Go Back   EcoModder Forum > AltModding > Saving@Home
Register Now
 Register Now
 


Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 07-20-2019, 12:16 AM   #21 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 7,573

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: 124.63 mpg (US)
Thanks: 178
Thanked 2,376 Times in 1,844 Posts
It all depends on what kind of motor the fan uses.

__________________
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
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-20-2019, 12:19 AM   #22 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 6,283

Acura TSX - '06 Acura TSX
90 day: 28.39 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: 28.88 mpg (US)
Thanks: 2,093
Thanked 2,304 Times in 1,695 Posts
PWM is more efficient than a rheostat, no?

... and that reminds me of this video:

__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
Old 07-20-2019, 02:32 AM   #23 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 13,495
Thanks: 3,283
Thanked 4,488 Times in 3,574 Posts
Similar to this:


https://thumbs1.ebaystatic.com/d/l22...hlr95oICJw.jpg
Quote:
PWM is more efficient than a rheostat, no?
What reading I did suggested varying the frequency instead of chopping into pulses. It made me wonder if you could use a diode to make a half-sine wave and then switch it in and out for a two-speed control.
__________________
.
Haiku are easy
But sometimes they don't make sense
Refrigerator

_________________
  Reply With Quote
Old 07-20-2019, 03:27 AM   #24 (permalink)
EV convert
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 7,573

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: 124.63 mpg (US)
Thanks: 178
Thanked 2,376 Times in 1,844 Posts
You can try half wave.
The only way to reduce speed on an induction motor with out burning it up is change the number of windings or changing the frequency.
Or design the motor to run horribly inefficient and not burn up with partial voltage.
__________________
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
The Following User Says Thank You to oil pan 4 For This Useful Post:
freebeard (07-20-2019)
Old 08-30-2019, 05:43 PM   #25 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 10,233
Thanks: 15,487
Thanked 5,443 Times in 3,219 Posts
air balance

Quote:
Originally Posted by redpoint5 View Post
I've got a 2-level house that has a single air handler in the basement level, as well as an air return on each level. The temperature in the basement level is 70 degrees while upstairs it's 80. Would it be a bad idea to block the upstairs return, forcing hot air down the stairwell into the basement return to get the air to mix? I'd also want to close the downstairs registers.
The protocol is to leave the returns alone,and add adjustable and lockable dampers behind the diffusers on the supply side.Intake ducts can collapse with a restriction,not so for the pressure side.
Systems which are engineered will spec out the design flow volume which can be directly measured with traversing of the actual duct with a pitot-tube and manometer/magnehelic,or at the face of the diffusers with an average of velometer readings,based upon the manufacturers criteria.
You're just trying to choke down an overflow condition until the entire space is at a uniform temp.By having the dampers behind the diffusers,you won't be accelerating the flow beyond 1,200 feet/minute,where things begin to get noisy.
Once its adjusted you shouldn't ever have to touch it again.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
The Following 2 Users Say Thank You to aerohead For This Useful Post:
redpoint5 (08-30-2019), slowmover (09-02-2019)
Old 08-30-2019, 05:58 PM   #26 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 6,283

Acura TSX - '06 Acura TSX
90 day: 28.39 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: 28.88 mpg (US)
Thanks: 2,093
Thanked 2,304 Times in 1,695 Posts
I've been running the fan in the evenings, but I'm still not sure that's efficient with just a 3 degree difference. I've read that an air handler can pull 500w, which is not insignificant. At that point it might be more efficient periodically running the AC, which also mixes upstairs and downstairs air, than continuously running the fan.

I've got the upstairs vents open and the downstairs vents closed at the moment. The idea is that when AC is called, it starts upstairs where it's warm and absorbs heat before going downstairs. When only the blower is on, the air will exhaust upstairs, and force heated air downstairs as it moves towards the return. There's also an upstairs return, but the extra positive pressure upstairs should force more of it through the downstairs return (I think).

In the winter my plan is to open bottom registers and close the top ones. It will be a struggle to even the heating out I'm guessing.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
The Following User Says Thank You to redpoint5 For This Useful Post:
aerohead (08-31-2019)
Old 08-31-2019, 01:39 PM   #27 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 10,233
Thanks: 15,487
Thanked 5,443 Times in 3,219 Posts
down stairs

Quote:
Originally Posted by redpoint5 View Post
I've been running the fan in the evenings, but I'm still not sure that's efficient with just a 3 degree difference. I've read that an air handler can pull 500w, which is not insignificant. At that point it might be more efficient periodically running the AC, which also mixes upstairs and downstairs air, than continuously running the fan.

I've got the upstairs vents open and the downstairs vents closed at the moment. The idea is that when AC is called, it starts upstairs where it's warm and absorbs heat before going downstairs. When only the blower is on, the air will exhaust upstairs, and force heated air downstairs as it moves towards the return. There's also an upstairs return, but the extra positive pressure upstairs should force more of it through the downstairs return (I think).

