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dehumidifier that lets you exhaust heat?

Coconutz

Active member
Veteran
To answer the original question, yes, dehueys are duct-able.

Santa Fe has seven models that are.

Except that the santa fe is supposed to be ducted to a crawl space where you want the dry/hot air.
Theyre made to be placed outside of a tight crawlspace thats too small for a dehuey to fit, or duct to the entire living space.
Its the hot air that is dry.
Its the opposite of an AC...
http://www.dantherm.com/gb/dehumidi...le-dehumidifiers/how-does-a-dehumidifier-work
The basic functional principle of a condense drying dehumidifier is really quite simple. A fan draws in humid air and carries it through a refrigerated evaporator. The air is cooled well below its dew point. The water condenses on the cold surface of the evaporator and drips into a water container or is led directly to a drain. Then the cold dry air continues through a hot condenser which heats it up and returns it to the room to pick up new humidity. This procedure is continued until the desired condition is achieved.
 

Devilman

Active member
"Trust me it works and is a relatively cheap fix."

It looks like it would probably work for getting the hot air out of the room, but the fact remains that the hot air a dehum puts out is the dry air that lowers your rh.
-granger


Erm, not really no... The water that comes OUT of a dehuey is what reduces the R/H in your room, The hot air that comes out the back is a bi-product of removing the water from the air... If reducing R/H via heat was the principle design of a dehumidifier then they would just be a space heater.

Heating up air does indeed lower R/H but only because warmer air can hold a larger quantity of water for a given R/H, Telling people to lower their R/H by increasing temp is just daft, most people get far too excited about shoving too much light into a space and its already too hot for the plants.

For people with sealed rooms, venting the Dehuey externally is a good idea, else all they are doing is dumping an extra couple hundred watts (minimum) into their electricity bill and heatload the A/C has to deal with.
 
If you remove the heat from a dehuey you now have an Air Conditioner. As a matter of fact I use my 8k window banger as my dehuey. I poked a hole in the bottom, popped it on a shelf and plumbed the water out and BAM almost 30 gallons a day! 200 bucks.
 

Granger2

Active member
Veteran
Erm, not really no... The water that comes OUT of a dehuey is what reduces the R/H in your room, The hot air that comes out the back is a bi-product of removing the water from the air...

Devilman,
And the water was removed from what? Ans.-the air that comes out hot that is then mixed with the rest of the room air, lowering the rh of the room air.


...If reducing R/H via heat was the principle design of a dehumidifier then they would just be a space heater.

Uhhh...yeah, IF that were the priciple, but it is not. See Coconutz's post #41, following the link, to clear this up for yourself.

Heating up air does indeed lower R/H but only because warmer air can hold a larger quantity of water for a given R/H, Telling people to lower their R/H by increasing temp is just daft,...

Daft, eh? Maybe so, but I don't recall anyone advising anyone to kick up their temps to lower humidity.

For people with sealed rooms, venting the Dehuey externally is a good idea, else all they are doing is dumping an extra couple hundred watts (minimum) into their electricity bill and heatload the A/C has to deal with.

If you vent out the [hot, low rh] air that comes out of the dehum., you're wasting the cost of the dehum and the power it takes to run it. As I said read Post #41, and follow the link to educate yourself.
-granger
 
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Coconutz

Active member
Veteran
So my stank air and co2 goes through the dehuey and out of the room?
how is my room still sealed?
Yes, the water that collects in the pan is where the moisture is reduced, but that air has to go back into the room. It cant be exhausted or the room is no longer sealed.
If you remove the hot air you are still left with just air that hasnt had the water removed from it... And you are intaking new air through cracks when forcing out the old air
The reason it goes past the hot condenser is to increase efficiency of moisture removal.
If the air comes out cold it would read as a really high rh.
Put a hygrometer next to the air coming out of the ac. It reads 100% RH
Peace
 

BubbaBear

Member
No theres no thermostat, you turn it to dehumidifier mode and thats it, no other adjustments. It definitely lowers the humidity more than running it in AC mode and it doesn't cool nearly as much as when its in AC mode, it kept the humidity in the mid 40s. The models the Soleus LX-140. Here's some info from the manual.

http://www.soleusair.com/lx140.html

NOTE: The unit operates at low fan speed during dehumidifier mode. The unit cools room slightly during the dehumidification. Keep the windows and doors closed to aid the effectiveness of the unit in removing the moisture from the room.
NOTE: When the unit is running on dehumidifier mode, the exhaust hoses are required and must be vented outside using the supplied window kit.
NOTE: The unit will not perform in dehumidifier mode when the room temperature is lower than 61°F .

I'm not saying its THE answer, but it definitely helped me out a lot this summer and opened my eye to the fact that there are dehumidifiers that dont give off heat.
 
