The world has been shaken to its core by a respiratory virus pandemic. Humanity has been raiding the toolbox for every possible weapon in the fight, whether that be masks, vaccinations, or advanced antiviral treatments.
As far as medicine has come in tackling COVID-19 in the past two years, the ultimate solution would be to cut the number of people exposed to the pathogen in the first place. Improving our ventilation methods may just be a great way to cut down on the spread. After all, it’s what they did in the wake of the Spanish Flu.
While most of us have been content with swing and sliding doors for the vast majority of our needs around the home, the revolving door remains popular in a wide variety of contexts.
It’s a confounding contraption that always feels ready to snatch and ensnare the unwary user. However, these doors do have certain benefits that have allowed them to retain popularity in many public buildings around the world. Let’s dive in to why below.
[Neighborino]’s smart home system controls the windows, blinds, outlets, and HVAC. But by the time the high-rise apartment was ready for occupancy in 2015, the smart home controllers were already showing their age. You see, the contractor had installed an app to run the home’s programmable logic controllers (PLCs) on stock Galaxy Tab 3 hardware. Yes, that’s a tablet originally released in 2013. They then built the tablets into the wall of each apartment, dooming the homeowner to rely on the vendor forevermore.
It was not long before [Neighborino] and their fellow residents were dealing with stability problems. Bloatware from both Samsung and Google was causing major slowdowns, and the PLC system’s unpublished WiFi password prevented replacement of the controllers.
Being an Android developer by trade, [Neighborino] set siege to the walled garden before him. The writeup details the quest to execute what would be a straightforward hack on anything but the x86 hardware that was being targeted.
A debloating app strips all non-essential software.
The first fruit of [Neighborino]’s efforts was a hack for the aged tablets that would display the WiFi password, allowing owners to connect their own controllers to their smart homes. Of course, this is Hackaday, so you know that [Neighborino] didn’t stop there.
Despite having to deal with two different versions of Android and tablets that were built into the wall of the apartments of non-hacker neighbors, [Neighborino] succeeded in sideloading an APK. This freed them from the shackles of the company that installed the original system and gets longer life out of their Snowden-era Samsungs. A de-bloating tool frees up memory and restores the systems to a nearly performant status. A reboot scheduler keeps the x86 tablets running without user intervention, and of course the WiFi password revealer makes yard waste out of the previously walled garden.
Portable air conditioning units are a great way to cool off a space during the hot summer months, but they require some place to blow the heat they’ve removed from your room. [VincentMakes] got a portable AC unit for his home, but he found that the place he wanted to put it was too far from the only window he could use to dump the hot air. Having too long of a duct on the hot air exhaust increases the back pressure on the fan which could cause it to prematurely fail, so [Vincent] used an extractor fan to automatically give is AC unit’s exhaust a boost on its way to the window.
Because his AC can operate at low, medium, and high speeds, he chose an extractor fan that also supported multiple speeds and took care to match the airflow of the AC and extractor fan to avoid putting too much strain on either fan. He designed a system to automatically set the speed of the boosting fan to match that of the AC using a Hall effect current sensor to measure the AC unit’s power draw and an Arduino Nano for control. A custom PCB interfaces the Nano to the Hall Sensor and control relays, and we have to applaud [Vincent] for keeping the +5V DC and 230V AC far, far away from each other. In addition to this fine electronics work, [Vincent] also built an enclosure for the fan controller that allows the fan to be mounted on top at an angle, which helps avoid having hard bends in the exhaust duct.
There’s just one week left until Hackaday Remoticon, our online gathering in place of our traditional in-person conference during this time of social distancing. Joining the more than 20 hands-on workshops that make up the bulk of Remoticon, we’re excited to announce the two keynote speakers who will be taking the virtual stage: Alfred Jones and Kipp Bradford.
Tickets to see these keynote talks, to watch the SMD Challenge, to see hardware demos, and to take part in the show and tell are free, so get yours today!