In the winter my plan is to open bottom registers and close the top ones. It will be a struggle to even the heating out I'm guessing.
Seems that since the unit is in the basement,that there would be less restriction in the return air there,just like you're thinking.
Question? When the thermostat is satisfied and the unit shuts off,does the air stratify upstairs?
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
Old 08-31-2019, 02:16 PM   #28 (permalink)
EcoModding Newb
 
redpoint5's Avatar
 
Join Date: Aug 2010
Location: Oregon
Posts: 6,283

Acura TSX - '06 Acura TSX
90 day: 28.39 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: 28.88 mpg (US)
Thanks: 2,093
Thanked 2,304 Times in 1,695 Posts
Yes, I think the hot air rises upstairs, unimpeded by the open stairwell. That, and I'm not sure how well the insulation between the levels is, but a layer of drywall and layer of MDF probably isn't much. Finally, it's a daylight basement, so the portion in contact with the earth is having heat drawn away.

I bought a FLIR phone attachment on sale ($150) to play with finding areas lacking proper insulation. I'll have to spend some time with it to see what I find. I'll probably never recoup the cost, but I like playing with new gadgets, and I can use it at multiple houses to help others.
__________________
Gas and Electric Vehicle Cost of Ownership Calculator







Give me absolute safety, or give me death!
  Reply With Quote
The Following User Says Thank You to redpoint5 For This Useful Post:
aerohead (09-04-2019)
Old 09-02-2019, 12:21 PM   #29 (permalink)
Master EcoModder
 
slowmover's Avatar
 
Join Date: Oct 2009
Location: Fort Worth, Texas
Posts: 2,308

2004 CTD - '04 DODGE RAM 2500 SLT
Team Cummins
90 day: 19.36 mpg (US)
Thanks: 1,305
Thanked 665 Times in 506 Posts
Quote:
Originally Posted by aerohead View Post
The protocol is to leave the returns alone,and add adjustable and lockable dampers behind the diffusers on the supply side.Intake ducts can collapse with a restriction,not so for the pressure side.
Systems which are engineered will spec out the design flow volume which can be directly measured with traversing of the actual duct with a pitot-tube and manometer/magnehelic,or at the face of the diffusers with an average of velometer readings,based upon the manufacturers criteria.
You're just trying to choke down an overflow condition until the entire space is at a uniform temp.By having the dampers behind the diffusers,you won't be accelerating the flow beyond 1,200 feet/minute,where things begin to get noisy.
Once its adjusted you shouldn't ever have to touch it again.
Winner chicken dinner.

Most $$ disappear with duct leaks (30% is norm). After that is ducting improperly-sized. Then, “tight turns”.

In short - with an AC system — the money is in the ducting both as to integrity, but mainly as to design where flow is emphasized. Any radius reduction or turns are a problem (which will have been “solved” as cheaply as construction permits allow).

It’s perilous to mess with it as Aerohead notes. Flow to each room needs balance with each other. Have a look in the GRAINGER catalog as to the types of tools sold to pros (will aid in understanding).

Flow measurement is the thing.

On the oldest houses with designed-in HVAC the far more efficient ceiling-central location was used for a circular diffuser. I far prefer these and would retrofit for them. The supply air flow is EVERYTHING (versus SEER ratings, etc).

Ducting for returns isn’t as critical. The basic measurements suffice so long as supply and return have a basic match in each room.

Were it possible (floorplan) a single chimney from the basement upwards with its own time-controlled fan would be worth looking into versus screwing with the HVAC system.

The guys using in-ground cooling loops might have insights.

.
__________________
2004.0 DODGE Ram QC/LB 2500 2WD/NV-5600 305/555 ISB. 7,940-lb. Stock. 200,000 miles/5000-hrs @ 40-mph average.
1990 35' Silver Streak TT 7,900-lb.
11-cpm solo & 19-cpm towing; 21-mpg average past 54k-miles
Sold: 1983 Silver Streak 3411
  Reply With Quote
The Following User Says Thank You to slowmover For This Useful Post:
aerohead (09-04-2019)
Old 09-04-2019, 03:14 PM   #30 (permalink)
Master EcoModder
 
aerohead's Avatar
 
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 10,233
Thanks: 15,487
Thanked 5,443 Times in 3,219 Posts
circular

Quote:
Originally Posted by slowmover View Post
Winner chicken dinner.

Most $$ disappear with duct leaks (30% is norm). After that is ducting improperly-sized. Then, “tight turns”.

In short - with an AC system — the money is in the ducting both as to integrity, but mainly as to design where flow is emphasized. Any radius reduction or turns are a problem (which will have been “solved” as cheaply as construction permits allow).

It’s perilous to mess with it as Aerohead notes. Flow to each room needs balance with each other. Have a look in the GRAINGER catalog as to the types of tools sold to pros (will aid in understanding).

Flow measurement is the thing.

On the oldest houses with designed-in HVAC the far more efficient ceiling-central location was used for a circular diffuser. I far prefer these and would retrofit for them. The supply air flow is EVERYTHING (versus SEER ratings, etc).

Ducting for returns isn’t as critical. The basic measurements suffice so long as supply and return have a basic match in each room.

Were it possible (floorplan) a single chimney from the basement upwards with its own time-controlled fan would be worth looking into versus screwing with the HVAC system.

The guys using in-ground cooling loops might have insights.

.
As of the mid-1980s,the TITUS TMS was considered one of the most efficient diffusers on the market.They were primarily for commercial applications though.

__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
  Reply With Quote
The Following User Says Thank You to aerohead For This Useful Post:
slowmover (09-10-2019)
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com