Oxygen concentrator power requirements.
verdigo
Solar Expert Posts: 428 ✭✭
I just un-plugged my father's oxygen concentrator from the Kill-O-Watt. 4.42 kwh for a 12 hour period. The thing runs 24/7 so 8.82 for a 24 hour period. So far in searching the internet for specifications I have found that manufacturers don't advertise much in the way of power requirements. Hoping someone on the forum may have already researched this topic, and could provide some guidance.
Comments
What sort of guidance? One that doesn't use such a whopping amount of power? That would be nice. That really is a lot of power use daily; no wonder they don't want to talk about it.
Wow, that's a pretty heavy consumption, roughly 370 watts continuous. That's major for an off grid system. Over 8.8 Kwh/24 hours, that's enough to power perhaps 9 new full size Energy Star fridges! That sucks!
Since the units are basically air compressors you can see why it would be a big power user. Hard to compress any significant volume of air without using a lot of power, and then having to run it all the time ...
I wonder if any supplier of these would mind if you brought along the Kill-A-Watt and measured a few in operation? If they were smart they'd see it as a selling feature; "this one uses the least energy for the volume of oxygen produced".
Interesting info on how it works. Looks like considering what it does/how it operates, perhaps it's no wonder it sucks back on the power.
http://en.wikipedia.org/wiki/Oxygen_concentrator#How_oxygen_concentrators_work
There are some portable units out there. This thing is a dinosaur, and a rental at that. Maybe there has been some progress. I'll call up some medical supply stores and see if they have some info.
Yeah. It has a compressor that doesn't ever shut down.
Some discussion on a CPAP that may give you some ideas,
http://forum.solar-electric.com/showthread.php?14881-CPAP-Backup&highlight=cpap
http://forum.solar-electric.com/showthread.php?3276-Solar-Backup-for-CPAP-Machine&highlight=cpap
another about a feeding pump
http://forum.solar-electric.com/showthread.php?11455-Wanted-to-Share-an-Interesting-Project-Looking-for-Input-Advice-amp-Feedback/page3&highlight=oxygen
hope they help
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
CPAP's are tiny compared to O2 concentrators. No comparison at all, other than they both move air somewhat.
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
you haven't mentioned what you have in mind with this info. are you on grid and just want backup power for it in case of an outage and if so then for how long? if you are looking at off the grid then as was said this is a huge draw of power constantly running and could compromise an offgrid pv system from supplying enough power for that and other items if not accounted for in the initial design.
For now I have grid power. So yes this is back-up, and I do have a generator. My current plan is for 8 to 10 280 watt panels facing due south. My shed is still under construction. I will be using a generator transfer switch panel to power selected circuits. The bottom line on the oxygen concentrator is to find a more efficient one. There are portable battery powered units available that can be operated on AC. I don't have any specific power consumption numbers on those yet. I hope to find on line operator manuals to get an idea. The portable units are expensive. The grid is pretty reliable here in southern KY. A typical outage would be from thunder storms or in the winter an occasional ice storm. We lost the grid a couple of years ago for 18 days due to ice.
I wonder if a couple days of O2 in tanks would be a better backup, than generators & fuel? If you have bad storms, solar is not effective if skys are cloudy or panels smashed up from falling ice.
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
We have O2 tanks. Ice storms are not the same as hail storms. An ice storm is the result of freezing rain. I read somewhere that a Midnight Solar Classic charge controller can be told to melt snow or ice off of the PV array. (I may have dreamed that)
I think there was talk about melting ice off of solar panels--But, so far, that has never been implemented (as far as I know--which is not very far :roll:).
-Bill
Check out this link. http://www.wholesalesolar.com/products.folder/controller-folder/MidniteClassicChargeController.html Here is a copy / paste of the statement.
"Another significant advance with the Classic is the ability to access your power system remotely via the internet. If you’re out of town, you can call in to the system to troubleshoot problems, and get it back in working order. If you have plenty of excess power, you can even turn on the snow-melting feature while you’re away. Remote control of Midnite power systems will be invaluable for installers, dealers and homeowners alike. "
Interesting--See if anyone here has tried it...
-Bill
I know what the retailer says, but according to the people who make it this function has not been implemented yet. The Classic seems to still have a lot of unrealized potential, which is amazing considering how much it will do already.
from a Feb 02, 2012 post by bOB on Midnite forum
Not yet but we did do some more experimentation and I will say that snow melting did work for about 400 watts of
PV in about 30 degree F weather with about 2 inches of snow on the modules. Melting time took about 45 minutes.
Array tilt angle was about 20 degrees.
It will not work at 20 degrees F with 4+ inches of snow on the modules. There may be an option for this in the future but for the moment, may I suggest putting Rain-X on the modules before the snow. That appears to work great at keeping snow off at least.
