Considering a Glacier evaporative cooler

[stevo777]

As a preface, I’ve pored through all the chiller threads, but would still appreciate any advice from all you knowledgeable contributors….

With the combination of daytime temperatures regularly above 100-105 degrees F, and covering the pool at night or when away, I’m finding the pool temperatures sitting around 95-97 degrees. Yes, I could leave the cover open at night, and yes, that does help, but my wife goes “ick” when she discovers yet another dead rodent in the pool. I have sorted out what the plumbing would look like to retro-fit a chiller, and see some possibilities of automating the setup into our EasyTouch system. I think the chiller would be effective in St George’s hot, dry desert climate.

Yet, some questions remain…

1. (Maybe the biggest). In their user/installation manual, Glacier recommends running the variable speed pool pump on max. All night. That would completely negate the cost savings of a variable pump. I usually run it at around 1800-2000 rpm, which is a good balance for me between energy efficiency and skimmer/filter effectiveness. Does anyone have experience or knowledge on this requirement?

From the manual, pg 4:
NOTE : Variable Speed Pumps – If you have a variable speed pump, you have to set the pump speed on high and run the unit during night time hours on this speed to cool. Once the variable speed RPM’s change to low the unit sprinkler pipes will not spin and it will not be cooling. The cooler relies on the flow rate from the pump at high speed.

2. Glacier recommends use of 3-way automated valves on the input and output side of the chiller, and to set the valves:

From the manual, pg 13:
“Do not pre- set the actuator. Allow the actuator to open 100% for the water flow rate to the cooler. ONLY set the ball valve at the cooler to 10 -15% percent open for the flow rate into the cooler. This ball valve setting is permanent.”

This does not make sense to me. Why is a 3-way valve needed? What does make more sense to me is to use cut in PVC tees at the filter output and at the pump input, and place 2-way actuators on the legs that go to/from the chiller. Opening these valves let water flow to/from the chiller; closing them isolates the chiller from the filter loop. Then the ball valves and the chiller’s float valves regulate flow through the chiller.

I’ve attached the manual. Can anyone illuminate?

 

[1poolman1]

As a preface, I’ve pored through all the chiller threads, but would still appreciate any advice from all you knowledgeable contributors….

With the combination of daytime temperatures regularly above 100-105 degrees F, and covering the pool at night or when away, I’m finding the pool temperatures sitting around 95-97 degrees. Yes, I could leave the cover open at night, and yes, that does help, but my wife goes “ick” when she discovers yet another dead rodent in the pool. I have sorted out what the plumbing would look like to retro-fit a chiller, and see some possibilities of automating the setup into our EasyTouch system. I think the chiller would be effective in St George’s hot, dry desert climate.

Yet, some questions remain…

1. (Maybe the biggest). In their user/installation manual, Glacier recommends running the variable speed pool pump on max. All night. That would completely negate the cost savings of a variable pump. I usually run it at around 1800-2000 rpm, which is a good balance for me between energy efficiency and skimmer/filter effectiveness. Does anyone have experience or knowledge on this requirement?

From the manual, pg 4:
NOTE : Variable Speed Pumps – If you have a variable speed pump, you have to set the pump speed on high and run the unit during night time hours on this speed to cool. Once the variable speed RPM’s change to low the unit sprinkler pipes will not spin and it will not be cooling. The cooler relies on the flow rate from the pump at high speed.

2. Glacier recommends use of 3-way automated valves on the input and output side of the chiller, and to set the valves:

From the manual, pg 13:
“Do not pre- set the actuator. Allow the actuator to open 100% for the water flow rate to the cooler. ONLY set the ball valve at the cooler to 10 -15% percent open for the flow rate into the cooler. This ball valve setting is permanent.”

This does not make sense to me. Why is a 3-way valve needed? What does make more sense to me is to use cut in PVC tees at the filter output and at the pump input, and place 2-way actuators on the legs that go to/from the chiller. Opening these valves let water flow to/from the chiller; closing them isolates the chiller from the filter loop. Then the ball valves and the chiller’s float valves regulate flow through the chiller.

I’ve attached the manual. Can anyone illuminate?

You need the three-way in front of the device to send ALL the water to the unit. If it is just plumbed with a T and 2-way valves, the restriction in the chiller will force some water to the pool and it will not be as effective. You want to chill ALL the water going through the system. Very old saying applies here: "If all else fails, follow the instructions." A lot of engineering goes into those devices.

