Aprilaire humidifier not getting it done?

[swyman]

Search didn't give me the results for my issue.....I cannot get enough moisture in my house during the winter, lots of static! I have a forced air system with a Aprilaire 700 power whole house humidifier (evaporation style) mounted on the return just before the filter. I had a ducted version when furnace was installed but switched to this powered unit last year. One thing to note is that the humidifier only runs when furnace is calling for heat....should I set the furnace fan to run off the humidistat also? Is there other ways to add moisture into my home? Do the steam units work better? Please help, sick of getting shocked!

 

[zmaxmotorsports]

Leave your bath tub filled full of hot water.

 

[larry4406]

Looks like that unit is a fan/forced feed type unit. Our hvac contractor installs those on the supply plenum AFTER the furnace, not on the return upstream of the filter. The humidistat sensor is located on the return UPSTREAM of the humidifier. Our hvac contractor connects these to a hot water line vs cold. Yes if wired properly, you should be able to put your furnace in FAN mode and activate the humidifier if there is a demand senses by the humidistat.

 

[swyman]

Looks like that unit is a fan/forced feed type unit. Our hvac contractor installs those on the supply plenum AFTER the furnace, not on the return upstream of the filter. The humidistat sensor is located on the return UPSTREAM of the humidifier. Our hvac contractor connects these to a hot water line vs cold. Yes if wired properly, you should be able to put your furnace in FAN mode and activate the humidifier if there is a demand senses by the humidistat.

Thanks Larry, that makes sense. I do have the hot water line hooked up but will move unit to the hot side and I might get lucky and have the humidifier hooked to run off the fan now, will have to check. Anyone have the steam version?

 

[tomroblee]

Hot water will evaporate faster than cold water, but having the humidifier connected to a hot water line rather than a cold water line may not make much difference. The humidifier is going to use less than a gallon of water an hour. Depending on where the furnace is located in relation to the water heater, such a small stream of water may not be very warm.

Warm air can hold much more moisture than cold air. The reason that indoor humidity drops during the winter is that the colder outdoor air "leaks in. When this colder air is heated, the RELATIVE humidity drops. It is possible that you may have some sort of issue with heated air leaking out of ducts located in an attic or crawl space. This air will be replaced with colder outside air leaking in. If your heating bills have also been higher than normal, you may want to examine any ductwork that is located in unconditioned areas.

 

[Rockhead261]

I was in the HVAC trade for 20+ years and always viewed humidifiers as a placebo. They *do* help. A little. BUT there's no way an itty bitty evaporative pad or centrifugal mister attached to a residential furnace is going to add the amount of moisture it would take to raise a 2,000 sq. ft house from 15% to 40% RH, AND maintain it.

Want to stop static? Add a little liquid fabric softener to a spray bottle of warm water and mist your carpets/furniture. Repeat once a month or so during static season.

 

[larry4406]

My company now installs Clean Comfort HS Series steam humidifiers. This is my only experience with steam humidifiers so take it with a grain of salt.

These steam units specifically say to only use cold water supply (opposite the blow thru evaporative pad type). My understanding of the basis of this is that minerals are inversely soluble with temperatures (minerals plate out with higher temperatures yet dissolve with colder temperatures). The device subjects a canister of filled water to current to generate steam. The minerals in solution improve conductivity. There are troubleshooting instructions which has the technician add table salt to mineral deficient installations.

We had issues where the units could be energized yet not have air flow. Created mold in ductwork and drywall. First solution was use of a sail switch to only energize when fan was on. This was later changed to special wiring off the furnace board to allow operation only when the heat cycle was energized (so no "fan only" operation of humidifier). This final method was done to ensure there could not be a mold issue due over humidificstion.

 

[Jackfre]

How oversized is the furnace? Short cycling will cause the problem you are having.

 

[brewchief]

I've installed hundreds of humidifiers, it's rare that we can't get enough humidity out of a aprilaire 600 or 700, we do very few of the 700s as we prefer the bypass style with fewer things to break.

Hot water on a fan powered is a must if mounted on the return, the fan powered will work better on the supply as they need the heat to help evaporate the water. Be careful of the A/C coil if moving to the supply side, you don't want the humidifier to be mounted on the back side of an A coil where the airflow would be blocked, you also don't want to damage the A coil when cutting a hole.

