temperature in hydroponic (and surrounding) tiles

[darknotezero]

Hi all,

I'm diagnosing a problem and wanted to get either confirmation or, um "no that's wrong dummy" about temperature in hydroponic tiles.

I'm trying to create a sleet wheat farm. I'm managing the temp of the atmosphere by cycling in chilled hydrogen. It's a large hydrogen loop and it's not quite at a state where it can keep it under the 41F (sorry, i'm used to F numbers) needed for Sleet Wheat, but it's bordering on the edge and will eventually reach stability.

But it's been happening super slowly, much more slowly than I thought it would have, and I think the main issue I'm having in dropping the temperature effectively has to do with the temp of the water I'm using to irrigate. I think what is happening is this:

Irrigated Water comes in. Let's call it 100F just for round numbers. Fertilizer (dirt) is in the hydroponic tile. Let's say it's at 40F.

(The tile *above* the Hydroponic tile, where the sleet wheat graphic is located, is where my radiant pipe is running with the chilled Hydrogen.)

100F water doesn't inject into the Sleet Wheat itself and cause its body temp to shoot up, but it *does* exchange heat with the fertilizer. So ever so slowly, the 100F water is getting cooled while ever so slowly the fertilizer dirt is absorbing that heat. This then exchanges with the surrounding tiles, heating the tile that the sleet wheat is occupying, which makes the chill time move much gradual.

Is this accurate?

 

[Orzelek]

Two things to try:
1. Make pipes with water insulated if you don't yet (so they won't exchange heat with water)
2. Try to put thin layer of salt water or brine on top of farm tiles - it should make temp exchange with hydrogen cool down also tiles themselves a bit faster.

(not tested only seen some done - didn't try to farm it yet)

[sakura_sk]

Even if the pipes are insulated, hydroponic tiles are not, so they still leak heat to their surrounding area. 1kg of gas can't catch up to 10kg of liquid and cool it. I usually would try to feed sleet wheat, water at 5C (41F). I found it was better to heat up water from a slush geyser than cooling water from a CSV.

[NewWorldDan]

The hydroponic tiles are exchanging heat with the 5 kg of water that they are holding as well as the dirt.  They're going to heat up.  The sleet wheat itself is exchanging heat with the air that it's in, which is in turn absorbing heat from the adjacent hydroponic tiles.  The air also exchanges heat with the gas pipes which then exchange heat with their contents.

I'm feeding around 32 plants with 70F water and using an AETN for cooling.  The water in the hydroponic tiles is generally about 8F warmer than the surrounding air.  In my case, each farm plot requires around 2300 DTU/s of cooling.  In an ideal case, I could probably grow a few more plants off that AETN, particularly if I put in a cooling loop of some sort to even things out, but things are working, so why change?

[ChrisPBacon000]

I feed 60+ C water to my sleet wheat no problem by limiting flow with a valve. Each plant needs 33 grams per second so I set the valve flow as an appropriate multiple. So about 260 g/s for 8 plants, which leaves them basically on the edge of running out of water at all times. 

This keeps the amount of water in the pipes to a bare minimum. The plants themselves are growing in a cold room approx -20 C.  It is just a part of the cold space biome so I'm not actively cooling the farm. 

[JRup]

4 minutes ago, ChrisPBacon000 said:

So about 260 g/s for 8 plants, which leaves them basically on the edge of running out of water at all times. 

This keeps the amount of water in the pipes to a bare minimum.

This!

I'd guess you've chosen a practical solution to a rounding particularity that happens when planning for plants that use "3's" in their requirement. Since feeding 8 plants would take "exactly" 266⅔ g/s of water (or about 266.66 g/s) then I'd guess you've been setting the valve to 266.65 g/s or a little less...

I actually went the other way and feed exactly 100g/s to 3 plants and have a return pipe for the 96 mcg surplus so that it doesn't build up and eventually bust the line, water is collected from freshly molten ice. My wheats are happy, oh so happy ...

[ChrisPBacon000]

9 hours ago, JRup said:

This!

I'd guess you've chosen a practical solution to a rounding particularity that happens when planning for plants that use "3's" in their requirement. Since feeding 8 plants would take "exactly" 266⅔ g/s of water (or about 266.66 g/s) then I'd guess you've been setting the valve to 266.65 g/s or a little less...

I actually went the other way and feed exactly 100g/s to 3 plants and have a return pipe for the 96 mcg surplus so that it doesn't build up and eventually bust the line, water is collected from freshly molten ice. My wheats are happy, oh so happy ...

I prefer under watering so the hot water never builds up in the pipes. . It's ok if I'm not getting perfect growth because I'm only using the wheat for berry sludge for my rockets. General food is grubfruit preserves.

 Just reread and I see you mention the return pipe. That's a good plan too!

[Ntr1cate]

The water and dirt exchanges heat with the tile they are in, not to each other (meaning it becomes a fight for dominance until equilibrium is achieved with the two heat sources), however that is still governed by thermal conductivity rules so using this design of farming hydro tiles are better built out of metals with less TC values (don't make it out of steel).

When the game calculates if a plant withers or not is decided by the plants temperature and not the tile its sitting in or the materials feed to it (you can feed it 100'c [212'f] water and still have the plant grow as long as you keep the plant itself cool)

You can check the plants temperature by clicking on the plant (not the tile the plants planted in) and checking its properties.

I have used this type of design myself a few times with a proper insulated area, p/water aquatuners and a petrolium layer (run your converyer dirt lines thru the insulated tiles, only the conveyor recepticale with dirt should be in the farm area) with the cooling loop to direct cool the plants themself where I fed the plant 95'c (212'f) water (its cooled a little from said process but the piped water is still hot) direct from a geyser to the hydro tile, my issue I faced is large amounts of plants (I run 20-25 duplicant bases) require alot of cooling so you might have a aquatuner running 24/7 for 40+ plants (which is still less cooling than cooling before hand 95'c (212'f) water), The aquatuner useage is alot less noticeable when you run 5-10 plants as the aquatuner turns off for intermediate times.

The plants themselves only eat a small amount of water at a time so the water is only injected into the hydroponic tiles at a really small rate meaning its being cooled a little by the heat exchange, but is also being eaten by the plant before it hits 5'c (41'f) so it equalises about 30'c-50'c (86'f - 122'f) from 95'c (212'f)

Edit: As a side note, hydroponic tiles don't let liquids injected phase shift (water can't become ice unless you empty/decontruct the tile), so the use of a extremely colder chamber or super coolant is fine)