# Venting PC heat outdoors



## ibegettinmoney

Hows it goin guys?

I'm not sure about you but my office can get to 85-90 degrees while video editing and gaming. Now granted I do live in Florida and my CPU is clocked at 4.5ghz, but I'm not willing to down-clock or relocate. So, I decided to conduct a little experiment over this 4 day Labor day weekend.

I have searched the forums and I've found some threads that have attempted this before but none really provided a clear answer on whether this is a practical solution for reducing heat so Ive decided to make my own attempt.

*Here are the parts that I will be using in this experiment:*
(all are available via HomeDepot, Walmart, Amazon)
• 4in Ducting
• 2x 4in Dryer Duct to Wall Connector http://www.homedepot.com/p/Everbilt-4-in-Dryer-Duct-to-Wall-Connector-EZCNHD/203626503
• Black Foam Board
• White Foam Board
• Old Server Fan High CFM

I will construct a manifold out of the black foam board to fit on top of my PC which currently exhausts all the hot air out of my case. I will post pictures and instructions on how I constructed it this afternoon.
The white foam board Ill use to create a baffle in the window to vent it outside. This is only a temporary solution to see if this project is viable before investing in a long term solution.

If the experiment is successful I will buy a portable AC vent kit as well as a 4in inline fan with variable speed to move the air from the PC to the window. The amount of air the inline fan will move will be plenty to overcome the difference in pressure and in theory create a negative pressure in my case allowing for better ventilation. I would build a stand for my tower where I would be able to mount the inline fan in the base of the stand. Below are pictures of the parts I would purchase:

*Portable AC Window Kit*


*4in Inline Fan*


Ill post progress pictures this afternoon, If you have any questions or suggestions id love to hear them!


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## Lady Fitzgerald

subbed


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## Girryn

Subbed


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## ibegettinmoney

Sorry for the wait guys I've been busy trying to juggle this project and a social life lol. So I ended up finishing the first prototype and all I can say is wow. The amount of heat the system moves outside is impressive. I immediatly noticed a difference in room temperature after venting the heat outside, I can actually enjoy working without the ac set to 60F and my fan on wind tunnel mode.

Currently I'm working on creating a more astetically pleasing manifold out of black foam board. I made a model last night of a revised mani allowing for 2 case fans in series to fit inside. I put together this model very quick and glued the seams before I could remove the paper from the inside of the mani. This cause it so give me a lot of vibration drone and that's not gonna work. I'm going to put together V3 this afternoon and will post pictures of the project up to this point.

So far this is turning out to be a very viable solution for me and could mean the same for many of you. Although manifold design will vary with every case there are purpose built brackets that can allow you to connect ducting right up to a 120mm exhaust fan on the back of many cases. Thanks to all that have subbed this thread and if you have any questions or suggestions I'd love to hear them!


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## jimmyhackers

ive been doing something similar....

my 240mm rad for cpu cooling hangs out the rear of my pc. i have ducted this to suck in cooler air from outside using its existing 2x120mm fans. keeping it cooler than ambient (room temp) by a few deg C

the successfullness of this kind of setup will depend on the difference between outside and inside temperatures and how warm you want your pc room to be.

when outside is hotter you want to be exhausting all your heat from your case outside and be drawing in the cooler room air.
when outside is colder you want to be sucking in the cold air..........and exhausting a certain amount back outside depending on how warm you want your room to be (free heating of sorts).

i live in the uk and the summer is almost over now meaning ill be on the second option for ages now.

heres my ugly but very functional version

http://s1228.photobucket.com/user/jimmyhackers/media/IMAG04431_zpsgblswghu.jpg.html

http://s1228.photobucket.com/user/jimmyhackers/media/IMAG04441_zpscfnygiw6.jpg.html

i can switch between exhausting or intaking by simply swapping my janky carboard manifold to either side of my radiator.


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## ibegettinmoney

Nice! I had the same idea when I began this project. I was going to create a box with foam board to house my radiator with a push/pull setup that would then vent outside. The reason I didn't go in this direction was that although my CPU was generating a lot of heat when gaming my GPU would produce an equal amount if not more heat than the CPU. Also I didn't want to have to re plumb my setup to extend the liquid supply and return.


