DIY ventilation heat exchanger - Page 3

Daox · 03-04-10, 10:07 AM

Thanks for the explanation AC Hacker. I am familiar with laminar and turbulent flow. I just didn't expect that a higher speed created that much more turbulence. Very interesting!

Piwoslaw · 03-04-10, 12:16 PM

I think this forum needs a Thanks button!

Quote:

Originally Posted by Daox

I just didn't expect that a higher speed created that much more turbulence.

I recently read that an airflow speed of at least 5m/s in ventilation ducts creates unacceptable noise. This may be the speed at which laminar turns to turbulent flow.

AC_Hacker · 03-04-10, 12:22 PM

Quote:

Originally Posted by Piwoslaw

I recently read that an airflow speed of at least 5m/s in ventilation ducts creates unacceptable noise. This may be the speed at which laminar turns to turbulent flow.

That's it exactly.

-AC_Hacker

Daox · 03-04-10, 12:36 PM

Quote:

Originally Posted by Piwoslaw

I think this forum needs a Thanks button!

I recently read that an airflow speed of at least 5m/s in ventilation ducts creates unacceptable noise. This may be the speed at which laminar turns to turbulent flow.

I'd give you a thanks, but... We'll get on it. Its a nice feature.

Thanks for that tidbit of info too!

Daox · 03-09-10, 03:09 PM

Yeah, it would be interesting to see what the European makers have done besides increase the size to get the extra efficiency.

Piwoslaw · 04-14-10, 12:23 AM

Thanx AC

Downloaded the program, now I'll have to find some time to play with it.

Xringer · 06-01-10, 06:10 PM

Sounds like an interesting experiment. Be sure to post some pics..

And welcome to the group..

Cheers,
Rich

Piwoslaw · 06-02-10, 12:02 AM

Hello 1blueox.
What kind of foil are you planning on using? I'm afraid that typical kitchen-grade aluminum foil is to flimsy and may not be able to handle the pressure differences between the channels it's separating. Aluminum that's slightly thicker than the kitchen stuff should be OK, you may also look around for thin copper foil, which is also a good heat conductor.

As for condensation, you'll get it anywhere that there is a temperature difference and at least some moisture in the air. The incoming air may have more moisture in the morning or during rain, the outgoing air will be carrying moisture from the house (showers, cooking, breathing). You'll have to make a small drain for both channels.

Daox · 06-02-10, 06:04 AM

Welcome to the site 1blueox. Sounds like a very interesting project. I too would love to see pictures as it progresses.

Xringer · 06-17-10, 09:26 PM

I saw some HRV units on Ebay in the $450 range. Looked up the maker and found this
site: HRV Airiva Heat Recovery Ventilator with a video.. http://www.suncourt.com/Flash/Suncourt%20Video.swf

Here's an installed review.. Amazon.com: Suncourt AIRIVA HE150 Heat Recovery Ventilation System: Everything Else

I've been thinking about air quality a lot lately. My wife has been experiencing
a hacking cough for years and it seems to be getting worse.
Doctors don't have a clue, so I'm wondering if it's airborne irritants.?.
Besides, I kinda like the idea of getting some fresh air during the winter,
when everything is shut up tight.

03-04-10, 10:07 AM	#1
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Thanks for the explanation AC Hacker. I am familiar with laminar and turbulent flow. I just didn't expect that a higher speed created that much more turbulence. Very interesting! __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

03-09-10, 03:09 PM	#5
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Yeah, it would be interesting to see what the European makers have done besides increase the size to get the extra efficiency. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

06-02-10, 06:04 AM	#9
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Welcome to the site 1blueox. Sounds like a very interesting project. I too would love to see pictures as it progresses. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

04-14-10, 12:23 AM	#6
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 961 Thanks: 188 Thanked 110 Times in 86 Posts	Thanx AC Downloaded the program, now I'll have to find some time to play with it.

06-01-10, 06:10 PM	#7
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Sounds like an interesting experiment. Be sure to post some pics.. And welcome to the group.. Cheers, Rich

06-02-10, 12:02 AM	#8
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 961 Thanks: 188 Thanked 110 Times in 86 Posts	Hello 1blueox. What kind of foil are you planning on using? I'm afraid that typical kitchen-grade aluminum foil is to flimsy and may not be able to handle the pressure differences between the channels it's separating. Aluminum that's slightly thicker than the kitchen stuff should be OK, you may also look around for thin copper foil, which is also a good heat conductor. As for condensation, you'll get it anywhere that there is a temperature difference and at least some moisture in the air. The incoming air may have more moisture in the morning or during rain, the outgoing air will be carrying moisture from the house (showers, cooking, breathing). You'll have to make a small drain for both channels.

06-17-10, 09:26 PM	#10
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I saw some HRV units on Ebay in the $450 range. Looked up the maker and found this site: HRV Airiva Heat Recovery Ventilator with a video.. http://www.suncourt.com/Flash/Suncourt%20Video.swf Here's an installed review.. Amazon.com: Suncourt AIRIVA HE150 Heat Recovery Ventilation System: Everything Else I've been thinking about air quality a lot lately. My wife has been experiencing a hacking cough for years and it seems to be getting worse. Doctors don't have a clue, so I'm wondering if it's airborne irritants.?. Besides, I kinda like the idea of getting some fresh air during the winter, when everything is shut up tight.