[motydesign]

so i did a search and couldnt see where anyone has tried a custom viv using 1" insulated glass(for the viewing part of the viv, not all sides). i understand the viv would be a bit heavy. However it was a thought of only using the insulated on the display side. you might ask why 1"? well because i went to the Zoo the other day and saw it used on the storefront between some larger enclosures and the outside. The reason they did that is condensation. it could be 100% humidity in the display, with a delta of 30 degrees between the two faces of glass and still not have a drop of condensation on the glass. this got me to thinking about how much i love to sit and watch my frogs, but hate having to watch them through a view like this

anyone ever try it? or have some pics, or additional thoughts on how this could be a flawed idea?

 

[Pumilo]

At the zoo where you saw this, did they claim that the insulated glass was responsible for the lack of condensation? I work with insulated glass and the theory strikes me as flawed. Insulated glass units in homes still have problems with condensation on the interior pane (pane in the living area) of glass. In fact several of the bigger window manufacturers (Pella, Anderson) have pages on their web sites explaining why this problem can still remain, even after spending a huge chunk of change on new windows. In fact, the tighter sealed the window is, the more this is a problem. Most windows have "weep holes" to help alleviate this problem.
I would have to think that in reality, they may be using some de-humidification, or simply air motion, to control the humidity.
In practice, your viv would have to be extremely well sealed as the sealants used in insulated units are not going to be frog safe.
Further, this would be expensive to build. An internal circulation fan would be simpler and cheaper to alleviate condensation.

 

[motydesign]

Doug, are we talking about the same windows (the one i am talking about tries to eliminate thermal bridging)? im speaking about storefront or the same that is used in high rise construction
rough sketch

same idea they used on drinking glasses
http://www.amazon.com/Double-Wall-Insulated-Drinking-Glasses/dp/B000BH0XC2
cost could be high if one were to order it.

 

[Pumilo]

Yes we are. I know in Colorado's conditions at least, there is still appreciable condensation. Must be in other conditions too, as both Pella and Anderson address the problem on there websites.

 

[Brotherly Monkey]

Yes we are. I know in Colorado's conditions at least, there is still appreciable condensation. Must be in other conditions too, as both Pella and Anderson address the problem on there websites.

wouldn't there be a difference in the condensation effect, in regards to the glass having exposure to out side conditions vs a controlled environment?

PS ed should be able to add alot to this, given his history working in zoos, (I believe) and his hand in helping design such enclosures in the past

 

[motydesign]

Doug, lets talk about this i think we can figure something out.
ill tap back to mechanical classes and pull up the trusty Psychrometrics chart
Psychrometrics - Wikipedia, the free encyclopedia
pella states there are situations where condensation will take place... but they do not give me the U value of the window (kinda needed for these calculations)
http://www.pella.com/owners-manuals-and-warranties/owners-manuals/PellaCondensationManual.pdf

so

inside viv worse case senerio is 70-80F and 80-90% RH.
from there you can find the dew point to be anywhere from 64F (at 70F and 80%) and worse case dew point at 78F (at 80F and 90%)

the one we need to worry about if we want pretty see through glass is 78F. Most houses i would guess are kept at 73F (i imagine there are a few that get the 69F? but i would like to stick with normal people haahh).on a single pane of glass 80F 90%RH viv a 73F house would obviously have condensation present. however if you were to have a insulated piece of glass where thermal bridging is reduced greatly. at what value do you think the window would need to be at to keep a delta of 5F or better(this takes the temp out of the dew point)? this would required heat loss calcs and blahhh

id love to hear more on this topic if someone knows a bit about thermal cals and designs.

 

[Pumilo]

wouldn't there be a difference in the condensation effect, in regards to the glass having exposure to out side conditions vs a controlled environment?

PS ed should be able to add alot to this, given his history working in zoos, (I believe) and his hand in helping design such enclosures in the past

Doug, lets talk about this i think we can figure something out.
ill tap back to mechanical classes and pull up the trusty Psychrometrics chart
Psychrometrics - Wikipedia, the free encyclopedia
pella states there are situations where condensation will take place... but they do not give me the U value of the window (kinda needed for these calculations)
http://www.pella.com/owners-manuals-and-warranties/owners-manuals/PellaCondensationManual.pdf

so

inside viv worse case senerio is 70-80F and 80-90% RH.
from there you can find the dew point to be anywhere from 64F (at 70F and 80%) and worse case dew point at 78F (at 80F and 90%)

the one we need to worry about if we want pretty see through glass is 78F. Most houses i would guess are kept at 73F (i imagine there are a few that get the 69F? but i would like to stick with normal people haahh).on a single pane of glass 80F 90%RH viv a 73F house would obviously have condensation present. however if you were to have a insulated piece of glass where thermal bridging is reduced greatly. at what value do you think the window would need to be at to keep a delta of 5F or better(this takes the temp out of the dew point)? this would required heat loss calcs and blahhh

id love to hear more on this topic if someone knows a bit about thermal cals and designs.

Very true guys. I fired off a quick answer this morning but after thinking about it, I am used to dealing with freezing, super cold, Colorado winters, in conjunction with warm and humid conditions in the house. Inside conditions are more humid than some people realize in the winter due to cooking evaporation, showers, toilets, etc. Generally, several gallons a day are added to any homes air supply.
So this could be a completely different story when only dealing with a temp difference of 10 or 20 degrees.
So I'm going to withdraw my earlier comments unless you normally keep the inside of your home at about 3 degrees below 0!!

 

[GRIMM]

Cool idea. I think this would be best used in a rack style setup, or something built into a wall. That way the double layer isnt as apparent. Im sure it is common knowledge, but you could even try pumping some helium or argon into the gap to help the effect. Do it!

 

[Pumilo]

Argon has been used in insulated units. It makes a miniscule difference over just plain insulated glass. It is pretty much a selling gimmick. My manufacturer offers that option while at the same time saying "don't waste your money".

 

[motydesign]

hahah, i have similar products, you have to have the option to prove your capable, but people dont realize sometimes you have you use common sense over a crazy gimmick