LintAlert® Development and HistoryBeing totally focused on the dryer venting business for over 10 years, it quickly became obvious that dryer fires were incredibly common and caused a tremendous amount of grief to the respective families. It didn't take rocket science to figure out why the Boy Scout manual suggested dryer lint as an aid to starting a campfire.
As you've likely read here already, electric and gas-fueled clothes dryers continue to be associated with a large number of fire incidents in the U.S. annually. The U.S. Consumer Product Safety Commission estimates that 15,500 fires associated with clothes dryers occur annually causing 10 deaths, 310 injuries, and more than $ 84.4 million in property damage.
Everything we read indicated clearly that the most common cause of dryer fires was the lack of maintenance to the exhaust conduit or duct run. Over time lint would build-up on its own but the build-up would accelerate greatly if one of these five rather common conditions existed:
- Duct run itself excessive in length or restricted by numerous bends
- Bird or rodent nests in the vent hood itself
- Flex transition hose behind the dryer crushed, kinked or twisted excessively
- Screen-like features on the termination vent hood
- Duct-run through a cold crawlspace or attic creating internal condensation
What was needed was a means to monitor the back pressure in the dryers' exhaust duct and then warn the user of any significant blockage. After many tests we determined that the mass of dryers currently out there are possible of creating a varying degree of pressure based on motor size and the design of the fan housing. Therefore a factory set pressure switch would not work on everyone’s dryer. What was needed was a sensitive differential pressure sensor that could provide electrical digital feedback so that the onboard intelligence could capture and record the “like new” pressure levels and then show a progression of lint buildup in a visual LED array. I also knew we had to come up with a low-profile tap fitting apparatus that would penetrate into the dryers' exhaust hose and be almost invisible in airflow signature to minimize lint buildup on the penetration fixture itself.
After the SmartTap™ fitting design was completed, a small digital pressure sensor that would be accurate at the lower levels of pressure the dryer exhaust deals with was needed. The design of the printed circuit board and module housing was the next challenge. Throughout the design phase these features were critical: 1) not to power the product with a battery, 2) not use up an outlet in the laundry room, 3) to provide night light illumination and 4) to be accurate for all dryer types, brands and venting circumstances.
From initial concept to production of our current design it took three and a half years and four completely different conceptual ideas. Over-tweaking of the product became an issue as it seemed we would never get off the ground. Unsolicited reactions from strangers to the product was and remains consistently positive, enthusiastic and upbeat with a certainty of success.
We launched the LintAlert in May of 2009 at The International Hardware Show in Las Vegas as the first lint-sensing safety alarm for the dryer and took two first place honors for best in show as well as Retailer’s Choice. The much more intelligent Gen 4 version of the LintAlert has successfully completed beta testing and is available on Amazon, many appliance parts outlets and available through duct cleaning contractors as an add-on sale. A launch on QVC and several catalogs are in the works.
Rick Harpenau, Owner and Inventor