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View Full Version : So here's my problem. 72*F dew point



Jeff Body
05-01-2017, 12:35 AM
359416
So far my system has been working great. I replaced the tube back in Oct/Nov for the 2nd time since I got my laser. I'm about 95% sure the cause of both of my failures was due to condensation. Since the last replacement of my tube I keep track of the dew point and never go below it but it's been the fall/winter so the air is normally alot drier here in Florida.

Well here's my problem. My laser is in my garage which isn't climate controlled. I'm at the mercy of mother nature. With summer here and the temperature increase the dew point has increased as well. During the day it's been around 22*C. I like to run my laser chiller at around 18*C.

My only solution that doesn't involve installing an A/C unit is a dehumidifier. What are everyone's thought on running a 70 pint dehumidifier in the garage. It's only about $200. I know once the garage door is open it'll completely exchange the air but if I keep the garage door closed and run a dehumidifier for 1-2 hours before I use the laser I think it should lower the dew point enough. Has anyone tried this?

Just some facts
A 70 pint dehumidifier is designed to remove 70 pint of water in a 24 hour span. It's suggested for up to a 4,500sqf room and my garage is about 400sqf.

Just curious what people thoughts are?
Any suggests?

Keith Downing
05-01-2017, 1:32 AM
359416
So far my system has been working great. I replaced the tube back in Oct/Nov for the 2nd time since I got my laser. I'm about 95% sure the cause of both of my failures was due to condensation. Since the last replacement of my tube I keep track of the dew point and never go below it but it's been the fall/winter so the air is normally alot drier here in Florida.

Well here's my problem. My laser is in my garage which isn't climate controlled. I'm at the mercy of mother nature. With summer here and the temperature increase the dew point has increased as well. During the day it's been around 22*C. I like to run my laser chiller at around 18*C.

My only solution that doesn't involve installing an A/C unit is a dehumidifier. What are everyone's thought on running a 70 pint dehumidifier in the garage. It's only about $200. I know once the garage door is open it'll completely exchange the air but if I keep the garage door closed and run a dehumidifier for 1-2 hours before I use the laser I think it should lower the dew point enough. Has anyone tried this?

Just some facts
A 70 pint dehumidifier is designed to remove 70 pint of water in a 24 hour span. It's suggested for up to a 4,500sqf room and my garage is about 400sqf.

Just curious what people thoughts are?
Any suggests?

I'm about to start doing the same thing with my dehumidifier in the next week or two when it starts getting bad here.

I think it will help quite a bit, especially if you have a fairly well sealed garage. My concern is what it's going to cost in electricity to run this thing virtually 24/7 for the next 5 months. Of course, I could only run it at times I'm going to be using the shop, but that won't help with with moisture building up on electronic parts.

I've also looked into a stand alone ac unit, which I would plan to run starting in early afternoon on days I will be in the shop. There are some good stand alone and window units around $650-800 now. But I'm going to try the dehumidifier with fans first and see how that goes.

John C Cox
05-01-2017, 9:07 AM
I run a dehumidifier in my shop (I build guitars... No lasers around.. But I did do a lot of work with precision lab equipment in my previous day job)... Often, those units are more sensitive to humidity than to temperature. And condensing will ruin your day...

In my current shop - I run the dehumidifier through a hose into the toilet. There is no bucket emptying. I would suggest thinking about the same.... Just run a hose out somewhere... That way - your dehumidifier doesnt shut down in the middle of the night because the bucket is full... And you come out to the shop and it hit the dewpoint over night.... And you now cant run your business till it all dries back out.

If you can do it - you may want to consider drying in your garage at least for the time being while your business is in there. Much easier to keep the humidity down.

Jeff Body
05-01-2017, 1:37 PM
If you can do it - you may want to consider drying in your garage at least for the time being while your business is in there. Much easier to keep the humidity down.


I'm not sure what you meant in the above sentence.


At the moment I don't think I have any other choice. I'm going to get the dehumidifier and give it a try.
I'm going to set it up at a continuous drain for sure because I don't want to worry about emptying the bucket.

I'm just hoping this works.

