Most helpful critical review
283 of 342 people found the following review helpful
Bad CMA Design
on February 23, 2012
There is no doubt that short and long term Carbon Monoxide exposure can cause brain damage and/or death.
A Carbon Monoxide Alarm (CWA)detector is even required in all homes in my state of Pennsylvania and many other as well; yet I know of no one who has one in their home here. So, after getting a new HVAC system I thought the time had come to be the first one on at least my block to break down and get a CMA.
A small number of other Amazon Customers have reported (one star) that their Kidde CMA demonstrated random readings,
Unfortunately, mine did as well.
Readings of 22-29 ppm were always the readings in my house for two days.
I then took it outside for a day and it produced the same readings!
This is not acceptable to me since 22-29 ppm are either definitely problematic or at least close to it, as follows:
[OSHA PEL] The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for carbon monoxide is 50 parts per million (ppm) parts of air (55 milligrams per cubic meter (mg/m(3))) as an 8-hour time-weighted average (TWA) concentration [29 CFR Table Z-1].
[NIOSH REL] The National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit (REL) for carbon monoxide of 35 ppm (40 mg/m(3)) as an 8-hour TWA and 200 ppm (229 mg/m(3)) as a ceiling [NIOSH 1992]. The NIOSH limit is based on the risk of cardiovascular effects.
[ACGIH TLV] The American Conference of Governmental Industrial Hygienists (ACGIH) has assigned carbon monoxide a threshold limit value (TLV) of 25 ppm (29 mg/m(3)) as a TWA for a normal 8-hour workday and a 40-hour workweek [ACGIH 1994, p. 15]. The ACGIH limit is based on the risk of elevated carboxyhemoglobin levels [ACGIH 1].
Therefore, an actual/theoretical (relatively) small leak of 22-29 ppm could be harmful be over time.
But, if readings of 22-29 are this units "zero point" then how would I know?
Why have this unit!? Not good.
So, I sent this "Kidde" back (for free) and exchanged it (Love Amazon!) for a "ProTech 7035 Lithium Battery Powered Carbon Monoxide Detector with Digital Display and Memory". This unit has a safer/lower sensitivity level of 10ppm (Not apparently 30ppm or more.) which, now that I have looked into it, is as low as I can find for under ~$700 or so!
Yes, the ProTech costs twice as much as the original Kidde; but only that...The reason is that it works on a different, more efficient and accurate principle (and is, of course, more expensive) than the Kidde.
At least for me and my family, I look forward to receiving it.