Hooking up humidifier to water supply

Can't comment on the plumbing, but my humidifier is on the cold side. Works fine.

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Your choice...if your soldering skills are good so you can "git in, git out" may as well just solder the valve. Only deal is if one is inexperienced can sometimes overheat the valve seat.

I've never, ever seen one connected to a HW supply, personally...

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Also the threaded approach allows for later replacement of the valve, if necessary without soldering. I'd probably go with that approach, but it's a personal choice thing.

You can connect them to either hot or cold water. Using hot will increase the capacity of the humidifier. Whether that matters depends on the size of the house, humidity needed, capacity of the unit, etc.

You might think that using hot water is a big waste, since most humidifiers send a signifcant amount of water down the drain. But if you measure the temp of the water leaving the drain, it's about room temp. Meaning it's cooled from

Again, it's a personal choice thing.

Mikepier wrote in news:77cb26b0-5501-4997-a242- snipped-for-privacy@c14g2000vbd.googlegroups.com:

If you have a water softener, you should connect it to soft water. Maybe that's why it's connected to the hot side?

I was recently reading up on that very subject and the answer was: It depends.

Some say that it is better to use hot water since it evaporates quicker thus putting more water vapor into the air. Others say that it cools faster than it is used so you've wasted the heat used to heat it up. Still others counter that that is true with older style "tank based" humidifiers, but the newer self cleaning units fill up with water as needed and then empty themselves to keep them clean. Ah, but that's a waste of hot water the excess goes down the drain - some say.

Then there are those that say that scale and bacteria are a bigger problem with hot water vs. cold, but the same "tank vs. self cleaning" argument might apply there also. However, some parts of any unit (such as the orifice) will be in constant contact with the hot water and may require more maintenance.

For me, the old style tank units got to be such a hassle that I don't have a humidifier now. For the most part we don't need one, but when the cat starts sparking when we pet her, I boil some water on the stove and make pasta. Heats the house, adds humidity and the pasta certainly never goes to waste.

I remember the convector style radiators that we had in my parent's house. We used to put little tin foil loaf pans filled with water on top of the radiators to add moisture to the air. They looked similar to this:

Where does the wasted heat go? Into the house. With the furnace running to provide heat, that doesn't equate to wasted, it's helping to heat the house. If you put cold 40F water into the humidifier, then the furnace has to heat it. No free lunch.

I don't know of any currently on the market that fill up and then drain. The ones I'm familiar with just have a constant small flow through them. Some of the water gets evaporated, the rest flows out taking most of the minerals with it. I would think they all probably work that way because it's a simple, cheap system that works.

That's why I think the tank type have probably gone the way of the dinosaurs. I know Aprilaire and Honeywell both make flow-through type.

I connected mine to the hot water outlet of the water heater knowing that hot water evaporates quicker. However, in my case, by the time the water gets to the evaporator it is cold again. Furthermore, there is the issue of waste water. I'd go for the cold if I were to do it again in my layout.

" snipped-for-privacy@optonline.net" wrote in news: snipped-for-privacy@ck1g2000vbb.googlegroups.com:

We had a new furnace installed in the summer. The installer told us pretty much that the older-style humidifiers with a tank and drum are obsolete.

Our humidifier is a "GeneralAire" connected to the cold water. It is tankless, and has the sort of "air filter" matrix you find in table-top humidifiers.

I like hot water feed, think it puts out more humidity. That said, might call the building department, see if they have any code on the matter.

Christopher A. Young Learn more about Jesus

Where does the wasted heat go? Into the house. With the furnace running to provide heat, that doesn't equate to wasted, it's helping to heat the house. If you put cold 40F water into the humidifier, then the furnace has to heat it. No free lunch.

Looking at my set up, the water travels through about 8 feet of small copper tubing, so, if it were hot, it would certainly be near room temperature by the time it got to the humidifier.

Also the heat of vaporization of water is considerably higher than the temperature differential between hot and cold water.

Wild guess, I seem to remember the ice makers were suspose to be hooked to the hot water. The reson was the hot water tank acted as a filter tank for the trash in the water.

Ice makers should have their own filters. Freezing hot water makes no sense, though it'll rarely, if ever, get to the ice maker.

One of these days I'm going to add a "standard" filter in the line. I have a lot of room in the basement for it. ;-)

I have an Aprilaire hooked up to hot water through about 8 t of 1/4" copper tubing. The water is still very hot when it enters the unit. You just don't lose that much heat in

Sure, it goes into the house, but it sure isn't the most efficient way to heat a home. Heating water and then letting it cool off for heat is pretty expensive. OK, so the heat isn't wasted, just the money used to provide that source of heat.

I can't seem to construct the search string I used recently that led to a forum where they talked about the humidifier draining between uses. Maybe it was a flow through and the way he worded it was different and I took it as draining between uses. Like I said, I haven't had a humidifier in years so I don't know what's on the market these days.

Per question 33 of this FAQ, Aprilaire requires hot water.

Why would that be? That is exactly what is done with a boiler and baseboard heating or radiant heating, both of which are an efficient means of heating.

