Karim's 1500gal dream reef

[karimwassef]

hmmm. my concern was actually pollution. These pads would be sucking in outside air directly. I was planning on using the wet pads to adbsorb dirt and bugs rather than having them end up in the tank.

I have that problem now living by the lake and having a semi-exposed system. The dirt/bug ingress is already severe during some summer months... driving me to run 3 different ATSs and a GFO.

Maybe I can run both. My biggest concern with using a swamp cooler is that they lose efficiency during high humidity seasons. Dallas unfortunately can have hot days and rain...

Extracting the humidity during the summer is my most pressing issue today... I run an AC and that helps, but 20 gallons of water a day is a lot to export though an AC.

In the winter, I have a dehumidifier than runs continuously and can keep me under 60%.

[OllieNZ]

Use carbon pads?

[karimwassef]

I think I'll have two separate loops. One with outside air and fresh water to cool the air, and another one with internal air and salt water to cool the reef.

In both cases, the issue is removing the humidity without increasing the temperature in the summer.

[Subsea]

With respect to debris pollution from the outside air, consider using nylon or fiberglass screen material in front of wet pads.

If humidity removal and people confront level in sunroom is your priority, then forget about economy of operation. Use titanium tube & shell heat exchangers to control temperature of system water with a heat pump.

[karimwassef]

I will certainly have a chiller, even if as an emergency backup.

My primary concern is running the reef efficiently and keeping it cool, but having a comfortable space to work is not insignificant.

The humidity removal is actually key to the cooling and safety. High humidity limits evaporative cooling, so having dry air is an important element of air cooling the tank. Condensation is also a big deal. When I first set up my garage-reef, the 20gals of water coated everything. I have a 12ft skimmer that looked Ike it was leaking as the humid air condensed on the large surfaces and ran down to the floor creating a puddle of freshwater.

The damage to everything metal was a secondary issue.

As far as using screens... Maybe, but it would increase the flow impedance, reducing efficiency. But maybe that's better than running two loops. Since the intake is low, close to the ground, I'll need some protection against dirt or mud, especially during rain storms, etc...

[FloformAustria]

Love it Karim!!!

Every single page of this thread is amazing!

I am tagging along!!!

[McPuff]

Originally Posted by Subsea

I suggest you use system water in your wet pads. The specific heat content of air is minuscule compared to the specific heat content of water. Meaning it will take many, many more BTU of cooling for system water than for sunroom air. The only possible downside would be salt scale on your drip pads. If you ran sufficient volum, I can't see salt scale as a problem.

I'm not sure you understand. It seems the water will be used for evaporative cooling (vs radiative) of the room itself. If he were to use system water, it would be a huge mess of salt everywhere and he'd lose system volume.

[Subsea]

Originally Posted by McPuff

I'm not sure you understand. It seems the water will be used for evaporative cooling (vs radiative) of the room itself. If he were to use system water, it would be a huge mess of salt everywhere and he'd lose system volume.

Yes, I understand evaporative cooling very well. Swamp coolers are used in low humidity environments for cooling air. However, the same physics that cools the air also cools the water. Thermodynamics 101.

I cooled a 10,000G system in a greenhouse using evaporative cooling. There was no huge mess of salt. The only system volumn lost was due to evaporation only at 100GPD during 100 degree summer days.

[Subsea]

http://pentairaes.com/water-to-water...-packages.html

I personnally think you do not want to use swamp coolers to satisfy your confront level in your sunroom. IMO, it will be noisey. Choose a seperate AC for your sunroom or run a large dual zone unit that maintains house and sunroom as seperate zones. When you are not in it, don't spend the money to cool the air.

If you use the above heat pump, your system water will act as a cooling source for the air in your sunroom. The above heat pump skid is very quiet. By using lake water you will achieve maximum efficiency transferring BTU's compared to using air.

[karimwassef]

Where would you place the swamp cooler? It would need to be in a cool dry area.

Maybe I can combine it with my external sun-lit ATS in a mini-greenhouse with forced air ventilation?

[Subsea]

I think you should leave swamp cooler out of consideration. Instead use titanium heat exchanger skid with water to water cooling and heating from lake water to maintain system temperature.

To maintain sunroom temperature use a seperate AC or use zone cooling with your main AC.

[karimwassef]

A geothermal loop would be good, but I don't have access to the lake in the new location.

I actually buried titanium lines under my backyard deck in an experiment but never completed it. I have too many projects in the air sometimes.

The cooling cost is not an insignificant element of this sunroom design.

I was first planning on an AC cooled area...

but then I wanted fresh air for some months of the year, so I migrated to a combination of automatic rooftop glass vents with fresh air intake fans from the ground level...

I didn't feel like that would have enough airflow, so that morphed into vent fans on the roof (back away from the sunlight) and intake windows at ground level...

But then, that air inlet could be hot, so it needs cooling and a wet screen would provide evaporative cooling for the inlet air...

So ... Swamp cooled sunroom (for some months) and HVAC/heat pump for other times...

But then you asked about using salt water for the cooling...

I talked about dirt ingress through the low window intakes...

I had concerns over humidity extraction and you had concerns over noise... All valid...

Now back to just AC!

So... I still like fresh air, so maybe I'll just have more windows that can automatically open, as well as the large folding doors to the backyard?

That seems to be the middle ground balancing point

[dave.m]

Sun rooms are a a design disaster. They are either too hot or too cold, and will cost you a fortune over time to heat/cool them. Perhaps it would be easier to rethink the sun room option altogether (?).

Dave.M

[Subsea]

Karim,

If the primary goal is to use natural sunlight, consider fiber optics to bring in the intense light without the associated heat.
As Dave said, sunrooms are a disaster for heating and cooling.