T

TREE KING

i appreciate the info guys. i think im just gonna do it how coconutz does it and call it a day. no need to overthink it. that portable ac would cost alot of money anyway
 
Just wanted to say, coconutz is 100% correct with all advice given in this thread :respect:.

I'll second that. My only exception is I have to run a dehuey and AC during the entire photoperiod and my AC is pretty maxed, runs almost 100% so adding more light wont do it in my case. But I do agree adding or allowing more heat to keep that ac working and drying your room is key. Open hood sure works out well with a properly sized AC.

I'm cooling 9k open hood w/c co2 gen and an 8000 btu window AC converted to a dehuey with 36k of cooling.
 

Coconutz

Active member
Veteran
Once its maxed its not gonna be able to pull more moisture.
Theres a balance you have to make.
You want it sized properly, but not too oversized, and you need to leave a little headroom for the most extreme conditions you will be operating in.
I like the idea of using some sort of AC set to dry mode, but the dual exhaust portables probably cost a fortune to run, even if you can really seal them.
Even the big box store dehueys arent very efficient compared to commercial dehueys.
I think they are still the best bet for the long term.
The more efficient the unit, the less wasted heat.
It would be really cold in my room without the dehuey, though.
I like it 72-77 at night until the last few weeks
 

Devilman

Active member
If you vent out the [hot, low rh] air that comes out of the dehum., you're wasting the cost of the dehum and the power it takes to run it. As I said read Post #41, and follow the link to educate yourself.
-granger


See, this is a common problem I see from you time and time again Granger... you walk into other peoples threads with a half-baked knowledge of the technology at hand and start spouting nonsense as fact.

For once, I suggest you stop typing and start reading, you MIGHT learn something...


If you really think a dehumidifier works most effectively by dumping all the extra heatload back into the room, then you sir, are a total clown. While dumping hotter (and therefore lower R/H air) into a room will indeed reduce its R/H, it is NOT the design or idea of a dehuey to work this way and ANYONE who says otherwise is an imbecile.

The sole principle that a dehuey works on for lowering R/H is by extracting the WATER in the air and removing it (hence why Dehuey's have a water catcher in them, not just a giant space heater dumping out "hotter air") The heat created is a byproduct of its WORKLOAD removing the water from the air, NOT the method by which it does it. Making the assumption, as you clearly have that this "hot and dry air" is the way a dehuey reduces R/H in a room is laughable, if dumping hot dry air into a room was the principle method of lowering R/H we would just use heaters.

End of the day, no matter how you want to dress this up for yourself, telling people to exhaust the hot air from a de-huey back into the room is just moronic. you have ALREADY LOWERED THE R/H by extracting the water from the air with a Dehuey (or modified A/C), so why the hell do you really want to dump a good few hundred extra watts of heat into the room when you have already done what was needed?

I STRONGLY suggest you stop walking into threads and telling people how to use equipment and how that equipment works when you clearly haven't got the faintest idea. The very fact you think a humidifier lowers R/H in a room by dumping hot air into it shows just how poorly educated you are on this matter.
 
T

TREE KING

See, this is a common problem I see from you time and time again Granger... you walk into other peoples threads with a half-baked knowledge of the technology at hand and start spouting nonsense as fact.

For once, I suggest you stop typing and start reading, you MIGHT learn something...


If you really think a dehumidifier works most effectively by dumping all the extra heatload back into the room, then you sir, are a total clown. While dumping hotter (and therefore lower R/H air) into a room will indeed reduce its R/H, it is NOT the design or idea of a dehuey to work this way and ANYONE who says otherwise is an imbecile.

The sole principle that a dehuey works on for lowering R/H is by extracting the WATER in the air and removing it (hence why Dehuey's have a water catcher in them, not just a giant space heater dumping out "hotter air") The heat created is a byproduct of its WORKLOAD removing the water from the air, NOT the method by which it does it. Making the assumption, as you clearly have that this "hot and dry air" is the way a dehuey reduces R/H in a room is laughable, if dumping hot dry air into a room was the principle method of lowering R/H we would just use heaters.

End of the day, no matter how you want to dress this up for yourself, telling people to exhaust the hot air from a de-huey back into the room is just moronic. you have ALREADY LOWERED THE R/H by extracting the water from the air with a Dehuey (or modified A/C), so why the hell do you really want to dump a good few hundred extra watts of heat into the room when you have already done what was needed?

I STRONGLY suggest you stop walking into threads and telling people how to use equipment and how that equipment works when you clearly haven't got the faintest idea. The very fact you think a humidifier lowers R/H in a room by dumping hot air into it shows just how poorly educated you are on this matter.

so devilman how come they dont make units that let you duct the heat out? that shit is idiotic even if it was for my house i wouldnt wanna heat the house certain times of the year
 

Devilman

Active member
so devilman how come they dont make units that let you duct the heat out?


