Good morning!
Wednesday Afternoon from 12-430 there will be HVAC maintenance going on in the woodshop for all units. The woodshop will be closed off at that time from the main working areas.
I apologize for the disruption and we hope to have our units in a more easily maintainable state afterwards.
Robert
What’s the plan now?
We’ve (@Cput11 and @bwatt) booked the Large CNC for 1-5 PM on Wednesday 12/10. Based upon your message we are wondering if the Large CNC will be available then, because the HVAC Upgrade did not “book” that CNC?
@Rolo Am I allowed to be on the Large CNC today with Corey from 1-5 or does the HVAC maintenance cancel it?
Y’all are good today, thanks for asking.
Thanks
The Free work by Airstrike HVAC is done.
I will ensure proper filters are in place this week for the new returns.
Please be cautious around the small CNC.
The return is hanging extremely low. And the corners are right about where my forehead is. We will get something to put padding around this, but very likely we will make an adjustment soon so it is not hanging so low.
The overall project is intended to help keep dust out of the HVAC, I’m not a fan of how low this one is hanging right by the CNC, and I don’t think it’ll help with that cause very well. Please stay tuned and we will get it tightened up.
They donated a lot of materials so we at least have what we need to make things how we need them.
This setup looks like it will break the standard design rules, the static pressures and face speeds are both too high.
This makes it really sensitive to dust loading, if it’s even able to get enough airflow without loading. It loses efficiency and could have a higher tendency to freeze up. Another factor of concern is that bringing the inlets down collects the ultralarge particles into the filters. Before, we didn’t have a high potential to ingest the larger particles because they don’t float up that high (gravity filter), but this will be putting them into the HVAC. From one perspective, it’s good to take dust out of the air, but the ultralarge particles can clog the filters at a very high rate and is especially a problem if you use pleated paper media.
I would strongly recommend that you need continuous monitoring of the static pressure at two points to try to protect the units, due to the extremely low operating margins and complexity it creates. Otherwise you’re just changing filters kinda randomly at high cost, with no guarantees it’s helping.
We could take a face speed measurement easily enough to see if it’s getting the cfm needed at any particular time.
There are great ways to do a two-stage system. It can be much more cost-effective, reliable, and highly effective at PM2.5 and near 100% first-pass capture of ultrafine dust. The collection loads get separated into different types of filters. But there’s several key differences between this and that system.
For something immediately actionable, get MERV8 polyester filter media and frames. Pleated paper will cause more problems.
There’s a lot of technical differences. It’s less static pressure drop than pleated paper, that’s critical because there really isn’t any free operating margin to begin with.
The polyester media can handle much, much more dust loading than pleated paper and maintains low static pressure throughout its load life.
The place to get filter frames made is JoeFlyCo 512-441-4448, they’re in town by Bergstrom airport. They’re cheap and a great design. You give the the dimensions of filter and they custom make them, and they’re drop-in replacements. Best to get two sets so there will be a spare set with media mounted in them ready to change out
Also, what MERV and exact product name is the 20x25x4? There’s a large amount of variation in these and, given how thin the margins are, can make or break the system.
Actually, one other key factor- which speed tap is the blower set on?