#Humidity automation based on Exhaust Fan-Speed

1 messages · Page 1 of 1 (latest)

grim finch
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didn't want to send text wall in challen so created a thread, sorry not beeing engllish native I have sometimes difficulties in explaining well and tend to write rather more than less

hello community
I am struggling with an humidity automation
in a closed environment with a constant undrpressure, created by an exhaust fan I can control the humidity manually from lovelace with a slider on the % of RPM of the fan, and that workz well when interacting manually

the humidity target to kepp varies automatically depending on the measured temperature
what I do is, I have a formula that calculates the corresponding RH depending on a measured temp, that is target RH
and then with fan-speed I can dial it in manually to be like +/- 0.3 % measured RH vs target RH, so my graph oscillates wich is fine, but th peaks a super low

now I want to automate that
RHtarget < RH measured -> too hum -> increase fanspeed
when RH target and RH measured are very close or in a certain range, than apply that to fanspeed
and of cause when too low same vice versa

I can raise the RPM on change of measured RH automated, but than when the turning point comes RPM needs to counter that and there I am stuck

any help would highly appreciated, thx

smoky swift
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trigger:
- platform: numeric_state
  entity_id: sensor.measured
  above: sensor.target
action:
- service: fan.set_percentage
  target:
    entity_id: fan.whale
  data:
     percentage: 80
grim finch
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yep correct, thx, that is what I experimenting with since a week
so now I have sth lige this:

description: ''
trigger:
  - platform: state
    entity_id:
      - sensor.vpd
    for:
      hours: 0
      minutes: 0
      seconds: 5
condition: []
action:
  - choose:
      - conditions:
          - condition: numeric_state
            entity_id: sensor.vpd
            below: input_number.vpd_target
          - condition: and
            conditions:
              - condition: numeric_state
                entity_id: sensor.exhaust_fan
                below: '58'
        sequence:
          - service: fan.increase_speed
            data:
              percentage_step: 1
            target:
              entity_id: fan.exhaust_fan
      - conditions:
          - condition: numeric_state
            entity_id: sensor.vpd
            above: input_number.vpd_target
          - condition: and
            conditions:
              - condition: numeric_state
                entity_id: sensor.exhaust_fan
                above: '26'
        sequence:
          - service: fan.decrease_speed
            data:
              percentage_step: 1
            target:
              entity_id: fan.exhaust_fan
    default: []
mode: restart```
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and yeah it somehow works

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but
lets say all is in balance and fine
now meadured RH is not as target RH, it is too high

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no it triggers and raises the RPM by 1%
as that is not enough it might get 3-4 trigger and than be like 3-5% higher than it was

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now comes the turn point where humidity starts decreaseing

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and for ever step of sensor.vpd (the 3-4 steps up it made)
it will make 3-4 steps up again whilest it should at the turnpint do them down again

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and that leads to overoscillatiion 😦

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see last hour from 1500 on

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hmhh how can I post images?

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oh not at all I see just links

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well it overoscillates as when RH turns going down RPM should too but the triggers are triggereing alson on way down to target

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hope ya understand my problem, so difficult for me to explain in english

grim finch
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oh and don't be confused by all the VPD sensors
vpd is vapour pressure deficit and basically nothing else than apllying it to humidity values

grim finch
#

maybe I shall simplify things ?!

RHt - RH target ( a manually set value and a generally a constant)
RHm - RH measured (value coes every 3 seconds)
FS - fanspeed (% value of max RPM)

best case:
RHt (40%) = RHm (40%) at let's say fanspeed 50%

now a sample:
. RHT < RHm
. trigger ( any change of RHm )
. action ( fanspeed increased by 1 )
. fanspeed 51
now RHm is still rising
. trigger action fanspeed 52
let's assume that happens 3x times
by than fanspeed will be at 55 and the measured RHm to make it easy is 5% higher e.g. 45% rRH
now RHm starts dropping by 1 to 44
what happens now is
. RHT < RHm (still more humidity but turnpoint 45 is passed we are one the way down to RHt)
. trigger ( at RHm decrease 45 -> 44)
. action fanspeed increased to 56%
. RHm dropping exponentially fast and overshooting RHt

here is the problem in the automation
when the RHm turnpoint is reached, on the way dropping towards RHt the fanspeed should drop too, and maybe even faster than just by 1

smoky swift
grim finch
#

thx

grim finch