EcoRenovator  

Go Back   EcoRenovator > Improvements > Other Improvements
Advanced Search
 


Blog Register 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
Thread Tools Display Modes
Old 02-10-16, 09:04 PM   #11
MEMPHIS91
Journeyman EcoRenovator
 
MEMPHIS91's Avatar
 
Join Date: Apr 2015
Location: Oxford, MS USA
Posts: 494
Thanks: 69
Thanked 76 Times in 56 Posts
Default

Quote:
Originally Posted by SDMCF View Post
@MEMPHIS91: Why not try it?
WILL DO!!

So the big orange big box store had some 8" duct on sell today, SO that is what I got!!

I used some left over duct from another project as well, total cost today was $20. Total cost if bought all today maybe $60ish?

6" right angle and 6" fan.


I stuff foam all around the fan, I wanted ZERO vibrations.


I also put foam on the brick hearth, I wanted ZERO vibrations.


And this is the install, I will paint in hammered bronze, and extend in another foot or so. This was just for testing.


The temp at the same height the air blows out at.


The temp of the air coming out!! And this is with 2 fans still going on low. Of course numbers don't matter as much. The success/fail will matter in added comfort.


And a thermal just for fun.


So some good things I have learned, This works best for me because of the high ceilings, the wood heater, and the fact that I put it against the chimney to pull any added heat from it.

Right now the fan is kinda loud, so I will be looking for a quieter 200ish cfm fan.

I post more data the longer it runs.

Attached Thumbnails
Click image for larger version

Name:	KIMG0553.jpg
Views:	397
Size:	286.3 KB
ID:	6641   Click image for larger version

Name:	KIMG0554.jpg
Views:	392
Size:	270.4 KB
ID:	6642   Click image for larger version

Name:	KIMG0555.jpg
Views:	391
Size:	269.6 KB
ID:	6643   Click image for larger version

Name:	KIMG0556.jpg
Views:	393
Size:	307.9 KB
ID:	6644   Click image for larger version

Name:	KIMG0557.jpg
Views:	376
Size:	262.5 KB
ID:	6645  

Click image for larger version

Name:	KIMG0558.jpg
Views:	384
Size:	268.5 KB
ID:	6646   Click image for larger version

Name:	img_thermal_1455155026189.jpg
Views:	389
Size:	259.5 KB
ID:	6647  
__________________
שְׁמַע יִשְׂרָאֵל ה' אֱלֹהֵינוּ ה' אֶחָד
MEMPHIS91 is offline   Reply With Quote
The Following User Says Thank You to MEMPHIS91 For This Useful Post:
Daox (02-11-16)
Old 02-10-16, 09:16 PM   #12
MEMPHIS91
Journeyman EcoRenovator
 
MEMPHIS91's Avatar
 
Join Date: Apr 2015
Location: Oxford, MS USA
Posts: 494
Thanks: 69
Thanked 76 Times in 56 Posts
Default

Maybe a couple of these?
http://www.amazon.com/Cooler-Master-...KZ823HQ5XG5HQE
__________________
שְׁמַע יִשְׂרָאֵל ה' אֱלֹהֵינוּ ה' אֶחָד
MEMPHIS91 is offline   Reply With Quote
Old 02-11-16, 01:05 AM   #13
SDMCF
Apprentice EcoRenovator
 
Join Date: Jul 2014
Location: Finland
Posts: 109
Thanks: 5
Thanked 27 Times in 26 Posts
Default

MEMPHIS91, That looks really good, and a whole lot better than the temporary lash-up I used for my test. I look forward to your longer term impressions.

Would a thermal shot from further away, covering the length of the tube, show anything interesting? I wish I had a thermal camera. I'm jealous!

I think I will try a new test, logging temperatures for a longer period, perhaps a week. I don't think the top fan does anything so I might put that in a second tube for the new test (if I can find a tube).
SDMCF is offline   Reply With Quote
The Following User Says Thank You to SDMCF For This Useful Post:
Robaroni (03-02-16)
Old 03-02-16, 11:01 AM   #14
Robaroni
Journeyman EcoRenovator
 
Robaroni's Avatar
 
Join Date: Jun 2013
Location: Delhi, NY
Posts: 309
Thanks: 18
Thanked 43 Times in 35 Posts
Default

Thanks! Interesting stuff we all probably wonder about, I know I have.

I think you have to figure (if you did and I missed it - sorry) the CFM of the fan and the area of the room.
It also seems to me that two small fans running wouldn't give you that much more movement than just one. I guess you'd have to measure the rpms of the one and two fan arrangement?

I have radiant heat in the floor and 14 ft (4.3M) ceilings. I use the ceiling fan in the summer, in the winter the moving air seems to be more cooling than warming. I wonder if our opinions might change if the fan only ran when we were out of the room?

Fun stuff!

Rob
Robaroni is offline   Reply With Quote
Old 03-09-16, 04:08 PM   #15
SDMCF
Apprentice EcoRenovator
 
Join Date: Jul 2014
Location: Finland
Posts: 109
Thanks: 5
Thanked 27 Times in 26 Posts
Default

You are correct that the CFM of the fans is important information but unfortunately I see no easy way to determine that. Any ideas?

My test room had an area of about 25 sq m (270 sq ft).

You are also correct that 2 fans (in series) seems to be no better than just one. I suspect that may depend on the fan design though. The fans I used seem to be better at pulling air than pushing it; maybe if one of the fans was good at pushing air I might get better results - if such fans exist.

