Humidifier: Installing An AprilAire Whole House Humidifier and More
Introduction To Home Humidification
Adding a whole house humidifier to your heating and air conditioning system is something you can do yourself to improve your air quality and comfort.
These easy to follow, step by step instructions and photos will show you all you need to know to install, operate, maintain and understand your furnace humidifier using an AprilAire 600M unit as an example.
~ Table of Contents ~
- Considering the Purchase of a Humidifier
- Benefits of Humidification
- What You Need to Install a Humidifier (Materials / Tools With Photo References)
- Planning Out Your Humidifier Installation
- 13 Step Humidifier Installation Guide (With Photo References)
- Setting and Controlling Your Humidity Level
- Basic Humidifier Maintenance and Parts
Humidifiers | Simple Units With Great Benefits
Cre8tor has 15 years of experience in HVAC Installation and Service as well as an EPA certification and completed coursework in electrical theory, thermodynamics, and refrigeration.
Thinking About Buying A Whole House Humidifier?
The cost of installing or having a heating and cooling professional install a humidifier for you is really rather reasonable. If you're doing it yourself, you can expect to spend in the range of $250 for the unit and necessary materials to install it. Even if you have to purchase a tool or 2, you'd likely get out if the HVAC system upgrade for around $300 since you likely have most of the tools you need.
If you have an HVAC contractor perform the installation for you, the cost will still be "earthly" and in the neighborhood of $400 - $500.
Aside from cutting down on your use of moisturizers and boiling pots of water on the stove, here is a list of benefits a whole house humidifier will provide to help pay for itself.
Benefits of Humidifiers
Significantly reduces the amount of air born dust in the home thus reducing the suffering of those with allergies.
Lower or even eliminate static electricity.
Save on energy bills - Your furnace works harder to heat dry air.
Deters the spread of viruses that thrive in drier environments.
Wood floors and cabinets will maintain their appearance and last longer.
Prevents skin from drying and itching as well as lips from chapping
Helps keep house plants healthy - Looking at dying plants doesn't exude a feeling of comfort.
Home Value - Humidifiers are rather inexpensive and value to your HVAC system, thus your home. They will more than pay for themselves.
Colder Regions of the World Benefit Most From Whole House Humidification
What You Need To Install A Whole House Humidifier
Now that we've decided adding a humidifier is a good and affordable idea, let's get started with how to install a unit ourselves using a rather basic April Air humidifier as an example. If you're going to hire a heating and cooling service provider for your install, perhaps you'll want to skip down to the maintenance and humidity control section of this page.
Whole House Humidifier Kit
AprilAire Humidifier Kit
Humidifier Installation Materials - Reference PhotosClick thumbnail to view full-size
- AprilAire Humidifier (recommended) (Confirm model is sized properly for your home.)
- Unit with filter/panel and built in damper
- Transformer (110v/24v)
- Saddle Valve (to tap into existing hot water piping)
- Humidistat (humidity control)
- Installation template (for unit and humidistat)
- 3/4" PVC Pipe (10' should be sufficient if you have an A/C or furnace drain you can tap into.)
- PVC Cement (Very little is required and could be done with a waterproof silicon.)
- 3/4" PVC Fittings (1-tee, 4-90's, 2-45's and 1-coupling should do in most cases.)
- Foil or Duct Tape (Again, very little is needed.)
- 1/4" Copper Tubing (Length will be the distance from humidifier to nearest hot water line.)
- 18/2 Thermostat Wire (low voltage / 24V)
- Small Wire Nuts (small, usually blue - 6 would be the most you'll use)
- 2 Spade Terminal Connectors (small, usually blue)
- 1" Sheet Metal Screws (6 - 10 should be fine)
- 1/2" Sheet Metal Screws (10 or so should do)
- 5 Feet 6" round warm air pipe
- 1 - 6" Take Off (A 6" start collar and elbow could be used instead.)
- 6" Adjustable Elbows (Depending on your set up, no more than 3 should be necessary.)
Tools Used for Humidifier Installation - Reference PhotosClick thumbnail to view full-size
NOTE: You may only need some of these depending on your humidifier installation and you may find that you have a tool that can be used as a viable substitute for some of these HVAC specialty tools. Before you buy any of these items, perhaps you should assess your installation compared to this example.
- Battery Drill and 1/4" Hex Driver
- Flathead and Philip's Screwdriver
- Tin Snips
- Tape Measure
- Pliers (You will want 2 pair of standard pliers or channel locks.)
- Torpedo Level
- Tubing Cutter
- Crimping Tool
AprilAire 600M Review
AprilAire is one of the most well known names in air quality. I have used their products for years and feel they live up to their reputation. I am not in anyway affiliated with AprilAire, I just like the product and feel it is well made and installer friendly. When properly installed, used and maintained, I know you'll be happy with AprilAire products.
