Frost on New Dehumidifier


  #1  
Old 04-22-21, 03:05 PM
R
Member
Thread Starter
Join Date: Aug 2004
Location: United States
Posts: 234
Received 1 Vote on 1 Post
Frost on New Dehumidifier

I unpacked a dehumidifier and ran it on "Continuous" overnight, as per the manual.

21 hours after first turning it on, room humidity had only dropped two percentage points - and there was a fair amount of frost on the coils.

Unit is unobstructed, running into a drain hose. Rated for 4500 sq feet, in a space that's about half that.

Normal or problematic?
 
  #2  
Old 04-22-21, 03:13 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,078
Received 356 Votes on 321 Posts
Normal. You humidity and temperature are low enough. Set back the dial. In winter and spring the humidity tends to be low. Unless you have some unusual circumstances, wait for the weather to get warm before turning on the unit.
 
rjbinney voted this post useful.
  #3  
Old 04-22-21, 03:31 PM
R
Member
Thread Starter
Join Date: Aug 2004
Location: United States
Posts: 234
Received 1 Vote on 1 Post
It's a finished basement 25 feet away from the Pacific Ocean where I have over 2700 LPs stored. I don't know if that counts as "unusual", but I want to keep it in the mid- to low- 40's.

I figured that was OK behavior, but I'm about to head out for about ten days and didn't want to screw the pooch. Thanks!

rjb
 
  #4  
Old 04-22-21, 03:46 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,078
Received 356 Votes on 321 Posts
You need to get a relative humidity reading for your basement. It just not temp but outside temp and dew point and all that. If your basement temp is between 60-65 and it "feels" dry you should be OK. But if your concerned about a special collection of items then you might need expert advice and a number of reading for trend report. Do you see and possible mold? If you want to be sure while your gone then go and buy some DAMP-RID cannisters. That should take up any latent moisture you might have without over working or freezing the coils on the humidifier.
 
  #5  
Old 04-23-21, 05:56 AM
T
Member
Join Date: Jun 2012
Posts: 1,036
Received 23 Votes on 19 Posts
If you're looking to keep humidity levels down throughout the year and the temps in your basement drop to around 60 in the winter season, you should have purchased a unit for cool weather operation. They will go through a defrost cycle similar to a heat pump when the temp is below a set point. That unit will continue to remove humidity in lower operating temps.
 
  #6  
Old 04-24-21, 03:47 AM
S
Member
Join Date: Jan 2017
Location: USA
Posts: 561
Received 12 Votes on 9 Posts
The first thing you need to do is find out the actual % of relative humidity in the room where you are using that dehumidifier. Then, If the humidity is actually too high and the temperature in the room where the dehumidifier is running is 60 degrees or above and the coil develops frost on the cold coil, I would return it for a replacement under warranty. Most of the dehumidifiers made today are built cheaply. Anytime I buy one, I take out the insurance on them for the longest time possible since most only last a couple years and I buy them from only the large box stores that take stuff back easily. (the orange, blue or the largest stores) You did not say how much water it removed. Use the container that comes with the unit to make sure that it is removing moisture. If it has a pump or empties through a hose to a floor drain, use the container for the first couple days befire switching to the pump or hose. .
 
  #7  
Old 04-24-21, 05:15 AM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,078
Received 356 Votes on 321 Posts
Most of the dehumidifiers made today are built cheaply.
You have that right. I have an old White-Westinghouse at least 40 years old. Even it becomes a block of ice because I forgot to turn it off it still continues to operate. New units have lots of bell and whistles but do not last . 5 years at best.

Again to the OP, if you don't have time to get all the data you need and you want to be covered buy several of the DAMP-RID cannisters. That will hold you over.

Another trick is to buy a bag of calcium chloride. Place the salt in a calendar (or is it cullender, the thing with the holes in it) and place it in a bucket or suspend over the sump pit. I use this trick to keep my cabin dry and free from mold. The trick is to dispose of the water.
 
  #8  
Old 04-24-21, 03:58 PM
R
Member
Thread Starter
Join Date: Aug 2004
Location: United States
Posts: 234
Received 1 Vote on 1 Post
OP here. I was running it directly into a drain, so I have no idea if it's doing anything other than creating a sheet of ice on its coils. My hygrometer has gone up from 53 to 56 percent, so I suspect it's going back.

The smaller one I've been running for 15 years, pretty much nonstop, kept it around 45% (same hygrometer) but was just so loud that I was thinking, now would be a good time to replace it.

