Challenge Program Furniture

Sit-stand desks

Now that the word is out – that sitting all day is bad for you* -- the market for sit-stand desks has responded with a profusion of vendors, features and prices. Some desks cost a few hundred dollars; others cost a few thousand.

How to make sense of it? What explains the cost difference -- and which features really matter? With more and more requests to add a sit-stand desk to our own line up, we’ve had to find out.

We’ve evaluated high-end and low-end models, imported and American-made. Briefly, there were no big surprises: there’s a pretty strong correlation between price and performance. While it’s not necessary to use the most expensive mechanisms, we found that the low-cost options do indeed underperform.

Here’s a summary of what we’ve learned.

The attributes that really matter

Speed

When the novelty wears off, you will quickly become impatient waiting for your desk to arrive where you want it. Much more than 10 seconds starts to feel like a long time. This translates to using mechanisms that move at least 1.3 inches/second.

(Note: Unfortunately, manufacturer representations are not uniformly reliable; rates are often over-stated. We’re surmising some vendors report results for bases that are not loaded. For our own tests, we used an oversized desktop carrying the equivalent of two large monitors, a laptop and a tablet.)
All CP sit-stand bases travel at least 1.3 inches per second.

Noise

The essential mechanism of the elevator desk is the motorized “linear actuator.” Each telescoping leg houses one. The actuators are driven by one or two electric motors. Cheaper motors can be quite loud, approaching the decibel level of a blender. This gets old fast.

Another problem we noted, when evaluating a promising lower-cost unit from China, was intermittency: for a few seconds at a time, the motors were impressively quiet, but this was interrupted by periodic, disconcerting noises. No degree of adjustment fixed the problem.

Whisper: 20
CP sit-stand desks: 42-46
Household refrigerator: 55
Normal conversation: 60
Vacuum cleaner: 75
Power mower: 107
*Common noise levels, decibels (http://ehs.yale.edu/sites/default/files/files/decibel-level-chart.pdf)
All CP sit-stand mechanisms run smoothly and surely, and are among the quietest available.

Stability when elevated

Any desk can be short and squat. Those that aspire to something more need to be well-engineered.

The engineering challenge is to maintain stability when the legs extend, which leaves diminishing bearing surfaces within the telescoping sections to promote rigidity. For stability at height, higher-end manufacturers (which we found in the US and Germany) enforce tight tolerances, which are more difficult (and costly) to achieve.

Instability (wobble) is also a matter of frame design. To reduce cost, some manufacturers reduce metal thickness and use less bracing.

All CP sit-stand bases feature tight tolerances and beefy components to promote stability at height. Models are available for especially tall users and for those who use treadmills.

Lifting capacity

Lifting capacity is a common source of disappointment. Knowing published weight limits is insufficient, as there’s more to lifting capacity than weight alone. Friction matters, too. Either can cause overloading of the motors -- and overloading is a problem to avoid.

Put simply, overloading leads to overheating. Overheating is expensive and annoying – expensive, because it shortens motor life; annoying, because it shuts down the motor mid-motion. This is a sensible safety default (to prevent fire), but it can typically take over 15 minutes for motors to cool sufficiently to regain function. To avoid this, here is what you need to know about weight and friction.

Weight

Vendors of sit-stand bases typically specify weight limits. We’ve learned they should be taken with a grain of salt and should be understood to be best-case figures. To reduce the risk of overloading and overheating, it’s best not to approach too closely the published weight limit.

Be sure to do the math. Consider these two scenarios, describing relatively light and relatively heavy installations:

Scenario 1: a relatively small, light installation
total weight to be lifted: 73 lbs.
wood top, 60” x 30” x 1”: 50 lbs.
one large monitor: 13 lbs.
laptop: 5 lbs.
other items: 5 lbs.
Scenario 2: a relatively large, heavy installation
total weight to be lifted: 214 lbs.
wood top, 84” x 36” x 2”: 168 lbs.
two large monitors: 26 lbs.
satchel/purse (on hook): 10 lbs.
laptop: 5 lbs.
other items: 5 lbs.