Just a sheet of ice may work better with powered snow melting mode as opposed to not doing anything at possibly low temperatures but we haven't seen that kind of module covering here in the northwest.
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
Someone clever could rig up their own way of doing this external of the charge controller and specific to their particular array. The trick is to be sure you don't exceed the array current rating of course.
If the sun ever got on it for a few min the ice would probably slide off anyway.
Hi Everyone,
I've been asked how to power an oxygen concentrator in a totally off-grid, non-electric power situation. They wanted to know whether a solar-pv system might be configured, and/or whether a cabin 'kit' might work.
The power requirements are almost exactly the same as verdigo's father's oxygen concentrator, 8.82 for a 24 hour period. I was wondering if adding greater numbers of battery storage might cover the greater draw. And 'extra' panels too?
On another site I read that one needs a 'pure sine wave' inverter or the concentrator could be ruined.
Also I found a 'cabin kit' whose battery can be recharged via car-lighter-port, running a regular gas-generator, or by solar panel. From my notes: http://inergyhome.com/solarvillage/?p=221 http://www.outsidesupply.com/cabin-solar-kits/
The concentrator would be the only item run from the solar array, or all-in-one kit (at least, so they say now). Certainly for back-up, I'll surely suggest oxygen-tanks or a portable concentrator whose 5-hr-duration battery could be charged with a car lighter port.
What do you think might actually be viable? This person lives in an extremely remote area which is not served by any electric company, and the oxygen tank suppliers are beginning to gripe that the deliveries are too remote to be profitable. Don't ask me what I think about that!
Thanks,
The Type Doctor
Tanks of cryo oxygen. the 160 liter should last a couple weeks.
Tasking solar with a life critical chore is going to really cost you to get the 99.5% reliability needed to keep the air on. As you develop layers of redundancy, (auto-start genset, stack of backup tanks,.....) you can relax a bit, but remember, when the big storm hits, the solar stops in cloudy weather, and you hope the generator was serviced and fueled properly, and the spare tanks are really full. Storm = supply truck is 2 weeks away.
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
The old answer is anything is possible, but is it practical (cost effective)... Just to run through some numbers. Being conservative (for example, 5% to 13% rate of charge on batteries, choose 10% at least. 2 days of battery storage and 50% maximum discharge, or 25% per day use)...
For now, don't even bother looking at "kits" until you have done the math/paper design.
The numbers:
- 8.82 kWH per 24 hours.
- 8,820 Watt*Hours / 24 hours = 367.5 Watt average load
A battery bank would need to be (2 day, 50% max discharge) would look like:- 8,820 WH * 1/0.85 inverter eff * 2 days * 1/0.50 max discharge * 48 volt battery bank = 865 AH @ 48 volt battery bank
A Large, but not unreasonable size battery bank for an off grid home (this is about as much electricity as my suburban home near San Francisco uses per day--Natural gas for heating/cooking, no A/C).The minimum solar array to properly charge such a bank with a 24 hour per day 367.5 Watt average load at 10% rate of charge would be:
- 865 AH * 59 volts charging * 1/0.77 panel+controller losses * 0.10 rate of charge + 367.5 Watt load * 1/0.77 panel+controller losses = 7,105 Watt array minimum
And, you need to figure out how large of solar array based on the amount of sun you get... You did not say (that I recall) where the system would be installed (near major city)... In much of the US, you can get about 4 hours of sun minimum for 9 months of the year. Will this system need to run during the winter too? Pick 3 hours of sun "break even" -- A little safety factor since this is medical:- 8,820 WH per day * 1/0.52 end to end efficiency * 1/3 hours of sun per day = 5,654 Watt array minimum (based on sun+load)
So, the ~7,105 Watt array is more than big enough to carry the loads for most of the year--probably even pretty deep into winter for much of the US.Obviously, you would need a good size backup generator to recharge an 865 AH battery bank (around 8-10kWatt genset+a forklift type battery charger). For bad weather and emergency backup).
Just some round numbers:
$10,000 for 7kWatts of solar panels
$7,000 for Battery bank
$600 for solar charge controller
$3,000 for racks/wiring
$2,000 for AC inverter
===================
$22,600 plus labor+generator+AC charger+shipping ($10k more?)
New battery bank every 5 years (guess), new electronics every 10 years. A 20 year system life. Solar power system rough estimate:
Or, get a Honda eu2000i generator that runs about 9 hours on a gallon of gas with 400 watt load. Assume you need 3 generators per year (~3,000 hour life from each):
And there is utility power... Assume $0.20 per kWH:
The solar power system looks cheaper--But it would take a few years to break even (assuming nothing major goes wrong and unknown amount of fuel for winter).
