How will a new oil furnace humidifier work.

[mm]

If I get a new oil furnace with humidifier and with AC, is there a method provided to turn the humidifier off, especially the water, OTHER THAN the little valve on the water pipe that feeds the copper tube to the humidifer?

Is it *automatic* that the humidifier doesn't run when the AC is on?

Or will I have to turn off the water supply? My little tapping valve worked fine for a few years and then it got difficult. And it was accessible for a few years, and then things got piled where I need to put a chair to reach the ceiling. So it would be nice if it turned off some other way.

When the humidifier doesn't run in the summer, is it only that the electric motor doesn't turn the wheel? Or is the water turned off too?

I had no room for a motorized humidifier in my current furnace and the only one that fit used T-shapped fiber plates to suck water out of the pan, which filled up the ends of the T so that the hot air going past was humidified. A valve turned the water off when the water level in the pan was high enough, but eventually that didnt' work well and the water overflowed the pan through some little hole, and dripped on the flue collector of the furnace, causing that to rust out. Maybe some water even dripped down the main heating duct back into the furnace.

Is there any trick to replacing the tapping valve in the same place that the current valve is? Or would there be an advantage to tapping a hot-water pipe instead?

Thanks a lot.

[dpb]

Assuming you put it on a humidstat, it'll only run when demanded...

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[Stormin Mormon]

You really need to talk to the installer. Ask these same questions. The ones I installed, only work on heat, and the valve on the humidifier is fine. No need to close the saddle valve.

Yours may be installed that way, or some other way. Ask the installer. We can't see through the computer to see how s/he installed.

[mm]

It's not even bought yet. These were planning questions.

Thanks.

[Jim Elbrecht]

My Aprilaire has a humidistat so it only goes on if the humidity is low. It would be an easy task to put a switch on the 24v solenoid valve so I never had to mess with my other settings in the summer. [I don't have/need central air so all I do in the summer is change a water panel.]

I wouldn't want to mess with one of those little taps. If I really wanted to turn off the water supply frequently I'd put in a proper ball valve.

-snip-

Aprilaire recommends using hot water. There is a monster thread from last fall where someone tried to convince us all that it was a waste of hot water. He didn't convince *me* - I suspect there are others who feel that Aprilaire knows what they are talking about.

Jim

[Frank]

I turn off the tap valve in the summer. There is a control and it does not run constantly in the winter. You set it for where you want it. Advantage of tapping into hot water pipe is minuscule as it takes considerably more calories to vaporize than heat to boiling point. My Aprilaire advises a new evaporation honeycomb like unit once a year. Some units may have water filters needing occasional cleaning.

[ransley]

April Air makes some of the best humidifier units, System 2000 is maybe the best oil unit and efficency nears condensing units, you wont have problems with an April Air

[trader4]

With any reasonable unit, yes. You can turn it off using the humidistat, which is usually mounted on the return plenum. It could also be mounted in the living space by the thermostat.

Usually not, but it could be. Most are wired so the humdidifier is powered up when the furnace blower is on. In which case it has power and you use the humidistat to turn it off during AC season. Or it could be wired to only be powered up when the furnace gas valve is powered, ie when the burner is on.

Normally the water is left on. If the humidifier is actually running, it would activate a solenoid valve to get the water running. If you use a bypass model humidifier, you will need to move the damper to close off the bypass during AC season. With a self-powered unit with a fan, you don't need the bypass duct.

You can't tap the pipe again in the same place. Provided it doesn't leak, you could just shut it off and tap nearby. Or else remove it, and repair the pipe at the current location.

According to Aprilaire, using hot water gives a higher evaporation rate. We had a big debate about that here about a year ago. I did some tests on mine and measured a substantially higher evaporation rate using hot water than cold. Whether you use hot or cold depends on the size of the house, unit size, and the relative cost of fuel you use for heating water versus the furnace fuel. The extra heat doesn't get lost, it winds up in the house.

I agree about Aprilaire. Over the years many people here have used them and everyone I can recall was very happy with them, including me.

[Stormin Mormon]

In that case..... you can plan to have the installer wire it to the heat only part of the system.

[Mark]

I would think you do not want to leave the unit filled with water all summer when it is not in use..

Mark

[trader4]

All of the new ones I've seen do not have any water in them when they are not running. Most use panels that the water trickels over and the excess drains out. Others use a spray mist. There may be some of the old type with tubs and floats, but I think they are dinosaurs.

[Stormin Mormon]

The older units did use a basin with a fill valve, and rotating drum. The newer Aprilaire (and I've seen similar Honewyell) use a drain under the evaporator pad. No water remains in the unit during the summer.

Note.... it's important to close the damper on the humidifier when summer starts, open it for winter.