HC150, rainout, inline filters for allergies

I'm looking into getting an inline humidifier to use with a PR1. (I don't have the PR1 yet, and I'm also considering the S9, but it winds up being too expensive if I don't use the integrated humidifier.) This brings up three questions from my never-ending supply.

What do you think of the Fisher & Paykel HC150? Should I consider others?

I let my house get down into the mid 50s at night in the spring and fall. Will a hose cozy be enough, or do you think I'll need a heated hose to prevent rainout?

Being able to keep the humidifier when my flow generator gives out is a plus, but the main advantage to me is that I could use an inline HEPA filter between the generator and humidifier to help with my allergies. I'm not worried about bacteria or fungi growing in the humidifier chamber, and viruses are irrelevant to home cpap use. It would be just for pollen, mold spores, dust mite feces, etc.

But would an inline filter actually be better than just using the "ultra fine" filters on the back of the generator? I've been told by one DME that he contacted the manufacturer for the aftermarket filters he sells and they do meet the HEPA standard. OTOH, if it's true, you'd think the manufacturers and vendors would say that instead of using vague descriptors like "ultra fine" or "allergy" that could mean anything, and hence mean nothing.

Otter wrote: I let my house get down into the mid 50s at night in the spring and fall. Will a hose cozy be enough, or do you think I'll need a heated hose to prevent rainout?

Depending on relative humidity where you live, probably will need a heated hose. To get a hose cozy dense enough it would weigh so much it would be counterproductive. I actually did this with towels one time.. Just about dragged my face off the bed it weighed so much. SW Missiouri, average humidity for the area and I sleep with temps at 60 or below when cold weather is here. I battled rain out all winter even with 2 layers of heavy fleece over the hose.

I have no experience with the F & P humidifier, so can't comment one way or the other.

I currently use the slightly older M series with its humidifier and I have it set to 3. It is what my nasal mucosa needs so I just deal with the rain out best I can. I also only just use the fine white and gray foam filters.

Pugsy wrote:

Otter wrote:Depending on relative humidity where you live, probably will need a heated hose.

I'm in Indiana, just south of Lake Michigan, and in the winter, it tends to be dry inside simply because it's cold outside. I run a steam humidifier sometimes to mitigate this, but I'm not sure I'll need it as much if I'm getting humidified air all night.

What does the ambient humidity have to do with it, though? Does evaporating more water raise the temperature in the tube that much?

I was thinking I might run the hose partway up my headboard, so that only the the last section would drain toward my face, and the rest would drain back to the humidfier. It seems like this might be help me avoid getting tangled up in the hose if I roll over to my other side. How much would the up and over route help with rainout?

Would I be better off with the hose under the covers, and the humidifier near the floor?

I never found a difference in my allergies with using the white filter on the back or the bacteria filter on the hose of the machine.

So... I'm sticking with the white filter on the back.

Otter wrote:What does the ambient humidity have to do with it, though? Does evaporating more water raise the temperature in the tube that much?

It isn't so much the temperature inside the hose as the outside room air temp and the humidity in the hose. I was commenting only because you prefer the cooler temps. I never have rain out except in winter and relative humidity here doesn't change that much for the most part season to season. The temperatures sure do though and though typically winter heating dries the relative humidity some, you will find that most people who complain about rain out will be in the winter time or lots of AC. We can also get rain out in the mask from exhaled breath. People complain about it that have humidifier turned off. As you will find with all cpap stuff and opinions. There are no hard fast rules and often your mileage may vary.

Now I don't have that fancy heated hose either, that is why I mentioned what machine I have. Though I have seen users with the heated hoses complaining of rain out also.

Pugsy wrote:It isn't so much the temperature inside the hose as the outside room air temp and the humidity in the hose. I was commenting only because you prefer the cooler temps. I never have rain out except in winter and relative humidity here doesn't change that much for the most part season to season. The temperatures sure do though and though typically winter heating dries the relative humidity some, you will find that most people who complain about rain out will be in the winter time or lots of AC.

So are you saying rainout is more likely in a dry house, or not? If you are, I'm sure there's something to it, but the physics of this is still not clear to me. It seems to me that the humidity of the air in the tube, the temperature of the tube walls, and hence, the ambient room temp, would be the main factors. Hmmmm, maybe in the winter, radiant losses to the outer walls of the house and windows would be significant too. If the tube is cold enough, water will condense on it's inner surface. I can see how both winter temperatures and drafts from the AC could cause that, but if ambient humidity factors in, it seems like dry air would cause less rainout because it would carry away less heat from the tube... though dry air would allow more radiant loss to the windows than humid air. Or does humidifying dry are cause something unfortunate happen in the humidifier itself? What am I missing?

I don't mean to be a physics nazi. I'm asking for clarification because physics is an important part of the way I understand things, but I realize that it's not as important to most people. If you're not sure how it works, I'm not trying to put you on the spot, and I do appreciate you lending me your experience. I just want to figure this out so that I can come up with a plan that has a chance of actually working without several revisions.

