With the downstairs airhandler fitted with the Aprilaire 700 automagic humidifier, I am not happy that the home humidity is only 30%.

I finally saw the unit actually working as I was pouring myself a Costco 7-year old Tennessee whiskey out in the garage. The light came on, suggesting it was ON, and I could hear the water running through the panel. I could feel the hot water line (copper) being very hot, so I am certain that all mechanical aspects of the system are working.

So, what do I do to improve the performance and raise the humidity to 50%?

Mine is the manual version and is capped at 40%, not sure if you could get it to 50%, even if you did you are likely to get a lot of condensation on your windows when it's below 40 degrees.

Did you change out your panel this year?

Additional info needed, like how long have you had it, are lines the correct size, and is the control dial compatible and working properly?

I have one and due to hard water in my area it is useless. We set a kettle of water on the woodburner.

It’s my understanding you don’t want to get to 50% with these. I have the Aprilaire 600 with the manual control and my installer put a thick red mark with a sharpie at the 35% tick on the dial.

It is nine months old. No maintenance yet as it is the first usage.

quote:

Aprilaire 700 automagic humidifier,

Does this mean that you have the automatic controller pictured below with the external temperature probe?


If yes to both, what number is the dial turned to?

Let me guess, its mounted to the supply ducting?

Need way more information. How big a home? What outside temperatures? How well it's the home insulated? How well it's the home sealed against outside air ingress? Do you have at least double-glazed windows? Are you getting much condensation on them? How often does the furnace run? Is the humidifier wired to run when the burner is on, rather than the fan?

I have an Aprilaire. When I check the humidity in the house it's usually 35-38%. We sleep well ( no dryness in the nose ,throat) and no static electricity. So I figure that's good enough.

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Originally posted by tatortodd:

quote:

Aprilaire 700 automagic humidifier,

Does this mean that you have the automatic controller pictured below with the external temperature probe?


If yes to both, what number is the dial turned to?

Yes to both. The initial setting is 5 as the system learns the home and adjusts humidity levels. This goes on for 48 hours at which point you can fine tune the adjustment. Doing this I noticed condensation on my windows initially with humidity levels in the high 40's. I dialed my controller (same as pictured) back to 4, then to 3 on my Aprilaire 400 and am now sitting at a comfortable 31-35% humidity level. I installed my unit on the upstairs zone where our bedrooms are and use 2 hygrometers to measure humidity levels upstairs and down. It's a cheap check on what the humidistat is telling me as well.

OP, I would remove the water panel and replace if it's been more than 5 months. Check the frame for clogs, turn the dial all the way up with the cover removed and verify the water is going were it should. Also check the damper to make sure it's in the winter position, even if externally it looks like it is. All that said, you do not want humidity levels at 50%, it will create other problems in the house over time. The ideal range is between 30-35%.

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Originally posted by LBAR15:
Yes to both. The initial setting is 5 as the system learns the home and adjusts humidity levels. This goes on for 48 hours at which point you can fine tune the adjustment. Doing this I noticed condensation on my windows initially with humidity levels in the high 40's. I dialed my controller (same as pictured) back to 4, then to 3 on my Aprilaire 400 and am now sitting at a comfortable 31-35% humidity level. I installed my unit on the upstairs zone where our bedrooms are and use 2 hygrometers to measure humidity levels upstairs and down. It's a cheap check on what the humidistat is telling me as well.

Obviously, my question was directed at the OP not you. It’s not guaranteed to be yes to both for 2 reasons:
1. Not sure what he meant by automatic and wanted to make sure
2. Even if the answer to having the controller pictured there is no guarantee the external temperature probe was installed outdoors and wired to controller. The reason I state this is when I lived in Alaska, I had an Aprilaire installed with the controller pictured. The HVAC tech tried to get out of the 10 minutes of work to hook up the external temperature probe which was crazy because my furnace was in my garage and about 10’ away was an external wall where I made him install it. If Someone didn’t know how important the external temp probe was they could allow for a lazy install and be left dissatisfied with a poorly performing humidifier.

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Originally posted by LBAR15:

Also check the damper to make sure it's in the winter position, even if externally it looks like it is.

The 700 doesn't have a damper.

I think 40% would be about as high as you'd want to go for a normal home.

I’m going to have to respectfully disagree regarding relative humidity in the home.

The research we’ve done has shown that a RH between 40 and 45% is ideal.

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Originally posted by smlsig:
I’m going to have to respectfully disagree regarding relative humidity in the home.

The research we’ve done has shown that a RH between 40 and 45% is ideal.

You may of course disagree, but maximum RH inside the home is dependent upon outside temperature. The lower the outside temperature, the lower one can reasonably maintain indoor humidity.

I will look into some of the questions raised.

The controller is in the return duct and the water vapor emitter is in the supply duct.

I cannot achieve any different humidity regardless of setting.

The indoor humidity varies with outside temperature.

If the humidity setpoint is 40% and the measured and reported humidity is less, why is the device not operating every furnace cycle? It should be trying its best and pouring water on the panel. This is not happening.

My floor boards are separated and my violins are at risk.

Just so you are aware, it will raise and lower the humidity automatically based on indoor humidity and outside temperature. It will not keep it at the set %. I believe the colder the temp gets the lower it will keep the humidity but I might have that backwards.

I just happen to be installing one of the same units this weekend.

Never been happy with mine. It is my second one and I am still getting shocks off the sofa and have a dry throat in the morning.

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Originally posted by 4MUL8R:
The indoor humidity varies with outside temperature.

Even if you do not have an "automatic" humidifier that automatically adjusts indoor humidity based on outside air temperature, that will still happen.

As outside air temperature drops, so too does the inside temperature of your outside walls, your windows and outside doors, and even the ceilings of your top floor. So what happens is the warmer, humidified air hits those and condenses, taking humidity out of the air as it circulates past them.

The clue that you've reached maximum reasonable indoor humidity is your windows. Are you getting condensation on them?

quote:

Originally posted by 4MUL8R:
If the humidity setpoint is 40% and the measured and reported humidity is less, why is the device not operating every furnace cycle?

If you do have an automatic humidifier that automatically adjusts maximum indoor humidity based on outdoor temperature, it will automatically set lower humidity maximums at lower outdoor temperatures.

Our humidifier, probably similar technology to your AprilAire, was dumping all sorts of humidity into the air. Too much, we found, when we started getting stains and water dripping from the perimeter of parts of the ceiling. We at first thought it was ice dams on the roof. Nope, it was condensation.

I since installed a Honeywell automatic humidistat and adjusted it to call for the maximum safe humidity levels at various outdoor temperatures for our home.

Have you checked that the humidistat is in the automatic mode? It's possible to run it in manual mode with a change to a switch under the cover. Worth a shot just to rule it out at least.