but with so many different shapes, sizes, types, and prices, it can be difficult to determine which fan is right for you. We decided to put some fans to the test to find the best one for indoor training.
Unlike many cycling components and accessories, fans are a popular product in high demand across different markets. The list of fan offerings to meet the demands of indoor training is almost endless. Search “floor fan”, “desk fan”, or “table fan” online, and you could be scrolling through the results for a week. As such, it would be impossible to review and rate every fan on the market. Instead, I decided to take four different fans with various designs and price points to recommend the best fan type for indoor training.
What makes a good fan?
When we exercise, we accumulate heat within our body. The body has a natural ability to dissipate this heat through conduction, convection, radiation, and evaporation through sweating. Outdoors, the cooling effect of air moving over the body compliments this natural ability. Indoors we lack that natural cooling airflow, and that’s where problems arise.
As many of us have experienced, the body’s ability to dissipate heat is limited. Whether it be a hard climb on a stiflingly hot day outdoors or a hard indoor session, the heat build-up eventually becomes too much for the body to dissipate. With specific protocols and managed correctly, this increased heat and core body temperature in training can result in performance gains on race day. More often, though, and especially when mismanaged, this heat build-up is detrimental to training at best and even quite dangerous, causing severe heat exhaustion, among other harmful side effects.
When training indoors, we want, as much as possible, to replicate the same cooling airflow we get over the body when riding outdoors. Training in a well-ventilated area with a lower room temperature is key in creating conditions in which the body can perform adequately. In combination with the right fan, these ambient conditions can make a world of difference to your indoor training comfort and effectiveness.
Humans are great at thermoregulation compared to other species. However, the body’s capacity to lose heat is not unlimited and at a certain point these processes are unable to match the accumulation of heat during exercise which can ultimately lead to mild hyperthermia or even severe heat exhaustion.
Dave Bailey – WorldTour performance consultant.
As already mentioned, the sheer number of fans on offer makes it impossible to test them all. We decided to narrow our focus to several fan types and selected a fan to represent each in our testing. First, I selected a generic 9″ desk fan, commonly seen in indoor setups around the world. Next up, I wanted to determine in testing if a large enough circulator fan could double up as a fan for Zwifting. For this reason, I included a large circulator fan from Black & Decker.
The Black & Decker fan’s intended use is for air circulation purposes. As such, it is not designed to generate high wind speeds. I wanted to test if its sheer size still makes it useful for indoor training.
I opted for exercise-specific options to fill the final two spots in the test. Firstly, the Vacmaster Cardio 54 which promises high wind speed and CFM (cubic feet per minute) ratings with an added bonus remote control. Last but not least I simply had to include the Wahoo Headwind given its status as probably the best-known fan in the indoor cycling space.
I assessed each fan across a series of tests and measures. I first noted and measured each fan’s price, speed settings, wattage use, ease of use, noise level, size, wind speed, and measured CFM to determine the easily distinguishable characteristics of each fan. I then partnered with Swiss company Core, manufacturers of the core body temperature sensor, to test the effectiveness of each fan. Lastly, I took numerous subjective measures of each fan’s performance during the testing and over longer-term general trainer use. We combined the findings to recommend the best fan(s) for indoor training.
Undoubtedly we could have easily determined whether the storm-like air movers such as the Vacmaster and Wahoo are better for indoor training than a 9″ desk fan without a full day of testing. Nor does it seem fair to pit the big friendly giant-like circulator fan against the wind tunnel-like workout-specific centrifugal fans. That said, desk and circulator fans such as these are often much cheaper than the two dedicated training fans we have on test, and many riders will already have similar fans in the house.
We picked these four fans specifically because 1) they represent the fan types I most often see riders using and 2) we all want to know if the dedicated fans are worth the extra money. As such, we wanted to determine the variation, if any, in key response metrics from fan to fan and the benefit of any fan versus no fan at all. We also wanted to provide a cycling-specific resource on different fan types for those looking for the best fan to Zwift with.
Indoor cycling fans tested
As previously mentioned, some of the fans on test are representations of countless other very similar, sometimes identical, fans on the market. Many of the details in this section are included for reference and comparison to other fans you may be considering.
Basic 9″ desk fan
- Price: Various, I paid £19.99 for this fan.
- Fan type: Axial desk fan
- Footprint: 27.5 cm x 14.5 cm
- Speed settings: 3
- Remote included: No
- Cable length: 1.35 m
- Power & consumption on max speed: 25.7W, 0.0257kWh (KilowattHour), 0.198amps, (239.5volts)
- Decibel level on max speed: 60.9 average / 63.1 max
- Measured CFM: 308.58 ft³/min
- Alternatives: Too many to list
- Strengths: Compact size, relatively cheap options available, quiet.