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## ibegettinmoney

The experiment is finally complete! Yesterday I ran some tests and the air in my office only increased by 2 degrees from the original base temp of 76. I can finally enjoy my office without leaving it drenched in sweat. Below are some pictures I took while working on this project, Enjoy!









Whole setup in action.


First Manifold Concept made with old cardboard.




Manifold V2, I wanted to make this one out of one piece of foam board to reduce leaks.


I scored where the folds were going to be then used the end of my exacto knife to push the foam down a little bit to make the fold easier.


When making your bends go slow and apply even pressure. If you go fast you run the risk of tearing the paper on the outside of the bend.


This is what the end result should look like. It should all fold together into one piece and you can then hot glue all the seams. I also removed the paper from the inside of the manifold where the fans would be located to reduce vibration. After installing V2 on my computer noise was greatly reduced by removing the paper but if i could go back id remove all the paper from the inside as the section I left causes some resonance.


This is the fan configuration ill be running. I went with 2 different fans because its the only 2 I had on hand and the first black fan has a square frame that seals against the foam board.


This if the view from the outside, I just doubled up some laminated foam board and used a 4in Duct check valve that will close when theres no flow to the outside.



I do have more pictures on my camera, I just had some down time at work and wanted to update on what I had. Anyways when I get home today Ill download and upload the rest. For right now the next move for the project is to order the slimmer vent which will also include a metal baffle. Unfortunately this current setup will have to be taken down this weekend due to the possible threat of a Cat 5 hurricane







But hopefully the new slim baffle will arrive just as the hurricane is retreating and it will be a smooth transition.


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## profundido

Hey,

as a purely fun experiment I find this very interesting because I have thought about doing something similar for a similar situation.

But as an overclocker and custom watercooler I know now that the very best and absolute way to achieve this would be by installing a custom waterloop into your pc and use e.g Koolance QDC (quick disconnect) or equivalent connectors to connect your tubing to 1 or 2 big 560 radiators that you hang outside. That would be amazingly effective and practical with thin tubes of less than 2cm diameter going through your wall and no need to keep your window open.


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## 8051

Subbed.


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## Simmons572

This is a very fascinating thread! I have been thinking about doing something like this for a while now, as all of the computers I am running generate quite a lot of heat throughout the year.

However, since I live in the DC area, I experience the 4 seasons, ranging from sub-zero temps in January, to 105+ F in July and August.

My thoughts are to add some sort of "T", with one side exhausting outside, like you have done here, and the other side exhausting into your house's HVAC system.
In theory, you could set up some sort of toggle that switches the exhausting air between the two outlets, allowing you to use your computer heat to offset the heating bill by a little bit in the Winter.

This is just something I've been spitballing for a while, and I thought it may add to the conversation a bit


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## bajer29

Spitballing off Simmons572's idea. What if you could reverse the blower to intake cold air in the winter, late fall, and early spring months. Exhaust in late spring, early fall and summer months.


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## Simmons572

Quote:


> Originally Posted by *bajer29*
> 
> Spitballing off Simmons572's idea. What if you could reverse the blower to intake cold air in the winter, late fall, and early spring months. Exhaust in late spring, early fall and summer months.


My biggest concern with that would be high humidity scenarios. He mentioned that he lives in Florida (best of luck to you with the storms, btw







), which is especially known for getting a lot of rain.
You would need to factor in a way dehumidify the air without losing too much air speed, IMO.


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## bajer29

Quote:


> Originally Posted by *Simmons572*
> 
> My biggest concern with that would be high humidity scenarios. He mentioned that he lives in Florida (best of luck to you with the storms, btw
> 
> 
> 
> 
> 
> 
> 
> ), which is especially known for getting a lot of rain.
> You would need to factor in a way dehumidify the air without losing too much air speed, IMO.


Very true, however, this was more of a suggestion for you to look at.

I like the idea of attempting to feed existing heat from the case to your furnace/ ductwork to help contribute with the heat bill, but would you really be contributing that much? Wouldn't the heat dissipate pretty quickly? Figure the heat from your furnace is probably around 60C-77C; the air venting from your case is probably, what... 40C-50C by the time it exits your case and hits the cool sides of the duct? Maybe if you punched a hole in the adjoining room and added a diffuser to the end of the duct from your PC, you'd have better heating solution.