[karimwassef]

Yes, they are painful to control temp. Light tubes are incredibly inefficient.

If they were effective, we wouldn't have greenhouses...

I prefer the aesthetic of a sunroom. So tank or not, the sunroom is a design element I enjoy. The tank just complicates the cooling, heating and humidity.

[McPuff]

Originally Posted by Subsea

Yes, I understand evaporative cooling very well. Swamp coolers are used in low humidity environments for cooling air. However, the same physics that cools the air also cools the water. Thermodynamics 101.

I cooled a 10,000G system in a greenhouse using evaporative cooling. There was no huge mess of salt. The only system volumn lost was due to evaporation only at 100GPD during 100 degree summer days.

It was no offense meant. But I still don't see how using salt water would not result in salt creep everywhere.

[karimwassef]

Evaporation would drive water into the air and it would have some quantity of salt. But since the medium itself (pads or cloth) is constantly wet, it wouldn't necessarily creep. It's not evaporation to the point of drying, just enough to cool.

[Subsea]

Originally Posted by karimwassef

Evaporation would drive water into the air and it would have some quantity of salt. But since the medium itself (pads or cloth) is constantly wet, it wouldn't necessarily creep. It's not evaporation to the point of drying, just enough to cool.

Adjustment of water flow rate determines the balance of evaporating to the point of drying. If flow rate was too low, scale could form and possible build up. Keep the flow rate up.

[karimwassef]

I was thinking of a passive water trough with fabric pads that wick the moisture up. As the water level in the trough drops, I automatically add water back.

[Subsea]

Originally Posted by karimwassef

I was thinking of a passive water trough with ofabric pads that wick the moisture up. As the water level in the trough drops, I automatically add water back.

I don't think water would wick up with air coming across pads.

Standard swamp cooler operation uses a water header at top of water pads. Adjustment to water flow rate is made with fans running.

[karimwassef]

so the evaporation rate, even with no forced air (no fans) would be higher than the wick rate into the pads?

My idea was to go with passive cooling - windows at the bottom and vents (not forced) at the top. The idea being that hot air naturally rises up and out and the inlet air is cooled through evaporation and stays low... pushing the hot air up.

[Subsea]

Using wick water makeup would be extremely passive, with little efficiency. Like anything else, there is a balance to be achieved. First, I would use vent fans in the ceiling. They would move heat from the highest point of air rising naturally with temperature gain. Vent fans could be adjusted for both air flow and quiet operations. You will have to find the balance between air flow three wet pads and water flow from top to bottom. Heat gain and evaporative cooling required in April will be differrent in Ausgust. With fan air volume adjustable to BTU demand and noise pollution all requirements can be satisfied.

When I spoke about specific density, I was addressing the thermal stability of water in your large system. Dry air takes fewer BTU to change temperature than damp air. The biggest consumer of energy in room air conditioning is "latent heat" or water vapor which we call humidity. Consider a large volumn of water contained under ground to benefit from geothermal energy gain. Use that same geothermal sink as an extender of system volume. The biggest advantage to thermal stability with a large reservoir is that heat removal equipment could be undersized. Meaning that system volume was large enough to prevent excessive temperature swings during the hottest parts of the day or the coldest part of the night.

I would use a heat pump with titanium tube and shell heat exchanger for my tank water. Use the link that I provided and get good engineering tips. I guestimate you will need a 5 ton unit.

As climate calls for it, use evaporative cooling in sun room but allow for central heating and cooling for big segments of the year.

[karimwassef]

I agree.

That's another design point on the continuum of cooling options I discussed earlier. Using DC fans and a trough water level monitor, both can be optimized to self adjust. I haven't figured out how to automatically trigger shutdown during inclement weather events though. I was thinking of an online weather alert trigger.

On the humidity - yes. This is by far the most worrisome. Not only for comfort or metal degradation but because it significantly reduces the cooling capacity of the air. Unfortunately, this puts the swamp cooler above at a disadvantage since the output is cool humid air that may be ineffective at cooling the tank water. I just imagine beads of water running down the sides of the tank glass and making little puddles on the stand and floor.

This is why a humidity sensor is just as important as a temp sensor. Above a humidity level, the swamp cooler should shut down and let the HVAC remove heat and humidity. In a warm rain for example, only the HVAC could provide any value. On a cool dry summer day, the swamp cooler can add value again. It may be best to actually monitor the five variables: outside and inside air temp, humidity + inclement trigger, then use a decision matrix to control the five elements- chiller, heater, HVAC, swamp cooler and dehumidifier (winter use).

The geothermal has been a back burner concept for years. I think the heat pumps are pretty expensive and was leaning towards buried titanium rods to pass filtered tank water through. I even buried 200 ft of titanium tubing to test, but never completed the experiment. Using an underground water reservoir with a heat pump is interesting. The inaccessibility is what bothers me though. If something goes wrong, it becomes irrecoverable.

Maybe a buried water basin with titanium tubes running through it carrying tank water? There would be fewer heat exchange elements and cost would be the lowest. The water would need to be sterilized and filtered first though it I might develop sponges in the long dark tubes.

Maybe use PEX for the in and out to avoid ground stresses from damaging the connection.

[karimwassef]

Here's my incomplete geothermal project in my backyard

[karimwassef]

Finished


Ok. It wasn't a real geothermal because I could only go down 2ft... But the idea was to collect data on flow, temp, degradation over time.

I took it seriously enough to lay the pipes, but didn't have the bandwidth to follow through... Silly scientist!

The pipes are still there though, waiting to be run and tested. And that may have been the engine of procrastination... I can always do it tomorrow, umm.. Two years later