Friction

Friction also causes overheating. It’s typically caused by binding. Binding occurs when the desk base is slightly flexed or racked. This can happen if the floor is not level or when the weight on the desktop is not centered. And typically it isn’t. Monitors, for instance, commonly perch on the desktop’s back edge. Such uneven weight distribution -- on bases with too much slop in the telescoping mechanism (i.e., insufficiently tight tolerances) -- can introduce enough friction to significantly reduce lifting capacity.

This is not a theoretical problem. It happened right out of the box to a widely used Chinese base we evaluated – and this was before we applied any weight to the desktop. The better American and German mechanisms we evaluated, which offer the tightest tolerances, do not show this tendency.

All CP sit-stand bases have been selected, in part, because they feature especially tight tolerances that minimize friction loads. This permits exceptionally long warranty periods.

Warranty

Most sit-stand bases are made in China and marketed by American firms. Chinese manufacturers typically warrant their products for 1-2 years. But unless you buy a sea container load (about 700 bases), you have no direct recourse to the factory. State-side, certain re-sellers offer their own warranty, with some extending the period, typically by 1-3 years.

Experience suggests it is reasonable to question the value of warrantees extended by companies that compete largely on price. This is generally not the sturdiest business model.

At the other end of the scale, certain American manufacturers, which have elected to sell on quality instead of price, offer warrantees up to 10 years.

All CP sit-stand bases are made in the US (some with certain German components) and are backed by a 10-year warranty.

Control pad

Reliability: It would seem obvious that a good control pad should consistently deliver the desktop to the desired height. But once again, we found a correlation with cost, as a relatively inexpensive unit we tested failed to control position reliably -- sometimes running past the chosen height, sometimes stopping short.

SAFETY NOTE: Some vendors offer one-touch, “hands-free” controllers with memorized settings. UL does not certify such controllers. Experience demonstrates that contact with chairs, cables that pull up short, unanticipated events and momentary inadvertence can present potentially serious risks.

All CP sit-stand controllers are accurate, reliable and UL-approved.

Cord management

When your desktop moves, cord management becomes important. Many manufacturers resort to adhesive-backed plastic clips. We are not confident these will stay put.

All CP sit-stand bases come with a concealed ledge (shelf) that keeps everything tidy.

Accessory

Power hub with USB ports and surge protection

Why crouch? A proper work station should make it easy to plug in your phone, your laptop, and maybe a tablet. After looking at many of the available options, we found one we especially like.

Our power hub features three outlets and two USB ports. It’s small, low-profile, and movable, making use of a discreet, secure and easily operated screw clamp. Left side, right side, or anywhere along the back edge – the system provides maximum flexibility.

  • * Bauman, Adrian, et al., 2011. “The Descriptive Epidemiology of Sitting: A 20-Country Comparison Using the International Physical Activity Questionnaire,” American Journal of Preventive Medicine 41(2):228-235.
  • Hamilton, M. T., Hamilton, D. G., & Zderic, T. W. 2007. “The Role of Low Energy Expenditure and Sitting on Obesity, Metabolic Syndrome, Type 2 Diabetes, and Cardiovascular Disease.” Diabetes, 56(11), 2655-2667.
  • Katzmarzyk, Peter T., Church, Timothy S., Craig, Cora L., and Bouchard, Claude, 2009. “Sitting Time and Mortality from All Causes, Cardiovascular Disease, and Cancer,” Medicine and Science in Sports and Exercise 41: 998-1005.
1124 E. 7th St. Wilmington, DE 19801
302-384-6081
Furniture@challengeprogram.org
1124 E. 7th St. Wilmington, DE 19801 <br> 302-384-6081<br> Furniture@challengeprogram.org