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Model # 12HF

Internet # 202771119

Whole House Furnace Mount Flow Through Humidifier

This item has been discontinued.
The Home Depot no longer carries this specific product.

$147.30 /box

  • Create a healthier environment with a whole house humidifier
  • Product sold without installation or permitting
  • Equipment should be sized/installed by a qualified professional




Model # 12HF

Internet # 202771119

Create a healthier environment and Increase the comfort of your entire home by installing the 12HF whole house furnace-mounted flow through humidifier. Having the proper amount of humidity in your home can help reduce respiratory infections, control static electricity, prevent house plants from wilting, and stop wood from drying out and cracking. You may also save money on your utility bill, as you can lower your thermostat and feel just as comfortable since humidified air feels warmer.

  • Uses up to 80% less water than other brands of whole house flow through humidifiers which will save you money on water and sewer charges from your municipality
  • Output of up to 13 Gal. per day for well insulated homes up to 3,000 sq. ft.
  • Lightweight housing design makes the humidifier easy to install on either the warm air supply or return air duct of any forced-air furnace
  • Everything needed for most typical installations is included
  • Evaporator pad is enclosed in plastic frame that ensures water flows through proper path for evaporation and makes it easy to replace
  • 24 VAC transformer simplifies installation as it plugs into a standard outlet and no hardwiring is required
  • Designed for use with all forced-air heating applications
  • Cut-out areas required for installation:humidifier housing: 8-1/4 in. H x 9-1/4 in. W
  • By-pass duct: 6 in. Dia
  • Humidistat: 3-1/2 in. H x 2-3/8 in. W
  • Equipment should be sized, selected and installed by a qualified professional to ensure proper installation, safe operation, adherence to federal, state and local codes and for valid warranty; see installation guide for more details
  • Recommended for professional purchase only
  • Click here for more information
  • Home Depot Protection Plan:

    Home Depot Protection Plan

Info & Guides

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Maximum Room Size (cu. ft.) 
Product Depth (in.) 
Product Height (in.) 
Product Width (in.) 
Air Treatment Product Type 
Whole House Humidifier 
Color Family 
Control Type 
Floor drain required 
Humidifier Features 
Automatic Moisture Control 
Humidifier Tank Capacity (Gallons) 
Humidifier style 
Bypass flow-through 
Included Items 
Drain Hose,Installation Kit 
Installation kit included 
Product Weight (lb.) 
3.2 lb 
Room Size (sq. ft.) 
Whole House 
Voltage (volts) 
Water Filter Replacement Model# 
Warranty / Certifications
Certifications and Listings 
No Certifications or Listings 
ENERGY STAR Certified 
Manufacturer Warranty 
1 year limited parts warranty, lifetime warranty on frame and cover 


