Evaporative Cooler for Basement Grow room

[PeteM]

Hi All,
I wanted to post this information that I collected after using an evaporative cooler during this past summer in my basement grow room. I wanted to post all the details as my time is limited, I'll come back and expand on parts that need more clarity.


Baltimore, MD basement orchid grow room specs:
- The room measures 19ft wide by around 22ft long with a ceiling height of 7 1/2 feet.
- 4mm 'coroplast' sheets (Laird Plastics, Baltimore) seal the ceiling.
- Sliding patio door installed for access from the interior of the house. The room runs the entire width of the townhouse.
- Two large windows located on the front side of the grow room (front of the house), are opened in the summer to help air transfer during the warmer months of the year.

6 lights total, almost all on light rail Gualala Robotics / LightRail movers:
- 5 LED grow lights
- 2 PARFACTWORKS RA2000 w Full Spectrum LED Grow Light Growth Lighting Bulb
- 2 1800 Watt X6 Cob Led Grow Light Full Spectrum Led Plant Light with Daisy Chain
- 1 COB LED Grow Light Full Spectrum, CFGROW 360W LED Plant Grow Lamp
- 1 HID, Sun System Grow Lights - Digital 400 Complete System - 400W | 120/240V
- running a Hydrofarm BUSUHL400HZAS Hydroponic Growing Bulb

Water:
- RO system, (First Rays Grower’s RO System)
- 35gal storage tank (trash can) with float valve is connected to a watering wand / hose with a SEAFLO 33-Series Industrial Water Pressure Pump w/Power Plug for Wall Outlet - 115VAC, 3.3 GPM, 45 PSI.
- Floor is treated concrete, with 4 triangular shaped 'panels' sloped to an X shaped drain in the middle of the room that dips to one end at the lowest point towards a sump pump.

These are my target grow room Temps / Humidity:
Temps:
- Day 78F / never over 80F
- Night: 68F

Humidity:
- Day: irrelevant in Baltimore with open windows, this will always be OK.
- Night: 90% RH.


Evaporative Cooler:
Purchased April 2. 2020, on Amazon for $199, discounted for damaged package.
Hessaire MC37M Portable Evaporative Cooler, 3100 Cubic Feet per Minute, Cools 950 Square Feet:




- Installed for first time use at the end of Jun 2020.
- It's important to note that you need to provide airflow through the room you intend to cool. There needs to be two sides of the room open to promote airflow, or else you will be pushing and trapping large amounts of water into the air. For this I kept the sliding patio door open on the back side of the room directly behind the evaporative cooler, and the front two windows located on the opposite side of the room, open on 24/7.

- Connected to a hose, this model requires the user to physically set the three dials,
1- water pump on / off, 2- fan speed, 3 - oscillating wind direction. Generally, how this works is the pump pushes water up from the reservoir tank at the bottom of the machine and spreads the water across the top of multiple vertically positioned cardboard like corrugated 'cooling pads'. The water wets the pads and the fan blowing behind these pads pushes air over the pads and evaporates the water, cooling the air. This requires very little energy compared to an AC unit.

- My initial operation included setting the machine to the medium fan speed 24/7 with the pump on 24/7. This was found to decrease the temperatures on drier days, and increase nighttime humidity significantly. However, after experimenting I found it best for my conditions to run the medium fan speed 24/7 and the water pump on only at night. Stopping the pump in the early morning and draining the tank reservoir completely allowed the fan to dry out the evaporative cooling pads during the day. This promoted higher daytime temps, allowed for a change of fresh water to the system / tank, and targeted cooler night temps with increased humidity. Also on occasion, during heat waves, where the temps were over 95F, I would turn on the evaporative cooler pump during the day.

- One draw back to this method was rainy weather. If it rained at night when the pump was set on, the humidity built up to a level where the cooler was unable to drop the night temps as needed.

2019 summer Temps and Humidity for comparison:


2020 Summer Temps and Humidity:



- During the heatwave we endured in July, the outside temperature was hitting 100, and the evaporative cooler kept my basement at 74F with the front grow room windows wide open. That in itself was amazing to me, and made me think more about why this energy efficient technology is not dialed in more for residential use in our region. I guess it is not consistent enough at night.

