Humidifying with Geothermal

Page 1 of 2  
It's 13F outside and our new geothermal system is working very well (and inexpensively); however, the air in our house is drier than we'd like.
The installer suggests that a steam-generating humidifier is the only way to go because of the geothermal system's lower operating temperature. My research indicates that steam-generating humidifiers use a lot of power (similar to keeping a kettle plugged in for hours on end), waste a considerable amount of water down the drain, and suffer from orifice-clogging when used with well water. I don't want to deal with any of these (especially with water down the drain - we don't have a drain in the basement floor).
So ... has anyone out there had success/failure with other kinds of whole-house humidifiers connected to geothermal units?
(Please, I don't want to hear from folks who "...know someone who..." or "...heard somewhere..." or do not have a geothermal system themselves)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

We have a new geothermal install, and have taken to humidifying the house the same way we did with the propane furnace. There's a large humidifier in the middle of the house which uses about 4-5 gallons of water a day.
It's doing an adequate job, keeping the cats from getting shocked when we pet them. (That's the first sign of low humidity.) ;-)
I'd like a furnace unit myself, so I didn't have to fill the humidifier every day.
Puckdropper
--
On Usenet, no one can hear you laugh. That\'s a good thing, though, as
some writers are incorrigible.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You have the most efficient heat and he says put in the least efficient humidifier, plants work. April Air has very good units and an auto humidity system that works, I am sure April Air knows how to size you for your system.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
borealbushman wrote:

We didn't seem to need it in TN particularly so didn't do anything. But, the outlet temperatures were adequate I don't think there would have been a problem w/ the plenum units.
But, we didn't normally have 13F outside air temp's, but if had the system would have been sized somewhat larger, too.
Which geothermal unit is it? I'd suggest talking to a rep directly; WaterFurnace was super in that regard.
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 4 Feb 2009 23:02:35 -0800 (PST), borealbushman

I think you are mis-informed about humidifiers. Steam type humidifiers dont run water down the drain. They pretty much put it all into the air. They all have their ups and downs. Try this link. Its is an evaporative type which stops all the water down the drain yet doesnt build up all the calcium deposits like the old drum types did. http://www.aprilaire.com/index.php?znfAction=ProductDetails&category=5&item@0 Honeywell makes a new one called True Steam that is supposed to be the latest in steam technology. I havent tried one of those yet so the jury is still out. Bubba
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
x-no-archive:

There are only three places the minerals present in the input water can go:
1) down the drain with the bleed water, 2) into the air as white dust or 3) stay in the humidifer and gunk it up..
If there is no bleed water it can't be #1.
Of the three choices, I think #1 is the least bad choice.
Mark
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Feb 6, 11:19am, snipped-for-privacy@yahoo.com wrote:

Agree. I'd also suggest that the real question here has little to do with geothermal. It comes down to using a humidifier with a heat pump, which presents lower air temps for evaporation. One solution to this is to use hot water, which everyone (except Bubba) acknowledges evaporates faster.
I would think all the major manufacturers of humidifiers would have info on their websites about using them with heat pump systems.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@optonline.net wrote: ...

Geothermal properly sized generally has quite a lot higher exit temperatures than will an air-exchange heat pump owing to (again generally) higher quality heat source.
Hence my recommendation to speak to the rep of the particular equipment for the particular installation.
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

If it has higher exit air temps, then what's so specific about geothermal that presents a unique problem? Humidifiers are routinely used with heat pumps. If it were lower air temps, then I could see an issue.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 6 Feb 2009 08:56:28 -0800 (PST), snipped-for-privacy@optonline.net wrote:

And I thought an EE learned to think "out of the box". Bubba

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

you know you guys should stop arguing about this becasue you are BOTH right.
In order to evaprorate, water has to absorb the "latent heat of vaporization". The amount of heat needed to raise the temperature from "cold" to "hot" is pretty small compared to the latent heat of vaporization. If you start with hot water, some of the heat is already there but it is a small fraction of the total amount needed to evaporate it...so yes if you connect a hot water feed to a humidifer it might evaporate a little more water but not much, probably not enough to notice the difference. Compare how long it takes water on the stove to heat from cold to hot, compared to how long it takes to boil it all away...
Mark
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Feb 6, 10:22pm, snipped-for-privacy@yahoo.com wrote:

Well, Mark, we're gonna find out. Because I'm going to run the test on my humidifier and actually measure it. My position is that evaporation is not a simple process like boiling water in a closed container. It's a complex process that involves both heat and mass transfer. For water to evaporate, the higher energy water molecules just need to break the surface tension of the water and be carried away by the force of the moving air, which in a furnace humidifier is substantial. The more energy the water has, the more readily some of those molecules will escape the surface. The obvious factors that affect the rate of evaporation are the water temp, the surface area, and the air speed.
If temp doesn't make a significant difference, then why does a warm cup of coffee evaporate when you go outside on a cold day, while a cold cup does not? And why do humidifier manufacturers recommend using hot water to increase the output? They should know more about it from a practical standpoint, than any of us. Here's what Aprilaire has to say. I know Bubba has dismissed them but I'd be interested in why you think they would be misleading customers? What motivation could they have?
http://www.aprilaire.com/index.php?znfAction=OwnersManual
"Hot supply water, 140F maximum, is recommended with drain type humidifiers for increasing capacity and is required for heat pump and air handler applications."
http://www.aprilaire.com/index.php?znfAction=FAQs&product=Humidifiers#10044
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 Model 400 should be connected to cold water due to the wicking Water Panel as it cannot be guaranteed that the water will stay hot while waiting for the next heat call on the Water Panel. With any drain-though Aprilaire Humidifier 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 cold to the touch. ^back to top
Here's a link from a HVAC company. BTW where's Bubba's website?
http://www.hauckbrothers.com/humidifier_questions.html
Should my humidifier be connected to hot or cold water?
All humidifiers can be connected to hot or cold water, although there are some instances where it is necessary to supply hot water. For instance, on a system with a heat pump, or on a fan forced humidifier attached to a return air duct. This is because all humidifiers need a source of heat to evaporate the water. In other situations, while it isnt absolutely necessary, it is helpful to use hot water for supply as it increases the efficiency and flexibility of the humidifier system. For example, in a large house where a humidifier operates at its highest capacity. Any humidifier system will benefit from hot water supply although it isnt necessary on an average or smaller installation.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 7 Feb 2009 06:53:27 -0800 (PST), snipped-for-privacy@optonline.net wrote:

Cmon trader. You arent that stupid/niave, are you? Aprilaire is in the business of selling humidifiers. "Uh oh, we have customers that want to put a humidifier on a heat pump or air handler with no heat or they just want to add moisture but dont have a nice warm gas or oil furnace to evaporate the water. What do we do? " Aprilaire is brilliant enough in marketing to tell everyone that if you use the hot water, that will do the trick. I say BULL! Show me one place where you find Aprilaire showing an actual test where they can tell you how much more humidity it adds? Let me give you a hint. You wont find it. Look at a steam humidifier. Look at the energy it takes to put that moisture into the air stream. Its a fair amount. Now look at how much moisture you are going to add by using typical 120 water water supply, that travels maybe 10 or 20 feet through a 1/4" copper line in a cool basement that is then squeezed through a tiny orifice, slowly distributed over a distribution tray and then FINALLY gets to drip down on a honeycomb panel with semi rapidly moving air going across it. Next to NOTHING more is going to be evaporated. Again, Ive told you time and time again to try the test Ive already done but you still wont do it. Instead you are just a follower.....reading and believing without ever doing just the absolute simplest of tests. Anyone can do this simple test: Turn the fan on your furnace on. Do not use the heat. Not turn on the cold water to the humidifier. Start a timer and catch the excess water in something measureable. Do it for 5 mins or however long you wish. NOW, do the same exact thing with the humidifer hooked to the hot water line. Look at the difference in the water in the bucket. If you can show me any measureable difference in the amount of water in the two buckets I'll send you a free humidifier. If you like, you might want to read some of "teddy bears" posts in hvac-talk. He seems to have a grip on it too. Trader, Im really disappointed in you. Without testing a thing you seem to be as hardheaded/stupid as even ransley. Pull yourself out of the gutter a bit. Bubba

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I fail to see how telling people to use hot water will do any good. All they would have is unhappy customers returning product. And if they wanted to lie, all they would have to do is say their humdifiers work the same with either hot or cold water. But they don't. In fact, telling people to use hot water works against them. They could just tell people that to get more output, you have to buy one of their bigger and more expensive models.
As for who's stupid, I'll leave that for others here to judge. You seem to have a lot of folks here who respect you, right?

Show me one place where anyone did a test that shows it doesn't add humidity.

Explain then how it is that a cup of hot coffee readily evaporates when you take it outside on a cold day, with visible condesation, while a cold cup of coffee does not? Funny how you can't answer that simple question. The answer is obvious: Hot water evaporates at a faster rate.
Now in a water panel humidifier, your assertion that the water is cold by the time it gets to the humidifier is silly, but it's what you're left with to try to dig yourself out of your hole. In my house the water heater is right next to the furnace and it's not going to lose much. So, big deal, let's say it goes from 135 to 120. I still say, from everyday experience, it's obvious to just about everyone but you, that 120 deg water evaporates faster than 40 deg water. Pour 120 degree water on a towel and take it outside. Do the same with 40 deg water and see what happens.
And if you look at what goes on inside the humidifier, I would expect that the water goes from 120 down to it's final temp as it moves down the panel. At some point, it's probably equal to the temp you would have with cold water, because it reaches a steady state. However, I'm fairly certain that point is a good ways down the panel, maybe half way. And during that part of the water's journey, it's evaporating MORE because hot water evaporates more readily. And it makes enough difference for it to make a substantial difference in the output rate. Which is what Aprilaire and the HVAC company I provided say.

As I stated, I am going to do the test. But somehow I already know that you won't accept the results. BTW, isn't testing and validating theories part of science and engineering? And we know how you eschew anything to do with that.

Now this is even more bizarre. If heat has no effect like you say it does, then why do we have heated clothes dryers? Why not just tumble the clothes in cold air?