John Lifer
05-01-2017, 1:40 PM
But to both Keith and Jeff, you guys are both in HOT climes...... I was in central MS until the past few years and understand hot humid Months.... Wouldn't YOU be more comfortable using an AC to cool the room down to a passable level?
I'd think that it would be better for both you and the laser to be 75 degrees and 40% humidity than 95 degrees and 30%.... Just say'n! Your chiller would not work as hard either.
If the AC won't bring down humidity quite enough, you could get a much cheaper dehumidifier to go along with it. And be cooler still. THANK GOODNESS I'm in NWA! And in a COOL DRY basement to go along with it!

Keith Downing
05-01-2017, 2:13 PM
But to both Keith and Jeff, you guys are both in HOT climes...... I was in central MS until the past few years and understand hot humid Months.... Wouldn't YOU be more comfortable using an AC to cool the room down to a passable level?
I'd think that it would be better for both you and the laser to be 75 degrees and 40% humidity than 95 degrees and 30%.... Just say'n! Your chiller would not work as hard either.
If the AC won't bring down humidity quite enough, you could get a much cheaper dehumidifier to go along with it. And be cooler still. THANK GOODNESS I'm in NWA! And in a COOL DRY basement to go along with it!

We definitely would be more comfortable! The issues are:

1. A reasonable stand alone AC for a 500-700 square foot space runs about $800+, and a window unit stil about 1/3 to 2/3 of that.

2. Running it 24/7 would probably triple my utility bill, which already spikes to over $300/month in the summer months here. Even running it just on "shop days" would probably add 50%. I may be forced to do this, it really depends how much consistent work we get this summer. But even if I do, it will probably be in conjunction with a dehumidifier running 24/7.

3. Even running an AC, my garage just isn't sealed that well. And I don't think it has the same insulation as the house. So, there's a good chance that the AC might cost an arm and a leg, and only be good for about 5-10 degrees of cooling. That would still leave me working in 80-90 degree temperatures.

David Somers
05-01-2017, 2:23 PM
Just a couple of thoughts. One is that the space your laser tube is in is usually pretty small volume. With a little fussing you can probably seal it off pretty well, including the door/cover for that area. It is not like you need to be in there all there time. Once you have it pretty reasonably sealed off you could put a few cans of reusable dessicant in there and keep it dry without expending $$ in AC. You can buy cans of dessicant in various sizes and recharge them in the oven when they are spent. Their color changes when they are spent so you can easily see when they need to be changed. You could even put a small clear panel on the tube space door so you can see in to check the color without opening the door. I would not bother with products like Dry Z Air. Go with a dessicant instead that is rechargeable.

A second thought would be to take the small space model and go even further. Get some reasonably heavy rubber, like a butyl pond liner and make a generous balloon around around the working end of your tube. Obviously you need to leave the discharge end of the tube exposed. Seal it with a silicon sealant to the tube on one side, and to the end of the tube on the other without blocking the output of the tube. Now the working end of the tube is sealed from moisture without having to use energy to do it.

Having said that, I am a heat wimp....a big time, major league heat wimp. My favorite climate to live in was Crater Lake National Park in a zone that saw 600 inches of snow each year for 8 or 9 months. Seattle is nice too without all that snow. (OK....it may rain here on occasion, every now and then) So my approach to your problem in Fla and other hot humid climates would be to insulate the heck out of your garage, Bay door included, and run AC so I would be as comfortable as my laser. I used solid insulation to insulate my garage door here in Seattle and raised my garage temp 10 degrees on cold days here in winter. The walls were already insulated.

Let us know what you end up doing?

Keith Downing
05-01-2017, 2:51 PM
Having said that, I am a heat wimp....a big time, major league heat wimp. My favorite climate to live in was Crater Lake National Park in a zone that saw 600 inches of snow each year for 8 or 9 months. Seattle is nice too without all that snow. (OK....it may rain here on occasion, every now and then) So my approach to your problem in Fla and other hot humid climates would be to insulate the heck out of your garage, Bay door included, and run AC so I would be as comfortable as my laser. I used solid insulation to insulate my garage door here in Seattle and raised my garage temp 10 degrees on cold days here in winter. The walls were already insulated.