- Lows: Low air speed, limited cooling effect.
This is a fan. A small, quiet fan, cheap to buy and easy to store. It’s the kind of fan you might find in many homes or offices. Perfect for a light breeze on a warm day or keeping a desk area fresh. I used this fan, along with at least two others, for much of my indoor training during our first COVID lockdown. While it was fine for short easy rides in cooler conditions, it simply can’t offer the airspeed or channelled airflow to create any real cooling effect when the hammer goes down.
Black & Decker 20″ circulator fan
- Price: £49.99 / prices vary locally.
- Fan type: Axial air circulator fan.
- Footprint: 60 cm x 23 cm
- Speed settings: 3
- Remote included: Yes
- Cable length: 1.60 m
- Power & consumption on max speed: 64.3W, 0.0643kWh, 0.257amps (239.4volts)
- Decibel level on max speed: 71.3 average / 72.3 max
- Measured CFM: 1,801 ft³/min
- Alternatives: This same fan is available from several manufacturers.
- Strengths: Circulating large volumes of air around a room.
- Lows: Low air speed, limited cooling effect.
This Black & Decker is a noticeable upgrade from the basic fan above. The fan is much larger overall and with relatively huge blades it looks impressive too. The inclusion of a remote control ticks another box. The much larger blades and power do create an uplift in airspeed compared to the basic fan. However, taking the first step in front of the Black & Decker at full power I was somewhat underwhelmed.
The airspeed and cooling effects were much less than you might anticipate given the sheer size of the fan. This is because the Black & Decker is a circulator fan, designed to calmly circulate large volumes of air around a room, rather than channel high-speed air directly at a rider.
What the Black & Decker lacks in airspeed it makes up for in CFM. At 1,801 ft³/min the Black & Decker has more than treble the CFM of the Vacmaster in second place. I wanted to include a circulator fan in our test to determine if the underwhelming airspeed of this circulator fan could be offset by an increased CFM (think weight versus aero in a road bike). Much like wind speed, we can subjectively measure weight quite easily. Aerodynamics, much like CFM, are much harder to subjectively quantify but can have a bigger impact on performance.
Vacmaster Cardio54
- Price: £99.99 / prices vary locally.
- Fan type: Centrifugal air mover.
- Footprint: 25 cm x 28 cm
- Speed settings: 3
- Remote included: Yes
- Cable length: 3.70 m
- Power & consumption on max speed: 142.7W, 0.1427kWh, 0.584amps (240volts)
- Decibel level on max speed: 74.3 average / 75.8 max
- Measured CFM: 474 ft³/min
- Alternatives: DeWalt CentriFugal Air Mover / X-Power Mini Mighty Air Mover / Vacmaster 550 CFM Air Mover
- Strengths: Highest air speed, narrow channeled air flow, cooling sensation.
- Lows: Limited to three angled positions.
The Cardio54 Gym Floor Fan is a workout-specific offering from the vacuum cleaner and fan specialists, Vacmaster. I say workout-specific, but the Cardio54 is effectively Vacmaster’s standard Air Mover fan with the inclusion of remote control speed adjustment. This upgrade is a good thing. The Air Mover is a very powerful fan and the addition of remote speed adjustment makes for easy adjustment of the airflow as required. Of course, a remote wall plug can get the standard Air Mover halfway there, but such a setup is limited to on or off.
The Cardio54 on full power delivers an almighty wind speed. The narrow rectangular opening channels the gale-force-seven wind speed directly at the rider. So strong is the airflow, I most often kept the fan off, or on the lowest setting, until well into my spin when I had completely warmed up. This is where the remote control proved most useful.
The small remote clips directly to the handlebars or trainer desk for quick and easy on/off and speed setting adjustment. Mounting pegs on the side make the Cardio54 stackable for those after the ultimate wind tunnel-esque environment.
The Vacmaster’s relatively small footprint and shape are an added bonus for those stuck for space. The relatively restricted three-position setup is the only negative I could point to in the Cardio54. If you have an awkward space or crowded trainer desk you might find it a little challenging to get the right angle for airflow onto your body.
Wahoo Headwind
- Price: US$249.99 / £199.99 / AU$449.45 / €229.99
- Fan type: Centrifugal air mover
- Footprint: 31.5 cm x 42.5 cm
- Speed settings: 4 + Speed/Heart rate matching
- Remote included: No. Remote function available in the Wahoo app.