July 20, 2020: Outside Temp 99F @ 4PM



July 20, 2020: Inside grow room Temp 73.9F @ 4:53PM:




- Interesting note, this evaporative cooler is illegal in California and possibly other western states, directly related to water conservation measures implemented in dry aired environment.

I hope this information is useful to someone. It feels good to get these details posted finally.

Pete

 

[Linus_Cello]

growing draculas next?

 

[PeteM]

growing draculas next?

Anything is possible, I have not been running a monkey face fever .... yet.

 

[musa]

Your setup is very impressive, Pete!
Your average temp is my minimum and your average humidity is my absolute maximum (peaks after watering). You see, you have done a great job!

Is there any reason for combining all these different light systems or is that just by chance and availability?

 

[PeteM]

Your setup is very impressive, Pete!
Your average temp is my minimum and your average humidity is my absolute maximum (peaks after watering). You see, you have done a great job!

Is there any reason for combining all these different light systems or is that just by chance and availability?

Thanks. I migrated from all HID 250w fixtures and bulbs to LED. The selection was mostly based on the most powerful LED lights in the broadest spectrums available at the time for a reasonable price. Under $150 US was my target. However, since the technology is so new, I wanted to test a few different models. I like the COB lights as they have a much wider footprint than the individual diodes and my other non orchid plants lining the perimeter of the grow room like Airoids have responded very well to this particular spectrum, which seems to be shifted in the lower microns .4, possible UV, but definitely not UVB, I have a UVB meter for a reptile I keep and none of my lights produce UVB.

One drawback I have seen with this particular LED COB light (1800 Watt X6 Cob Led Grow Light) is that new growth in cattleyas show a strong anthocyansis in some species, specifically one of my Laelia milleri was a dark dark purple until I moved it under a different light. However, other orchids like Phrags and cattleya hybrids have no response and they sit directly under the light rail at nadir.

This sector continues to evolve at a fast clip with the help of the US cannabis industry. The metal halide bulbs and fixtures are becoming harder to source. But I do like having one in the grow room, a little added heat, and it also helps to zap any stray bugs. Eventually I will need to replace it.

 

[littlefrog]

Awesome setup! I've seen that reddening of the cattleya leaves under my LEDs as well. I don't think it is necessarily bad.

I was big on COB lights for quite a while, and still have many, but I'm starting to lean towards these : Horticulture Lighting Group Premium LED Grow Lights for Agriculture Main problem with the COBs was when the fan goes out, and they seem to go out with some regularity, they overheat and cook. The panels are passively cooled (or at least the ones I use are, there are panels that need active cooling).

Definitely been lots of changes since I started using LEDs. Almost 11 years ago now. Early adopter, means I have lots of scrap aluminum and LED strips.

 

[PeteM]

Awesome setup! I've seen that reddening of the cattleya leaves under my LEDs as well. I don't think it is necessarily bad.

I was big on COB lights for quite a while, and still have many, but I'm starting to lean towards these : Horticulture Lighting Group Premium LED Grow Lights for Agriculture Main problem with the COBs was when the fan goes out, and they seem to go out with some regularity, they overheat and cook. The panels are passively cooled (or at least the ones I use are, there are panels that need active cooling).

Definitely been lots of changes since I started using LEDs. Almost 11 years ago now. Early adopter, means I have lots of scrap aluminum and LED strips.

Thanks. Agreed. I have already replaced two fans. Luckily I am in the orchid room every day and when the fan starts to go out it rubs and makes a slight sound. It seems easy enough to perform surgery on, but not a long term solution. William Green (My Green pets) has recently moved to spider farmer LED's. It's interesting to me to see this trend in LED's moving to these slim boards.. Do you find the boards on this link you provided to have the same footprint as a COB? which board model and light spectrum have you been using 3000k, 4000k? Thanks!

 

[NYEric]

Just curious, how is that a basement? Looks more like a first floor/ground level garage.

 

[richgarrison]

Hey Pete... thanx for posting this... wish i had seen a similar post a while back would have saved a lot of dough buying stuff i didn't need to...

Mostly i'm referring to your water setup... hopefully this slight diversion from the evap cooler topic is ok for most...

do you find the on demand pump you purchased sufficient to support decent water pressure from say a dramm yellow head?... do you ever run fogitt nozzles for watering? and if so, does the pump support that in a reasonable way?

separate topic...

what are you using for environment sensors/instrumentation, data capture, and reporting? nice visualizations of your environment...