The inline filters didn't seem to help my allergies at all, but I have always used the white filters. I change them out every two weeks during pollen seasons and every month for the rest. They do seem to plug up with moisture hooked up after the humidifier. After I finish my temperature controller for my reptile hose heater. I was thinking about building a sound isolation box to keep my cpap in, with a couple of 4in X 5in X 1in Hepa filters, replacement for vacuum cleaners, on the input vent My hope is that I should only have to change them once a year.

Otter wrote:So are you saying rainout is more likely in a dry house, or not?

So sorry, I ramble a bit. I think rain out is more likely in a normal humidity level home and cooler bedroom temps. My comment was about winter and normally we would think that running the furnace (or whatever) does dry the air a bit and thus we would think we would be less likely to have rain out but I have NOT found that to be the case. My only rain out issue season is winter.

May be if I still lived in Las Vegas I could tell for sure but I don't. Wood stoves definitely dry the air out in the winter time.

I think that the amount of rain out will depend on
choice of humidity level on the humidifier going to the hose and the associated warmth
room air temp
and may be slightly impacted by relative humidity

Someone who prefers a lot of moisture going up the nose is going to have a greater chance of experiencing rain out than a person who prefers passover mode. Doesn't matter where they live or the room temp. We add in cooler room air temps and chance increases more. So your chances of rain out are going to depend on your personal comfort needs, room air temp, and whatever protective material you choose to use to try to prevent the rain out,
if you even get it.

Heck, you may not even have a problem. I know you are trying to prepare for all possible scenarios but this one you are going to have to live to be able to judge. You might do better in passover mode. I don't. I have to have the added moisture, when I lived in Las Vegas my nasal mucosa were dry, bled easily and always "itchy" for lack of a better word. Other members here live in the high desert and use passover mode and even no humidifier at all.
This is strictly a personal choice thing.

Edit: I am aware of the physics involved. I explained it poorly. It is one of those things that sometimes happens when we try to explain how things work. You don't have the luxury of reading my mind and in between the lines.
Believe it or not but science was my strong suit. English composition I totally sucked in.

physicsbob wrote:After I finish my temperature controller for my reptile hose heater. I was thinking about building a sound isolation box to keep my cpap in, with a couple of 4in X 5in X 1in Hepa filters, replacement for vacuum cleaners, on the input vent My hope is that I should only have to change them once a year.

I've thought of building something like that too, once I'm rested again. There should be enough surface area on the filters to avoid restriction on the inlet. But I wonder suspect the box would need a fan to keep the equipment cool.

Another solution that occurred to me is to epoxy a fitting on the inlet so that a large, fine filter could be used. Bye bye warranty. But perhaps there is a way to nondestructively attach a fitting with a silicone gasket.

"Reptile hose heater" sounds interesting. Is it for your lizards, snakes, or turtles or for your CPAP rig?

Pugsy wrote:So sorry, I ramble a bit.

No need to apologize. I am similarly afflicted, especially when I'm tired.

My comment was about winter and normally we would think that running the furnace (or whatever) does dry the air a bit and thus we would think we would be less likely to have rain out but I have NOT found that to be the case.

Ah. I see what you meant now!

My only rain out issue season is winter.

I'd expect early fall and late spring to be worst for me, if I keep chilling the house at night so that I don't have to run the AC during the day. The spring window fan season is coming right up, so I'll get to experiment.

Heck, you may not even have a problem. I know you are trying to prepare for all possible scenarios but this one you are going to have to live to be able to judge.

You're right. Time will tell. I'm just trying to make educated guesses before I buy they equipment. Some things are much easier to fix in the beginning than after you're committed.

Edit: I am aware of the physics involved. I explained it poorly. It is one of those things that sometimes happens when we try to explain how things work. You don't have the luxury of reading my mind and in between the lines.
Believe it or not but science was my strong suit. English composition I totally sucked in.

Thanks for taking the time to clear things up.

Rainout also depends on the type of mask you use, and on your pressure.
Some masks are more prone to rainout than others.
The lower your pressure, the higher the chance of humidity condensing in your mask.

I'll need a full face mask, which I imagine is probably the worst for rainout because of all the water vapor in my breath. Pressure will probably vary quite a bit with my allergies, but I can't even guess the range at this point.

Actually, the worst for rainout for me was the nasal pillows Headrest - for most users I think. Most FFM mask don't have that additional thin, narrow hose between them and the main hose - they connect directly to the main hose.

Ah, I see your point. I hadn't thought much about the up your nose style because that wouldn't work for me unless I had surgery.

You may be surprised to find no rain out at all- the technology with the PR S1 seems to handle it quite well. We don't heat our house at night and I have a thin flannel cover on my hose but I've never seen so much as a drop of water in the hose at all--just the nasal pillows.