Alfred Jones
Head of Mechanical Engineering at Lyft’s Self-Driving Division
Alfred Jones is the Head of Mechanical Engineering at Lyft’s level 5 self-driving division. Level 5 means there are no humans involved in operating the vehicle and it is still capable of driving anywhere a human could have. What goes into modifying a vehicle for this level of self-driving? What processes does his team use to deliver safe automation? And will cars in the near future completely get rid of the driver’s seat? Alfred knows and we’ll be hanging on his every word!
Kipp Bradford
CTO fo Treau
Kipp Bradford is the CTO of Treau, a company bringing heating, ventilation, and air conditioning (HVAC) into the information age. These systems contribute as much as 20% of global emissions each year, so even small efficiency gains stand to have a huge impact. The industry has remained nearly unchanged for decades, and Kipp is at the forefront of evolving the hidden systems found in nearly every building. Will the air conditioner of tomorrow make the one we have today look like a rotary telephone? We look forward to hearing what Kipp has to say about it.
We’re so excited to have these two phenomenal speakers who have also both been involved as expert judges in the Hackaday Prize (Alfred in 2020, Kipp in 2017 and 2018). Help us show our appreciation by packing the virtual lecture halls for their talks on Saturday, November 7th! Get your free ticket now.
We have no idea whether [Nick Goodey] is a trained engineer or not. But given the detailed design of this DIY energy recovery ventilator for his home HVAC system, we’re going to go out on a limb and say he probably knows what he’s doing.
For those not in the know, an energy recovery ventilator (ERV) is an increasingly common piece of equipment in modern residential and commercial construction. As buildings have become progressively “tighter” to decrease heating and cooling energy losses to the environment, the air inside them has gotten increasingly stale. ERVs solve the problem by bringing fresh, unconditioned air in from the outside while venting stale but conditioned air to the outside. The two streams pass each other in a heat exchanger so that much of the energy put into the conditioned air is transferred to the incoming unconditioned air.
While ERV systems are readily available commercially, [Nick] decided to roll his own after a few experiments with Coroplast and some extensive calculations convinced him it would be a viable idea. One may scoff at the idea of corrugated plastic for the heat exchanger, but the smooth channels through the material make it a great choice. He built up a block of Coroplast squares with the channels in alternate layers oriented orthogonally, letting stale inside air pass very close to fresh outside air to exchange heat without ever mixing directly. The entire system, including fans, an Arduino for control, sensors galore, and the Hubitat home automation hub, is powered by DC, so no electrician was needed. [Nick] has a ton of detail in his build log, including all the tools and calculators he used to design the system.
Given the expense of ERV systems, we’re surprised we haven’t seen more stories about DIY versions. We have talked about HVAC systems a lot, though — after all, HVAC techs are hackers who make housecalls.
Obviously, if the air filters in your home HVAC system are dirty, you should change them. But exactly how dirty is dirty? [Tim Rightnour] had heard it said that if you didn’t change your filter every month or so, it could have a detrimental effect on the system’s energy consumption. Thinking that sounded suspiciously like a rumor Big Filter™ would spread to bump up their sales, he decided to collect his own data and see if there was any truth to it.
There’s a number of ways you could tackle a project like this, but [Tim] wanted to keep it relatively simple. A pressure sensor on either side of the filter should tell him how much it’s restricting the airflow, and recording the wattage of the ventilation fan would give him an idea on roughly how hard the system was working.
Now [Tim] could have got this all set up and ran it for a couple months to see the values gradually change…but who’s got time for all that? Instead, he recorded data while he switched between a clean filter, a mildly dirty one, and one that should have been taken out back and shot. Each one got 10 minutes in the system to make its impression on the sensors, including a run with no filter at all to serve as a baseline.
The findings were somewhat surprising. While there was a sizable drop in airflow when the dirty filter was installed, [Tim] found the difference between the clean filter and mildly soiled filter was almost negligible. This would seem to indicate that there’s little value in preemptively changing your filter. Counter-intuitively, he also found that the energy consumption of the ventilation fan actually dropped by nearly 50 watts when the dirty filter was installed. So much for a clean filter keeping your energy bill lower.
With today’s cheap sensors and virtually infinite storage space to hold the data from them, we’re seeing hackers find all kinds of interesting trends in everyday life. While we don’t think your air filters are spying on you, we can’t say the same for those fancy new water meters.
Kipp Bradford
