[RE-wrenches] Any experience with off-grid oxygen concentrators?

[Dan Fink]

Esteemed Wrenches;

A heartfelt THANK YOU to everyone who responded to my inquiry!

My client has decided to go with a liquid oxygen (LOX) system. The medical
supply company will be installing and filling a cryogenic LOX tank at his
primary residence in town, from which he will fill 2 or 3 portable
cryogenic tanks to bring with him to the off-grid cabin. One portable tank
gives 20 hours at his rate of 2 liters per minute, so 2 tanks allows 4
nights without a trip to town! And the energy usage at the off-grid cabin
will be ZERO. Price is far less than a portable concentrator, and I wasn't
able to find a portable one where we could bypass the internal Li-Ion
battery and run directly from 12VDC lighter plug or 120VAC inverter.....all
the ones their local medical supplier had available used those inputs only
for charging the Li-ion battery. Townies! Sheesh.

The client was concerned about the safety of LOX because of the pilot
lights for their propane range, fridge, on demand DHW heater and furnace.
But my research (local paramedic / nurse friend, and NFPA 99) indicated
that ALL oxygen systems can be dangerous, but are very safe if proper
precautions are followed. LOX is no worse than any other.

Thanks again Wrenches! We have a happy doctor, happy insurance company
(they are paying for everything), happy Wrench here, and most importantly
happy Client.

Dan Fink,
Executive Director;
Otherpower
Buckville Energy Consulting
Buckville Publications LLC
NABCEP / IREC accredited Continuing Education Providers
970.672.4342 (voicemail)

>
> On 4/21/2012 12:12 PM, Dan Fink wrote:
>
>> Esteemed Wrenches;
>>
>> One of our clients, 79 years old, has an off-grid cabin at 8200 ft
>>  altitude that he built and has been using on weekends since 1982. Due to a
>> heart condition, his doctor is now advising supplementary oxygen at 2
>> liters per minute only at night when he is trying to sleep. Not a life
>> threatening condition, but very uncomfortable (and no sleep) during a bad
>> night.
>>
>> Does anyone here have any experience with clients who need to run oxygen
>> concentrators off the grid?
>>
>> The power system is 12 volt, 4 x L16 batteries, Trace DR series inverter.
>> Not a lot of backup there. We can add more PV easily and cheaply, but would
>> prefer not to completely replace the battery bank. This is mostly a weekend
>> cabin, it doesn't NEED a big battery bank.
>>
>> Of course the doctor, nurses, oxygen supply companies, insurance company
>> etc. don't even know what the words "off the grid" mean. My research so far
>> has shown that "Energy Star" ratings don't exist for O2 concentrators....
>> they assume that everyone has cheap, unlimited energy. I am seeing 280-550
>> watts load from non-portable units specs online. The portable O2
>> concentrators cost twice as much, and seem to work only off of their own
>> proprietary super expensive Li-ion battery packs, but only draw 75-150
>> watts...just barely in the range of the existing power system. Nobody in
>> the O2 business  seems to know if any of these can be powered directly from
>> the off-grid system (at either 120vac or 12vdc, he has circuits in each
>> room for both), as "off grid" is not in their lexicon. I just hate the idea
>> of using 2 battery banks -- the L16s to charge the Li-Ion? geez.
>>
>> Just to add to the imbroglio, the health insurance company refuses to pay
>> for a (twice the price) "portable" O2 concentrator for a patient that only
>> needs it at night, sleeping. They do not seem to understand the words "off
>> grid", "watt hours" , "solar" and also seem to have no concept of either
>> "Energy Star" or "Efficiency". Having been off grid since 1991 myself, my
>> only response can be "Dumb townies!" but that doesn't help much. They don't
>> even know that "townie" is a perjorative up here....they probably think
>> it's a compliment!
>>
>> Any help appreciated, thanks in advance, and I hope some other Wrench on
>> this list has dealt with this situation before so that maybe I can learn
>> from you.
>>
> --
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20120424/325b7c3f/attachment-0004.html>