Not sure feeding "lukewarm" air into a stream of hot air would make a huge difference.


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## Simmons572

Quote:


> Originally Posted by *bajer29*
> 
> Quote:
> 
> 
> 
> Originally Posted by *Simmons572*
> 
> My biggest concern with that would be high humidity scenarios. He mentioned that he lives in Florida (best of luck to you with the storms, btw
> 
> 
> 
> 
> 
> 
> 
> ), which is especially known for getting a lot of rain.
> You would need to factor in a way dehumidify the air without losing too much air speed, IMO.
> 
> 
> 
> Very true, however, this was more of a suggestion for you to look at.
> 
> I like the idea of attempting to feed existing heat from the case to your furnace/ ductwork to help contribute with the heat bill, but would you really be contributing that much? Wouldn't the heat dissipate pretty quickly? Figure the heat from your furnace is probably around 60C-77C; the air venting from your case is probably, what... 40C-50C by the time it exits your case and hits the cool sides of the duct? Maybe if you punched a hole in the adjoining room and added a diffuser to the end of the duct from your PC, you'd have better heating solution.
> 
> Not sure feeding "lukewarm" air into a stream of hot air would make a huge difference.
Click to expand...

Oh you are absolutely correct. It is not a practical solution at all, but still fun. Since I have 2 computers that are folding 24/7, I figured I could "pretend" to put the heat produced to good use in the winter.


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## DzillaXx

I've been thinking about doing something like this for years, but with a radiator and antifreeze to a reservoir that sits between the PC and Outside world. With Temp sensor that kicks a fan&pump on and off keeping the temp of the mixing tank (reservoir) a solid temp. Otherwise you have to deal with condensation and whatnot. Quick Disconnects to unplug the PC from the wall if needed.

Clean, Easy, Non Ugly. Is what I would go after.

I wouldn't deal with cardboard and Ductwork running allover my room. But hey, if it works.








I have a portable AC unit because of my small windows, and already deal with enough hoses. But that is soon to be installed for good with holes going out the side of the house.


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## amra88

Thought about it too, got stuck in the amount of rad space I'd need for that and the position of the rads... Living in São Paulo, rain would be some problem if I'd add fans, so the idea would be to go with passive rads... and since sun shines straight into my balcony late afternoon, which is when I'm on my PC, I'd have to have the rads close to the ground or the ceiling of the balcony


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## jimmyhackers

ducting the outside air to an external (outside case but inside room) radiator negates the rain damaging your fans.

it also helps with isolating the possible damage done by humid air to the outside part of your radiator.

also removal of the ducting is a lot simpler than disconnection of extended water lines (for an outside rad)

its also incredibly easy to swap round the duct in my "heath robinson" setup by hand depending if i want to expel heat. or draw in cool air. it all depends on inside/outside temp difference.

a lesser bonus is the manifold and ducting quietens down the fans noise a fair bit

im thinking about getting a 360mm rad so maybe my next manifold will look a bit less janky. the concept works and is worth doing if you need a cooler room or your setup to run a few degrees cooler.


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## SavantStrike

Quote:


> Originally Posted by *Simmons572*
> 
> This is a very fascinating thread! I have been thinking about doing something like this for a while now, as all of the computers I am running generate quite a lot of heat throughout the year.
> 
> However, since I live in the DC area, I experience the 4 seasons, ranging from sub-zero temps in January, to 105+ F in July and August.
> 
> My thoughts are to add some sort of "T", with one side exhausting outside, like you have done here, and the other side exhausting into your house's HVAC system.
> In theory, you could set up some sort of toggle that switches the exhausting air between the two outlets, allowing you to use your computer heat to offset the heating bill by a little bit in the Winter.
> 
> This is just something I've been spitballing for a while, and I thought it may add to the conversation a bit


This is actually doable, albeit with a slight modification.

Exhaust the hot air into your house's return air duct. If you set your fan to constant fan, you will get to recapture a good deal (if not all) of your waste heat. Going straight into your HVAC system on the positive pressure side will result in feeding hot air from the HVAC system into the computers you are trying to cool.


