Dirty filters. Increased static pressure. Both are common, unavoidable issues for anyone using commercial dehumidifiers. And each can cause a drop in performance – causing costly fluctuations in relative humidity. Until now.
Say what? Can’t be true? Yes. Seriously, it’s the real deal. This isn’t a late-night infomercial pushing miracle cures for performance issues. Quest engineers have developed a novel approach as part of their new Quest 335 that prevents large fluctuations in airflow. The goal is to help cultivators, facility managers and everyone in between maintain the precise relative humidity levels they expect.
So, what’s the secret? At the core of Quest’s new system is a pressure switch connected to a variable speed fan. When the switch detects a change in pressure, the fan slowly ramps up its speed to maintain the desired CFM, which results in consistent humidity control.
“We’re sensing pressure throughout the machine. When the pressure gets too low that means we aren’t getting enough airflow (or CFM),” said Jerome Verhoeven, an electrical engineer at Quest. “We turn the fan up just enough until the pressure is satisfied. That, in turn, keeps the unit’s performance level where it should be.”
Let’s break this down. We’re going to walk through the challenge, how our engineers tackled it, and why it’s important to you.
Here’s the deal. Filters get dirty. That’s not a bad thing. It means they’re doing their job. They’re a critical part of our dehumidifiers, responsible for removing pollen, dirt and things like powdery mildew from the air.
But as they capture particulates, something happens inside your dehumidifier: The pressure builds and air doesn’t flow as easily through the dehumidifier.
That matters because without changing something, your dehumidifier won’t deliver the results you need and performance will drop off – meaning optimum growing conditions won’t be maintained. The old solution was to change the filter more frequently. That costs money in product and labor and it’s yet another complication to manage in a complex business.
“Think about a screen on your window. It will be pushed harder and harder if you have a fan blowing hard against it,” Verhoeven said. “The same goes for filters. As they clog, they become more resistant to airflow and that puts more pressure on it – meaning humidity levels will be affected.”
The other issue that affects performance: Static pressure from ductwork. In many instances, cultivators, facility managers and other operators like to duct their dehumidifiers into a room. But as they do, static pressure increases. That leads to less airflow through a dehumidifier and causes the machine not to work as well.
That’s right, the fan. Inside the Quest 335 is an electric variable speed fan that pushes air through the machine. The keyword here is “variable.”
When the fan is installed, it’s set to use about 81% of its total power. At this level, the fan works with other parts of the dehumidifier to pull 335 pints of water at 80F and 60% RH, assuming the filter is clean and no ducting has been added. (Side note, the Quest 335 does this at 9.3 KWh, making it the most efficient dehumidifier in the world. Read more about that, here.)
That’s important because at 81%, Quest engineers have about 19% more power to play with. So if the fan is told pressure has changed inside the machine, it will slowly increase its power by 1% until ideal pressure conditions are achieved.
By increasing the fan speed, the appropriate CFM level is maintained and RH isn’t impacted by static pressure changes caused by a slightly dirty filter or ductwork.
“When the fan gets notified that pressure has changed, it slowly ramps up fan speed until it hits the ideal 1,000 CFM,” said Walt Waetjen, Quest’s product manager. “It’s then receiving constant feedback and will slowly drop back toward 81% if pressure changes.”
Well, it’s not a genius but it is the workhorse. The brains of the operation lie in a pressure switch.
The pressure switch detects when pressure levels decrease on the side of the filter opposite the fan. That, in turn, means pressure has gone up inside the machine and negatively affected airflow.
Using a proprietary algorithm, the switch triggers the fan to work harder. The switch then constantly measures airflow and updates the fan until proper pressure is achieved. Again, this matters because it keeps relative humidity stable despite static changes.
“If the pressure switch says you have a clogged filter you can ramp up CFM to compensate for dirt,” Verhoeven said. “If the fan hits 100% power but the pressure is still too high inside the machine, a new filter light will turn on, letting you know it’s time to change the filter.”
It sounds too good, right? But it’s valid.
First, with the variable speed fan, relative humidity doesn’t fluctuate when a filter gets dirty. That alone is significant because it keeps the environment consistent – hugely critical for cultivators and others.
But here’s the kicker. Having a machine that can deliver ideal performance levels as the filter degrades (but isn’t ready to change) saves a lot of money.
For instance, four Quest 335 dehumidifiers vs. four of the competitor’s similarly sized machines costs about $900 less to operate during a three-month cannabis indoor grow cycle. In this instance, we know the filter life drops to about 50% in weeks 7-10 and to 25% during weeks 11-12.
“Of course, there are other variables, including how efficient our machines are – but the key is that it costs less and performance levels never dip,” Waetjen said. “That’s an innovation that is going to have a significant impact on our customers”
Want to learn more about the Quest 335’s new system? Send us a note or give us a call.