home made blower door? - Page 2

MN Renovator · 05-15-12, 11:50 PM

Toss one of these in the doorway. 7200 CFM, you might want to skip the frame or open a few windows before the roof decides to fly off.

24" High Velocity Floor Fan

One of these would be more reasonable though for the average house, but overkill for anything even a little bit tight or not fairly large. Might still need to open a window. Since it's an axial fan it might be be able to generate that much pressure though. If it were actually a blower(sirocco/squirrel cage type) like a furnace blower, it would.
8" Portable Ventilator

If it were just for vermiculite remediation, couldn't you just load every window with a box fan? I got 5 box fans off a guy on craigslist for $40 in order to do some pretty serious cross ventilation, works like a charm. Decided to point them all outside with the windows shut and I was getting a similar amount of air drawing down through the furnace draft opening that I did when the house was at 50 pascals but I'm certain I wasn't there as axial fans don't perform that well under pressure since the air essentially leaks back through the corners and between the blades due to the nature of their design.

S-F · 05-16-12, 06:52 PM

Yes you can certainly put box fans in the windows but as you mention they aren't very air tight.

Also, people who are doing this at home should keep in mind that depressurizing a house with any asbestos is a no no and this includes vermiculite. You can pressurize it though. We did that today in a huge house with a small amount (about 4' visible) of asbestos pipe insulation. Last fall I was actually involved in a law suit against an energy auditing company that didn't notice some asbestos so they didn't mark off on the work order that a blower door was contraindicated. After we fired it up we walked around the house to look for leaks and saw asbestos insulation literally being sucked off pipes in the finished basement. The company had to pay for asbestos abatement and to replace all of the basement furnishing and carpet and so forth. I'm assuming the home owner also got a large cash settlement. I only got a blast of asbestos laden air in my face for about five minutes because I was in front of the fan taking siding off the house.

ValerieNelson1 · 03-18-16, 06:04 AM

Home made using tests such as industry resistance, misunderstanding on what plans and show criteria to usage, and incompatible programmers of those complicated,

stevehull · 03-18-16, 07:29 AM

It is really quite easy to create a pressure manometer. This can be some clear plastic tubing, some water, a bit of isopropyl alcohol (10%, reduces water surface tension) and a drop of food coloring.

A U tube, with vertical elements, can't measure air pressure difference with enough resolution. This is why many water manometers have one part of the "U" going up at a 45 degree angle. Remember that the pressure difference is 1/2 the water height between the two ends. The unit even has a specific designation: "inches of water" pressure.

Or just remember that there are 250 Pascals of pressure per inch of water.

Years ago (actually decades), I built a quick water manometer that was accurate to about 5 Pascals. I actually stapled the clear plastic tubing to a wall and one part of the U tube slowly went up the wall at a very gradual slope. Had to make measurements in a structure to serially document how build practices can be done to reduce infiltration.

Started with a conventionally built structure, but without drywall. Then sealed sill plate (silicone), then sealed window edges with silicone, then sealed outlets - on and on.

Took a picture of this after each intervention to show contractor (DoD) how small changes can make a big difference.

Just place one end of the air filled U tube in the house (pressurized or evacuated) and the other outside.

You can buy electronic manometers (really just pressure transducers), but a simple water filled manometer is cheap, easy to read and incredibly intuitive.

One advantage of a furnace blower is that they don't load down at the low speeds. You can easily measure the CFM measurement with a hand held device such as this:

Pyle Digital Anemometer Thermometer for Air Velocity Air Flow New | eBay

Steve

AC_Hacker · 03-18-16, 09:33 AM

This topic has already been discussed on EcoRenovator..

Link to a Build It Solar project, where Gary actually built a homemade blower door, rather than talk about it.

He also included pictures to prove his legandary moxie.

LINK_IS_HERE

Gary's site is really excellent. It is teeming with projects illustrated and described so that a reader can actually duplicate the results.

I'm afraid EcoRenovator is becoming a talking shop.

