Ca++
Well-known member
Has anyone metered their negative pressure? I think my brain hurts. I want an inlet fan, sensitive to the rooms pressure. So I set about measuring said pressure, and things got a bit wrong.
First up, we know most of us have an atmospheric pressure sensor in our pockets, right? To use my old midrange samsung, I must dial *#0*# to open the service menu, them select sensors. My Barometer is there on the list, bouncing around the 1002.46 mark, near an open window. In my lounge 1002.39 and as I move up the stairs towards the room my extract is in, 1002.14 by the door, which has a 15mm crack. So into the room, I push the door to, and it barely makes a difference. 1002.11 or something. I thought my eyes should be bulging or something. That door makes less difference, then I ever expected. I know my full fan pressure is really upon the tent, who's pressure I wanted to control, and have not measured as it's dark. However, these are small fry numbers.
I don't want to use just a pressure differential switch, I want a couple of sensors with fan speed control. My goal is unloading the extract fan. My extraction isn't really about temp or rh primarily. It's about negative pressure for smell containment. before anything else. With that covered, RH only ever needs increasing, which can't be achieved by slowing the fan, who's already at the minimum for containment. I just increase the fan for temp in summer, but not by much. If I could instead control the fans based on pressure, it would allow me a bit more leeway. I could lower extract speed, or even let my typical vpd tracking controler, actual do something. Knowing my containment is in order. Which eases the extracts job. It all just comes together better.
Has anyone else done such atmospheric pressure testing? Perhaps they would like to, having found it on their phones. While writting this, that 1002.39 has moved to 1002.74 as the weather has changed. It seems to use the baro for altitude measurements. Blowing on the phone, finds it in the earpiece. Waterproof phone.
So little difference shutting the door. It's just not what I expected. Hence I'm reaching out. Though I suspect atmospheric pressure changes over the height of my stairs, may simply dwarf my fan. Then the room is simply not as sealed as it looks.
Next up, I have an air speed sensor to go in the ducting. That might shine some light on how sealed my room is.
First up, we know most of us have an atmospheric pressure sensor in our pockets, right? To use my old midrange samsung, I must dial *#0*# to open the service menu, them select sensors. My Barometer is there on the list, bouncing around the 1002.46 mark, near an open window. In my lounge 1002.39 and as I move up the stairs towards the room my extract is in, 1002.14 by the door, which has a 15mm crack. So into the room, I push the door to, and it barely makes a difference. 1002.11 or something. I thought my eyes should be bulging or something. That door makes less difference, then I ever expected. I know my full fan pressure is really upon the tent, who's pressure I wanted to control, and have not measured as it's dark. However, these are small fry numbers.
I don't want to use just a pressure differential switch, I want a couple of sensors with fan speed control. My goal is unloading the extract fan. My extraction isn't really about temp or rh primarily. It's about negative pressure for smell containment. before anything else. With that covered, RH only ever needs increasing, which can't be achieved by slowing the fan, who's already at the minimum for containment. I just increase the fan for temp in summer, but not by much. If I could instead control the fans based on pressure, it would allow me a bit more leeway. I could lower extract speed, or even let my typical vpd tracking controler, actual do something. Knowing my containment is in order. Which eases the extracts job. It all just comes together better.
Has anyone else done such atmospheric pressure testing? Perhaps they would like to, having found it on their phones. While writting this, that 1002.39 has moved to 1002.74 as the weather has changed. It seems to use the baro for altitude measurements. Blowing on the phone, finds it in the earpiece. Waterproof phone.
So little difference shutting the door. It's just not what I expected. Hence I'm reaching out. Though I suspect atmospheric pressure changes over the height of my stairs, may simply dwarf my fan. Then the room is simply not as sealed as it looks.
Next up, I have an air speed sensor to go in the ducting. That might shine some light on how sealed my room is.