Not hard headed at all. It's just that I have a degree in engineering and know a lot more than you will ever know about the physical sciences. And what I know is consistent with what Aprilaire, who is in the business and should know, says.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Feb 7, 11:28am, snipped-for-privacy@optonline.net wrote:

I tried feeding my humidifier with hot water several years ago. The problem was it got cold by the time it got to my HVAC system.
Jimmie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
speed.

Actually, it's referred to as sublimation. And it's another good example to prove my point. Sure they get smaller over time. Now, I don't know about the freezer in your strange universe, but in mine, that process takes several weeks for the ice cubes to become noticeably smaller. Further proof that the rate that molecules leave the surface of a material, whether by evaporation or sublimation, is directly and substantiallly affected by temperature. If you put a tray of hot water into the freezer, it would lose mass at a much higher rate than the solid ice cubes. In the case of the coffee cup you bring outside, the rate is so high that you can see it evaporating.

LOL Of course it can be seen by the naked eye. I'ts called condensation. With a cold cup of coffee, some water is evaporating, but it's at such a slow rate that it can't be seen. With hot water, it's a significantly faster rate and can be seen as visible condensation.
Why do you think clothes dryers use heat to dry clothes instead of just tumbling them around?

I'm wrong that my water heater is next to my furnace? It's about 5 ft from the humidifier unless it ran away with your wife last night.

Sure it can be done. And I will do it. But any reasonable person here knows that to test a running furnace with hot and cold water going into the humidifier to measure the difference isn't going to be done in 5 or 10 mins. Which suggests that whatever you measured, if you did indeed measure anything as opposed to looking slack-jawed into a 5 gallon pail, couldn't really determine anything. For example, I'd take the first 5 mins of each test to allow the furnace and humidifier to run and get to a steady state condition. Do that twice, and your entire 10 mins is up, without time to measure anything. You never took any science lab class at all, did you?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 8 Feb 2009 06:05:39 -0800 (PST), snipped-for-privacy@optonline.net wrote:

very fast. Then the evaporation slows even more. and again................ Measure the amount in that hot coffee cup that evaporated. Now measure the amount that evaporated from that cold cup. I dare say you could even measure it with anything standard because the amount is Insignificant.

cycle. My wife uses it all the time on delicates. It dries clothes too. Just takes more time.

That's nice that your water heater is only 5 feet away. You ever going to take some temp and capacity measurements to show me how I'm not wrong about what I claim? You can talk all you want but you wont prove it to yourself or anyone until you DO IT!

of doing. If you'd like, you can spend all day or all week doing the test but you will still come up with the same thing. That being: Using hot water for a humidifier will do nothing but increase your operating cost while producing a very insignificant increase in humidity. Now go put that in your EE pipe and smoke it. Bubba
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

How long will it take the hot cup of coffe to fully evaporate? How long will it take the cold cup of coffe to fully evaporate?
Both will take ALMOST the time. Yes, the hot will evaporate a little faster, but very little.

That's not the same thing. The dryer puts heat into the system continuously, not just starting with hot water.
The humdifier analogy is more like putting clothes in a dryer that have hot water on them compared to clothes that have cold water on them, and then operating the dryer without heat.
Again, you (and the directions) are partly correct, hot water feeding a humidifer will evaprote a LITTLE faster, but I am saying the difference is small. Do any of the directions say HOW MUCH hot water will increase the capacity, no they don't becasue it is true it increases, but a very small amount. Compare the "specific heat" of water to the "latent heat of vaporization". Please look up those terms. I don't want to agrue with you about this... take care..
Mark
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Feb 8, 10:25pm, snipped-for-privacy@yahoo.com wrote:

I'll even do the math..
Cooling 1 gallon water from 150F to 50F gives up about 834 BTU of heat.
Vaporizing 1 gallon of water takes about 8000 BTU of heat.
So feeding the humidifer with hot water will increase its output by about 10%.
Mark
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 9 Feb 2009 10:03:23 -0800 (PST), snipped-for-privacy@yahoo.com wrote:

Im just asking here, not arguing......... Using your math, it looks like the hot water giving up its energy releases a very small amount (834btu) of heat then to the air (right?) However, you're showing that it takes a fair amount of energy(8000btu) to make the cold water get hot and give up its energy to the air (right?) Here is the problem then: To make the water hot takes a lot of energy because you are using a water heater. Yes I know a water heater has hot water in it already but if it doesnt have to be used then it saves you that much money. If you use a furnace it already has to be used whether you are going to use a humidifier or not because you want your home warm and comfortable. The 8,000 btu is given up to the air stream so it is not actually lost. Thus I still dont think it is worth using hot water for a humidifier and what I tested did not show a 10% loss of excess water. Your math figures may be correct, I dont know, but it just doesnt work out that way in the real world. Most people dont have 150 water coming out of their water heater. Thats a lot of energy being wasted and can scald someone. 120 to 125 is normal and recommended. It takes 2 seconds for a child to receive third degree burns from water at 150 degrees. It takes 5 seconds if the water is at 140 degrees, and 30 seconds at 130 degrees. Bubba
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Site Timeline

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.