Because most dehuey's are designed for use in a whole house, where the actual load they experience (how much water they need to remove) is often FAR LOWER than any growroom, coupled with the fact they have an entire house of airspace to dispate the extra few hundred watts of heat...


Pretty sure if you go around checking, not 1 company advertises their dehuey's as "suitable for grow-rooms, with external ventilation"

Just becuase something isnt made for our purpose doesn't stop us using it for that purpose and in our circumstances, the ONLY heat we want being dumped into the room (most times) comes from the lights we use... 300 watts of extra heat created by a dehuey dumping back into the room, is 300watts less heat from LIGHTS you can put into that room...

It really is that simple.... do you wanna have all your heat created only by lighting, or do you want to use less lighting, cus you have a load of heat being created by other sources that are not needed ?

Another thing to remember Tree-King... Air conditioners are "best designed" to vent externally. yet take a look around.. .plenty of "free standing" ones that vent back into the room... Does this mean that because manufacturers make them this way we should all decide to start dumping our A/C exhausts back into the room too?

No, ofc not.. so you wanna talk about idiotic ideas ad comments, how about the ones you just made?... Just because something WE USE FOR OUR OWN PURPOSES was not designed the way we use it, doesnt mean we are using it incorrectly, or inefficiently.

Simple fact is this.... Most of our growrooms are a SINGLE ROOM, not a WHOLE HOUSE, as such, throwing an extra 250-500watts of heat load into the room from a dehuey is going to change conditions in the room, however dumping 250-500watts of load from a dehuey into an ENTIRE HOUSE will not... THAT is one of the main reasons most dehueys are not "duct vented", because MOST are a free-standing unit, just like those free-standing A/C units that also vent back into the room and not out through a duct.
 

Granger2

Active member
Veteran
Devilman,
Other people's threads? So you and I should stay out of it? You see this time and time again? O...K.

Gear up your comprehension level to whatever your max is and re-read my posts. You keep putting words in my mouth, even tho I have clearly stated otherwise on this space heater nonsense. And relax. -granger
 

Devilman

Active member
And you keep putting nonsense into other peoples head's Granger... STOP trying to tell people that venting their Dehuey back into the room is a good idea, its not, PERIOD.

We already lowered the R/H by removing the WATER from the air, why you feel the need to go and dump that hot-ass air back into the room, for the A/C to have to deal with is frankly moronic... If you wanna get things hotter and drier, add more lights, use THOSE to increase temps and dry the air out even more... far more productive than throwing hot air back into the room and hoping for magic.

Hell, if you REALLY want to dump hot, dry air back into the room, get a bloody propane heater instead... might aswell get some CO2 out of the damn thing and actually get SOMETHING useful from the extra heat your throwing into the room.
 
T

TREE KING

your 100% right devilman thats why i started this thread why the fuck would i want this extra heat in the room lol. everything you said makes sense i appreciate the info
 

Devilman

Active member
I'm glad someone agree's and that the information is useful to you.

I should however, add in 1 caveat which I didn't consider at first, but is worth mentioning, regarding granger's comments etc...

At first I said that the most efficient use of a dehuey was to use it to remove water from the air and exhaust all excess heat etc.. externally to remove the heatload. This is not entirely accurate when dealing only with the dehuey itself and ignoring its location / circumstances..

Assuming all other things to be equal and "in control" (temps etc..) a Dehuey that is re-circ'ing back into the room WILL be more efficient at lowering R/H than one which is venting externally, simply because the warm/dry air from the Dehuey will also help lower the R/H of the surrounding air, effectively having a "dual action" of Dehumidification.

However, all of that goes "out the window" when we add in our specific requirements.. as mentioned previously, in an ideal world, the ONLY heatload in our growrooms we would have to deal with, is the heat generated by the lighting, this gives is the biggest "bang for buck" in terms of yields etc. and is prettymuch considered the most basic of "common sense" in growing circles... get as much light as you can while managing the heat effectively.

And right there becomes the issue... if our Dehuey puts out the same amount of heat as 1 of our lamps... then the choice becomes plain and obvious.... Do we vent the Dehuey externally and be able to run a whole extra lamp, for the increased lm/sqft (or w/sqft if you prefer) and all the goodness that will bring, while still maintaining our humidity levels, or do we choose to run 1 less light and.... well, you know where this is going right?

So to recap... Nobody in their right mind is going to willingly give up extra light, for a TINY BIT MORE EFFICIENCY from their Dehuey... not when the alternative might be a 5-10% loss in "total efficiency" on the dehuey, for the gain of perhaps another 400w or 600w HPS.
 

Coconutz

Active member
Veteran
See, this is a common problem I see from you time and time again Granger... you walk into other peoples threads with a half-baked knowledge of the technology at hand and start spouting nonsense as fact.

For once, I suggest you stop typing and start reading, you MIGHT learn something...