What control does it have on it? The newer ones can bring the blower on as needed if the humidity gets low.

Avoid the Honeywell pads that are fabric like as they tend to sag and cause leaks.

 

[csp]

Move it to the supply side vs. the return and you should see significant results.

 

[ford33]

I have a similar setup and find it insufficient to add humidity to the house. I run a separate humidifier in the bedroom day and night to add moisture during the winter months. I don't believe the Apriaire units do much good.

 

[swyman]

How oversized is the furnace? Short cycling will cause the problem you are having.

This could be an issue. When the furnace was installed we did oversize it because I knew I would be adding on. Since installation I have added 420sqft and am almost finished with another 520. That should definitely add to my cycle times.

 

[swyman]

What control does it have on it? The newer ones can bring the blower on as needed if the humidity gets low.

Avoid the Honeywell pads that are fabric like as they tend to sag and cause leaks.

I have the newer control but is not hooked up to come on when humidity is low. Now that I think about it I cannot just run the fan because I have a large water to air coil after the A coil and use a coal boiler for primary heat. I have 2 thermostats, one runs the furnace normally and the other just turn the fan on which is the one I use in the winter so I am not burning propane. I have an old farmhouse and when it gets really cold with wind the boiler will not keep up and I will switch thermostats and run the furnace also. When I do this I will see register temps of 150* which makes it warm in a hurry. Maybe that air infiltration in windy conditions is where I loose humidity?
My boiler is located in a barn 220' from the house and I currently have only 1 supply run that feeds 3 exchangers, this is the setup recommended by Central Boiler as I had a outdoor wood boiler for primary heat but switched to coal last season. Everything should change next year as the 520' addition has a full basement and I will be installing the boiler in there so I can have 3 zones instead of one continuous loop that circulates nonstop. Also all the radiant heat from the boiler will stay in the house.

 

[yeldogt]

I installed a Lenox bypass unit at one of my houses -- did the job. The control was in the return a few feat back from the furnace. Unit took heat from the supply using a dedicate duct and fed the humid air back to the furnace.

We had ours connected to the cold water line it was important to clean the unit -- I used ice maker cleaner. Having an extra media and nozzle allowed for quick change outs in the winter -- with required soaking -- I could clean at a litter date.

 

[starquestMM]

I have my 600 wired up to make its own fan calls.
The 700 i put in my moms house only runs with the furnace. Her house is much more air tight than mine and it keeps up there fine.
My 1500sqft house it won't keep up with just furnace calls. It might be able to take it from 19-20% up to 25-28ish. Being able to do its own calls, it can hold 40%.

Mike

 

[dsd]

I had an Aprilaire 700 and it did nothing. After years of frustration, we switched to an Aprilaire 800 steam unit.

It's awesome. It's integrated in our thermostat and keeps my 3700 two story house at 35-40% or as I chose no problem. Base humidity is usually 19-22%. Unit also integrates with the fans for condensation control.

It took 2 techs 8 hours to install, but they did a great job and I am very happy.

Old vs New in pics (no idea why 2nd pic is upside down).

 

[Showkey]

The last three homes I have owned ..........have been "tightened up" on air exchanges and insulation . So they all had humidifiers and I never used them. Between showers, laundry and cooking found no need to add extra moisture. Accurate measurement of the overall humity is critical. Think many homes are too humid during winter extremes or the cold dry infiltration makes the home dry out.

 

[LS6 Tommy]

I was in the HVAC trade for 20+ years and always viewed humidifiers as a placebo. They *do* help. A little. BUT there's no way an itty bitty evaporative pad or centrifugal mister attached to a residential furnace is going to add the amount of moisture it would take to raise a 2,000 sq. ft house from 15% to 40% RH, AND maintain it.

This. Also, using hot water makes a negligible difference in RH, uses more enregy, creates more maintenence issues in the humidifier from calcium/minerals and lukewarm water sitting in the air stream may end up giving you Legionella. Cold water for me, please...


Tommy

 

[PWC Repair]

I have a 55 gallon aquarium near the return air, works great!

 

[walta]

In my opinion humidifiers treat the symptom.

The real problem is the lack of anything in your wall to stop the warm moist air from escaping and being replaces with cold dry air.

Before you design and install a new heating system get a energy audit with a blower door test. This will help you locate and seal most of your air leaks.

Cutting your heat losses and fuel costs in half is possible.

Walta