Inverter Power for AutoSet II w/ H4i

[terrydk]

Newby here so pardon my question(s) if they have already been addressed. I did a search but found so many different posts I want to be sure I have the right information.

I am awaiting delivery of an AutoSet II with H4i humidifier. I will need to be able to use this machine while away from 115VAC power, camping, power outages etc... If I understand correctly I will need to use a 'pure sine wave' inverter to power the unit while using the H4i humidifier even though I can power just the AutoSet II with 12VDC power directly by itself, is that correct? What size of pure sine wave inverter will I need to power both the AutoSet II and the H4i?

Thanks for the help.

[JohnBFisher]

... I did a search but found so many different posts I want to be sure I have the right information. ...

Well, asking politely will get you an answer! BTW, Welcome!

... I am awaiting delivery of an AutoSet II with H4i humidifier. I will need to be able to use this machine while away from 115VAC power, camping, power outages etc... If I understand correctly I will need to use a 'pure sine wave' inverter to power the unit while using the H4i humidifier even though I can power just the AutoSet II with 12VDC power directly by itself, is that correct? ...

Bingo. The Humidaire H4i humidifier requires a pure sine wave inverter, instead of a less expensive modified sine wave inverter. As you get used to using a xPAP unit, you will find you may not need a humidifier, especially in more humid regions of the country.

... What size of pure sine wave inverter will I need to power both the AutoSet II and the H4i? ...

See page 7 of the battery guide from ResMed:

http://www.resmed.com/us/assets/documen ... lo_eng.pdf

In short, it says the inverter needs to provide a pure sine wave and 300 watt continuous power with a peak/surge rating of 500 watts. Without the H4i humidifier, you only need an inverter that provides a modified sine wave and 150 watt continuous power.

... Thanks for the help. ...

Helping one another makes the journey easier for each of us.

[terrydk]

John thanks for the response. Upon looking at page 7 as you suggested I see this warning "Note: HumidAire™ must not be used with inverters!" It's not clear but is that saying don't use a 'modified sine wave' inverter and that the 'pure sine wave' is Ok? The wording seems kind of screwy. The last thing I need is to burn something out by using the wrong power supply.

[falvesjr]

Terri,

Sounds to me like you should read that warning as: "Note: HumidAire™ [H1i] must not be used with inverters!" In other words, an original, first generation, HumidAire unit (before there was a need for numbering), the one before the HumidAire H2i. Does that make sense to you?

-F

[timbalionguy]

The unit cannot tell the difference between a pure sinewave inverter and mains power. The reason for needing the pure sinewave inverter is they are probably using a thyristor-modulated power control for the heater that works by 'sampling' portions of the AC power sine wave. This is essentially the same kind of circuit as a lamp dimmer, and is very efficient.

What I would do is get some experience with the machine first, and try using just passover humidification. If that works for you, just power the machine from 12 volts directly. Then when you travel, you will need a much smaller battery, and you won't need the heavy inverter (pure sinewave inverters can be quite heavy, as many designs use a transformer).

[desert rider]

I also use a Kill A Watt monitor to check for the initial startup draw from any questionable device I plug into my my inverter. Many devices with lower ratings have a big kick when they first start up.

[RedBackFur]

I have an APC SmartUPS 750Watt (http://www.upsforless.com/apcsmartups75 ... awodfjp4CA) and it works like a charm. And using PowerChute® Software, I turned off the alarm feature so it won't wake me up when the power goes out. I haven't had another power failure yet to see how long it will last with my 4Hi set to 2 (where it normally sits), but that should be plenty of juice. It is a pure sine-wave UPS.

But it is not what I would call portable unless traveling by car, as it weights about 30 lbs.

[terrrydk]

Yes that makes sense, thanks

Terri,

Sounds to me like you should read that warning as: "Note: HumidAire™ [H1i] must not be used with inverters!" In other words, an original, first generation, HumidAire unit (before there was a need for numbering), the one before the HumidAire H2i. Does that make sense to you?

-F

[terrrydk]

So the 'clean' power is only needed for the heater in the humidifier...so I will give your idea of no heat and just the passover humidification a try first. Thanks.

