Piano World Home Page Forums Our Most Popular Forums Piano Forum Swamp Cooler and Air Conditioner- Use only One of them!

Isn't that the correct advice?

Some people have both, and I tell them pianos
are sensitive to a CHANGE in humidity, mainly.

And since swamp coolers add moisture, and A/C
generally dries the air, one should only use
one or the other, but not both, if there is a
piano in the house.....

A swamp cooler works because the process of evaporation has a cooling effect. But evaporation is turning water into water vapor (i.e. humidity), so it's going to raise the RH. AC has a dehumidifying effect, so it would lower RH. The net effect would depend on which is "stronger," but I think using them together would sort of counter-balance them, although it would probably be difficult to sync them up so that there was no net change in RH. They both have the same effect on temperature, reducing it, but have the opposite effect on RH. But to the original question, I don't see any reason you couldn't use them both together unless the net effect on RH was undesirable. In theory, I think the net effect on RH would be less than using one or the other alone.

I'm from Georgia, and many people use a form of swamp cooling that would have no effect on the indoor RH (assuming the windows are closed). They sprinkle or trickle water on their roofs, in order to cool them down. Less heat is then transferred into the attic, and subsequently into the home, and therefore the air conditioner doesn't need to work as hard to cool the house. Now that I think about it, although this external swamp cooler wouldn't introduce water vapor indoors, it would have the indirect effect of raising RH, because the AC wouldn't run as much and therefore wouldn't lower the RH as much as it might have without the help of swamp cooling the roof.

I didn't mean use them at the same time. Nobody really does that.

Here in AZ, they use the swamp coolers during the dry
seasons, because it's much cheaper to run them. But when the monsoon comes in, the swamp coolers don't work well, and the A/C units are usually turned on. Some people have both, so they can choose, but I told these last customers of mine to only use one or the other, but not both, because the swing in R.H. might knock their piano out of tune.

Rickster, you're the HVAC expert. Feel free to correct me if necessary!

I'm kind of confused. You say nobody really does that (run both), but you told your customers not to run both. Do you mean to pick AC or swamp cooling, and never ever switch? i.e. not to switch when the season changes from wet to dry?

I think what matters is the RH, not the machine you're using to cool. Obviously, each approach has a different effect on RH, but if it's an issue you need to monitor that anyway. If it's humid, swamp cooling is going to exacerbate it, so AC would be better, and vice versa. But it needs to be monitored regardless, so you don't over correct too.

Yes, that's what I mean. They shouldn't switch, and should stick to one system year-round. This way, they will avoid a bigger swing in R.H. I mean, they do have a hygrometer, so they conceivably could turn on the swamp cooler when the humidity drops, but I'm thinking they should keep it simple and just use one system, for consistency, because pianos are sensitive to changes in humidity mainly.

Actually, you are doing very well, Retsacnal!

And, I'm far from an expert... I've always heard that an expert is a has-been that leaks under pressure.

In our Fundamentals of Refrigeration course we discuss how the ancient Egyptians realized that liquid seeping out of the porous clay pots they used to store liquid/wine created a cooling effect as the liquid evaporated. Hence, they learned the value of "change of state"; when a liquid evaporates or expands, it creates a cooling effect by absorbing heat. When a vapor condenses, (changes to liquid) the molecules reject heat….

So, you are doing just fine with your exhortation of swamp cooler vs. mechanical A/C. I couldn’t add anything of value to your comments.

Rick

The most important thing is to maintain a relatively consistent relative humidity. I like to keep my place at 45% and it varies +- 5%. Get three hygrometers. Put one in the piano. And put the other two at opposite sides of your room.

I can't see what harm it would do to use a swamp cooler in the hot, dry AZ summer (when you need to both cool the air and add humidity) and also AC in the winter when humidity is not so low. As long as you maintain consistent humidity.