I've found those Dri-Z-Air cups are pretty useless. I guess they're great for closets or something, but not for a room.
 
  #9  
Old 04-24-21, 04:08 PM
R
Member
Thread Starter
Join Date: Aug 2004
Location: United States
Posts: 234
Received 1 Vote on 1 Post
BTW - I don't have trends, just a digital hygrometer I monitor. House is built on a hill, so back wall of "basement" is buried but front wall has floor-to-ceiling windows.

Temperatures usually 55-65, it's 61 down there now. Didn't realize cold-weather units were a separate thing. (ETA - the one I bought is #8 on the first list of Top Cold Weather Humidifiers I just googled.)

No evidence of mold; the whole point is to avoid that entirely.
 
  #10  
Old 04-24-21, 05:25 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 27,163
Received 938 Votes on 856 Posts
Just an idea, but something you could try... get it up off the floor. Place it as high as is practical, on a table, or shelf, be sure it doesn't vibrate its way off.

The higher you put it, the warmer the air will be which will help melt the coils. Being early spring, it may just be too cold for it down there to properly melt the coils... since cold air sinks to the floor.

Alternatively, move it away from the buried wall and out where the sunlight warms the room. You may find that a few degrees makes all the difference. Obviously you are limited how far you can move it by the length of your hose. But I would try that first.

And you might monitor how much water it is collecting rather than just letting it drain. At least for a while. Once you're sure it is taking water out of the air, and not freezing solid, no reason to monitor the frost.
 
  #11  
Old 04-24-21, 07:29 PM
R
Member
Thread Starter
Join Date: Aug 2004
Location: United States
Posts: 234
Received 1 Vote on 1 Post
That's a good tip about moving it. To be fair, it *IS* in the same spot the old one was.

Letting it thaw now, but will try that overnight.
 
  #12  
Old 04-25-21, 12:27 AM
R
Member
Thread Starter
Join Date: Aug 2004
Location: United States
Posts: 234
Received 1 Vote on 1 Post
It's been off for about six hours and still not completely thawed. The room is 60+ degrees. It's advertised as being able to work in 41-90 degree environments.

What's most annoying is I have had the previous unit running nonstop for years, through the winter (and I don't keep the room heated, so it can drop to the 50s in the winter).
 
  #13  
Old 04-25-21, 03:37 PM
R
Member
Thread Starter
Join Date: Aug 2004
Location: United States
Posts: 234
Received 1 Vote on 1 Post
The Saga Continues
Cleared all the frost. Moved to center of room (not elevated). Ran all night.

Humidity had gone up to 60% while it was off.

Ran for 15 hours - 61 degrees, humidity is down to 52%. Coils are good and frosted. BUT - there is nothing in the bucket.

Time for it to go back?

(My chief concern at this point - I am frequently gone for 10+ days at a time. I believe when it defrosts, it drains into the bucket, not into the drain hose? So then it will fill the bucket when it defrosts... and then it's as good as useless. Testing to see how it drains now...!)
 
  #14  
Old 04-25-21, 04:54 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 27,163
Received 938 Votes on 856 Posts
Definitely.

Need more words.
 
  #15  
Old 04-25-21, 05:52 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,078
Received 356 Votes on 321 Posts
Frost but no water in the bucket? What's the temperature? I think the unit is OK.
 
  #16  
Old 04-25-21, 08:49 PM
R
Member
Thread Starter
Join Date: Aug 2004
Location: United States
Posts: 234
Received 1 Vote on 1 Post
Need more words.
What more can I tell you, XSleeper?

61 degrees, Norm.

And it looks like the frost does drain out the drain and not into the bucket so I'm less worried about catastrophe.
 
  #17  
Old 04-26-21, 03:04 AM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,078
Received 356 Votes on 321 Posts
If it's frosting then it's doing something. Could be a defective unit with low or leaking refrigerant. But if you have it set on a low (or high setting depending on how you look at it) setting then possibly it turns on, based on temp enough to frost up but not enough to remain on. The relative humidity may be just at that point that the unit may or may not need to go on. I can set mine to cycle on and off repeatedly by just tweaking the dial. When that happens I know it's to early to turn the unit on for regular use. So I set it just below that point so it won't go on until humidity and temp rise. Then when summer hits full force I up it so it runs about once an hour for maybe 10 minutes and the basement is dry enough to prevent mold. I have mine right over the sump pit. During those very muggy summer days the unit may run every 20 minutes or so.

 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: