river supplied truck radiator greenhouse cooling

As I'm currently looking for a property close to a stream/river, I was asking myself, if it would be a good idea to run river/stream water through something like
truck radiators with fans attached to cool a greenhouse? Evaporative cooling is not an option for me, as it already runs in the 80%.

It's either a really good idea or a really bad one, since nobody seems to mention it anywhere. To me it makes sense and would be fairly cheap to make and run.

I am not sure how long the radiator would last with fresh, oxygen rich river water flowing through it.
With a stainless steel radiator this may be not an issue, but a normal one… probably not too long.

Hi John;
Interesting idea.
I suspect that it doesn't make a big enough change to bother doing.
You mention your humidity is 80% I assume that the temperature is high as well.

If your greenhouse was situated directly next to a good size creek you should be having cooler temps, no matter the humidity.
If you try to plumb cool river water thru pipes of any distance, then your water isn't going to be very cool anymore when it gets there.
So I think the fans on the radiator would be the same as just having fans in the greenhouse.

Like you say, I haven't heard any mention of this in a humid environment...  I'm guessing its been tried and discounted as not effective enough.
Shade cloth does help quite a bit.
However that is just my thoughts on the matter.
If you give it a try, then let us know how well it works.

I've seen it done as a house AC with ground water from a well. The distance to the well wasn't that big and it worked surprisingly well. The distance would clearly be a big issue.

Not worth it.  My dad tried it when I was a kid.  Made 0.5 degree change.

What will make a change is to run radiant tubes under the beds and run the river water through them.  Or use a heat exchanger so you can keep clean water in the loops, that would make it easier to add a boiler and heat in the winter, too.

Consider installing a turbine generator in the creek to produce electricity to use
in the greenhouse to achieve what you have in mind.
In Australia there is one called a 'platypus' generator.
platypuspower.com.au

R Scott wrote:Not worth it.  My dad tried it when I was a kid.  Made 0.5 degree change.

What will make a change is to run radiant tubes under the beds and run the river water through them.  Or use a heat exchanger so you can keep clean water in the loops, that would make it easier to add a boiler and heat in the winter, too.

Smart dad! ;) Was thinking of that as an option, too.

John C Daley wrote:Consider installing a turbine generator in the creek to produce electricity to use
in the greenhouse to achieve what you have in mind.
In Australia there is one called a 'platypus' generator.
platypuspower.com.au

I'm only looking for mills with water rights, I just wanted to use it's thermal energy, besides using the kinetic one. Going as much Perma as I can.

this is verry doable but needs to be sized corectly things that need to be concidered is the difrence in water temperature to desired greenhouse temp size of the radiator air flow and  water flow genraly when ive seen people try this the most comon mistake is to have too little water flow and too small of a radiator a truck radiator would probably be big enough for a small greenhouse as for flow rate you would probably need somthing about equivelent to a pool filter pump obviously if you can just use the head presure from the stream that would be ideal but you would need that sort of flow rate  as for temps you would need your water temp to be at least 20 deg f below your target temp if you could achive all this you should have a good system.

another thing to keep in mind is you would want to have a verry fine filter on the system as the water ways in the radiator are easily blocked.

one pluss of this system is it would also help to dehumidify the air in the greenhouse and the condenced water could be captured for irigation

Like others,  I see a lot of potential problems with this... but I am fascinated. I suppose my first question is how big of a greenhouse? Then, how much do you want the temp to be lowered?  And, as long as i am letting my mind wander, what about a series of old home radiators? In the end, I remain skeptical,  but if you have the time and energy ....

Well...
For max bang for the buck I'd install 2 temp probes before and after the radiator, ......if your temp drop is not too drastic consider routing the outflow to another radiator, and if your temp drop there is not too drastic routing the outflow to another radiator.....

Also physics is worth its weight in mechanical energy, cold air sinks, so put your radiators near the roof to force convection.....