HVAC Effects / Meter Placement
I have my Dylos meter set up in the shop.
One of my employees had cleaned up in there this afternoon.
When I went in the shop about 4 hours later, the reading was about 165/35. At that point, I turned on my furnace fan and the particulate count quickly (in about 5 minutes) dropped to 35/1.
The machine room area is 32 x48 16 and my furnace moves about 1200 cfm. This means that the furnace fan would take about 20 minutes to change the air in the shop. If the clean air from the blower disperses evenly within the shop then that means that every 20 minutes I am actually only filtering half of the air. At the end of one hour, I have filtered 7/8 of the air in the shop (???).
So here's the weird part: Why does the reading from the Dylos meter drop so quickly --- when at the end of 5 minutes, I have actually only filtered 25% of the air in my shop?
One possibility would be if my Dylos meter was positioned on the opposite wall from the furnace registers and I am sending over a "curtain" of clean air that washes down the wall and across the meter (?).
One of the tractor companies is sending me to the Daytona 500 this weekend :D!!! so I don't have time to test this. In the meantime, I would be interested in your thoughts on this and if the meter's location within your shop makes a difference (??).
Note: my woodshop furnace is equipped with a purpose-built two-stage air filter and I intend to monitor the negative pressure within the blower compartment (to guard against a clogged filter creating temperature rise problems). So far the furnace based system seems to be many times more effective than my ceiling mounted air cleaner (Delta 3-speed) -- and a lot easier to service:cool::D.
Rob