Run my evaporative cooler at night?

[kwarren]

I've used my evaporative cooler for 3 years and it keeps my solarium at a maximum of 85 degrees when it is over 100 degrees here in Oklahoma. It makes all the difference with my success. It's on a timer to run from 10 am to 8 pm. Two ceiling fans take over during the night. Because the humidity is higher at night I thought it would make no difference to run the cooler at night. Besides, I'm afraid the cooler motor would overheat during the day being ran 24 hrs a day. Does anybody know if 24 hr. usage would cause overheating of motor and if not, and more importantly, would running it at night make the temperature go appreciably lower than the night's outside low of 70 degrees? I hope someone more experienced would please respond with your knowledge. Thank you.

[Ray]

I assume you're referring to a swamp cooler with water pump to wet the pads and a blower to move the air into the grow space.

The pump is likely submerged, so will stay cool, and the blower is likely designed for continuous use.

However, why not put the thing on a thermostat rather than a timer?

As to whether the thing will knock down the nighttime temperature further than ambient, that depends upon the relative humidity level outdoors at night.

[kwarren]

Thank you Ray for your imput. I think I'll stay with the timer to turn on and off instead of a thermostat. I would have to learn how to install it and besides, in May - Sept here in Oklahoma it is just HOT all day long.
Yes, my cooler is a swamp bucket with pads. But the pump is not submerged. Only the intake extention of the pump is submerged so I'm still concerned with overheating if it is running 24 hrs a day. I think I'll email the Champion Company (maker) for their advise. I don't know why I didn't think of that before I posted this thread.
It's obvious from your advice that once I hook up the swamp bucket next week I'll run a test for two nights in a row to see if being run all night will make a noticeable lowering of temperature in the overnight hours. You are right also that it depends on the relative humidity.
Thanks again for taking the time to respond.

[desertanimal]

In my experience of living in AZ, yes--when it's sufficiently dry for the swamp cooler to make a big difference in the daytime, it'll make a big difference in the nighttime as well. That's why people run them 24 hours a day. You can knock 20 degrees F off of ambient temp at night and get your house down to 65F, which helps keep the house from heating up quickly for the rest of the day, too.

[kwarren]

Thank you, desert animal for your responce. We all know how hot yet dry it is in Arizona so I'm not surprised you use a swamp bucket at night. I'm definitely going to do a test soon. Here in Oklahoma get almost as hot as you do in your state but it's also humid and even more humid at night. So maybe it won't lower the temperature much. If I do use it continually I hope it doesn't overheat the motor or make a huge difference in my electric bill as my bill is already high enough because I have central air in my home even though I'm very conservative cooling my home. Thank you again for your responce.

[silken]

I like using mine at night because it raises the humidity to around 75 all night. It seems like my orchids have nice turgid leaves in the morning which I hope will help them thru the day. My greenhouse can get to 100F in the day too and we have a huge air exchanger which kicks in at around 90F. So even tho the swamp cooler is rated for a larger room than the greenhouse is, I find it doesn't keep up as well in the day. At night windows are closed and the air exchanger isn't running since its not so hot, so the humidity builds up nicely.

[Discus]

Ratings for rooms don't map well onto greenhouses, because they don't expect a room to be all windows
If you have something like that professionally "sized" you'd end up with a MUCH larger unit than for a "normal", insulated room. Typically, greenhouses have entire wet-walls for cooling, with surprisingly massive fans driving the system.

The units I've seen (greenhouse coolers) use swimming pool type pumps which incorporate air cooling (built in fan that pushes air over heatsink fins on the body) - they are capable of continuous operation. Never seen a "domestic" "swamp cooler" so not sure what these use; they ought to have something capable of 24/7 operation in them, but I guess some people cut corners...

---------- Post added at 10:33 AM ---------- Previous post was at 10:30 AM ----------

Thermostats are basically the same as timers - automated switches. You could quite easily swap them out more or less part for part; if you're worried about installation, any competent electrician could swap them out in moments.
The only two complications you might find are the rated current and voltage; if these don't match, you either need a different unit or to install a relay.

Incidentally, if you want to retain time control, there's no reason you can't put the thermostat in circuit after the timer, but be aware the timer will "win" in any decision-making wrt being off (and the thermostat likely the opposite). Wired in parallel, both can "choose", but you lose absolute time control; I wouldn't recommend this configuration. I have one circuit that drives lights that has both timer and light sensor control; using a relay, I've reversed the output of the "turns on at night" light sensor to turn the circuit off at night; the timer gives me additional control if I want it (mainly, I use it to turn the lights of for 15/60 minutes as the ballast doesn't seem to like continuous operation). It was an annoyingly expensive ballast and has never worked right (a Hagen "glo" t5 model; the right size for the tubes I'm using).

If I owned the building I live in, I would long ago have installed an "exhaust" fan that turns on if my humidity gets too high, or the temperature too extreme (with some kind of circuit to not do that if the external temperature is even hotter, which happens; it can get to in excess of 45C here on a bad day).

[kwarren]

Well, my gosh, I had to read your comments slowly and twice. My solarium has a double-wide window (e-rated double paned) on both the east and west side and the south wall (18' long) is six 3' x 6' plate glass panels which I insulate with plastic in winter.The roof is solid-decked except for (3) 2'x4' insulated skylights. The swamp bucket injects fresh and humid air from the west window and the opposite east windows are open about 6" from the top to let out the hottest air. The flow of cooler humid air is quite effective as the temperature never rises over 86 degrees when it's over 108 degrees in the summer heat. So I'm happy with the swamp bucket. All I need to know is if I run it 24 hrs a day will it hurt the motor. I'm going to email the company for their advise.
But I want to thank you for your very informative information as you took time to try to help me. Bless you!

[Discus]

Yes, the company should certainly know what the duty cycle of their motors is.

If you're not averse to opening things up, you can often work out how likely a particular type of thing is to cope with 24/7 operation (i.e. by how hot the motor runs).

Of course, just asking is usually easiest

[kwarren]

Thank you for responding again. Sorry I didn't get back with you yesterday afternoon. I live in south Oklahoma City. I'm just 10 miles north of Moore, Oklahoma so I'm sure you'll understand. I didn't have any damage, just small hail. I had my skylights covered with several layers of bubblewrap. I don't have an insurance rider for my orchid collection. I have several thousand dollars worth of orchids so maybe I should ask State Farm if it is possible. Even so, my homeowners premium is high enough because I have full replacement on structure and roof and unfortunately,because of the devastation in Moore, I fear my premium will jump again next year.
I called Champion (maker of the swamp bucket) and they assured me that I can run it 24 hrs. a day. So I'm prepared to try it but have been advised that if the summer nights are humid it would not make much of a difference in temperature. If it doesn't, then I'll turn it off and just run the 2 ceiling fans at night for circulation. Thanks again for your info.