HVAC maintenance 2021-02

The semi-annual preventative maintenance on the HVAC systems was today.

We have 5 independent HVAC systems. 1-4 are in the main shop area and #5 is above the lounge.

#1 (over wood turning) was tagged out “defective” on the thermostat, but checked out OK electrically and mechanically except for a missing filter. I installed a filter (found media and a frame in the coworking area) and it’s back on.

#2 and #3 checked out fine except for loaded filters and dirty coils. They were shaken out and re-installed; I’m not sure if our filter media is intended to be washable or they just need to be replaced. @EricP or @dannym ?

#4 (over the 3D printers) is offline. The electrical service is dead on two legs so the HVAC tech couldn’t fully test it. It also appears to have a dead heating strip (tested open-circuit) which is tolerable if everything else works when it’s powered back up. Service notes indicate there’s been at least one bad strip in this handler for a while.

#5 (over the lounge) is also OK. Filter wasn’t even too bad.


  • re-label all the air handler and condenser circuit breakers with the right unit numbers.
  • repair electrical service to #4 air handler before next maintenance trip.
  • clean evap coils on all air handlers. Interior cleaning is apparently outside the scope of our preventative maintenance contract (though they’ll do it for an addition fee)
  • document policy & procedure on filter maintenance. We have a habit of stressing equipment by letting filters go too long between changes.
1 Like

I changed out the air filters for the lounge a few weeks ago, and am trying to do that on a roughly monthly basis

1 Like

That is one-time-use media for the 3 shop units, and should never be shaken out or reused. It’s cheap and very effective for our use. 1" Texair pleated paper filters work fine for the lounge and Front, but will not perform at all in the 3 shop units. Technical reasons there.

It’s semantics, but we’ve always used Lounge, Front, then 1, 2, 3. #3 being the one over the woodshop. They’ve never been labeled, but probably should be.

Lounge uses 3 filters, one in each room. All these filters need to be maintained regularly. COVID way lessened how much that needed to be done. When we were in full swing, they need changing more often than once a month. If someone went crazy hand sanding without a collection solution when the AC’s running constantly, the filters can be loaded up pretty much overnight. It’s hard to predict, they just need to be inspected often.

Thanks @da5idii - that must be why the lounge was the only unit with clean filters :slight_smile:

@dannym The air handlers and their corresponding condenser units on the roof are currently labeled according to the numbers in my first post – apparently AirCo labeled them a few trips ago so they could keep track of which unit was which in their service reports. Some of the thermostats are also labeled but I don’t think they all are.

Sounds like shop units two and three need their filters replaced. There’s sufficient media on the cart.

Regarding evap coils. apparently units 2 and 3 are noticeably dirtier than all the others. If we don’t clean all of them, we should start with those two.