Yeah, I would say my concerns are about equal between Laser tube, computer, all my other saws and tools, and then just not being completely miserable working out there during daylight hours this summer.

David Somers
05-01-2017, 3:26 PM
Hi Keith!

I used to live in Volcano HI, up around 4,000 ft. Our climate was mild (or I would have spent my life doing a decent imitation of a limp dishrag! <grin>) both in terms of temp and humidity. But the killer for us was Vog, volcanic fog or sulphur dioxide fog. Anything rubber or metal deteriorated at speeds that were hard to believe. I could clean and protect the ways of my lathe and then go traveling for 2 weeks and come back and have to use a pad sander to get the rust off it. Stunning. With the same lathe at sea level in Seattle, and only 100 yards from the water I could go months before I saw rust on any tools. And my bicycle? I lived on a boat and the bike lived on the dock next to it. I had to hose it off to get salt encrustation off it about once a week or more. No rust though. In Volcano? Holy cow.

Anyway.....in Volcano my tools in general were OK so long as I kept lubing them and treating the sliding surfaces like the lathe bed. I wasnt into the laser back then, but if I had been I might had opted to seal the tube chamber, or the end of the tube itself and use dessicants heavily. Anything to keep that SO2 away from the end of the laser. The climate up there was mild enough that no one used more than a fan to stay comfy. AC and dehumidifiers were unheard of at that altitude. I had a friend down on the coast who did have a laser but wasnt nearly as exposed to the Vog as we were. He did OK with it. And his garage was not climate controlled at all, and kept open when he worked. The exception was a room he did up with AC in it for finishing work.

I so hate heat and humidity. And of course my job kept me in the lowlands most of the time so I was in it about 3/4 of my time there. Wimp is an inadequate term for me. <grin>

John Lifer
05-01-2017, 4:53 PM
Yeah, I understand the power bill. I ran a 15,000 btu window unit in my MS shop on occasion just trying to keep some of the moisture off of me. My shop was metal building with the fiberglass batt backed by plastic sheeting. Probably a 4 R value maybe, and 10ft ceilings and 30x30 space. So large air volume. I couldn't afford it but on just every so often when I had 6-8 hours of steady work. And would have to start it the night before to make much difference. I thought about my current shop for just a bit for my laser, it is well insulated, (normal wall insulation r13 including ceiling along with sheetrock ceiling. and pretty tight fitting. Summer would be fine with relatively small AC, but I was more worried about the below freezing months in winter. Go with the dehumidifier, it will work. I don't think you could buy enough dessicant to be significant. But I just might try walling off the laser in a corner room. You could reduce volume of air to be dried/cooled and maybe keep yourself cooler. Just a thought.

Bill George
05-01-2017, 5:00 PM
A good ideas but from a HVAC guys viewpoint either wall or seal off that area and not do the rest of the room OR keep a fan blowing directly on the tube, so condensation can not form on the glass. I am thinking of one or two of those muffin fans, 12 volt or otherwise. The moisture will evaporate before it collects to do any damage.

Jeff Body
05-02-2017, 1:08 AM
Well of course adding AC would be ideal but just isn't an option I'm willing to pay for. Along with the AC I'd have to insulate the whole garage also. Currently there's no insulation over the garage (Why? I have no clue. They just don't do that in FL) and the walls are bare concrete block.
As far as the heat I'm a born and raised FL boy and it really doesn't bother me. I'm comfortable at around 90*. I've been working on cars in the garage for years in hot temperatures.

I can't wall off the garage or do anything too crazy because I still park my toy in there, a 600hp Chrysler 300 and it's a boat of a car.

I purchased a 70 pint dehumidifier at Lowes night because it was only $30 more then Amazon and this one has a pump that'll pump the water uphill if I need to.

Well here's the outcome after 1.5 hours.
Starting off temp was 90*F , humidity was 50% with a dew point of 70.5*F
That means I could only run the chiller at about 23*C

There's the outcome after 1.5 hours of the humidifier being on.
359451 With this low of a dew point I can run it at 16*C without forming condensation. Hell yea.....
Currently it's 77*F outside with a humidity of 84%.
I think this will work. I'll be keeping a close eye on it over the next few days and see how it does.