I'm not sure what I would gain by knowing the RPMs of the fans, but I could measure that. The fans I am using are PC case fans and they have a tachometer output feed so it would not be rocket science to log RPM when I log temperature. (RPM Should be constant I guess but that is as yet unconfirmed). If I got that RPM data, how might I make use of it?

With your higher ceilings I would expect the potential payback to be greater. I do understand that running the fans might subjectively feel as if it has a cooling effect even though objectively this cannot be the case. Running the fan whilst the room is not occupied would surely better than not running it at all.
SDMCF is offline   Reply With Quote
Old 03-09-16, 05:38 PM   #16
Robaroni
Journeyman EcoRenovator
 
Robaroni's Avatar
 
Join Date: Jun 2013
Location: Delhi, NY
Posts: 309
Thanks: 18
Thanked 43 Times in 35 Posts
Default

Hi,
My thinking is if one fan's rpms pick up appreciably when the other fan comes on that you might get more benefit with two fans as the single fan is loading trying to pull air through the tube.

Usually fans have CFM ratings on them. If you can find a number and do a search you might find a data sheet to give you the info you need. Then knowing the room area you could get a ratio of air moved to time and then calculate how long it takes for enough temp differential to take place to make it worth turning on the fan.

After a specific point it becomes a null. The air at the ceiling isn't warming fast enough for the air moved so you're just spinning your wheels (and fan) which consumes extra power so I would think balancing the system as best as possible is something to work toward.

Rob
Robaroni is offline   Reply With Quote
Old 03-09-16, 06:06 PM   #17
jeff5may
Supreme EcoRenovator
 
Join Date: Jan 2010
Location: elizabethtown, ky, USA
Posts: 2,273
Thanks: 338
Thanked 574 Times in 480 Posts
Send a message via Yahoo to jeff5may
Default

I have found in past experiments that sucking the unwanted air from where it doesn't belong yields better overall comfort. In a setup like Jake is testing, this means drawing cold air in at the bottom (through a large pipe if possible) and exhausting it at higher velocity up high. With a tall, open space like he has, major stratification happens pretty much no matter what you do. The laminar flow towards the suction line causes the air circulator to siphon the coldest air from the room naturally. When it is blown at high speed up top, lots of mixing occurs before the cooler air has a chance to drop. When it does drop, the "not so hot" air stratifies, it pushes the coldest air down to siphon its way into the circulator. This effect was addressed in another thread, titled something like "Cool your whole house with your basement".

In the summer, this method works well, too. In Jake's case, this is less of a problem, since his vaulted ceiling naturally collects the warmest air. Two houses ago, I wasn't so lucky. The finished attic "master suite" was horribly sealed and insulated, and was a sauna on sunny summer afternoons. A 1 ton window air conditioner wouldn't keep it cool. The first summer in that place was awful. By July, we had the 1-ton window unit in one end wall and a 3/4 ton unit in the opposite end wall. Combined with a 3 ton central air unit, all three would be running the electric bill up in a hurry.

What I ended up doing in that house will sound crazy, but it did the trick, keeping the 1 ton unit from running most of the time. I installed a squirrel cage fan in the lone floor register, which fed off the central unit through an 8 inch circular duct. I sent the hot air downstairs, running it backwards through the duct. I used a rubbermaid container as a hood for the assembly, installing some 6 inch flex hoses that extended up towards the ridge. I ended up running the blower on low speed, so that when the central unit kicked on, it would blow some cold air past my hack. When it shut off, the cold air went right back downstairs, followed by the warm air from the ridge.

On those same hot days, after my rig was installed, you could literally walk up the stairway and feel the cool air pour out and stratify into the room. The top of the cool layer was right about where the 3/4 ton unit blew its cool air into the other end of the room, about chest level. Quite a learning experience for Mama and the kids. That floor vent octopus might not have looked right, but there was no arguing it worked from anyone.
jeff5may is offline   Reply With Quote
The Following User Says Thank You to jeff5may For This Useful Post:
Robaroni (03-10-16)
Old 03-09-16, 06:54 PM   #18
jeff5may
Supreme EcoRenovator
 
Join Date: Jan 2010
Location: elizabethtown, ky, USA
Posts: 2,273
Thanks: 338
Thanked 574 Times in 480 Posts
Send a message via Yahoo to jeff5may
Default

Quote:
Originally Posted by Robaroni View Post
Hi,
My thinking is if one fan's rpms pick up appreciably when the other fan comes on that you might get more benefit with two fans as the single fan is loading trying to pull air through the tube.

Usually fans have CFM ratings on them. If you can find a number and do a search you might find a data sheet to give you the info you need. Then knowing the room area you could get a ratio of air moved to time and then calculate how long it takes for enough temp differential to take place to make it worth turning on the fan.

After a specific point it becomes a null. The air at the ceiling isn't warming fast enough for the air moved so you're just spinning your wheels (and fan) which consumes extra power so I would think balancing the system as best as possible is something to work toward.

Rob
This is very true. Being basically very large air pumps, all but the cheapest will have charts and graphs like a well or sump pump. Absolute maximum ratings, graphs plotted against static pressure, current draw, and the like. Most computer fans also have these ratings published (even many cheap chinese models).

The whole counterflow current-inducing process is another one of those processes the HVAC industry knows well, but holds close to the shirt. When asked, quickly point out that this a game of diminishing returns that quickly becomes uneconomical, due to the "low grade" heat source. Same story that used to be told about PV solar, low temperature hydronic heating, variable speed compressors, etc.

I don't agree.

jeff5may is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:58 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design