 

[stevo777]

You need the three-way in front of the device to send ALL the water to the unit.

Really? I am an engineer , I read manuals, and know the experts are usually the ones who designed the system. But I want to know the hows and whys and the trade-offs.

I guess I still do not have a good understanding of the system, as in this case, after the 3-way is a ball valve that seems to choke the flow through the chiller to around 10%. Thus reducing the entire filter circuit to 10%. And then cranking to VSP to full RPM. An apparent big trade-off, in terms of filter performance and overall efficiency.

 

[1poolman1]

Really? I am an engineer , I read manuals, and know the experts are usually the ones who designed the system. But I want to know the hows and whys and the trade-offs.

I guess I still do not have a good understanding of the system, as in this case, after the 3-way is a ball valve that seems to choke the flow through the chiller to around 10%. Thus reducing the entire filter circuit to 10%. And then cranking to VSP to full RPM. An apparent big trade-off, in terms of filter performance and overall efficiency.

My error. The only chiller I installed, as they are not in much use in this area, required all flow to it. The unit was huge, literally as tall as the customer's house. It was the first (and possibly only) installation in this area of an HVAC system that used pool water to accept the heat from the condensers (3 of them) instead of air. The pool ran simultaneously with the AC. Pool got too hot, so company hired me to install the chiller they supplied, as I had done the plumbing for the original system. Instructions required all flow to go through that enormous tower that was cooled by evaporation of water on sprayed conventional-type heat-exchanger fins from a water supply using the house domestic water supply. Seemed a crazy waste of water in drought-plagued California. Did the install, system did the job, never went back.

I should have re-read the instructions for the Glacier more closely. Your system, in a retro-fit application, does not require all water to flow as it actually, if plumbed correctly, re-circulates water from the pool back to the suction side of the pump. The flow to the unit is limited to not allow the "sprinkler wand" to rotate too fast and spray water out the top of the unit. The 3-way valve is there to isolate the chiller from the rest of the system if it is not needed.

 

[stevo777]

if plumbed correctly, re-circulates water from the pool back to the suction side of the pump. The flow to the unit is limited to not allow the "sprinkler wand" to rotate too fast and spray water out the top of the unit. The 3-way valve is there to isolate the chiller from the rest of the system if it is not needed.

Thanks, I appreciate the comment. As only a portion of the flow is bypassed through the chiller, should the 3-way be partially closed, in order to direct most of the filter pump’s output through the returns? What do you think?

 

[1poolman1]

Thanks, I appreciate the comment. As only a portion of the flow is bypassed through the chiller, should the 3-way be partially closed, in order to direct most of the filter pump’s output through the returns? What do you think?

The restriction of the first check valve, plus that of the reduction to 1" plumbing into the unit, should force the majority of the flow to the pool with the valve open to both pool returns and chiller, just like a simple T fitting.

 

[JoyfulNoise]

The reason why they want ball valves is so that you can fine tune the flow into the Glacier. You can't rely on automated valves as the older style ones are kind of annoying to fiddle with (you have to take the cover apart and adjust the two mechanical cams to determine the closure percentage) and the old ones only have two positions. The newer IntelliValves are supposed to give variable closure based using the RS485 serial comms wiring BUT they only work with IntelliCenters, not EasyTouch automation systems ... and the InteliValves are junk compared to old CVA actuators. You have to follow the Glacier instructions, they work well when people don't try to DIY the install with their own opinions. Not saying you can't ask the questions, but there are plenty of Glacier install threads on TFP with your exact same situation and people that tried, and failed, to do it their "preferred way".

I agree that the chiller will work well in your climate. As long as the humidity is low and water can evaporate, it will provide cooling. But don't expect miracles - many people have to run them all day long and into the evenings to maintain 4-5ºF cooler water. So plan for your electrical costs to go up as you will be running your pump longer and faster as well as the fan and submersible pump in the Glacier unit.

 

[jark87]

I can’t speak to your plumbing questions as I had my Glacier installed by a professional. I can speak to its effectiveness, though. I would have considered my pool a wasted investment without the chiller. Like yours, our pool would hit 95° by mid-summer. And that’s the time of year when you really want a pool. We had temps in the low 100s and higher than normal humidity last week and my pool never got above 83°. I would expect that you would see even more cooling efficiency with your less humid climate.