 

[littlefrog]

I've been using the QB120 boards, which are probably under-powered for your application. But they make bigger. I'm using a mix of 3500k and 4000k.

I have tiered shelves, and they are a bit over 30" apart. So on the most recent project, I used the QB120 boards, six of them over a 16' x 2.5' bench, evenly spaced at 30" above the shelf. A couple reasons. 1) they are flat, I gained three or four inches of height (they are attached directly to the wire shelf above). 2) I can drive them at whatever power I want. I replaced at least 15 of the lights I was using before. Since I'm fairly close to the bench below, I wanted the 'spread' of the board rather than a spotlight effect. The series of six can run off one driver, I picked one that I could adjust both current and voltage but I'm only adjusting voltage. So, I have one driver, running at something less than 50% of the rated power to get to the light level I was getting before. Of course if I wanted to grow something brighter than paphs I could just crank up the power... It is really bright at full power.

It is really hard to compare directly (I have a watt meter but I didn't check the old setup before I had to replace it because several lights were broken), but I'm definitely getting more light for less electricity. Plus the format is just a joy to work under, no lights hanging down, flat angle so that I can barely tell that the lights are there (I was always getting light in my face before). I'm very happy with it. Just in time for them to phase out those boards, I think. That worries me a bit, I should probably buy some extras.

The shelf below that is running a homemade light I built out of 30W COB chips. Not premium grade, I can't afford that, but a solid brand that I can't remember. Verilux? Something like that. The cheap ones on amazon are not good, don't buy them. I've done that research for you, it is expensive and frustrating... Those are attached to a heavy piece of aluminum ('T-bar'). Also not driving those all the way, they are running about 70%. I like those too. But the light spread is better with the panels than the COBs.

I have another string of six mounted a bit higher over my 'bright light' bench. Those lights are hanging from the ceiling. I made a rack for them out of two pieces of very lightweight aluminum angle. Looks great, really easy to do, easy to hang. That string is running at something closer to full power and I'm blooming terete vandas under them in the winter... I think that is a good sign. That set is covering an area 16' x 5'.

 

[musa]

Thanks for all the information!
To both of you. I'm glad for all the input.
I tried to do a LED lightening, but it was unaffordable for me. I grow my orchids on shelves (8 m alltogether), vertical farming so to say and therfore I need long units which can be placed quite close to the plants. Further on I grow in my livingroom, so only passive cooling is possible.
In your link, Pete, there is only the HLG saber 100 suitable, but at 229$ per unit thats unfortunately too expensive... so I'll go on with my tubes and will wait till LED tech. gets cheaper.
The shifted spectrum for aroids is interesting as Im growing Amorphophallus, will keep that in mind.

Sorry, didn't see the last post.

 

[littlefrog]

I think I may have confused myself. I'm probably running at constant voltage, and varying the current. That makes more sense.

I've been using the QB120 boards, which are probably under-powered for your application. But they make bigger. I'm using a mix of 3500k and 4000k.

I have tiered shelves, and they are a bit over 30" apart. So on the most recent project, I used the QB120 boards, six of them over a 16' x 2.5' bench, evenly spaced at 30" above the shelf. A couple reasons. 1) they are flat, I gained three or four inches of height (they are attached directly to the wire shelf above). 2) I can drive them at whatever power I want. I replaced at least 15 of the lights I was using before. Since I'm fairly close to the bench below, I wanted the 'spread' of the board rather than a spotlight effect. The series of six can run off one driver, I picked one that I could adjust both current and voltage but I'm only adjusting voltage. So, I have one driver, running at something less than 50% of the rated power to get to the light level I was getting before. Of course if I wanted to grow something brighter than paphs I could just crank up the power... It is really bright at full power.

It is really hard to compare directly (I have a watt meter but I didn't check the old setup before I had to replace it because several lights were broken), but I'm definitely getting more light for less electricity. Plus the format is just a joy to work under, no lights hanging down, flat angle so that I can barely tell that the lights are there (I was always getting light in my face before). I'm very happy with it. Just in time for them to phase out those boards, I think. That worries me a bit, I should probably buy some extras.