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## nanotm

if you have a dedicated system you could in theory use it like a solar water heater to give you the perfect temperature water for showers via the water cylinder, although once a week you would need to make the entire water cylinder hit at least 60 degrees Celsius to kill off any bugs, that would save you money in terms of heating the water for doing the dishes and so on.... but I suspect the cost of manufacturing the system would probably outweigh the savings in anything less than a decade of power use unless your running 10+ rigs in a "pc room" and having them all contribute heat, of course using quick release couplings would let you swap in new gear as and when needed...


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## 8051

Quote:


> Originally Posted by *nanotm*
> 
> if you have a dedicated system you could in theory use it like a solar water heater to give you the perfect temperature water for showers via the water cylinder, although once a week you would need to make the entire water cylinder hit at least 60 degrees Celsius to kill off any bugs, that would save you money in terms of heating the water for doing the dishes and so on.... but I suspect the cost of manufacturing the system would probably outweigh the savings in anything less than a decade of power use unless your running 10+ rigs in a "pc room" and having them all contribute heat, of course using quick release couplings would let you swap in new gear as and when needed...


You would have to heat the water to get it to 60° C that would kill any energy savings right there. A PC water cooling system that's running the water at 60° C isn't going to be much of a cooling system at all.


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## nanotm

Quote:


> Originally Posted by *8051*
> 
> You would have to heat the water to get it to 60° C that would kill any energy savings right there. A PC water cooling system that's running the water at 60° C isn't going to be much of a cooling system at all.


well sort of but no,
you would use a heat exchanger unit to move the heat from the cooling loop to the water in the insulated loop though the cylinder tank which would get hot over time and stay hot, if anything you might be in danger of getting it over temp if you have too many systems running on the setup for too long without using the heated water often enough....

its hard to explain if someone doesn't already understand about heat exchangers and hot water systems work, but suffice to say that it is doable and has been done with at least one data centre in the past to great effect and the water was kept above 60 degrees with ease whilst the servers were kept below 30 degrees, I guess it all depends how big a water tank how well insulated and how much heat your shifting to it, I dare say that a single or even a double pc setup running 24/7 wouldn't be enough to get the job done and you would need to fire up the boiler once a week to get things nice and hot but 5+ systems or a couple of mining rigs and you would probably have enough heat to barely need the boiler at all/


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## Fuzzywinks

I've done a few tests like this myself with mixed success. The problem with pushing air from inside the house to outside the house is the air coming in to replace it. The very slight negative pressure created by pushing air out has to be equalized somewhere, so outside air just seeps in through all the tiny gaps in windows and doors around the house to fill the void. It might make the room the computer is in cooler by removing the concentrated source of heat, but then the heat load is simply spread throughout the house where it is less noticeable but has the same (or greater) impact on the ability of the AC to cool the house.

There are a few solutions to this, all of which I've played with at some point:

- You could simply run low speed fans and allow the components to run hotter. This means the same amount of heat energy is moved out of the house but is more concentrated in slower moving, hotter air. Removing a smaller volume of heated air means less outside air needs to come in to replace it. So long as the air being blown out is hotter than the air already outside the net effect is at least less total heat for the AC to remove versus not ducting the air out at all.

- You could water cool the rig and duct outside air in through a sealed vent system, through the rad, and back outside. There will be minimal exchange of air from inside/outside but the water will run a little warm using the warmer outside air.

- You could water cool and have the entire radiator outside. This is a little more tricky because most computer fans don't like getting wet, especially Florida wet. I've done this using the electric cooling fan from an automotive radiator and that worked very well. Again the coolant will run hotter and you should probably insulate the coolant lines inside the house to keep some of that heat from soaking into the air in your room. At least in Florida you shouldn't have to worry about the coolant getting too cold and freezing or leading to condensation.