Best,

-AC

jeff5may · 03-18-16, 09:20 PM

You know you guys are replying to a spammer, right? This thread is long dead. Hmmmm...the end?

sunspot · 03-19-16, 08:23 AM

Quote:

Originally Posted by AC_Hacker

Gary's site is really excellent. It is teeming with projects illustrated and described so that a reader can actually duplicate the results.

Agreed. I was in the habit of checking his site daily. Sadly it hasn't been updated now since November 2015.

03-18-16, 07:29 AM	#14
stevehull Steve Hull Join Date: Dec 2012 Location: hilly, tree covered Arcadia, OK USA Posts: 826 Thanks: 241 Thanked 165 Times in 123 Posts	It is really quite easy to create a pressure manometer. This can be some clear plastic tubing, some water, a bit of isopropyl alcohol (10%, reduces water surface tension) and a drop of food coloring. A U tube, with vertical elements, can't measure air pressure difference with enough resolution. This is why many water manometers have one part of the "U" going up at a 45 degree angle. Remember that the pressure difference is 1/2 the water height between the two ends. The unit even has a specific designation: "inches of water" pressure. Or just remember that there are 250 Pascals of pressure per inch of water. Years ago (actually decades), I built a quick water manometer that was accurate to about 5 Pascals. I actually stapled the clear plastic tubing to a wall and one part of the U tube slowly went up the wall at a very gradual slope. Had to make measurements in a structure to serially document how build practices can be done to reduce infiltration. Started with a conventionally built structure, but without drywall. Then sealed sill plate (silicone), then sealed window edges with silicone, then sealed outlets - on and on. Took a picture of this after each intervention to show contractor (DoD) how small changes can make a big difference. Just place one end of the air filled U tube in the house (pressurized or evacuated) and the other outside. You can buy electronic manometers (really just pressure transducers), but a simple water filled manometer is cheap, easy to read and incredibly intuitive. One advantage of a furnace blower is that they don't load down at the low speeds. You can easily measure the CFM measurement with a hand held device such as this: Pyle Digital Anemometer Thermometer for Air Velocity Air Flow New \| eBay Steve __________________ consulting on geothermal heating/cooling & rational energy use since 1990

03-18-16, 09:33 AM	#15
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	This topic has already been discussed on EcoRenovator.. Link to a Build It Solar project, where Gary actually built a homemade blower door, rather than talk about it. He also included pictures to prove his legandary moxie. LINK_IS_HERE Gary's site is really excellent. It is teeming with projects illustrated and described so that a reader can actually duplicate the results. I'm afraid EcoRenovator is becoming a talking shop. Best, -AC __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

05-15-12, 11:50 PM	#11
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	Toss one of these in the doorway. 7200 CFM, you might want to skip the frame or open a few windows before the roof decides to fly off. 24" High Velocity Floor Fan One of these would be more reasonable though for the average house, but overkill for anything even a little bit tight or not fairly large. Might still need to open a window. Since it's an axial fan it might be be able to generate that much pressure though. If it were actually a blower(sirocco/squirrel cage type) like a furnace blower, it would. 8" Portable Ventilator If it were just for vermiculite remediation, couldn't you just load every window with a box fan? I got 5 box fans off a guy on craigslist for $40 in order to do some pretty serious cross ventilation, works like a charm. Decided to point them all outside with the windows shut and I was getting a similar amount of air drawing down through the furnace draft opening that I did when the house was at 50 pascals but I'm certain I wasn't there as axial fans don't perform that well under pressure since the air essentially leaks back through the corners and between the blades due to the nature of their design.

03-18-16, 06:04 AM	#13
ValerieNelson1 Banned Join Date: Mar 2016 Location: usa Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	Home made using tests such as industry resistance, misunderstanding on what plans and show criteria to usage, and incompatible programmers of those complicated,

03-18-16, 09:20 PM	#16
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	You know you guys are replying to a spammer, right? This thread is long dead. Hmmmm...the end?