At Dyson we engineer machines that work properly, and to help our customers understand how they work, we are transparent about all of the claims we make.
Unfortunately, some of our competitors do not act the same way. They often use misleading claims, which can be confusing.
Below is an explanation of how we calculate our claims. If you would like more information, please contact us at 855-720-6378
At Dyson we use the following figures in our calculations:
Number of paper towels per use = 2
This is based on our own internal research. We know that people can often take more than 2 paper towels to dry hands but we believe in estimating costs as cautiously as possible.
Paper towel cost = $0.01
This is based on our own internal research. We have taken paper towels costs from the five most popular sources and calculated the average cost across all territories.
Bathroom usage per day = 200
This is based on our own internal research into the usage of an average sized bathroom. For smaller bathrooms with low footfall we use a figure of 100, and for high footfall areas such as service stations or airport bathrooms we use a figure of 400.
Number of days the bathroom is in use = 365 days
We assume a whole year.
Electricity price per kWh = $0.10
This is based on our own internal research. We have taken electricity costs from 5 different sources and calculated the average cost across all territories.
Wattage = as stated by the manufacturer
Standby power = as stated by the manufacturer or as tested by Dyson.
Dry time is based on the National Sanitation Foundation’s Protocol P335 (NSF P335).
Annual carbon impact is calculated based on 200 uses per day, 365 days per year.
Watch out: most hand dryer manufacturers do not follow NSF P335, so may quote incorrect dry times. NSF is an independent hygiene specialist. If you want an accurate dry time, insist on the NSF P335 test results.
The annual running cost of paper towels is estimated by =
The average number of paper towels used to dry hands x the average cost of the paper towels x the assumed number of uses per day x an assumed number of days the bathroom is in use.
There are 2 steps to this calculation.
Step 1: Running costs when in use (without standby)
Dry time of hand dryer (in hours) x rated wattage of hand dryer (kW) x the assumed number of uses per day x the assumed number of days the bathroom is in use x electricity price per kWh.
Step 2: Running costs when in use (with standby)
Result of step 1 +
((Electricity price per kWh * number of hours in a year) – (estimated uses per day (100/200/400) * dry time of hand dryer (in hours))) * Standby power (kW)
= Annual running cost
Calculated using PE International GaBi software and method developed with Carbon Trust based on 5 years use and dry times measured using Dyson test method 769 based on NSF P335 with a measurement of 0.1g residual moisture.