If you really think a dehumidifier works most effectively by dumping all the extra heatload back into the room, then you sir, are a total clown. While dumping hotter (and therefore lower R/H air) into a room will indeed reduce its R/H, it is NOT the design or idea of a dehuey to work this way and ANYONE who says otherwise is an imbecile.

The sole principle that a dehuey works on for lowering R/H is by extracting the WATER in the air and removing it (hence why Dehuey's have a water catcher in them, not just a giant space heater dumping out "hotter air") The heat created is a byproduct of its WORKLOAD removing the water from the air, NOT the method by which it does it. Making the assumption, as you clearly have that this "hot and dry air" is the way a dehuey reduces R/H in a room is laughable, if dumping hot dry air into a room was the principle method of lowering R/H we would just use heaters.

End of the day, no matter how you want to dress this up for yourself, telling people to exhaust the hot air from a de-huey back into the room is just moronic. you have ALREADY LOWERED THE R/H by extracting the water from the air with a Dehuey (or modified A/C), so why the hell do you really want to dump a good few hundred extra watts of heat into the room when you have already done what was needed?

I STRONGLY suggest you stop walking into threads and telling people how to use equipment and how that equipment works when you clearly haven't got the faintest idea. The very fact you think a humidifier lowers R/H in a room by dumping hot air into it shows just how poorly educated you are on this matter.


Hey man... This is funny as hell!
Its the last time Im going to try and correct you.
If you dont get, theres something wrong with one of us...
Its true that removing the water from the air is how you reduce the Rh and not the hot air...
The problem you arent seeing is that if you exhaust the treated air the room is left with untreated air that the water has not been removed from!
When air is exhausted, new air comes in!
Holy shit!
Have you ever actually used a dehuey?
Too many dabs?
 

Coconutz

Active member
Veteran
I'm glad someone agree's and that the information is useful to you.

I should however, add in 1 caveat which I didn't consider at first, but is worth mentioning, regarding granger's comments etc...

At first I said that the most efficient use of a dehuey was to use it to remove water from the air and exhaust all excess heat etc.. externally to remove the heatload. This is not entirely accurate when dealing only with the dehuey itself and ignoring its location / circumstances..

Assuming all other things to be equal and "in control" (temps etc..) a Dehuey that is re-circ'ing back into the room WILL be more efficient at lowering R/H than one which is venting externally, simply because the warm/dry air from the Dehuey will also help lower the R/H of the surrounding air, effectively having a "dual action" of Dehumidification.

However, all of that goes "out the window" when we add in our specific requirements.. as mentioned previously, in an ideal world, the ONLY heatload in our growrooms we would have to deal with, is the heat generated by the lighting, this gives is the biggest "bang for buck" in terms of yields etc. and is prettymuch considered the most basic of "common sense" in growing circles... get as much light as you can while managing the heat effectively.

And right there becomes the issue... if our Dehuey puts out the same amount of heat as 1 of our lamps... then the choice becomes plain and obvious.... Do we vent the Dehuey externally and be able to run a whole extra lamp, for the increased lm/sqft (or w/sqft if you prefer) and all the goodness that will bring, while still maintaining our humidity levels, or do we choose to run 1 less light and.... well, you know where this is going right?

So to recap... Nobody in their right mind is going to willingly give up extra light, for a TINY BIT MORE EFFICIENCY from their Dehuey... not when the alternative might be a 5-10% loss in "total efficiency" on the dehuey, for the gain of perhaps another 400w or 600w HPS.

God damn man!
Running a dehuey with the lights on?
Get a grip!
Your entire philosophy of growing is hilarious!
Peace the fuck out!
 

Devilman

Active member
Hey man... This is funny as hell!
Its the last time Im going to try and correct you.
If you dont get, theres something wrong with one of us...
Its true that removing the water from the air is how you reduce the Rh and not the hot air...
The problem you arent seeing is that if you exhaust the treated air the room is left with untreated air that the water has not been removed from!
When air is exhausted new air comes in, too!
Holy shit!
Too many dabs?


Very true... however those are circumstances and conditions that are WAY too varied for you, or I to guess at, let alone be making half-ass guesses about...

But look at it this way.... even WITH what your attempting to suggest... it is STILL better to run the dehuey vented externally and be able to use extra lighting (even if it has to run 100% of the time to keep R/H in check, than it is to deny yourself of extra lights, because you want your plants to be supping on some hot, dry air.

If a dehumidifier has to run more often but lets you run 1 extra light, would you not do it?

And as for running a dehuey with lights on... what do you think an A/C is actually doing while its running during your lights-on time to keep the temps in check? thats right... its also dehumidifying the room..
 

Coconutz

Active member
Veteran
Dude!
I dont run a dehuey during lights on because my room is designed properly!
Treeking... This guy is just fucking with you!
 

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