Go Back   EcoModder Forum > EcoModding > General Efficiency Discussion
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 11-07-2020, 05:08 PM   #1 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 8,406

Acura TSX - '06 Acura TSX
90 day: 29.14 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.5 mpg (US)
Thanks: 2,836
Thanked 3,232 Times in 2,409 Posts
Fireplace Blower

I'm not sure how much a blower fan can increase the efficiency of a natural gas fireplace, but it seems like it would help extract at least some energy that would otherwise go out the exhaust.

My house has 2 identical 12,600-18,000 BTU gas fireplaces. One has a blower and the other does not, though there is electrical already installed.

The squirrel cage blower consumes 56 watts and is moderately noisy to run. I think these are typically rated to 130 CFM. My high school electronics teacher said squirrel cage blowers aren't very efficient.

As a proof of concept, I rounded up all the spare PC cooling fans I could find and set them into the intake of the fireplace. The 4 fans (3x 160mm, 1x 120mm) consumed 6 watts, was whisper quiet, and seemed to move about half the air.

I could purchase a purpose built squirrel cage blower with rheostat and temperature switch for $60, or I could purchase 6x 120mm fans for around the same price. I'm thinking if I mounted 6x 120mm fans, I could get equivalent air movement for 18 watts.

Amazon link


Attached Thumbnails
Click image for larger version

Name:	IMG_1172.jpg
Views:	90
Size:	61.4 KB
ID:	29516  
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 11-07-2020, 08:42 PM   #2 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 8,989

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Snow flake - '11 Nissan Leaf SL
SUV
90 day: 141.63 mpg (US)
Thanks: 215
Thanked 2,941 Times in 2,292 Posts
I use energy start quiet bathroom fans.
I don't know how many watts the 4 inch quiet fans draw but they move a lot of air.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
  Reply With Quote
Old 11-07-2020, 09:08 PM   #3 (permalink)
Master EcoModder
 
Join Date: Feb 2014
Location: Missoula, MT
Posts: 2,152

Dark Egg - '12 VW Touareg TDI Sport AWD
90 day: 25.81 mpg (US)
Thanks: 194
Thanked 905 Times in 622 Posts
Our old 1940's brick, wood burning, fireplace has a natural circulation setup where it pulls cold air off the floor, runs it through 4 thick walled 4" pipes behind and over the burn chamber, and then dumps them out about chest high in the room. It's neat to get it rocking and actually feel the air "blowing" out those pipes even though there is no fan, just natural heat rise.

So in your case, I wonder if you actually blew those fans into the back, beside, and over the insert, with the hottest air coming out the top would take better advantage of natural heat rising.

Edit- I see that's exactly what you are doing already!
__________________

  Reply With Quote
Old 11-08-2020, 01:13 AM   #4 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 17,567
Thanks: 4,741
Thanked 5,847 Times in 4,664 Posts
Quote:
As a proof of concept, I rounded up all the spare PC cooling fans I could find... and seemed to move about half the air.
So you're halfway there. Fabricate a log manifold (no pun!) to manage the airflow. Maybe get some matching fans?

When I worked at Nextstep electronics recycling, I started out in the warehouse, dismantling. I tore apart an Olivetti PC from the 1970s that was way overbuilt (the thing had three motherboards!). It had a [six inch in metric] cooling fan with a cast aluminum body. It would replace any two of the ones you show. Prolly still around here somewhere, it turned into sort of a souvenir.
__________________
.

Andrej Karpathy: If you bombard Earth with photons long enough eventually it will emit a Tesla.

_________________
  Reply With Quote
Old 11-09-2020, 11:48 AM   #5 (permalink)
Somewhat crazed
 
Piotrsko's Avatar
 
Join Date: Sep 2013
Location: 1826 miles WSW of Normal
Posts: 1,380
Thanks: 131
Thanked 382 Times in 321 Posts
Need maybe 4 more of the big ones to fill the gap. You're losing pressure out the front sides. Better heat transfer efficiency will occur if you slow flow through the system a bit.
  Reply With Quote
The Following User Says Thank You to Piotrsko For This Useful Post:
redpoint5 (11-09-2020)
Old 11-09-2020, 01:47 PM   #6 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 8,406

Acura TSX - '06 Acura TSX
90 day: 29.14 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.5 mpg (US)
Thanks: 2,836
Thanked 3,232 Times in 2,409 Posts
Quote:
Originally Posted by Piotrsko View Post
Need maybe 4 more of the big ones to fill the gap. You're losing pressure out the front sides. Better heat transfer efficiency will occur if you slow flow through the system a bit.
6 of the 120mm fans would just about fill the width, and would fully fill the height. I'd make some frame that blocks off any gaps.

I wonder why fans seem to be an afterthought to these fireplaces? It would be a simple matter to have a fully ducted and sealed system that draws air from the bottom and sends it around through the top. The fans themselves could be mounted to the grate in front so they are out of the way when accessing the gas controls, and would be easy to service if one went out. Plus those computer cooling fans are stinkin cheap.

At any rate, I've decided to buy a purpose built fan since it has a speed controller and thermostat switch built in.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 11-09-2020, 02:27 PM   #7 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 17,567
Thanks: 4,741
Thanked 5,847 Times in 4,664 Posts
Quote:
It would be a simple matter to have a fully ducted and sealed system that draws air from the bottom and sends it around through the top.
Exactly describes my friend's fireplace. I've helped them pull the sheet metal insert and re-grout the firebrick, twice.

Quote:
Originally Posted by Piotrsko
Better heat transfer efficiency will occur if you slow flow through the system a bit.
I suggested a manifold. It could be a cap across the full width with a single fan at each end. This would slow the airflow and stop reversion.
__________________
.

Andrej Karpathy: If you bombard Earth with photons long enough eventually it will emit a Tesla.

_________________
  Reply With Quote
Old 11-09-2020, 11:27 PM   #8 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 8,406

Acura TSX - '06 Acura TSX
90 day: 29.14 mpg (US)

Lafawnda - '01 Honda CBR600 F4i
90 day: 47.32 mpg (US)

Big Yeller - '98 Dodge Ram 2500 base
90 day: 21.82 mpg (US)

Prius Plug-in - '12 Toyota Prius Plug-in
90 day: 57.64 mpg (US)

Mazda CX-5 - '17 Mazda CX-5 Touring
90 day: 28.5 mpg (US)
Thanks: 2,836
Thanked 3,232 Times in 2,409 Posts
I knew the price was too good to be true at $60. The fan I received uses bushings despite being advertised as ball bearing, and arrived sans thermostat. I’m sending it back, which means I’m contemplating my own setup again. I need to find an outlet switch that can be closed via thermostat.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 11-10-2020, 08:04 PM   #9 (permalink)
Master EcoModder
 
Join Date: Feb 2014
Location: Missoula, MT
Posts: 2,152

Dark Egg - '12 VW Touareg TDI Sport AWD
90 day: 25.81 mpg (US)
Thanks: 194
Thanked 905 Times in 622 Posts
My grandpa gave me a home made electric smoker that has a thermostat that controls an outlet you plug the cheap hot plate into. Otherwise it's just an old BBQ. It holds temperature as well as the digital smoker I bought last year.
__________________

  Reply With Quote
Old 11-11-2020, 11:13 AM   #10 (permalink)
Somewhat crazed
 
Piotrsko's Avatar
 
Join Date: Sep 2013
Location: 1826 miles WSW of Normal
Posts: 1,380
Thanks: 131
Thanked 382 Times in 321 Posts
I use an old Airconditioning thermostat on the cool Side since that is the logic I need and the thermostat mercury switch is rated for 1/2 hp and never arcs the contacts shut. I have a newer one that has similar rated relays, plus the setback timer feature. Maybe $5 @ habitat for humanity

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com