Rated 3.8 out of 5 by 12 reviewers.
Rated 5.0 out of 5.0 by Great Product. I mounted it to the flex duct return. This is a great product. I read the reviews online and discovered the Honeywell model has issues, so I went with Hamilton. Very pleased and zero regrets. I have a 1,600 sq. ft. house and this unit can make the windows drip with condensation (I actually have to turn it down). No moving parts (except the water solenoid), no slimy drum to clean out, and best of all no humidifiers to refill. See the pictures, attached. The directions say it can be mounted to either the return or supply ducts at the furnace. I have a flex duct return, so I wanted the main body of the humidifier mounted to the solid surface of the supply duct. The directions did not describe this scenario, so I improvised. I hope the attached pictures and drawings help someone else in the same boat I was. I did have to install a 110VAC outlet for the power. However, I already had an existing drain (for AC condensation), for the drain tube. The unit works beautifully and no more dry skin. Great job Hamilton!!! December 12, 2014
Rated 5.0 out of 5.0 by Great Humidifier for the Price and Everything Needed for a Typical Installation is Included I have owned a 12HF for several years and have had good luck with my unit and recommended it to a neighbor that had mentioned their house gets dry in the winter. I did my own installation, so I offered to help them once they received their humidifier and a little over 2 hours later they were set. What I like about this unit compared to other brands is that it comes with everything needed for typical applications in one box and it has a plug-in transformer so no hardwiring is involved. Plus, it uses a lot less water than most other brands out there; the water valve on most flow through style units is completely open when there is a call for humidity, but this unit adds water in pulsed intervals. Lastly, maintenance is very low. I just put in a new evaporator pad at the beginning of each season and wipe out the shallow drain pan area to remove any mineral build-up. December 14, 2011
Rated 4.0 out of 5.0 by A quality product This humidifier works as expected and installed relatively easily with basic HVAC tools and knowledge. I didn't run across the leaking problem that others had mentioned. I did meticulously make sure the unit was installed level. The supplied 6" duct was long enough for my application. I connected the power source to my furnace circuit board rather than an AC outlet. I would have given 5 stars, but product has only been in service two weeks. I can't comment on long term use. I have noticed house feels more comfortable at lower set temps. October 23, 2013
Rated 3.0 out of 5.0 by Finally installed...not easy. I will update the performance I bought this product because it was advertised and the reviews stated the installation was simple. It took me about 4 hours to install it. Admittedly, most of this was due to my lack of knowledge, but a LOT of it was due to the poor installation instructions that came with the product. In particular, there was no information available on how to wire the system. No color coded, or keyed electrical connection. I called the company; closed on Saturday. I scoured the interned....nothing. I decided to just give it my best guess - IT WORKED! I assume the polarity doesn't really matter. There are many other gaps in the instructions that require some patience and careful reading. A few hints: -Buy good tools to cut the duct work. This was the most time consuming and difficult part (except reading the instruction and researching). -You have to take the humidistat apart to determine which connection is "COM" and which is "NO". -MAKE SURE you buy extra 6" flex duct. The amount supplied is not sufficient. -You will need some extra wire for almost any installation. -You will need extra wire nuts (2) -You will need duct tape -You will need a 3/4 wrench and a 5/8 wrench (instructions didn't say what size) -The wires that run between the controller and the valve don't seem to matter which wire goes where - or I just go lucky....not sure. -The hole in the duct work for the humidistat must be completely opened up to fit the mount. Go slow and make sure you understand what you are doing before cutting - the instructions suck. It is a warm and humid day, so I can't say if it works properly. It test mode, it seems to work. I will update the review in the coming months to rate the performance. I am worried the installation may affect the performance. Again, the instructions need to be more complete to help the average home owner. September 27, 2014
Rated 4.0 out of 5.0 by So Far So Good I installed the product about three weeks ago. At current it is working as expected. Installation was an easy task. It only took me a few hours to install. I'm a bit of a perfectionist so it took a little longer than it could of. Plus I hard wired the unit to the furnace so that I didn't have to install an extra plug for the unit and the drain pump. If you have access to a floor drain you won't need a pump. My last humidifier lasted for ten years so the jury is out on the longevity of this unit. January 25, 2014
Rated 4.0 out of 5.0 by Good product Instructions could be a little more detailed other then that it is a nice unit. Had help installing it and the person helping said they liked this one over the one they had installed and is going to switch. December 10, 2014
Rated 4.0 out of 5.0 by Good value While the instructions were not that clear, the unit was relatively easy to install. It worked fine the first time and has been doing its job now for a couple weeks. It is well constructed and does use less water than the free flowing humidifier I had on my last house. If not for the outdated or misprinted instructions I would have given it 5 stars. I consider myself fairly handy and it took me 4 hours to install. October 14, 2014
Rated 5.0 out of 5.0 by Good Product I purchased this humidifier to replace an older Lasko unit that had failed after 10 years. This unit had a slightly larger footprint and installed easily. I already had the power, water, and drain setup so install was a snap. It comes with everything necessary down to the saddle valve for supply and hose to connect to the drain. It makes an odd sound when the solenoid valve opens but other than that is completely quiet. It also includes a damper for tool free seasonal transitions. I purchased an additional wick to save searching for one later. The difference in the house is amazing. Cats are much happier. March 4, 2014
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