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HVAC humidifier duct dumper

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  • Jul 14th, 2021 3:21 pm
[OP]
Deal Addict
Aug 19, 2006
1807 posts
281 upvotes
Toronto

HVAC humidifier duct dumper

I have this duct dumper on the HVAC humidifier that is labeled to close in the summer and open in the winter.
Should I actually be doing this ? The humidifier get quite cold when the AC is running.
Wouldn't turning humidistat to 'off' position turn off the humidifier ? why close the dumper then ?
On a side note, how can I verify if this humidifier is actually working ? I tried to play around with humidistat in the winter and didn't notice any difference.
Thanks

https://ibb.co/SRHRtTV
2 replies
Deal Addict
Oct 19, 2020
1004 posts
622 upvotes
GTA
It's important to close that damper in the summer to prevent cold supply air from being dumped right back into the return.

If water flows when the heat is on and the humidistat is set above humidity level, it is working.
It can take hours or days to notice a difference in humidity level if you turn it on when the house is very dry - building materials take up humidity like a sponge.

Maintenance is important. The pad should be checked once a year and replaced when it is very scaled up.
Every year, check the drain line for blockages and clean the drain tray.
Some say to just change the pad every year, but they tend to last longer than that in flow-through models because most of the minerals get flushed down the drain.
Deal Addict
Jun 16, 2009
3125 posts
1480 upvotes
Woodbridge
If you happen to close the damper in summer, DO NOT FOEGET to reopen in winter. Many people tend to forget it defeating the purpose of having the humidifier.
krypton wrote: I have this duct dumper on the HVAC humidifier that is labeled to close in the summer and open in the winter.
Should I actually be doing this ? The humidifier get quite cold when the AC is running.
Wouldn't turning humidistat to 'off' position turn off the humidifier ? why close the dumper then ?
On a side note, how can I verify if this humidifier is actually working ? I tried to play around with humidistat in the winter and didn't notice any difference.
Thanks

https://ibb.co/SRHRtTV

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