Hi all,

Looking for a cheap(ish) hygrometer.

Any recommendations as im sure some of the ebay "specials" will be very un-reliable?

Cheers, Mark

Hi Mark,

I like your enthusiasm about your "new" piano!

Hygrometers are easy and no need to get fussy. The electronic ones are available at any good hardware or big box home center. For about 25 bucks, you can get one that reads Temp and RH and records over time and then you can see the trend. Some show the time on the read out screen, others don't. Mine doesn't show the time as I don't need it for a clock.

I keep one in the piano case and one in the room for a comparison. With the Dampp-Chaser system, I notice that the piano is more stable.

Early in the summer I had some work done on the humidifyer in my HVAC system and the serviceman had a very sophisticated one. I asked him what RH he was reading in the room. Mine matched exactly. Good enough for me.

I use a Lascar EL-USB-1, no longer made but similar to the "new and improved EL-USB-2".


Info can be found here:
Lascar EL-USB-2

The unit lives in the tail of my piano and comes out every now and then when I want to download recorded data into a spreadsheet.

In the US, I use a $10.69 unit that was checked against a Honeywell for accuracy.

http://www.amazon.com/Acu-Rite-Indoor-Hu...ords=humidistat

I have central a/c (oversized, it came with the house) as well as a dehumidifier that runs 24/7 but my concrete block house here in Florida is rarely below 70% RH in the summer. My tuner complained when he visited in August.

I've replaced the aluminum jalousie windows that didn't close all the way with double-hung vinyl that does.

I have a chimney that does not close, cracks under the door, and a mail slot for my front door as well as three large dogs who are constantly wanting to go in and out of the house.

A damp-chaser would be like putting a band-aid on a gaping wound.

I don't know how to keep my RH below 60% year round, aside from replacing the a/c. That's going to be at least $6K.

dsch,

I was raised in Miami and we had no a/c, but the simple damp-chaser worked well on my mother's vertical. Man, was that long ago!

Thanks for the replies.

I quite like the look of this one Acu Rite posted earlier.

I just want something simple but like the fact it has min and max. Cant find that one over in the UK but i'm sure i'll find something similar.

If your CAC system is over sized, that is part of your problem. It is cooling the air too quickly so it is not removing the latent heat (moisture) sufficiently. Over sizing a system is just as bad, if not worse, than under sizing when it comes to removing humidity. If you system is older, it will have a 3 speed fan on the air handler. Since you claim it is over sized, make sure it is on the low speed so it removes more latent heat.

On what do you base your conclusion regarding the sizing?

If your stand alone dehumidifier is "running 24/7" and you are still having a problem, perhaps only the fan is running which is making you think it is running. It may have lost it's charge in which case it may run constantly but do nothing. At 70% humidity you should be emptying the drain pain very frequently or, if it is connected to a drain line, condensate should be running out at a fairly steady rate... if not, the DH is not working either properly, or at all.

All the "envelope" items you mention have to be addressed as 70% RH is not only bad for a piano but also for almost everything else in your house. At that moisture level molds can thrive and then you will have a monster problem.

I lived in S Florida for 25 years so I know what you are up against. As a mechanical engineer I designed many commercial systems for the high rise condos on the beach... talk about moisture! If your home is older, (25+ years) you may not have a moisture barrier between the block wall and the inside wall. You may not have a moisture barrier under the slab either.

In any event, you need to successfully address the RH before you have a situation that is both unhealthy for you and for your bank account.

I bought one on one of those chinese gadgets store.

It is the size of a match box (remember those?)

Yes, it is tiny, and cost me about 4 bucks. It has temp and humidity, max/min.

Works great. What if it breaks down? well, I guess I´ll just buy another one.

It has been working for about 6 months with no problem.

something like this one:

http://www.ebay.com/itm/Digital-LCD-Temp...=item2312295809

If anybody is worried about the accuracy of the cheap Chinese ones simply buy several of them and take an average.
I bought two fairly cheap ones when I got my piano but they were always within 1-2% of each other which is pretty encouraging.
We're just looking for a rough estimate anyways and what I was mostly concerned with was seeing the humidity SWINGS over a few days and between summer and winter.
Here in Toronto in the summer it can swing as much as 50-60% in a few days and in the winter the humidity drops off completely.
(It's practically impssible to get the humidity above 20% in the winter without condensation or ice forming on the windows.)
The rapid humidity changes played havoc with my piano but being able to see the RH fluctuations displayed by those two cheap little meters was what spurred my to fork out the dollars for the DamppChaser.

I have an analog and a digital one.
The digital at the same time is a switch, it turns on my humidifier if it gets below some point.

I noticed that the analog consistently shows higher humidity than the digital. eg my analog now shows 68 and the digital 45. I have seen digitals showing low in many cases

I calibrated my analog (getting the right 100% point) so I believe the analog is closer to the actual. This is also confirmed by local weather indications on the web that now say 77% for my area.

It does not matter too much as a stable humidity is the most important, not the exact number.