The unit cannot tell the difference between a pure sinewave inverter and mains power. The reason for needing the pure sinewave inverter is they are probably using a thyristor-modulated power control for the heater that works by 'sampling' portions of the AC power sine wave. This is essentially the same kind of circuit as a lamp dimmer, and is very efficient.

What I would do is get some experience with the machine first, and try using just passover humidification. If that works for you, just power the machine from 12 volts directly. Then when you travel, you will need a much smaller battery, and you won't need the heavy inverter (pure sinewave inverters can be quite heavy, as many designs use a transformer).

[Lou Cypher]

I have spent hours reading posts here and trying to understand this lingo and what I really need.

I finally composed a list and called Res Med and refused to get off the phone until their technical support helped me weed out the lingo and suggest units for me....

Bottom line, VERY EXPENSIVE if you want to use the H4i heater........

As many folks suggested here and was approved over the phone by Res Med for my autoset II S8.... The Black And Decker Electromate 400..... Just plug your machine into the ac outlet. BUT FIRST TURN OFF the Humdifier and all will be well....

The battery backup can be recharged by the lighter in your car.

If you insist on the heater, then you gotta go the pure sinewave inverter, and then the battery backup. You will need an expensive setup that way .....

When in doubt call Res Med they were wonderful and talked to me until all my questions were answered.......especially the ones about what battery backup would work for what I wanted....

Make out your list, see how much money you want to spend and then give them a call....

My invoice will be in the mail.

[The Texan]

I am glad I started with the Respironics as I use mine on an inverter all the time and it works flawlessly. We are full time RVers and the plug I use is directly controlled by the inverter, a Magnum 2Kw.

[timbalionguy]

I am glad I started with the Respironics as I use mine on an inverter all the time and it works flawlessly. We are full time RVers and the plug I use is directly controlled by the inverter, a Magnum 2Kw.

Wow! That's a BIG inverter! What kind of battery system do you have to support an inverter that size? (2 kW at 12 volts is 167 amps) Is this a pure sine wave inverter?

[terrydk]

Having worked in the RV manufacturing industry for over 33 years I am real familiar with how inverters are used in RV's. In the largest of them (45' long with multiple slide outs) I have seen as many as eight 8-D AGM batteries rated at over 200 amp hours each with 8kw pure sine wave inverters and 200 amp battery chargers. That would probably run a CPAP and humidifier for a few days you think? However more common in RV's are a couple of Lead Acid 8-D batteries and 2 to 4kw inverters, some being pure sine wave and some being modified sine wave.

I am glad I started with the Respironics as I use mine on an inverter all the time and it works flawlessly. We are full time RVers and the plug I use is directly controlled by the inverter, a Magnum 2Kw.

Wow! That's a BIG inverter! What kind of battery system do you have to support an inverter that size? (2 kW at 12 volts is 167 amps) Is this a pure sine wave inverter?

[terrydk]

Any idea how long a 750 watt UPS would keep a CPAP running? I'm not sure that the battery reserve in a UPS is large enough to keep a CPAP going for any length of time. They would work great for short blips in power for sure.

Speaking of blips in power...what happens to the AutoSet II when it gets a short interruption of power? When the power comes back on does it restart where it left off or does it have to be manually turned back on and restarted? During storms our rural power grid can be interrupted several times in a night.

I have an APC SmartUPS 750Watt (http://www.upsforless.com/apcsmartups75 ... awodfjp4CA) and it works like a charm. And using PowerChute® Software, I turned off the alarm feature so it won't wake me up when the power goes out. I haven't had another power failure yet to see how long it will last with my 4Hi set to 2 (where it normally sits), but that should be plenty of juice. It is a pure sine-wave UPS.

But it is not what I would call portable unless traveling by car, as it weights about 30 lbs.

[Patrick A]

In my RV I have a Xantrex 2.0 ProSine inverter. (2000w) I have yet to run my Bi-pap on it. Being as my equipment will run off of 12vdc. I would say if your machine runs off of 12vdc don't worry about it and live with out the humidifier for a couple of days. I looked and your unit will run on 12vdc. The cost of a 12vdc power cord is by far cheaper than an inverter. The cost is really prohibitive if you want a Pure Sine Wave inverter of any size. JMHO