Porta Cool

[Ron_CA]

So, I did a test with my porta cool 48" yesterday and wanted to get a little feedback.

Humidity was at 10% and temperature @102 inside my garage when I did this.

After and hour temperature was 85 and humidity was around 45%. This was with the garage door open which faces north so no direct sun. So, noticeable improvement and felt much better

Is there a percentage that I should try to limit the humidity to a lower percentage with cars inside the garage or is this Not a big deal?

 

[therealjakeg]

I am interested in this to see if anyone chimes in. Past summers I have noticed that my stored scrap metal and anything not coated has a nice film of rust on it by fall. I am in Arizona and found that if I left my unit in the garage with water it would do this even when not on..

 

[Fixin'Stuff]

What is the ventilation method for getting stale air out of the shop as the Porta Cool pumps cool air in? Swamp coolers dump cool, moist air into the building. You need open windows to let the moisture out and some dry air in. I know it seems counter-intuitive to open the windows when you're trying to cool the space, but it's the only way to keep the humidity somewhat under control. You're dumping a LOT of water into the air.

 

[Ron_CA]

Garage door was open but no windows open. Shop is 2000'.

Did another test with garage door open one foot and one window cracked open and humidity went up to 58% and temp only dropped to 92 degrees. Felt better before with low humidity and higher temp.

So, Fixin'Stuff apparently you are correct with needing more ventilation.

 

[Shop Specialties]

36" should have been adequate for only 2,000 sq foot. Proper airflow is very critical is getting the most out of your cooler. Whenever I set one up I always try to go with the natural airflow of the shop. If you try to blow against even the slightest of breezes Mother Nature will always win.

 

[Ron_CA]

Yep, I'm kinda thinking that you are correct that a little smaller would have been better. I negotiated this one in to the deal when I bought this place so...

 

[Corndoggeh]

You can also use this handy chart that I learned to use in a thermo class, its actually a pretty helpful way to determine where you are at and where you can go. However, you should in real world application that a swamp cooler will be able to cool at least 30 degrees F from the outside temp and anything lower than that would be caused by an inefficient part of the cooler (squirrel cage RPM, motor, type of padding, etc).

https://teachengineeringprod.blob.c...es/cub_housing_lesson01_activity2_figure1.jpg

 

[Ron_CA]

CD I can't figure out what that chart means. I know it is some real smart sheit, but I be dumb

 

[Corndoggeh]

So you have your dew point which you can usually find on a weather app for your area. Wet bulb is when you dip a thermometer bulb in water and recorded the temp of the bulb when the water evaporates. Dry bulb is the thermometer temp before dipping it into the water.

Connect all your points on the chart and you can plot where your expected temperature can be. For a swamp cooler the chart will go up and left. Increasing humidity while decreasing temperature. So you going from 102 to 85 with 10% increasing to 40% is pretty close to ideal. Most likely what your difficulty will be is the saturation of your pads and the air flow through said pads. In my case (for a house swamp cooler)doubling the pads and using a 1hp motor like I have. If you live in the southwest you can run it all night where it drops to mid 60's and slowly increases through the day, however, by the time the temp hits about 75 - 77, its sundown and the house begins to slowly drop temperature again.

In the case of your portacool and for the garage, if you can get it at 82 I would consider that as a decent temp to work in where your not sweating like a pig and since you can't run said portacool all night it would be understandable that it would be difficult to get it any lower since everything around it was heated to room temp before turning the ports cool on.

 

[bdamico]

Florida guy says 45% humidity would be 50% improvement in garage

 

[Ron_CA]

CD thanks for the explanation. I got it.

bamico lol, I know...right...