I literally heat my house with computers in the Winter. I have electric heat and no gas in this house anyway so I can either run power through the furnace for nothing but heat, or run the same amount of power through several computers and servers to produce medical research and magic internet money


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## 8051

Quote:


> Originally Posted by *nanotm*
> 
> well sort of but no,
> you would use a heat exchanger unit to move the heat from the cooling loop to the water in the insulated loop though the cylinder tank which would get hot over time and stay hot, if anything you might be in danger of getting it over temp if you have too many systems running on the setup for too long without using the heated water often enough....
> 
> its hard to explain if someone doesn't already understand about heat exchangers and hot water systems work, but suffice to say that it is doable and has been done with at least one data centre in the past to great effect and the water was kept above 60 degrees with ease whilst the servers were kept below 30 degrees, I guess it all depends how big a water tank how well insulated and how much heat your shifting to it, I dare say that a single or even a double pc setup running 24/7 wouldn't be enough to get the job done and you would need to fire up the boiler once a week to get things nice and hot but 5+ systems or a couple of mining rigs and you would probably have enough heat to barely need the boiler at all/


If the cooling loops in your PC's aren't running @ 60°C how is it going to heat the water in the tank up to that final temperature? It doesn't make a difference if you have a hundred systems running their water cooling loops at 45° C, they're not going to raise the temperature of the tank to 60°C.


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## AmateurExpert

Quote:


> Originally Posted by *8051*
> 
> If the cooling loops in your PC's aren't running @ 60°C how is it going to heat the water in the tank up to that final temperature? It doesn't make a difference if you have a hundred systems running their water cooling loops at 45° C, they're not going to raise the temperature of the tank to 60°C.


Correct. One would have to use (probably several) secondary stages (such as peltier plates or phase change loops) to concentrate the heat from the primary cooling loop enough to able to keep heating the hot water tank to 60°C while maintaining primary coolant at temperatures useful for cooling PC components.


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## nanotm

you clearly don't understand temperature build up, if your hot water tank is insulated and doesn't loose heat then every joule you transfer adds to the total,

utilising a custom created heat exchanger your water in your pc cooling loop never gains heat, however it consistently transfers a couple of degrees to
Quote:


> Originally Posted by *AmateurExpert*
> 
> Correct. One would have to use (probably several) secondary stages (such as peltier plates or phase change loops) to concentrate the heat from the primary cooling loop enough to able to keep heating the hot water tank to 60°C while maintaining primary coolant at temperatures useful for cooling PC components.


2 stage heat exchanger would be fine, and yes it would require a peltier bridge, I cant see phase change working....

but then I did specify that it would be a custom configuration that wouldn't be cheep to make, just that it can be done and have a useful purpose (not that it necessarily made any logical sense, although if you were going all eco crazy it might make some sense, especially if your peltier and pumps were run off deep cycle batteries powered through pv panels, but that just pumps the cost up even more)


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## PCCstudent

I see something you missed. Good work so far. Your efforts to get hot air out of the room are working out. You need to look at anything else that is heating up the room. My first call is the lack of reflective film on the window in the picture. That window if it is facing the sun can destroy any gains you make otherwise, get some reflective film on the window. I bet you can get good quality film, installed for around 50.00 per window (this is what I paid).


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## Renairy

I'd watch out for Al Gore if i were you.

Subbed.


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## 8051

Quote:


> Originally Posted by *nanotm*
> 
> you clearly don't understand temperature build up, if your hot water tank is insulated and doesn't loose heat then every joule you transfer adds to the total,


You clearly don't understand basic thermodynamics. If the water in the tank is at 60° and the cooling loops are @ 45°C the tank will lose heat energy to the cooling loops and the cooling loops will gain energy from the tank until they reach equilibrium.


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## jimmyhackers

not sure if this has been mentioned......but has the OPs exhaust from the PSU been dealt with/addressed?

i.e is it still chucking unducted hot air out the back into the room?

or has the internal fan been reversed so its hot air is spewed into the case instead? not sure how healthy that is for the psu or the rest of the pc but it will also mean all the heat can go out of one duct making for a neater install.


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## nanotm

Quote:


> Originally Posted by *8051*
> 
> You clearly don't understand basic thermodynamics. If the water in the tank is at 60° and the cooling loops are @ 45°C the tank will lose heat energy to the cooling loops and the cooling loops will gain energy from the tank until they reach equilibrium.


only when your doing direct heat transfer from the cpu block to the hot water tank ....


