Reply to Thread

Originally Posted by Gernby

If I kept it dry, and only ran it during the cooler hours, like 10 PM to 10 AM (continuous), do you think there would be much risk?

There's lots of risk. Moisture alone can cause things to become energized. Things that arent supposed to be, like your body.

One option I'm considering is to relocate the chiller to my garage, but I would need to improve ventilation in the garage to keep the temperature down.

Originally Posted by HVAC_Marc

An outdoor unit is protected from water and may have low ambient pressure or fan cycling controls.

If I kept it dry, and only ran it during the cooler hours, like 10 PM to 10 AM (continuous), do you think there would be much risk?

An outdoor unit is protected from water and may have low ambient pressure or fan cycling controls.

I'm curious if you guys can help me figure out the best way to reconfigure my system for summer. I've had the chiller running inside the house with great results, but now that it's getting so hot, I need to relocate the chiller outside somehow. Does anyone know what about this condensor makes it "indoor", or what it would take to make it an "outdoor" unit? It's not clear whether the indoor designation is due to it needing to stay dry, or if it has to do with ambient temperature.

1. No heat change process is 100% efficient - something is always lost in each step of the exchange process.

2. The nature of an A/C evaporator's design is such that it cannot tolerate any frosting.

3. So the refrigerant evaporating temperature cannot fall below about 30-32º F.

4. The approach of the evap is unlikely to be less that 10º, and may be greater, so your minimum air 'off-the-evap' temperature is unlikely to ever be less than 42º.

5. Getting the heat out of water without large surface areas is difficult and slow.

PHM
---------

Originally Posted by Gernby

Hi, I'm working on an HVAC project, and am trying to figure out the best way to chill some barrels of water. My current plan is to buy an air-to-water heat exchanger (like a car radiator), and install it in an air box next to the air handler in my attic. I would connect that box to the air handler with 2 flex ducts (1 to the return side and the other to the supply side). I would also put a motorized damper in one of those ducts to prevent air flow through the air box during normal operation.

The damper would be closed almost all the time, but whenever the AC is running AND the thermostat is about to turn the system OFF, I would have a "piggy-back" controller take control of the system. If the temperature of my water tanks is higher than I want, then the controller will keep the AC running while the motorized damper is opened up and water starts pumping through the heat exchanger. While running like this, I believe there will be very little air flowing through the rest of the ducting, since most of the air should be "short circuited" through the heat exchanger.

I haven't done the math about how large the ducts and heat exchanger need to be, but it seems that as long as I can pump enough heat through the heat exchanger to maintain 15-20F across the evaporator coil, then I should be able to chill the water down near freezing. That might take a large sized exhanger and water pump, but it seems possible.

Do you guys agree? Am I correct that the air looping over and over between the evaporator coil and exhanger can be super-cooled (at or below freezing), as long as a 15-20F temp drop is maintained across the evaporator?

Do any of you guys have any suggestions about how I can derive some sort of "performance index" based on weather parameters, indoor parameters, power usage, and / or electric cost, in order to dial in my system a little quicker? It doesn't have to be elegant, and could even be unit-less. I just need some way to know whether some change to the system causes a positive or negative result.

Originally Posted by dave sulz

How do you think a compressor hat runs above freezing work below freezing. I hate nonsense. I'm not smart but recoconize dumbass. Sorry stupid should be told

Wow you should be outed..you don't belong on this forum...

I've really been enjoying the hot weather we've had over the last week! It gave me several days of much anticipated testing and development! It got up to 94 degrees F a couple days ago, and the "Cold-Pacitor" was able to keep the 1st floor at or below 73.2 F during peak pricing (3PM - 8PM) with just a few minutes of assistance at the end from the LG mini split.

Sorry I missed this post! That's interesting!

great work!

Originally Posted by dave sulz

How do you think a compressor hat runs above freezing work below freezing. I hate ***** {ranting deleted}

Should work great if it's not flooded. And, it has.

Back up, rethink what you say. It may not be overly efficient or pretty but the OP likes it and it works. Many things were thought of the same way in the way you talk, but are considered standard now.

Originally Posted by Gernby

Where are your sumps that would allow just a foot of head pressure?

In the back of the main tank

Try heating water for a pool

How do you think a compressor hat runs above freezing work below freezing. I hate nonsense. I'm not smart but recoconize dumbass. Sorry stupid should be told

Originally Posted by HVAC_Marc

I have about a foot of head, but I run everything except the wave maker wide open. The wave maker is pulsed 5 on/5 off.

Going way off-topic, but this is also an interesting topic...

Where are your sumps that would allow just a foot of head pressure?

I use a custom / non-conventional wave maker (no pumps), but do have a couple Gyre pumps for programmable linear flow. I don't know how much heat they contribute.

I have about a foot of head, but I run everything except the wave maker wide open. The wave maker is pulsed 5 on/5 off.

Originally Posted by HVAC_Marc

I also have Tunze DC pumps and LED lighting, plus the return pump and a sterilizer. I took out my heaters. They never run.

Wow... I'm surprised you would be getting so much heat out of those. Do you run a lot of head pressure? My pumps are smaller in size, and run at part throttle, since I only have a couple feet of head pressure. The sumps are located in a stairway closet (elevated), so that the overflows can run at full siphon without noise.

I also have Tunze DC pumps and LED lighting, plus the return pump and a sterilizer. I took out my heaters. They never run.

Originally Posted by HVAC_Marc

I run my tanks at 80-82. Most corals dont like temps above 90. I have an internal short in a UV sterilizer that acted like a heater. I had 94 for 2 days that caused green algae bailout. Most things recovered, some died, some came back with different colors. I let my pumps and lights bring the water temp up. My house runs at 70-72 all the time.

Damn ... My prior aquarium in my last house ran in the lower 80's, even with a chiller on it. However, my new systems have DC pumps and LED lighting that don't put out much heat at all.