- Cable length: 2.75 m
- Power & consumption on max speed: 175.7W, 0.1757kWh, 0.852amps (240volts)
- Decibel level on max speed: 71.6 average / 72.3 max
- Measured CFM: 456.2 ft³/min
- Alternatives: Dyson Cool Tower Cooling fan, See Vacmaster alternatives above.
- Strengths: Strong air speed, narrow channeled air flow, cooling sensation, speed and heart rate connectivity.
- Lows: Limited to two positions, costly, no remote (app available).
Is this what cycling has come to, paying for headwinds? All joking aside, the Wahoo Headwind includes several trainer-friendly features. The Headwind is a centrifugal type fan, with all the wind-generating parts hidden inside. The fan has no visible or external moving blades or parts. The high-speed airflow from the tall forward-facing vent is immediately impressive, especially if you are coming from smaller desk fans.
Much like the Vacmaster, the Headwind is powerful enough to be uncomfortable for all but the hardest efforts in average room temperature environments. I found myself most often using the middle two-speed settings in my relatively chilly garage. Again, like the Vacmaster, the limited standing positions are less versatile than angle adjustable fans. That said, Wahoo has included two foot positions for placing the fan on the floor or desk and the Headwind channels the air nicely onto the body from both positions.
The speed and heart rate link is a nice feature, but I more often found myself reaching for the Wahoo app to adjust fan speed manually as and when I desired. With that in mind, the decision not to include a remote is a major shortcoming for the Headwind in my opinion. Adjusting fan speed with sweaty fingers on a locked touchscreen device just complicates the process.
While not the biggest fan on our test, the shape and weight of the Headwind mean it will require a dedicated storage place; something to keep in mind if you are working out in a confined space.
The Headwind is the first fan specifically designed for indoor cycling. Designed for cyclists, so to speak, means the fan gets features such as the speed and heart rate link and the seriously cooling high-speed airflow. However, being designed for cyclists means any oversights another fan may be forgiven for are harder to look past on the Headwind. I’ve already mentioned the lack of remote, but I would also like to see Wahoo include fan speed control in its Elemnt head units.
The Headwind is not the loudest fan on test, but it is loud enough to relegate the almost-silent Wahoo Kickr’s low noise level to a moot point. The price is also a hurdle for many. It’s far from cheap, but I guess connectivity and dedicated design don’t come cheap.
Indoor training fan testing protocol
The goal of our testing was to compare the benefit of riding with a fan versus no fan and the individual performance of the various fans. The test itself – identical for all four fans and bookended by benchmark tests with no fan – monitored body temperature, skin temperature, and heat transfer (flux) in an otherwise identical environment. The protocol included a 10-minute warm-up to FTP, 20 minutes at ~80% FTP, and a 30-minute break between tests to dry, cool down, and change shorts and socks.
To collect the data I used six core temperature sensors provided by Core for the purposes of this analysis. While designed to continuously measure core body temperature, the Core sensor is also suitable for measuring the effectiveness of insulating or cooling properties of clothing.
Core regularly conducts similar tests with some of the most elite athletes in the world – such as the Olympic gold medal-winning Norwegian triathlon team – and sports clothing brands to assess the cooling capabilities of their fabrics. In this case, the same principles were applied to evaluate and compare different fans as a source of external cooling.
I positioned the six, specially calibrated Core sensors on specific parts of my body: the side of my torso, back of my torso, my head, upper arm, and thigh. Using the inbuilt thermal energy transfer sensing capabilities, the test results were fed into Core’s analysis software allowing us to accurately determine and compare thermal properties.
I used six individual but identical pairs of Pactimo Ascent Vector bib shorts and Pactimo summer socks, and rode topless throughout to ensure consistency throughout the tests. Room temperature and humidity were closely monitored using a Govee ambient sensor to ensure conditions remained stable through the test.
I conducted the testing at home in Ireland on December 8. Before, during, and after each test I logged a series of subjective measures and results for each fan. Upon completing all tests I exported all the sensor data and training files, including power and heart rate data, to Core for analysis. Each test was numbered 1-6 (four with fans, two without) to ensure Core’s research and development engineer Michele Zahner didn’t know the identity of each fan when analysing the data.
Indoor training fan test results and conclusions
Let’s start with my subjective analysis. On a scale of 1-10, I noted my perceived thermal heat stress at the end of each 30-minute test. Unsurprisingly, the 9″ desk fan fared quite poorly in this measure, scoring only slightly better than no fan at all. In third place in my perceived testing scores was the Black & Decker, leaving me feeling “hot” and thus scoring a five. In first and second place were the Vacmaster Cardio54 and the Wahoo Headwind.