But moving closer to utility power is really the more cost effective answer. The generator may be done better with a small diesel rated for Prime Mover power (if one exists that is small enough to be cost effective).
The above numbers are not accurate--Just trying to get an approximation of yearly system operational system cost. And compare that to oxygen delivery costs.
-Bill "SWAG" B.
It just takes a lot of energy to separate O2 from air.
The PSA (Pressure Shift Absorption) method is about the only practical way for small users.
We have a large (50 L/min) unit we run from a 5 Kw solar array with 15 KW inverter and a large battery.
It is used for Hyperbaric O2 treatment but obviously, it does not run full time.
Typical home units produce 5 L/min O2.
The smaller portable units produce 1 or 2 L/min and draw proportionally less power.
You might see if you could use a portable unit.
O2 administration is usually done with a nasal cannula.
This is easy and convenient but wasteful of O2.
There are more efficient ways to administer O2 but they require careful attention for safety reasons.
Thank you to mike95490, BB., and Ken Marsh,
All of your replies are incredibly helpful. I'll see if perhaps the portable O2 or cryo-160 L O2 is possible; moving closer to town isn't... and the location is Northern New Mexico, with at least 5.5 hrs sun daily.
Thank you all, again. Whenever we get this figured out, I'll be sure to let you know what works.
Best,
The Type Doctor
Here is a sieve that will fill a " E " cylinder that will give you 2 ltr flow in a pulsed dose for 17 hrs with a 6 hr fill time. It's 400 w and would be no problem to load shift on Solar. A couple extra cylinders would give you a fall back emergency stash. I used them in the Veterinary business for years.
http://www.devilbisshealthcare.com/files/LT-2006_Rev_G_iFill_043013_WEB.pdf
Here is the sun for Albuquerque New Mexico (fixed panel, tilted to latitude):
Month
Solar Radiation
(kWh/m 2/day)
1
5.33
2
6.06
3
6.44
4
7.16
5
7.40
6
7.10
7
7.13
8
7.02
9
6.71
10
6.55
11
5.73
12
5.14
Year
6.48
Certainly means a lot more energy than my overly conservative version.
Still the issue of size of battery bank vs solar array... Run a larger O2 generator during the day with lots of sun--You could probably cut the battery bank by 1/2 and the array down to 3,500 watts or so. Pump to tanks to store overnight (rather than running the O2 generator 24x7).
Can run into an energy issue--Pumping to a storage tank (storing O2 at pressure) uses more energy. However BC4's link appears that their 400 watt specification takes that into account for overall energy usage.
Need to review the actual power needs vs O2 needs more closely--But it does look possible.
-Bill
There plenty of DC portable concentrators out there, it's just coming up with the best strategy. There is plenty of sun thats for sure. Not to be morbid, but you have to think of the longevity of the patient and the value of the dollars spent vs the needs. I like the security that the cylinders offer.
If you have a concentrator that will output 5 ltrs and your using 1.5 - 2 ltrs the rest is wasted and the compressor just keeps on running. It's no different than using a diversion load on your solar harvest. Same with using demand dosage, if you don't use it, it's like leaving a faucet running so you can get a glass of water anytime without turning it on.
.
My thanks to Blackcherry04 for some unusual, creative and informative solutions. And again, and as always, many thanks to BB for exploring and listing the daily hours of solar radiation.
It sounds as though there may yet be a viable way to power oxygen equipment for the person living so remotely. I'll start researching your suggestions and present them to the medical advisor. If I'm lucky, they will keep me informed regarding further developments; then it will be my pleasure to report back to all of you.
This is a problem which will increasingly pop up, as numerous folk in rural New Mexico live as their forbears did, with no electricity, and interestingly, comfortably so.
Up until the US's new Affordable Care Act, it was just fine for companies to deliver tanks of oxygen. Now, suddenly, the insurers are demanding the upgrade to O2 concentrators. With the help you have provided, we may just have a few viable options and workarounds!
Alternatively, we now have a very strong argument in favor of maintaining status quo. Personally, I have a feeling bringing PV systems to rural NM might just seed the true energy revolution.
Thank you all so much. I am honored that you have given me so much of your time and creative problem-solving.
Best, Zi
The Type Dr
Zi,
Let us know what you find out and if you do any experimentation--It will be of great interest to others that read this thread in the future and will really help people improve their lives.
-Bill
The biggest stumbling block you have with any human use equipment is the FDA. They want their nose into everything, the only dealings I had with them is the size of the sticker " Not for Human Use " and how it was attached, of course most of the export stuff ended up being used on humans out of their jurisdiction with the sticker removed.
I am not sure where you cross over into their domain with Solar power. Just something to think about when you package two items together.