Let's say we have a gas furnace and a gas water heater. If we feed the humidifier with 140F hot water, heat is generated in the water heater, then moved into the furnace and transferred to the air. The water exiting the humidifier is around room temp. If we use cold 40F water, more gas is now burned in the furnace to put the same amount of heat into the house. It's not only not getting heat from the hot water, but it actually is heating the water too. In either case, it's not wasted. It's just an issue of is a little more burned in the furnace or in the water heater. There would be some differences based on the efficiencies of the two units, but in the grand scheme of things I don't see much of a difference.

I could not find #33. I did find this:

#10

Should our humidifier be connected with hot or cold water? All of our flow-through units can be connected to hot or cold water. Hot water increases the evaporative capacity of your humidifer, provides more humidity to the home and offers more flexibility in the operation of the humidifier. Some of our units can use hot air and cold water. All humidifiers need some source of heat for evaporation to take place whether it is hot water or hot air. We would recommend that if our power units are installed on the return ductwork, that they be connected to hot water, as this is their only heat source. Heat pumps and large capacity installations need hot water. Heat pumps are not hot enough for evaporation and some larger installations need maximum capacity so they will need to use both hot air and hot water.

The reason they are designed to pour some water down the drain is to reduce the mineral buildup. If you had distilled water, it would be unnecessary. Adding humidity to a house does make a noticeable difference in comfort. Can help with some medical issues too. And it does make the house feel warmer for the same temp setting of the thermostat. For me the main thing is the comfort. It doesn't put all that much water down the drain. I'm always below the min billing amount in winter anyway. Even if I wasn't it's $6 for 1000 gallons of water and the thing probably doesn't go through that in an entire season.

I don't have any numbers but it seems to me that baseboard and radiant heating is more efficient due to the mass of the radiating elements as opposed to water just cooling off into the open air. Maybe not.

Seem like there are more than one FAQ.

Try this link, although I've post #33 below.

1. Should our Aprilaire humidifier be connected with hot or cold water? Aprilaire evaporative humidifiers can operate with hot, cold, hard or soft water. Hot water is preferred as it supplements the heat from the HVAC system heat call to increase the evaporation rate. All Aprilaire humidifiers need some source of heat for evaporation to take place whether it is hot water or hot air. When the humidifier is wired to operate on a heat or HVAC fan call, hot water is required as it is the only heat source for the evaporation process during an HVAC fan call. In addition hot water is required when the humidifier is connected to a heat pump. This is due to the lower plenum temperature in a heat pump. Hot water ensures there is an adequate heat source for the evaporation process. When any drain-though Aprilaire Humidifier is connected to hot water, the heat in the water is used in the evaporation process and the water coming out of the drain will be cool to the touch. The model 800 Aprilaire steam humidifier requires cold water, which may be hard or soft. Hot water can not be used because the supply water is used to cool the water going to drain.

Yes, that is consistent with the other FAQ #10 that I posted. Neither say that Aprilaire *requires* hot water. Only that hot water is preferred because it increases the evaporation rate. That could be needed in certain applications, eg if you want to humidify during fan only operation where there is no other heat, or if you have a very large house and need max capacity.

Huh?

I quote from FAQ # 33, adding emphasis on the the word "required":

"When the humidifier is wired to operate on a heat or HVAC fan call, hot water is *required* as it is the only heat source for the evaporation process during an HVAC fan call. In addition hot water is

There are 2 specific scenarios where the word *required* is used.

By the way, I found the post that led me to use words related to "fill up and drain".

I guess "fill and drain" is not really the same thing as "flow through", which is what I now assume the gentleman below is really talking about.

From:

One nit picking comment/question: If the flow through types are using hot water and sending some of it down the drain while operating, does it all really cool off enough to get rid of all it's heat before going down the drain? Any water that is above room temperature as it goes down the drain is a waste of the BTU's used to heat it, but probably so minimal as to not be an issue when compared to the comfort provided if a humidifier is needed.

Yes, I agree. Requiring it IF you use an Aprilaire in those scenarios is not the same as saying Aprilaire *requires* hot water period. Those scenarios are the less common ones. Heat pumps, where the air is not as hot, or "fan calls", where you're running the fan with no heat at all. If you hook it up in a more typical application, on a gas or oil furnace, which is what, 80% of the cases?, then hot water is not required, it's just preferred because you'll get higher output. Whether that really matters depends on the size of the humidifier, size of the house, climate, etc. It's probably better to err on the side of having more capacity then you need, but given most of these humidifiers are hooked up with cold water and seem to work perfectly fine, I think in most cases it's not an issue.

I use hot on mine, but it's never been close to running all the time when the furnace is on.

He obviously hasn't felt the temperature of the water leaving the humidifier as it goes down the drain. It's at room temp, meaning most of that heat isn't wasted, it's gone into the house.

I have felt it and it's around room temp. At first thought, you'd think it would be hot because it's been in the furnace hot air stream. But if you think about it like a swamp cooler, with a lot of evaporation going on as the water trickles over a media with a lot of surface area, then it makes sense. I'll actually go measure it for you and see what it is just to verify.