The 600M is a rather simple, manually operated damper and stat model humidifier for somewhat larger homes however, April Air has many humidifier models that offer options for outdoor humidity sensing and more automated use to go along with varieties of other HVAC air quality accessories.
Where To Install A Humidifier
Before we start cutting holes into our duct work, we need to decide where we're going to locate our AprilAire humidifier. Your options may be limited by your existing heating and cooling system's set up or you may have a few choices to pick from. Again, I suggest you follow this example humidifier install to the end to have a good understanding of what we're doing and then make your decision.
Here are a few things to keep in mind and that I've applied to this home humidifier install.
- Mount the unit on the return air duct whenever possible. You can mount to the supply side but the system works much better on the return and poses less of a threat to your furnace should there ever be a malfunction involving water and electrical components.
- Make sure there is enough room above the unit to mount your humidistat. It's suggested to be at least 6" above the unit.
- Try to make the bypass connection as short and straight as possible.
- The AprilAire units are able to be flipped around so that the bypass can be on either side.
- Be sure you have room to remove the unit's cover, water pad/panel and so forth for easy maintenance and repair.
- Visualize your drain path to be sure you'll be able to maintain fall (a down slope) toward it's destination to insure proper drainage and prevent stagnant water from building up in the line. Again, the shorter, the better.
Without further delay, let's start installing our whole house humidifier.
12 Step Home Humidifier Install Guide
A picture is worth a thousand words so why don't I keep this as simple as possible. Below, I've listed the steps for my AprilAire 600M installation example but in order not to lose anything to your imagination, I've provide photos to go along with these steps. The 2 combined should give you a very clear picture of how to install your whole house humidifier.
Humidifier Installation Photo Guide | Steps 1 to 5Click thumbnail to view full-size
Steps 6 to 8Click thumbnail to view full-size
Humidifier Wiring Diagram
Steps 9 - 12Click thumbnail to view full-size
- Level and trace your humidifier template on to your return air duct work.
- Slit the duct just inside the pattern about 3" long.
Place your flat head screwdriver against the duct at a slight angle and hammer it into the metal. (You may want to shoot a screw in the duct and remove it for an easier start.) Twist the screwdriver to open the slit a little so that you can start your snips and cut out your pattern.
- Cut out the humidistat pattern.
Locate the humidistat 6" above the humidifier. It does not have to be located on the same side of the return air duct.
- Mount the humidifier casing and control body.
- Remove the cover and water pad from the humidifier and place the casing into the hole on the duct. Using 1" long sheet metal screws, mount the casing to the duct by running screws through the provided holes in the casing. This AprilAire unit requires 6 screws.
- Pull off the control knob so that you can pull the facing off of the main control body. Using 4 - 1/2" long sheet metal screws fasten the control body to the duct in the hole you cut. Don't forget the foam gasket that goes between the humidity control body and the duct.
- Locate, trace, cut out and install the 6" take off on the supply duct for your bypass.
Remember, the shorter and straighter the bypass, the better.
WARNING: If you have air conditioning, avoid mounting the take off right on the coil case and definitely don't pierce a hole in the coil when cutting into the duct if you have to place it there.
Now slide the teeth of the take off or collar into the hole and fold them over to lock it into place.
- Install bypass piping.
Your path may vary from mine but just keep in mind that you want to take the path of least resistance when possible. Connect your 6" elbow to the humidifier casing with 2 - 1" screws. The casing has holes at the top and bottom of the damper connection for this. Make sure you adjust the elbow first and check that the damper swings freely when done.
- When cutting straight pipe sections, measure from the edge of "Point A" to the edge of Point "B" and add 3" for your connections.
- As you complete connections, put tape around each one and then install 2 - 1/2" screws in each.
- If it's summer, close the damper. If it's winter, leave it open.
- Run the drain piping.
Assuming you have air conditioning or a high efficiency furnace, you can easily tap into one of those 3/4" lines by cutting in a "tee" and running your pipe from there to the humidifier. You can measure edge to edge plus 1" to get your cuts for straight pipe. Be sure to glue each joint and secure the pipe to the furnace or duct with 1/2" screws. You can use pieces of your scrap metal for strapping.
- If you don't have a drain already, you can run the pipe along the floor to a laundry drain or you'll have to add a condensate pump to the equation to pump the water to its' destination.
- Connect your transformer. **Make sure the power is off to the unit.**
Modern furnaces have terminals on the circuit board for easy humidifier hook up marked "HUM" and "NEUTRAL" Be sure you don't tie into the 24V common by mistake. The neutral is for 110V use. Use pliers to squeeze your spade connectors onto the transformer's black and white wires. Then just press the black connector onto the "HUM" terminal and the white connector onto the "NEUTRAL" securely.
- If you don't have these terminals, you'll have to tap into another 110V source using wire nuts.
- Run the low voltage wiring. (thermostat wire)
I have chosen to run most of my wiring through my duct work in this example because it keeps it protected and looks much neater when you do. However, with so many options and situations, I've provided you photos and a wiring diagram that I believe will give you a better idea on how to tackle your specific needs. Just keep this in mind...
