Whole house humidifier working?

malaujai wrote: ↑ Hey! So I bought a house and have been having some renovations done in it. I put in new hardwood floors into the house so I also installed a whole house humidifier (Aprilaire 400). We have yet to move into the house so it is fairly empty at the moment without furniture. Something I noticed was that our ecobee humidity reading is showing ~27% at 22 degrees celsius. The furnace doesn't come on that often (there's barely any in/out traffic as renos are done now and we visit the house only every so often). The humidifier is set to the "winter" mode, and I've set the humidity to somewhere between 35-40% but it doesn't seem like the humidity in the house is going up. My understanding is that the humidity can probably only go up if the furnace is on and so if the temperature in the house doesn't require the furnace to be on, then the humidifier won't be able to push the humid air out anyway.

Is the fact that no one's in the house and the furnace not always coming on the reason the humidity doesn't hit the level that I've set? Is there another quick/easy way to test if my humidifier is working? Thanks!

That's the answer. Regarding how to test if humidifier works. Solenoid valve is usually the most common point of failure. Stand near your furnace when it's on and rotate the dial on humidistat to increase the desired humidity. Do you hear a click when you move the dial beyond 20-25%. If yes, then the solenoid valve is working. Also you should be able to see few drops of water coming out of the humidifier's drain pipe every once in a while.

Yes you will need the heat on to significant evaporation in a flow-thru or drum type humidifer.

As mentioned check the solenoid and the plumbing. Hopefully it's not using a saddle valve tapped to a cold line.

IndyBeak wrote: ↑ That's the answer. Regarding how to test if humidifier works. Solenoid valve is usually the most common point of failure. Stand near your furnace when it's on and rotate the dial on humidistat to increase the desired humidity. Do you hear a click when you move the dial beyond 20-25%. If yes, then the solenoid valve is working. Also you should be able to see few drops of water coming out of the humidifier's drain pipe every once in a while.

Dumb question: It's currently set somewhere between 35-40. To test the solenoid valve, I'd need to set it to under 20-25 first, then wait for the furnace to come on and finally move the dial right? Would it come on if I didn't set it under 20-25% and just moved the dial up 15-20% from where it is at currently?

also to add on to my initial question... Assuming the humidifier actually works, then the solution seems to get the furnace on more often... This is my first home so I'm not 100% sure what to expect but wouldn't more people in the house + furniture, etc retain more heat in the house and therefore my furnace would be on even less often? Or would the daily traffic in and out of the house allow heat to escape and have the furnace on?

Check the humidifier pad. If its dry/hard and yellow looking (which means its calcified) you need to replace it.

I have a 400 model as well and the pads this winter generally only last 1.5 months. The furnace coming on less also causes the pad to become calcified quicker to.

davidmr wrote: ↑ Check the humidifier pad. If its dry/hard and yellow looking (which means its calcified) you need to replace it.

I have a 400 model as well and the pads this winter generally only last 1.5 months. The furnace coming on less also causes the pad to become calcified quicker to.

Thanks for that tip. I should read up the manual more... The HVAC guy who installed it for me also mentioned something about the two small (plastic?) rods and something about them moving up and down... I didn't really understand at the time lol

malaujai wrote: ↑ Dumb question: It's currently set somewhere between 35-40. To test the solenoid valve, I'd need to set it to under 20-25 first, then wait for the furnace to come on and finally move the dial right? Would it come on if I didn't set it under 20-25% and just moved the dial up 15-20% from where it is at currently?

As long as the humidistat is set higher then the humidity in the house it will turn on.
BUT you have a 400 model, this unit has a reservoir for the water with in it. If the reservoir is full the solenoid will NOT turn on. the solenoid valve only turns on to refill the reservoir.

Check to see if the reservoir is empty or not (the pad sits in the reservoir at the bottom). If it is empty then the humidifier is not working. Whether thats the solenoid or the humidistat or something else, this will need to be determined.

On the humidistat when you turn it from say between 20% to 40% do you hear any click noises?

malaujai wrote: ↑ Thanks for that tip. I should read up the manual more... The HVAC guy who installed it for me also mentioned something about the two small (plastic?) rods and something about them moving up and down... I didn't really understand at the time lol

you really dont need to worry about them to much. essentially they are floats and act as switches that turn the solenoid on and off (depending of course on if the humidistat is also calling for humidity). The Solenoid is basically an electric valve/switch that turns on the flow of water into the reservoir.

With this humidifier you need to clean the reservoir when you change the pad. simply wash it out with vinegar. If you dont you will get mold growth.

malaujai wrote: ↑ Dumb question: It's currently set somewhere between 35-40. To test the solenoid valve, I'd need to set it to under 20-25 first, then wait for the furnace to come on and finally move the dial right? Would it come on if I didn't set it under 20-25% and just moved the dial up 15-20% from where it is at currently?

also to add on to my initial question... Assuming the humidifier actually works, then the solution seems to get the furnace on more often... This is my first home so I'm not 100% sure what to expect but wouldn't more people in the house + furniture, etc retain more heat in the house and therefore my furnace would be on even less often? Or would the daily traffic in and out of the house allow heat to escape and have the furnace on?

There is no fixed formula, but overall I would agree that an empty house will cool down faster than the one which is occupied. Human body and activities like cooking etc also generate heat. Daily in/out traffic will cause some heat loss, but it depends on how frequently doors are being opened. Also better insulation would further slow down the heat loss. Better insulation also helps retain humidity.