The shelf below that is running a homemade light I built out of 30W COB chips. Not premium grade, I can't afford that, but a solid brand that I can't remember. Verilux? Something like that. The cheap ones on amazon are not good, don't buy them. I've done that research for you, it is expensive and frustrating... Those are attached to a heavy piece of aluminum ('T-bar'). Also not driving those all the way, they are running about 70%. I like those too. But the light spread is better with the panels than the COBs.

I have another string of six mounted a bit higher over my 'bright light' bench. Those lights are hanging from the ceiling. I made a rack for them out of two pieces of very lightweight aluminum angle. Looks great, really easy to do, easy to hang. That string is running at something closer to full power and I'm blooming terete vandas under them in the winter... I think that is a good sign. That set is covering an area 16' x 5'.

 

[Duck Slipper]

WOW!
I’m impressed!

 

[PeteM]

Thanks for all the information!
To both of you. I'm glad for all the input.
I tried to do a LED lightening, but it was unaffordable for me. I grow my orchids on shelves (8 m alltogether), vertical farming so to say and therfore I need long units which can be placed quite close to the plants. Further on I grow in my livingroom, so only passive cooling is possible.
In your link, Pete, there is only the HLG saber 100 suitable, but at 229$ per unit thats unfortunately too expensive... so I'll go on with my tubes and will wait till LED tech. gets cheaper.
The shifted spectrum for aroids is interesting as Im growing Amorphophallus, will keep that in mind.

Sorry, didn't see the last post.

I don’t think i provided a direct link, you are probably referencing the other reply from littlefrog. Let me know otherwise and I can be more specific if needed.

 

[PeteM]

Just curious, how is that a basement? Looks more like a first floor/ground level garage.

Almost didn’t post this.. embarrassing planter boxes. I got so sick of watering these ever day I just decided to see what weeds would survive the fully exposed conditions.... I’ve got lots of other excuses too, just ask the wife. Although these boxes are unpopular with the neighborhood garden club, with the basement windows open I get a lot of foot traffic from neighbors walking dogs, kids peeking in with both hands on the screen, Millennials snapping pics, and many complementing conversations while I’m watering that usually end with.. ‘Well What do you do with all of these?’. l..

For the most part people are inspired and it feels good to share these plants and blooms.. especially this past summer when a walk around the neighborhood was the only daily escape for being stuck at home.

 

[PeteM]

Hey Pete... thanx for posting this... wish i had seen a similar post a while back would have saved a lot of dough buying stuff i didn't need to...

Mostly i'm referring to your water setup... hopefully this slight diversion from the evap cooler topic is ok for most...

do you find the on demand pump you purchased sufficient to support decent water pressure from say a dramm yellow head?... do you ever run fogitt nozzles for watering? and if so, does the pump support that in a reasonable way?

separate topic...

what are you using for environment sensors/instrumentation, data capture, and reporting? nice visualizations of your environment...

Hi Rich, hope you are doing well.
I do not have a yellow head, I do have a red head, and there is not enough pressure. However, I use a hose that has a lot of surface area in the coils and probably does a decent number on the overall psi.

This is the water setup and what the stream looks like when it hits the break. I have found with my over crowded tables I prefer the smaller nozzle/ stream. I’m able to focus water on the roots only.



I keep a chameleon in the room, so I also have a separate mistking pump, Dedicated to a mister in the cage. I would highly recommend looking into this product for misting, it runs super quiet, has a nice digital timer and a very fine mist. This pump runs water out of the white bucket reservoir, which is kept on top of the main RO storage tank.



For temp and humidity I use SensorPush
You can find them on amazon, these little blue squares you can set around the room. A little pricey, but I also purchased the router so I can log in anytime from my cell. Batteries are easily changed when they run low. You can also set alarms for temp and humidity dips or spikes so you can be alerted on your phone. It makes growing much easier when you are really trying to dial in conditions. Hope that helps.

 

[richgarrison]

yup all good info....
I went the shallow well pump route (more complex and pricey, but great delivery... ) money already spent so it's in the oh 'well' category ;-)

i have sensors from acurite, which have some issues with water, but mostly reliable... as they start to crap out i'll look into your stuff seems nicer.

thanx for all the info, and especially the photo of the water stream most communicative

 

[NYEric]

I see, the old Brownstone step down! I would have put Cyps in that box!

 

[gego]

Pete, watch that humidity in the evening.
Nice piece of work you have.
Good luck

 

[magnoliasplanties]

Oh my goodness, I'm in baltimore MD too. Your set up is amazing!