The Cardio54 narrowly defeated the Headwind thanks mainly to its increased wind speed which left me feeling even colder. Both fans were vast improvements over the 9″ and the Black & Decker.
The first 10 minutes of the Cardio54 and Headwind tests were actually uncomfortably cold as I tried to warm up with the top two fans on full power. My perceived thermal stress rating is closely linked to each fan’s wind speed. I felt very little benefit from the barely noticeably wind speed from the 9″ desk fan, whereas the two top fans left me almost shivering with the wind chill.
Moving on to the tests from the Core sensor data and the results are not quite so clear-cut. As previously mentioned, Core’s research and development engineer, Michele Zahner, could only identify the fans by the numbers one, two, three, and four. For the purposes of interpreting the data here are the names for each fan number.
- Fan #1 – 9″ desk fan
- Fan #2 – Black & Decker circulator fan
- Fan #3 – Vacmaster Cardio54
- Fan #4 – Wahoo Headwind
Before delving into the results, it is worth remembering my testing was over a single, 30-minute period of steady state efforts for each fan. We had planned to conduct follow-up testing and will do so in future, but that has been significantly delayed by my current injury.
Starting with the most obvious results, Zahner found the data clearly shows using any fan is much better than no fan.
Zahner looked at the average energy transfer for the final 10-minute periods of each test. The average energy transfer (flux) is the measure of how much energy is leaving the body in each test. In contrast to skin temperature and heart rate, energy transfer is much less sensitive to fluctuations in ambient temperature. The higher the average energy transfer bar the better the cooling. On average, the use of a fan led to 52% higher heat dissipation from the body than not using a fan.
Sticking with the basic skin temperature, energy transfer, and core temperature data, Zahner found the 9″ desk fan to be the least effective. “Fan #1 was not as effective in aiding cooling as the other fans and recorded the lowest heat dissipation (+36% compared to using no fan),” Zahner said. Given the desk fan is the smallest on the test, with the lowest wind speed, this is hardly surprising. These findings back up my subjective scoring for the 9″ desk fan with a 7/10 on the thermal stress rating.
Somewhat more interestingly though, Zahner found almost identical results between the Black & Decker, the Vacmaster Cardio54, and the Wahoo Headwind. “Fans #2, #3 and #4 exhibited a similar effect on cooling (+57%, +55% and +57% respectively) compared to no fan and as a result are fairly comparable.”
These findings are particularly interesting given how they relate to my subjective scoring during the testing. The Vacmaster Cardio54, with its higher wind speeds, won out in my perceived thermal stress rating and also tested with the lowest average skin temperature and average core body temperature. The Wahoo Headwind was a close second, so it makes sense both of these produced similar results with the Core sensor testing. However, the Black & Decker had me feeling noticeably less chilled and also scores higher in both skin and core temperature.
While further testing is required to find a true answer for this, my personal belief is that the body was capable of dissipating heat at the same rate across all three high-performing fans for the 30-minute steady effort test. Based on my subjective rating for each fan during the testing and over a longer period of indoor riding, I believe follow-up testing with longer or more intense riding might further separate the fans, but more on this later.
Looking into airflow distribution, the various sensors around the body threw up one further interesting result. As Zahner reported, “Fan #4 (the Wahoo Headwind) has the same average heat flux level as the others, but exhibits a strikingly different distribution; Airflow around the “back torso” is increased while around the head is lower. This fan seems to have a somehow more ‘focused’ airstream. Maybe it’s focusing on cooling the body parts that need it the most?”
Delving deeper into the data we decided to further explore the reasoning for almost identical results from three of the four fans, despite the very different sensations I had. We decided to explore whether calculating each fan’s heat transfer coefficient could quantify its heat transfer capability.
Wikipedia lists the heat transfer coefficient as “the proportionality constant between the heat flux and the thermodynamic driving force for the flow of heat (i.e. the temperature difference, ΔT)” or in our case, heat flux (heat transfer) divided by skin temperature minus air temperature, expressed in watts per squared meter kelvin: W/(m2K).
As Zahner explained, “heat transfer coefficient is used in mechanical engineering to quantify how well a surface can transfer heat.” The advantage of using this coefficient is that it incorporates both differences in skin temperature as well as differences in heat transfer. By taking the room temperature from our Govee sensor and applying the formula to our data we start to see a separation in fan performance.
Given the heat transfer coefficient shows not how much heat I have built up but rather how well I am dissipating heat, it should provide a more indicative quantity to estimate the “cooling potential” of each fan/test. Zahner likened the heat transfer coefficient to pouring water into a sink and the rate at which the water can drain.
The rate at which you pour water into the sink corresponds to the waste heat you generate within the body during exercise.