If anyone is interested I'll keep posting updates.
I'm excited I may actually have no limitations this summer.

Doug Fisher
05-02-2017, 1:30 AM
>>this one has a pump that'll pump the water uphill if I need to. <<

Which one did you buy? That is nice it has a built in pump. While reading through the thread I was going to suggest buying one of those AC condensation pumps for your humidifier (I just routed my humidifier's tube into the current pump for my AC) but if you found a unit with a built in pump you are golden.

My main dehumidifier for my basement (laser location) must be about to go bad because it trips my GFCI, thus I am using my backup dehumidifier which does not seem very efficient anymore.

Jeff Body
05-02-2017, 1:09 PM
>>this one has a pump that'll pump the water uphill if I need to. <<

Which one did you buy? That is nice it has a built in pump. While reading through the thread I was going to suggest buying one of those AC condensation pumps for your humidifier (I just routed my humidifier's tube into the current pump for my AC) but if you found a unit with a built in pump you are golden.

My main dehumidifier for my basement (laser location) must be about to go bad because it trips my GFCI, thus I am using my backup dehumidifier which does not seem very efficient anymore.


This is the one I bought.
https://www.lowes.com/pd/Hisense-70-Pint-2-Speed-Dehumidifier-with-Built-in-Pump/50134738

It has 3 options to handle the water. You can use the bucket and empty is when it gets full, You can hook up a hose and have the water gravity feed (Continuous drain), or you can hook up the pump hose and it'll pump the water out as needed.

Matt McCoy
05-02-2017, 2:02 PM
Jeff: Are you closing up the space for the dehumidifier or leaving the garage door open?

Jeff Body
05-02-2017, 5:37 PM
Jeff: Are you closing up the space for the dehumidifier or leaving the garage door open?


I'm keeping the garage door closed. It'll never work if I have the garage door open.

David Somers
05-02-2017, 5:43 PM
Jeff,

Leaving the door open would help reduce the overall humidity in the FLA area!! You could also run an AC unit with the door open and help reduce climate change!!! <grin>

Matt McCoy
05-02-2017, 7:15 PM
I'm keeping the garage door closed. It'll never work if I have the garage door open.
Ha! OK, I'm up to speed after reading through the thread.

I'm in North Texas and we get punished in the summer for all the nice weather the rest of the year. I have a laser in my garage (insulated, but not conditioned) and run a chiller at 23 degrees 24/7. I haven't had any condensation and the tube is still hardy. The smaller lasers at my shop (insulated with HVAC) run off buckets and pumps. They're more susceptible to power loss after long jobs. I don't know if that helps, but hope you get it figured out.

Jeff Body
05-02-2017, 11:37 PM
Jeff,

Leaving the door open would help reduce the overall humidity in the FLA area!! You could also run an AC unit with the door open and help reduce climate change!!! <grin>

I'm not sure I follow. If I open the garage door how would it help reduce the humidity in the garage. I'm trying to drop the humidity in the garage lower then the outside humidity.


Ha! OK, I'm up to speed after reading through the thread.

I'm in North Texas and we get punished in the summer for all the nice weather the rest of the year. I have a laser in my garage (insulated, but not conditioned) and run a chiller at 23 degrees 24/7. I haven't had any condensation and the tube is still hardy. The smaller lasers at my shop (insulated with HVAC) run off buckets and pumps. They're more susceptible to power loss after long jobs. I don't know if that helps, but hope you get it figured out.

I've always tried to run the chiller <20*C. With the dew point at around 22-23*C I'm not willing to take the risk. I've spent way too much money on blown tubes.

Bill George
05-03-2017, 7:52 AM
Jeff you need to read what Stan posted.... its about helping reduce the RH% in your neighborhood.:D


Matt. Dew point depends on humidity and Texas may have a lot less than Florida.

Bert Kemp
05-03-2017, 8:31 AM
Jeff Dave was making a funny:rolleyes: He meant you could lower Florida's over all humidity by leaving the door open:eek:


I'm not sure I follow. If I open the garage door how would it help reduce the humidity in the garage. I'm trying to drop the humidity in the garage lower then the outside humidity.



