[Ottawa62]

Hi, are there issues installing a fan operated furnace humidifier in a basement that includes a natural gas water heater? I am wondering about it reducing pressure in the basement, and drawing the venting from the hot water heater now going outside instead into the basement.

I am considering what seems a pretty good fan operated furnace humidifier, the Honeywell HE360A1075. There are no such restrictions in the documentation. Still, am wondering.

Any pointers or wisdom?

Thanks,
Bill

 

[user_12345a]

Those humidifiers take hot supply air, pass it over the pad and put it back into the supply.

They don't draw air from the basement/mechanical room so you shouldn't have issues.

 

[Ottawa62]

Interestingly, this kind does not take hot supply air, but instead air straight from the basement. It comes in from the top of the unit.

I can't post links unfortunately. You can find the unit by searching for: HE360A1075

So that is why I am wondering.

 

[user_12345a]

this is straight from the manual of your unit:

"How Your Humidifier Works
Your Honeywell humidifier uses the principle that vapor (evaporated water) is created
when warm air blows over a water-soaked area. As the vapor circulates, the relative
humidity rises.
Your humidity control monitors the relative humidity and activates the humidifier
accordingly. The humidifier has a water supply that dispenses water evenly over a
humidifier pad. The warm dry air, from the furnace, passes over the humidifier pad and
picks up the moist air to circulate it throughout your home.
Humidified air feels warmer and more comfortable so you may be able to lower your
thermostat heating setpoint, which saves money on your heating fuel bills. The end
result is that your humidifier gives you a comfortable environment that is also energy
efficient."

it doesn't take air from the basement to my knowledge. if it did, it would need hot water to function properly.

 

[Ottawa62]

Oh, ok, thanks. I was fooled because my current and ineffective bypass humidifier is installed on the cold side, and has tubing that takes air from the hot side, and passes the air back over the pad.

This Honeywell has no such tubing. So I guess it is somehow fully self-contained, and both draws hot air and pushes it back out completely from within the unit itself. Quite the trick that.

 

[yuri]

I think it takes the air from outside BUT if your room is so airtight that it can de-pressurize it then you have a big problem.

The amount of air it moves will be very small and you should have a louvered door to the room to supply combustion air for the heater burner anyway. If the room is open then don't worry.

If it is sealed then you may need a combustion air pipe from outside.

Make sure you have 2 new CO detectors in your house.

You can install it and test it. Start the furnace and then put a match near the heater chimney pipe and see if it blows back out.

I have never heard of a powered humidifier causing a problem. Usually it is open fireplaces or oversized Jenn Air kitchen exhaust fans etc sucking too much air out of the house.

Most good bypass humidifiers if maintained properly can do the same job.

 

[surferdude2]

I'm not familiar with that model number but if it isn't a bypass type, it does indeed take air from the basement. The non-bypass types have an internal fan that forces air into the unit where water is heated to the point of evaporation. From there it is injected into the home air duct system on the warm air side at some arbitrary point.

I recently,install a bypass type, AprilAire 600, so all that info is still swirling around in my peanut brain.

ps. just looked up your model... it is not a bypass unit, so you are correct... it takes air from the basement and injects it into the warm air duct of your furnace. I doubt the small amount will create any backdraft problem but verify to be sure.

 

[surferdude2]

Most good bypass humidifiers if maintained properly can do the same job.

My AprilAire 600 bypass unit keeps up very well. I initially thought I would need to give it the ability to turn the furnace fan on in order to keep up with the demand so I rigged that possibility up from some parts I had. Turned out it wasn't necessary, it runs and keeps up ok from the control board hum connections so I'll be removing that stuff. I'll attach a schematic in case someone may find that it could be needed in their case. That will somehow allow me to think that all my work wasn't in vain. :vs_laugh:

1. The purpose of relay R1 is to allow the humidifier to operate independently of whatever mode the environmental air system is operating under at any time. It also prevents backfeeding the fan control wire up to the wall stat, which would engage the cooling mode.

2. The purpose of the interval timer is to make it possible to leave the system enabled year-around without having to be disabled manually during the summer season.

The timer has two modes of operation that occur in a repeating sequence, the first is 8 hours in length and the next one lasts 30 minutes. During the first mode, the humidifier is allowed to operate independent of whatever mode the hvac thermostat is operating under at the time. When it times out of the 8 hour mode and enters the 30 minute mode, it will only allow the humidifier to operate if the hvac thermostat is in the heat mode. This will cause the timer to stall during the summer season when no heat mode is called for, effectively disabling the humidifier for the summer season yet re-enabling it when the room thermostat is switched back to the heat mode.

If the change over to summer mode occurs during the 8 hour sequence of the interval timer, there will be some humidifier over-run into the summer mode but this will time out when the 8-hour mode terminates. This over-run will also occur if the room thermostat is switched to the off position during the 8-hour sequence of the timer.

I even was so kind as to paste a schematic and instructions alongside the one on the furnace door. Yes, I do need a hobby. :vs_laugh:

 

[yuri]

I live in a brutally cold dry area ( Winnipeg aka Winterpeg ) and we have hundreds of thousands of bypass units installed. Very few fan powered.

The bypass work well. However if it won't keep up then you can run hot water to them as long as you use copper tubing for the water line.

There are some special plastic lines that are heat rated but the cheap stuff may get soft and blow off and flood your house.

Point is use 1/4" copper from HDepot and you may get some extra humidity. Change the pad once a year and it should work OK.

 

[surferdude2]

I connected hot water to it from the git-go, didn't use that puncture valve and plastic line they ship with it though, just sweated in a tee at the water heater nearby and ran 1/4 copper. Like I said, keeps up with no problem... I doubt it would have if using cold water. I love how I can take off my robe now and not get electrocuted and also don't miss the winter time bloody nose from the dry air... should have done this years ago.

 

[yuri]

I just leave the bathroom door cracked open in the winter when showering and the steam goes into the house and helps.

No kids to see my sorry a*ss or get scared or offended now.:vs_laugh:

 

[surferdude2]

I just leave the bathroom door cracked open in the winter when showering and the steam goes into the house and helps.

No kids to see my sorry a*ss or get scared or offended now.:vs_laugh:

I always do that even though it may offend... part of the fun. Gives a temporary humidity bump. My sainted mother always hung the washing to dry from a line rigged from 16's angle driven into door frames and it did a nice job of humidifying the entire house, albeit somewhat tainted with the smell of laundry. :smile:

 

[surferdude2]

I'm stylin' so far! Of course the lowest day we have had was 24°... that would be a balmy winter day in Winnipeg, no doubt.

 

[user_12345a]

I'm not familiar with that model number but if it isn't a bypass type, it does indeed take air from the basement. The non-bypass types have an internal fan that forces air into the unit where water is heated to the point of evaporation.

At :50 - see the spaces at the sides of pad?

The panel the fan is attached to has the same gaps.

Hot air gets into the humidifier through the spaces, enters the fan and gets pushed through the pad and back into the plenum/duct.

If cool basement air was forced across the pad, with cold water it wouldn't be a very effective humidifier.

 

[surferdude2]

AprilAire units are great, either bypass or the other. They pretty much have taken over the market, and rightly so. I decided to go with the bypass.

However, the fan powered room air inducting units I was referring to operate quite differently from the way the AprilAire units do. There were several brands of fan powered units installed around here before AA hit the market. GeneralAir is the brand I have seen around here since back in the 50's. They do take room air and blow it over a pad and into the supply duct cutout. I didn't go into business until the early 60's so never installed one. I did however remove a few of them because the customer said they didn't want that on there anymore. It wasn't my bailiwick at that time but I wasn't so proud as to turn down a gravy job and the easy money. :smile: The big $5 service charge in the 60's seems pretty paltry compared to the big bucks being charged now. lain:

 

[user_12345a]

Are any still made like that?
I hope not.

 

[surferdude2]

Are any still made like that?
I hope not.

I couldn't say... I'll Google for them and get back.

 

[surferdude2]

Yep, Google shows they're still going strong and still selling humidifiers! Some people never learn... although I shouldn't dis them, never had one.

https://www.google.com/search?rlz=1.......0i71j0i22i30j0i333.-a0B87w_ZQk&ved=0ahUKEwiQ5K_7lpPmAhWVop4KHdXlAnUQ4dUDCAs

 

[bfrabel]

Yep, Google shows they're still going strong and still selling humidifiers! Some people never learn... although I shouldn't dis them, never had one.

https://www.google.com/search?rlz=1.......0i71j0i22i30j0i333.-a0B87w_ZQk&ved=0ahUKEwiQ5K_7lpPmAhWVop4KHdXlAnUQ4dUDCAs

I think you're wrong about any modern humidifier taking room air from outside of the furnace and forcing it into the ductwork.

First of all, think about how powerful the humidifier fan would have to be in order to overcome the furnace's fan to be able to force humidity into the supply duct. Secondly, think about how returns are prohibited from being in a mechanical room (due to safety reasons). If this thing were forcing air into the ductwork from the mechanical room, how could that be allowed?

Here's a description from GeneralAire's website that describes how their unit works...

"A fan inside your GeneralAire® 1137 Elite Series Flow Through Humidifier pulls warm air from your furnace through the water-soaked Vapor Pad®, where it absorbs additional moisture. The moistened air then returns for distribution throughout your home via your home’s duct system."

Also, there is a picture of a parts breakdown for it. It is a little confusing when you look at it because it does indeed have a fan with a ventilated cover right on the back of the thing, but if you look close you will see that the motor is a double shafted motor, and the fan blade on the back of it is called a "cooling fan".

That little fan blade back there is not the same one that's forcing air across the water pad.

 

[yuri]

Thanks for the info

They are very very rare where I am as they are more expensive. I have never opened one up to see what was inside and yeah I did think it would have to be a powerful fan to overcome the air pressure in the plenum.