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## 8051

Quote:


> Originally Posted by *nanotm*
> 
> only when your doing direct heat transfer from the cpu block to the hot water tank ....


So the heat transfer comes from the radiators or cooling coils immersed in the water?
How does that fix things?

Heat always flows from a region of high temperature to a region of lower temperature unless there's some mechanical or electronic device to reverse this flow.


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## microchidism

?

couldn't you just run a loop and run the lines outside to an external radiator?


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## nanotm

Quote:


> Originally Posted by *8051*
> 
> So the heat transfer comes from the radiators or cooling coils immersed in the water?
> How does that fix things?
> 
> Heat always flows from a region of high temperature to a region of lower temperature unless there's some mechanical or electronic device to reverse this flow.


well I did mention previously that a peltier would be required.....


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## 8051

Quote:


> Originally Posted by *nanotm*
> 
> well I did mention previously that a peltier would be required.....


So you would be dumping the peltier's heat load into the water tank through a separate loop while using it to cool your watercooling loop for your PC?

Would you use two waterblocks (one for each loop) and the peltier sandwiched in-between?

You have a really interesting idea -- although I think plumbing it would be a nightmare. How big a tank of water were you considering?


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## SavantStrike

Quote:


> Originally Posted by *nanotm*
> 
> only when your doing direct heat transfer from the cpu block to the hot water tank ....


A truly open loop then using potable water. He he.

That would do wonders for corrosion!


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## nanotm

Quote:


> Originally Posted by *8051*
> 
> So you would be dumping the peltier's heat load into the water tank through a separate loop while using it to cool your watercooling loop for your PC?
> 
> Would you use two waterblocks (one for each loop) and the peltier sandwiched in-between?
> 
> You have a really interesting idea -- although I think plumbing it would be a nightmare. How big a tank of water were you considering?


standard house size so I guess around 240 Litre, most of them are nice copper tanks so no problem with legionnaires, having it properly lagged will be the biggest problem (most standard ones are really poorly insulated) and yeah it would need to be a fully custom setup because your looking at needing a completely copper radiator to go inside the tank, the tank will need to be custom made and most of the pipe work will need to be high pressure copper with soldered joints, I suspect that once the radiator being used in the bottom of the tank has been designed and fitted the actual pipework would be relatively simple, yes you could connect each rig in series with the tank loop, think a wide section of pipe with several flat bits on it each with a peltier plate each with a custom waterblock the heat will be moving from each cooling loop into the tank loop no reverse transfer (so long as the peltiers are set up correctly) another options is to have the transfer pipe swapped into several parallel lines again moving from a thin bore to a wide bore with the flat block + peltier mounting points

the ins and outs of how its done, are all the pc's connected into a series/ parallel loop for a single transfer point how much lagging is needed on the pipework, whats the gauge and flow rate and all that are things that would need tested and checked, it would likely take months to sort out the best way of doing it and even then it might not be a whole lot better than just putting an extractor hood behind the pc's and sucking all the heat out through the roof .... but I suspect the correct setup would be very good, and whilst a single pc would likely take several days of 24/7 running at max chat just to heat that volume of water to 30 degrees never mind pushing it all the way to 60+ the loop would still work to a degree, indeed if there was a second heating loop that moved through a boiler its even possible the water could be made hotter on demand as required.... but I don't know and no i'm not a plumber,


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## _02

Just a thought - make sure that you secure the inside of the window against the windowframe so it can not be further lifted. I would also secure the baffle to the window frame so it can not easily be pushed in. Very easy to gain access to an otherwise locked house by pushing in or pulling out a window AC baffle.

ESPECIALLY on a first floor.


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## 8051

Quote:


> Originally Posted by *_02*
> 
> Just a thought - make sure that you secure the inside of the window against the windowframe so it can not be further lifted. I would also secure the baffle to the window frame so it can not easily be pushed in. Very easy to gain access to an otherwise locked house by pushing in or pulling out a window AC baffle.
> 
> ESPECIALLY on a first floor.


That's exactly what I thought.

My friend has an interior plastic insert into this casement style window for his portable A/C unit so he can close and lock the window over the ducting.


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