ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
UL 508A SPACING
by ale348 - 03/29/24 01:09 AM
Increasing demand factors in residential
by tortuga - 03/28/24 05:57 PM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (Scott35), 372 guests, and 18 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 2 of 2 1 2
Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
I got pretty heavily involved in energy saving in the last oil crisis (Carter days). The trick with fresh air makeup is a heat exchanger that scavenges the heat from the air going one way and transfers it to the air going the other way. Granted you only save half the energy as a theoretical max but that is better than zero.
In reality the efficiency of most heat exchangers you might have in a dwelling wasn't worth the expense and hassle but I have seen it done in big commercial fairly successfully.
The National Geographic building in Germantown Md heat exchanged everything and used water as a transfer and storage medium. They ended up with so much excess heat from normal building loads they could keep the building warm and still had enough left over to keep the lake out front from freezing.


Greg Fretwell
Stay up to Code with the Latest NEC:


>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides
 

Joined: Jan 2010
Posts: 10
M
Member
Gas logs dont really know they made vented and unvented systems .my house has a co detector in the living room where the gas logs are good idea.How long will it be before they put that in the NEC for houses

Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
"in the living room"

You've hit on one of my primary objections to mandating CO detectors: placement.

There's no settled doctrine as to the placement of CO detectors. The NFPA standard, after a lot of doubletalk, refers you back to the manufacturers' instructions. The instructions ... well, summarised simply, do not find a problem with any placement you might suggest.

Part of the problem lies in the nature of CO. It's not much different, in density or temperature, from the surrounding air. There is no compelling reasom to place it in any particular location.

The other problem lies in the way CO affects our bodies - and, by extension, the way detectors are designed to operate. The less CO that is present, the longer they take to to go into alarm. This is quite different from a smoke detector, which won't ever go into alarm until a specific level is reached. It's also why having a CO detector with a readable display is a good idea, and why there is such an advantage to the corded units. Just like with the "Valentine One" radar detector ads say: there's no way for a battery unit to perform as well as a corded unit.

Getting back to 'the problem.' The sensing elements can be fooled. Instructions often illustrate placing one in the mechanicals closet, for example. The problem here is that the initial plume of CO or even hot air from an appliance igniting can create a false alarm. Likewise, gas fumes can set it off. So, that initial puff of gas before the igniter strikes, and the momentary flare of a poorly burning flame, can set off the detector - even though no hazard is present.
IMO, you don't want these alarms anywhere near the appliances.

As others have pointed out, we percieve sleep time as the time where we are most at risk from this 'silent killer.' With that in mind, I DON'T want the detector outside the sleeping area. Simply closing the door can create a situation where the air in one room differs from the air in the next. I want that alarm near my sleeping head - but that's my opinion, and IMO a design matter.

As far as the requirement ever being added to the NEC goes, I doubt that will ever happen. As with smoke alarms, you'll find these requirements in the 'other' codes. Copies of the IBC, IRC, IMC, etc., can be found at BulkResource.Org . You need to know more than just 'your' code.

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
I was almost killed in a friend's house a few times because of a bad furnace. I used to sleep over there and I noticed I woke up with a hangover (for a lack of a better term) and I noticed a bad taste in my mouth a few times. I was just a kid but I always suspected it was an air quality problem. I started sleeping near an open window when I was there even in the winter.
They had the furnace serviced some time later and the "gas man" condemned it because he had a cracked heat exchanger.

I have a hard time describing what CO poisoning feels like but I will never forget it. It is like you are breathing cotton or something. Your lungs are taking in air but it isn't working for you.
I am pretty happy that I am "all electric" here.


Greg Fretwell
Page 2 of 2 1 2

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5