DIY ventilation heat exchanger - Page 27

kostas · 12-16-12, 11:00 AM

Quote:

I'm sure that energy is even more dear where you live.

Oh yes, you can say that!

TimSmall · 12-16-12, 12:53 PM

Quote:

Originally Posted by kostas

Talking about motors, what do you think about this one?
It is a dual centrifugal with these specs:
130 W

2300 rmp

Fan diameter 80 mm (aluminum)

Fan length 83 mm

450 m3/h

static pression 237 PA

For comparison, those mixed flow second hand DV6224 fans which I mentioned (available at 25 euro or so each - I saw a set of four fans on US eBay for $30 I think), do the following at max speed:

89 watts

650 Pa (static)

700 m³/h (open flow)

http://img.ebmpapst.com/products/dat...224TDA-ENG.pdf

but they're speed controllable with an EC motor, so will go down to 10% speed giving 100 m³/h (open flow) and if similar fans which I've used in the past are anything to go by, they probably use less than 5 watts at that speed.

Have a look at the fan curve on the last page of the PDF.

Piwoslaw · 12-17-12, 12:29 AM

Two fans are good not only for flexibility, but can also (potentially) reduce energy usage. During the nice warm spring and autumn there will be a few weeks or months when you won't really need the heat exchanger since the outdoor air will be in a good temperature range. Then you can open your windows and turn off the intake fan, using the other one as a house fan to remove stale air from the bathhroom and kitchen.

kostas · 12-17-12, 04:38 AM

Quote:

Originally Posted by TimSmall

Have a look at the fan curve on the last page of the PDF.

They are surely interesting, and moreover they could be easily controlled by the Arduino...
I can't see the noise figure, though.
Could you please pm me the ebay link?

Quote:

Two fans are good not only for flexibility, but can also (potentially) reduce energy usage. During the nice warm spring and autumn there will be a few weeks or months when you won't really need the heat exchanger since the outdoor air will be in a good temperature range. Then you can open your windows and turn off the intake fan, using the other one as a house fan to remove stale air from the bathhroom and kitchen.

Yes. In addition you can always use one of them as mentioned on post #245

TimSmall · 12-17-12, 06:36 AM

Quote:

Originally Posted by kostas

They are surely interesting, and moreover they could be easily controlled by the Arduino...
I can't see the noise figure, though.

I found another data sheet, which gives min and max values:

Full Speed:

69 dB(A)
89 watts
700 m³/hr (open flow)
5500 rpm

Min Speed:

29 dB(A)
2 watts
100 m³/hr (open flow)
800 rpm

So the 2 watts figure looks pretty good.

Careful, because I can't say for sure that the Sun variant will be able to go down to the minimum stated (they may have asked EBM Papst to change the firmware for them).

Try these searches (title and description):

DV6224/2tdp
371-0094
x4600 fan
papst 2tdp

Quote:

Originally Posted by kostas

Could you please pm me the ebay link?

I'm a new user so I can't send PMs! You should be able to track them down with the search strings above - PM me your email address if you don't.

kostas · 12-17-12, 04:54 PM

Quote:

Originally Posted by TimSmall

I'm a new user so I can't send PMs! You should be able to track them down with the search strings above - PM me your email address if you don't.

Ops! Same for me, too!

Ok, I'll try to search better in the Bay

kostas · 12-18-12, 02:33 AM

I found this one in a fairly good price:
PAPST RG160-28/18N/13TDTV
(http://www.ebmpapst.us/allpdfs/RG160DC.PDF)

The curve is not very clear but it goes at least at 225 qm/h, maybe could do the job..

AC_Hacker · 12-19-12, 02:10 PM

Here is another look at the problem...

This is a thru-wall HRV. It mounts on the wall and vents to the room, so no ducting is involved.

I thought it is very interesting how the assembly is layed out:

CLICK HERE for higher detailed illustration.

It's interesting how the air flow is incorporated into the design, also the use of an unusual fine wire heat exchanger.

Best,

-AC

kostas · 12-20-12, 03:43 PM

Interesting variant, Ac

In the meantime I finished the exchangers assembling.
I made one with coroplast sheets and another with aluminum, as I had already the material for both of them. Dimensions are 301x301x400mm each.
Here are some photos of the construction process:

Piwoslaw · 12-20-12, 11:26 PM

Quote:

Originally Posted by kostas

I made one with coroplast sheets and another with aluminum, as I had already the material for both of them. Dimensions are 301x301x400mm each.

I can't wait to see a side-by-side test of them! I'm very interested in the difference in efficiency of the two materials.

12-17-12, 12:29 AM	#263
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 961 Thanks: 188 Thanked 110 Times in 86 Posts	Two fans are good not only for flexibility, but can also (potentially) reduce energy usage. During the nice warm spring and autumn there will be a few weeks or months when you won't really need the heat exchanger since the outdoor air will be in a good temperature range. Then you can open your windows and turn off the intake fan, using the other one as a house fan to remove stale air from the bathhroom and kitchen. __________________ Ecorenovation - the bottomless piggy bank that tries to tame the energy hog.

12-19-12, 02:10 PM	#268
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Thru-Wall HRV... Here is another look at the problem... This is a thru-wall HRV. It mounts on the wall and vents to the room, so no ducting is involved. I thought it is very interesting how the assembly is layed out: CLICK HERE for higher detailed illustration. It's interesting how the air flow is incorporated into the design, also the use of an unusual fine wire heat exchanger. Best, -AC Attached Thumbnails __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

12-20-12, 03:43 PM	#269
kostas Helper EcoRenovator Join Date: Dec 2012 Location: Venice, Italy Posts: 89 Thanks: 15 Thanked 41 Times in 19 Posts	Interesting variant, Ac In the meantime I finished the exchangers assembling. I made one with coroplast sheets and another with aluminum, as I had already the material for both of them. Dimensions are 301x301x400mm each. Here are some photos of the construction process: Attached Thumbnails Last edited by kostas; 12-20-12 at 04:06 PM.. Reason: Adding text

12-18-12, 02:33 AM	#267
kostas Helper EcoRenovator Join Date: Dec 2012 Location: Venice, Italy Posts: 89 Thanks: 15 Thanked 41 Times in 19 Posts	I found this one in a fairly good price: PAPST RG160-28/18N/13TDTV (http://www.ebmpapst.us/allpdfs/RG160DC.PDF) The curve is not very clear but it goes at least at 225 qm/h, maybe could do the job..