- Any wiring out side of the duct from the ceiling down, should be protected by some sort of flexible conduit.
- Don't leave the wire to rub on sharp edges.
- Make sure you make good connections. Don't over tighten but be sure the wire is secure on whatever terminal type you're using.
- Install the water line and valve.
Again, I think the photos will help you the most so as you look at those, keep in mind...
- Make sure the rubber gasket is seated properly, the "tee" handle is tightened to the mounting bracket and the valve needle is retracted when mounting the valve to the hot water line.
- Don't over tighten anything and use 2 pair of pliers to make sure you don't twist things as you tighten.
- Once you've cut the line and completed the install of it, twist the valve "tee" handle all the way down to pierce the main and then loosen it to open the valve and allow water to flow to the humidifier.
*** Make sure you know where the nearest water shut off is.***
In case of a problem, once you pierce the line, you'll have to shut off the water to that pipe in order to stop the leaking and fix the issue. It is probably just a matter of tightening the connections a bit more but worst case scenario, you can install an inline valve and make the repair to the main at the same time using push fittings to keep the repair to the main simple as pie.
- Re-install the water feed tube, panel and humidistat cover.
Insert the feed tube into the water panel housing where it was and snap the panel back into the humidifier by putting the bottom in first and snapping the top back into the humidifier housing. The humidistat cover will also just snap into place and the knob back onto the control post. (The knob only goes on one way.)
- Run a test cycle.
Make sure the power to the furnace is turned back on and that the main thermostat is set high enough to make the furnace run. Place the doors back onto the furnace and then turn the humidistat all the way up or to the "test" marking. Within a minute or so, you should here the "click" of the humidifier's solenoid valve opening and the water flowing into the water panel. You can remove the hose to see the water is coming but when you do, make sure you point it at the panel near the bottom to catch the water that is coming out. If all is well, replace the cover on the humidifier and adjust your humidity control setting.
Humidifiers Promote Love!!!
Are you tired of getting shocked every time you kiss your loved ones?
Humidistat | Humidity Control
Once your humidifier installation is complete and you've checked that all of your plumbing connections are leak free, we can run a test to make sure it's operating properly and set our humidity level. There is no magic number for your home's humidifier setting.
First, turn the humidistat all the way up or to it's "test" level. This will force the unit to operate. You can confirm this by hearing the solenoid valve open (click), listen for the flow of water and drainage coming from the unit.
Now, the suggested starting humidistat setting will vary a bit based on region. That being said, 35 to 45% is the suggested range for most of us but we want to ease into that. Start at 30% and let the humidity settle into the home before deciding to make adjustments. Remember that things will begin to expand and soak up the initial humidity so you won't get a true feel for what the proper level is until you let the unit work for a while and even out in the home. Consider waiting 4 or 5 days before fine tuning your humidity control setting.
Tips for making adjustments:
- A little at a time. You'd be surprised how much 1 or 2 % can make a difference.
- If windows and horizontal surfaces feel damp, you're set too high. This can cause woods to take in too much humidity and ice to form on windows.
- If static is still keeping you from wanting to be near your loved ones and you still feel the air seems dry, you're likely still a bit low and should bump up your humidistat until your comfortable yet avoiding the previous tip.
Once you find a level that you're comfortable with, mark it on the humidistat with a marker for next year so when you shut down the humidifier for the summer, you'll know where to set it again when cold weather swings back in.
Improve Your Air Quality Even More
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Humidifier Parts PhotosClick thumbnail to view full-size
Universal Solenoid Replacement
Humidifier Maintenance and Parts
One of the best things about having a humidifier is that it's so simple to maintain and there are only a couple of working parts.
I have provided you photos of these parts as well as a brief description of each for easy reference should you need them and as far as maintenance goes, just replace your water panel as needed.
A water panel doesn't have an exact life span. It greatly depends on the water that it uses and home that it's in. Be sure to check it for mineral build up and/or deterioration. These are the signs that your water panel needs replaced. Other than that...
...remember, when we have plenty of summer humidity and we want our humidifier shut down. Turn your humidistat all the way down or "off" and shut the bypass damper between the unit and the plenum. (Turn it to "summer")
This may be a good time to replace your water pad or panel since it's also a good time to replace your furnace filter with spring coming.
Change your filters after you do your spring cleaning since you'll likely be stirring up dust.
That Concludes Our Session of Humidifier 101
Perhaps this is more than you ever wanted to know about humidifiers but I wanted to provide a complete guide not just on installing a whole house humidifier but also all the things that go with it.
Whether it be the AprilAire model I used in this example or any other humidifier brand, all of this information is applicable and the project should only take about 4 hours to complete for the average homeowner.
Learn more about your heating and air conditioning system here with me on HubPages if you'd like to learn more.
© 2014 Daniel Robbins