The rate at which water leaves through the drain corresponds to the heat transfer to the environment.
If the sink is not capable of draining all the water you put in, the water level (= body temperature) will rise.
In this analogy, heat transfer coefficient would correspond to the diameter of the drain pipe. This makes it clear now why the better fans “max out” – if the drain is large enough to drain all the water you put in, even increasing the pipe diameter will not let more water through. However, if you increase the water input, jamming will occur at some point even for the “larger diameters”.
Michele Zahner
We hypothesised that, under our test conditions, the stronger fans assisted the body in “maxing out” at the same energy transfer level simply because I had reached a steady-state where the body was capable of dissipating 100% of the waste heat it generated for the short duration of our tests. Or to go back to our analogy, I wasn’t pouring enough water into the sink.
Longer tests and/or higher intensities could have created the accumulated heat build-up required to further show each fan’s cooling potential but we had decided pre-test to opt for lower intensities to prevent excess fatigue from influencing the test. For subsequent testing we can reduce the number of fans and thereby increase the physical demand.
In the weaker fan and “no fan” tests – think smaller-diameter sinkhole – the lack of cooling assistance meant I could only dissipate part of the heat build-up to the environment, with the remainder contributing to a slowly increasing core body temperature. Due to the rather short measurement period, this increase in core body temperature was not visible yet, but the effects on average energy transfer were already clear to see.
Looking then at the heat transfer coefficient we can see the no fan and Fan #1 tests are still rooted to the bottom of the results. However, moving to the top fans from the initial results, we can now see a clear separation between the three. The Black & Decker (Fan #2) is still performing much better than my subjective conclusions conveyed, but it has notably dropped behind the Vacmaster and the Wahoo. Again, longer or more intense tests might have produced further separation or closer alignment between any of the fans.
The Vacmaster Cardio54 and the Wahoo Headwind stand as clear leaders in the heat transfer coefficient results and are still almost inseparable as was the case in the initial results.
Conclusions
We didn’t need testing to tell us that any fan is better than no fan. As mentioned in our perfect pain cave series, a fan is essential when riding indoors and both my subjective ratings and the Core testing have confirmed this. I will again recommend that anyone who’s buying on a budget but considering a top-end trainer, might benefit by opting for a mid-range trainer and putting the saved cash into a top-end fan.
Beyond that, we plan to conduct follow-up Core testing at higher intensities or longer test durations on the top three fans to clarify the cooling potential during these harder efforts. However, as we know all too well in cycling, an athlete’s feedback is often as important as any science-based numbers. Based on my own subjective testing I am happy to give a definitive answer to the question: which fan is best?
In third place in my list is the Black & Decker fan, representing the circulator fan family. The circulator performed much better than anticipated in the testing with the current protocol. That said, I felt noticeably hotter for the same effort in the same environment when using the circulator. It’s not that the Black & Decker is a bad fan or of no use for indoor training. Indeed, it is significantly better than the fans I have previously used for an entire winter of indoor training. Furthermore, used as an air circulator as intended, in combination with any of the top two fans on this list, it can ensure the room will stay fresher, while the fans we are about to look at can focus on keeping you cooler.
Second place for me goes to the Wahoo Headwind. Both the Headwind and the Vacmaster were too powerful for most of the training and testing I did. The max speed could have me almost shivering at low ride intensity or when just getting warmed up, so the potential for improved cooling during the hardest efforts is there. When the intensity ramps up, the high-speed airflow of the max setting is like a godsend.
The Core testing results suggested the Wahoo provides an overall better airflow distribution in the riding position, suggesting if you only have space for one fan, the Headwind might be the answer. The Wahoo’s heart rate and speed link are neat features, and the speed setting helps boost the immersive feeling of Zwift. Top tip: set your max heart rate lower to get the most of the Headwind’s heart rate link and max speed at intensities you most often need it. The Headwind also integrates neatly into the Wahoo ecosystem with the feet specifically designed to sit on the Wahoo trainer desk.
All that said, the Vacmaster, at half the price of the Wahoo and, crucially, with its push-button remote control, edges it into first place for me. The ease of use of the standard remote is essential for me with these high powered fans. That high power is a blessing and a curse and on-the-go adjustment is essential as ride intensity changes.
Yes, the Headwind adapts automatically, but I prefer to adjust the speed manually and touchscreens do not play ball with my sweaty paws. Better yet, if the airflow distribution is a concern, I dare suggest setting up two Cardio54s in front and to the side of the trainer could provide even better airflow and still only match the price of the Wahoo.
One word of caution though, double the fans means double the power usage, and no one is a fan of higher electricity bills.
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