I've always tried to run the chiller <20*C. With the dew point at around 22-23*C I'm not willing to take the risk. I've spent way too much money on blown tubes.

Matt McCoy
05-03-2017, 9:39 AM
Matt. Dew point depends on humidity and Texas may have a lot less than Florida.

It seems Dallas in July is typically ~80% in the morning and ~40-50% in the afternoon. August is a good time to take a vacation, when the temps are over 100 degrees and the humidity is high. Houston/Galveston Island/Corpus, etc. are very humid in summer, since they're right in the Gulf of Mexico. Probably closer to typical Florida climate.

Keith Downing
05-03-2017, 12:47 PM
It seems Dallas in July is typically ~80% in the morning and ~40-50% in the afternoon. August is a good time to take a vacation, when the temps are over 100 degrees and the humidity is high. Houston/Galveston Island/Corpus, etc. are very humid in summer, since they're right in the Gulf of Mexico. Probably closer to typical Florida climate.

Yep. I grew up in South Houston, and it's almost as bad as Florida, especially in the summer months.

And Austin (where I am currently located) is about in the middle between Dallas and Houston in terms of humidity.

Jeff Body
05-03-2017, 1:36 PM
Jeff Dave was making a funny:rolleyes: He meant you could lower Florida's over all humidity by leaving the door open:eek:

Yea, that flew right over my head. LOL

I'll leave the environmental changes to the politicians.

David Somers
05-03-2017, 1:48 PM
Jeff,

Apologies....I was teasing. I do that a lot. Can be a bad habit when folks dont know my sense of humor.

An old joke about Air Con systems is that we could solve summer heat in places like FLA if we all left our doors and windows open and ran our AC units a few hours every day to cool off our neighborhoods. <grin>

Along the same line.....We could probably stop climate change altogether if we simply got rid of Daylight Savings Time. That extra hour of sunlight we get is in the hottest part of the year! It has to be having an effect. <double grin>

That last one came from a conversation I was trying to have with a coworker in WA DC while I was in OR. The receptionist said that lady would be back shortly. I told her that about 1 my time would be good for a call back and there was a pause on the part of the receptionist. She finally said "buts its nearly 3 already?" I apologized and said I forgot to mention I was in OR on the west coast and and it was just coming up on lunch time for us. We were 3 hours earlier than WA DC. There was another pause and she asked "whhhhhhhyyyyyyyyy?" I was sorely tempted to explain how the planet rotates and about time zones and what not. Then I had a more evil thought and almost went on my tirade against daylight savings and the warming planet. I managed to restrain myself though. Safer, but not nearly as much fun. <grin> I never did get to talk to my coworker that day.

Malcolm McLeod
05-03-2017, 1:49 PM
Yep. I grew up in South Houston, and it's almost as bad as Florida, especially in the summer months.

And Austin (where I am currently located) is about in the middle between Dallas and Houston in terms of humidity.

Houston doesn't have humidity. They have viscosity.

Bill George
05-03-2017, 3:42 PM
In Iowa when its 95 Deg and 75% Rh they call it Corn Growing weather, I call it turn on the AC!

David Somers
05-03-2017, 3:59 PM
There is an old tale in Maine about one summer where it got soooo hot....... there was a herd of cattle out in one field with a crop of corn growing next to them. As the day got hotter the corn started popping and a light breeze carried that popped corn over into the herd of cattle. The cattle saw that white fluffy stuff floating down around them and some of them got so confused they froze to death! That was a wicked hot summer to hear folks tell it! Pretty high humdidity too as they say up there.

Christopher Cambridge
05-18-2017, 11:41 PM
I have the CW5200 chiller and am running it in what it calls "Intelligent mode" This varies the tube temp with room temp and I believe this is to minimize the risk of condensation. I have it set to keep the tube about 3.5 deg C lower than the room temp. Within a 17-25C range. So it won't go lower than 17 or allow the tube to get higher than 25 no matter what the room temp is but it will vary the temp within that range to keep things just above the dewpoint. I had to adjust a number of parameters on the chiller to get this all set but it's been working great since then. The 3.5deg split was determined using an online dewpoint calculator using the worst case temp and humidity for my area.