So I didn't have time to go over to the house yesterday but I ran a mini experiment via my ecobee... I turned the temperature up to 24 from 22 and left it like that for 3 hours or so... I noticed the humidity went up from 27% to 29%. Assuming my humidifier actually works and it's sitting at a lower humdity % than I want, what would the long term solution be? turning the temperature up and keeping it at 24? Not sure I'd want that for comfort or energy use...

I guess the problem is that my humidifier setup has no feedback or control based on the humidity level

malaujai wrote: ↑ So I didn't have time to go over to the house yesterday but I ran a mini experiment via my ecobee... I turned the temperature up to 24 from 22 and left it like that for 3 hours or so... I noticed the humidity went up from 27% to 29%. Assuming my humidifier actually works and it's sitting at a lower humdity % than I want, what would the long term solution be? turning the temperature up and keeping it at 24? Not sure I'd want that for comfort or energy use...

I guess the problem is that my humidifier setup has no feedback or control based on the humidity level

25-30% humidity in winter is not entirely bad if no one is living there.

How many sqft is the house (not including the basement)? 1 or 2 story?

Does it have a HRV or ERV? do you know if its running all the time?

What kind of furnace? 2 stage or modulating?

malaujai wrote: ↑ So I didn't have time to go over to the house yesterday but I ran a mini experiment via my ecobee... I turned the temperature up to 24 from 22 and left it like that for 3 hours or so... I noticed the humidity went up from 27% to 29%. Assuming my humidifier actually works and it's sitting at a lower humdity % than I want, what would the long term solution be? turning the temperature up and keeping it at 24? Not sure I'd want that for comfort or energy use...

I guess the problem is that my humidifier setup has no feedback or control based on the humidity level

It does seem like humidity is being added. If there wasn't then the humidity should go down slightly as the temperature increases.. The pad could still be hard and not wicking enough moisture up into the air stream.

davidmr wrote: ↑ How many sqft is the house (not including the basement)? 1 or 2 story?

Does it have a HRV or ERV? do you know if its running all the time?

What kind of furnace? 2 stage or modulating?

The house is a 1700 sqft 2 story semi. I do not believe it has an HRV or ERV (are they pretty common?) and the furnace is a 2 stage furnace.

Check to see if it's hooked up to the cold or hot water line. It'll preform better hooked up to a hot water supply as it makes it easier for the water to evaporate.

schade wrote: ↑ Check to see if it's hooked up to the cold or hot water line. It'll preform better hooked up to a hot water supply as it makes it easier for the water to evaporate.

on a model 400 that is not true. because it uses a reservoir the water will be at room temperature anyway.

malaujai wrote: ↑ The house is a 1700 sqft 2 story semi. I do not believe it has an HRV or ERV (are they pretty common?) and the furnace is a 2 stage furnace.

In new houses they can be fairly common..

at this point you need to go there and check the pad and also that the reservoir has water in it

davidmr wrote: ↑ on a model 400 that is not true. because it uses a reservoir the water will be at room temperature anyway.

Of course its still true for the model 400, it's even recommended in the installation manual. The water won't be sitting in the reservoir for days. Even if the water is warm by the time it gets evaporated that's still better than trying to do it with cold water

According to Wikipedia, there are a few types of furnace mounted humidifiers, The two main types are the "Drum" type and the "Bypass Flow-through"

The drum type contains a pan of water (the reservoir), and the height of the water is kept constant by a float valve. The wick is usually a foam pad mounted on a drum. As the drum rotates the foam picks up the water from the reservoir, and as the air blows through the foam it carries moisture into the duct-work and throughout the house. In this case the drum will only turn when the "Hygrostat" signals for additional humidity (see Note Below).

The Bypass Flow-through type contains a vertical pad/mesh of metal, similar to steel wool. When the "Hygrostat" signals that more humidity is required, it activates a water valve at the top of the mesh which allows water to trickle throughout the mesh (see Note below). As the air flows through the mesh it carries the moisture throughout the house.

It appears that your Aprilaire 400 is a Bypass Flow-through type, so it will not contain a reservoir as has been mentioned in some of these posts.

NOTE:
I think the key point that everyone is missing is that no humidifiers will operate unless the blower motor is also operating (i,e, the drum will not turn in the drum type, and the water valve will not open in the bypass type). There are different ways of doing this, from using current sensing relays on the wires to the blower, or by obtaining the 110V directly from the blower motor connections. More recently, smart thermostats like Ecobee can control the humidifier directly.

So to answer the OP question, your current humidity may be low, if the furnace has not been operating frequently. You could solve the problem by turning the blower control on manually. The manual operation will not carry as much humidity (since the air will not be heated, and the blower will run at a slower speed)), but it should help increase the humidity all the same.

To test for operation of your Aprilaire 400, simply turn up your thermostat so that the furnace starts operating, then turn up the Hygrostat to maximum and verify if water starts flowing through the mesh inside the humidifier.

schade wrote: ↑ Of course its still true for the model 400, it's even recommended in the installation manual. The water won't be sitting in the reservoir for days. Even if the water is warm by the time it gets evaporated that's still better than trying to do it with cold water

I have this humidifier. In my house the solenoid turns on for less then 10 seconds every half hour.

do you think thats enough time for hot water to get from the hwt to the humidifier? NO only the cooled off water that has sat in the pipe reaches the humidifier, and by the time the humidifier calls for water again that fresh hot water in the pipe has cooled off again. Only humidifiers that run the water for a prolonged time benefit.