Propane (R-290) for heat pumps? - Page 4

Xringer · 04-15-11, 12:00 PM

Around here, the leaks normally come from broken pipes in the street.
They have thousands of leaking gas pipes in the Boston area.

Many of the house explosions are caused by dumb work crews digging into a pipe.
Once it starts leaking, it follows along the outside of water pipes or underground conduits
and gets into the basements of homes, where it goes off like a bomb.

The last one we had in this area was caused by a new gas co. worker who reset
a low pressure line for high pressure and over-pressured a large area of Lexington MA.
It looked like a bomb went off in the house that blew up.

S-F · 04-15-11, 02:32 PM

Ha! I'm a landscaper in Lexington. I bet the residents and neighbors were none too happy about their 2.5 + million $ houses blowing up. Oddly I haven't seen any burned out / blown up houses. Is the utility company still in business? Who is it out there?

Xringer · 04-15-11, 05:04 PM

It's on page 7 (item 5) of this report.. www.mass.gov/Eoeea/docs/dpu/gas/6409ngex.pdf

2005, that was longer ago than I remembered.. I guess the damage wasn't
all that bad.. 375k in damage..

S-F · 04-15-11, 05:09 PM

375K?! That's only a garage in Lexington! Not including the cars in it. Then tack on another 300K.

Xringer · 04-15-11, 05:53 PM

It didn't look like minor damage..

Gas Explosion, Fire Level Lexington, Massachusetts Home | Firehouse.com

But, I didn't see the Before pic.. Maybe it was just a little dump.?.

Untitled | Flickr - Photo Sharing!

Xringer · 04-29-11, 09:09 AM

High Sensitivity LPG Gas Sensor 2pcs - MQ6 - eBay (item 350458645155 end time May-03-11 20:10:37 PDT)

www.sparkfun.com/datasheets/Sensors/Biometric/MQ-6.pdf

And,
Electronic brick - Gas sensor(MQ6) - Garden

Geo NR Gee · 04-29-11, 09:49 AM

Excellant Xringer! Hook that up to a alarm, exhaust vent fan, a flashing light and bingo. It seems every time I mention the idea of propane as a refrigerant to HVAC folks, every one has said the safety factor is an issue.

I hear that conditions have to be right for a explosion, so do you know or anyone else know what type of exhaust vent fan would work in a garage for the propane as a refrigerant? There has to be some kind of electronics that wouldn't cause a spark when turning on?

Xringer · 04-29-11, 10:34 AM

I have not looked too close at the gas sensor's analog output, but I'm pretty sure it could
be connected to an adjustable comparator circuit that can drive an SSR for AC or a power FET for DC..

The little comparator vector board in this picture is driving an SSR (upper right).

That SSR will control a 120vac 25amp load. (3000w) Which could be a very large exhaust fan..

If you wanted to use a few of these sensors, I think a small controller board
would be needed (with some analog ports). That would make it easier to
calibrate, since you could monitor the room temperature and compensate for it.
Use some of the digital output ports for controlling alarms and fans etc.

You could call the controller board, "The Alarmist"..

Geo NR Gee · 04-29-11, 05:29 PM

Xringer,
So what are all the acronyms that you are using?

Xringer · 04-29-11, 06:40 PM

LOL!! If you're gonna be a DIYer, you got to learn to Goggle acronyms..

SSR is a Solid State Relay (in Hacker-speak).
FET is a Field Effect Transistor (in Ham Radio jargon)..

Of course you already know what AC / DC is, or you wouldn't be here..

Or, maybe not..

http://www.boston.com/ae/theater_art...hell-front.jpg

04-29-11, 09:09 AM	#36
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Gas sensors.. Not too expensive.. High Sensitivity LPG Gas Sensor 2pcs - MQ6 - eBay (item 350458645155 end time May-03-11 20:10:37 PDT) www.sparkfun.com/datasheets/Sensors/Biometric/MQ-6.pdf And, Electronic brick - Gas sensor(MQ6) - Garden

04-15-11, 12:00 PM	#31
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Around here, the leaks normally come from broken pipes in the street. They have thousands of leaking gas pipes in the Boston area. Many of the house explosions are caused by dumb work crews digging into a pipe. Once it starts leaking, it follows along the outside of water pipes or underground conduits and gets into the basements of homes, where it goes off like a bomb. The last one we had in this area was caused by a new gas co. worker who reset a low pressure line for high pressure and over-pressured a large area of Lexington MA. It looked like a bomb went off in the house that blew up.

04-15-11, 02:32 PM	#32
S-F You Ain't Me Join Date: Nov 2009 Location: Northampton MA Posts: 662 Thanks: 6 Thanked 71 Times in 58 Posts	Ha! I'm a landscaper in Lexington. I bet the residents and neighbors were none too happy about their 2.5 + million $ houses blowing up. Oddly I haven't seen any burned out / blown up houses. Is the utility company still in business? Who is it out there?

04-15-11, 05:04 PM	#33
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	It's on page 7 (item 5) of this report.. www.mass.gov/Eoeea/docs/dpu/gas/6409ngex.pdf 2005, that was longer ago than I remembered.. I guess the damage wasn't all that bad.. 375k in damage..

04-15-11, 05:09 PM	#34
S-F You Ain't Me Join Date: Nov 2009 Location: Northampton MA Posts: 662 Thanks: 6 Thanked 71 Times in 58 Posts	375K?! That's only a garage in Lexington! Not including the cars in it. Then tack on another 300K.

04-15-11, 05:53 PM	#35
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	It didn't look like minor damage.. Gas Explosion, Fire Level Lexington, Massachusetts Home \| Firehouse.com But, I didn't see the Before pic.. Maybe it was just a little dump.?. Untitled \| Flickr - Photo Sharing!

04-29-11, 09:49 AM	#37
Geo NR Gee Journeyman EcoRenovator Join Date: Jan 2011 Location: Seattle Posts: 326 Thanks: 109 Thanked 23 Times in 18 Posts	Excellant Xringer! Hook that up to a alarm, exhaust vent fan, a flashing light and bingo. It seems every time I mention the idea of propane as a refrigerant to HVAC folks, every one has said the safety factor is an issue. I hear that conditions have to be right for a explosion, so do you know or anyone else know what type of exhaust vent fan would work in a garage for the propane as a refrigerant? There has to be some kind of electronics that wouldn't cause a spark when turning on?

04-29-11, 10:34 AM	#38
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I have not looked too close at the gas sensor's analog output, but I'm pretty sure it could be connected to an adjustable comparator circuit that can drive an SSR for AC or a power FET for DC.. The little comparator vector board in this picture is driving an SSR (upper right). That SSR will control a 120vac 25amp load. (3000w) Which could be a very large exhaust fan.. If you wanted to use a few of these sensors, I think a small controller board would be needed (with some analog ports). That would make it easier to calibrate, since you could monitor the room temperature and compensate for it. Use some of the digital output ports for controlling alarms and fans etc. You could call the controller board, "The Alarmist"..

04-29-11, 05:29 PM	#39
Geo NR Gee Journeyman EcoRenovator Join Date: Jan 2011 Location: Seattle Posts: 326 Thanks: 109 Thanked 23 Times in 18 Posts	Xringer, So what are all the acronyms that you are using?

04-29-11, 06:40 PM	#40
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	LOL!! If you're gonna be a DIYer, you got to learn to Goggle acronyms.. SSR is a Solid State Relay (in Hacker-speak). FET is a Field Effect Transistor (in Ham Radio jargon).. Of course you already know what AC / DC is, or you wouldn't be here.. Or, maybe not.. http://www.boston.com/ae/theater_art...hell-front.jpg