Perhaps if you hooked up both systems to a hygrometer,
and automated the switching, it would work. But doing it manually seems like it would be a pain, so that's why I suggested to use either system exclusively year-round, for
a more consistent R.H.

But really, since swamp coolers REALLY suck during the Monsoon, I would just say use the A/C full time!

I tried to hold off and say nothing. This thread is pretty bad. Yes, conflict.

I've lived in the desert. I know Swamp Coolers. They work fantastic when it's over 100 degrees out and the humidity is single digits. They're wonderful. All you have to do in that environment is get wet. And you cool off, big time. Go swimming at 120 degrees and that low humidity? You freeze when you get out of the water. And it's 120 out! You learn why people sweat.
You try using a Swamp Cooler when it's 85 and you freeze.

Now you people are talking about an instrument that is sensitive to humidity. And you're going to take it in a very dry environment and blast it with wet air? Basically you're misting it with water. Does that sound very smart? You can't run that Swamp Cooler all the time. They're too much to consider controlling humidity in any way.

I talked to two members here who live in Ariz.
One in Scottsdale. Says the monsoon is only a couple days of rain there. No big deal for any change. That person runs their AC all the time. Don't worry too much. This person would never consider using a Swamp Cooler with their piano.

The other lives up in the mountains above Phoenix. Said last month it was 3% humidity. This month the monsoon is raining everyday. The doors on their house are swelling and difficult to open and close from soaking up all the water. That person owns an M&H. Says it's so overbuilt it's ridiculous. It has never changed tuning over ten cents. That person imagines any other piano would twist apart in what they subject their M&H to.

The one thing I'm learning here is to keep the humidity consistent. Even if it's low. Keep it low.
One thing I worry about. The experience I have with wood. Geesh... even soft Pine wood. When it's been in the desert in that low humidity and heat for a couple years. Try driving a nail into that pine? You'll bend a bunch of nails. The stuff turns to rock. Now what does that do to a piano? I imagine that M&H with it's wheel on the sound board to change the tension on it. That would work great for this to release tension on that board where it gains it's own.

I'm learning where one really needs to control humidity is where it changes all the time. Like where I live now. It can be dry as a desert. It can be the opposite. And it's always changing. Winter and summer.

Either way. It's ludicrous to consider using a Swamp Cooler with a piano.

EDIT: On hygrometers. They're notorious for being off. Get one of those that you twirl around like a martial arts weapon. Those are the only accurate ones. Even use it for correction on other hygrometers. Also take three readings with that hygrometer. Two must be very close. Use those.

Ron, I completely agree.

The main point, is that it is the CHANGE in humidity
that throws a piano out of tune.

And since the swamp coolers are ineffective when the humidity
gets higher during the monsoon, you are better off just
using the A/C year-round, if you have a piano in the house.

Any money saved using the swamp cooler will simply be lost to your piano tuner anyways!!! (Hmmm....maybe I should keep my mouth shut?)

Paul... even without the monsoon.

Geesh... people are going to turn the Swamp Cooler off at night when it gets below 90. Otherwise they'll freeze. Now what is that going to do night and day, wet and dry, to a piano?
Besides... you're misting the piano with water. Might as well turn on a fan and walk around it with a spray bottle misting it with water all over.

It sounds just plain stupid to me.

That's called a "Sling-Psycrometer"; we have several of them in our HVACR lab. And, you are right, they are kind of fun to twirl around in the air to get a wet-bulb/dry-bulb temperature reading (make sure no one is standing close by).

And, they are very accurate as opposed to some of the cheaper digital ones.

Rick

I used one of these back thirty years ago when working in an explosives plant.
I'll be repeating myself, but have to stress... even these can take errant readings. That's why you take three readings. Use two if the two are extremely close. If all three are.. great! That doesn't happen often. If you don't get two very close readings. Redo all three tests. I have done that.

Thanks, Rickster. Methinks you are too humble.

I agree... that sounds just plain stupid.