I have a single speed pump and run my chiller 17 hours per day (3am - 8pm), every day. It’s off right now because we’re on vacation, so I’ll probably return to a pool in the 90s. It will take 2-3 days to normalize back to where the pool stays in the low to mid 80s. Again, with your climate, you may be able to cool your pool off in less time and may not need to run the chiller as long. When our humidity drops, it’s not unusual for my pool to drop down to mid to upper 70s, even with ambient temps in the 100s. If it gets too cold, you can always turn the chiller off.

Some things to consider:

1. While our pool gets lots of direct sunlight, the chiller is completely shaded and never gets direct sunlight. I’m sure that helps. If your equipment pad is shaded, you’ll be a step ahead.

2. Speaking of the equipment pad, you’ll need lots of space. Our Glacier is the GPC-210 and it’s huge. I had recently replaced an AC unit and had a concrete pad left over that was used for the chiller.

3. The fan isn’t that noisy, but some people have commented on it. It’s less noisy than our 30” pedestal fan on the patio, but hopefully your equipment is away from the house. Ours is in a good location near the back corner of our yard, so it’s not near our house or any of our neighbors’ houses.

3. I’m kind of surprised Glacier hasn’t addressed it, but sump pump failure is an ongoing concern. If that pump fails, the basin will overflow and I assume would drain the pool. Seems like a simple float valve or water level sensor would resolve this problem, but Glacier still hasn’t done anything about it to my knowledge. And you have to run the chiller at night, so there’s no way to monitor. That’s why my chiller is off while in vacation. I’ve had my Glacier for around 10 years and the pump is still going, but it worries me.

4. My fan motor lasted 5 years. Granted, I run the chiller pretty hard, but that was a little shorter life than I expected. I replaced it myself and it wasn’t that hard, but getting the fan blade off the motor shaft took 2 people.

5. Get a large tarp to cover the chiller for the winter and secure it with bungee cords on top and bottom. I had rats that nested in the basin one winter. No fun cleaning that up.

In the end, we’ve been able to enjoy our pool because of the chiller. I’ve read in threads here on TFP where people don’t want to spend $5k to cool their pool off. I realize that $5k isn’t insignificant, but if you’ve invested more than $100k in a pool that you don’t use, it’s a small percentage of the investment to get the value that you were looking for.

Good luck!

 

[jark87]

One other note - you’ll fill your pool much more often with a Glacier due to the evaporation. Depending on your fill water, that may mean a change to pool chemistry. My fill water has high alkalinity which contributes to pH rise. Plus, the chiller aerates the water, so I go through quite a bit of muratic acid.

 

[JoyfulNoise]

I wonder if you couldn't add some kind of level sensor or water spill sensor to the unit in a way that if the water level gets too high in the basin you either get a shrieking alarm or an email notification alert.

I have washing machines with very strong drain pumps on them and they can generate quite a bit of foam in the drain pipe when they start pushing air. The foam can overflow the pipe and lead to a mess so I put a very simple moisture sensor in the wall drain that will send out a shrieking signal off foam comes up the pipe. The sensors cost like $20 on Amazon. There are definitely more hi tech ones that connect to your LAN and let you monitor them by an App. I would think a simple sensor like that would work well enough to take some of the worry out of having the chiller overflow.

It's definitely a design flaw of the Glacier ... there should be a float sensor in one of the two drain ports that shuts down the chiller in the event of an overflow ...

 

[jark87]

I wonder if you couldn't add some kind of level sensor or water spill sensor to the unit in a way that if the water level gets too high in the basin you either get a shrieking alarm or an email notification alert.

I was thinking the same thing as I typed that message. I’d rather take the same signal and send it to my controller to shut the chiller off, but I don’t know how to do that. But a text to my phone would probably be the next best thing.

 

[JoyfulNoise]

Something like this would be a WiFi enabled water sensor -

D-Link Water Leak Sensor Starter Kit & Additional Sensor Pod - (COKT3)

• DCH-S1621KT + DCH-S163: 1x Master Unit (DCH-S162) + 2x Sensor Pods (DCH-S163) • Help Avoid Costly Water Damage: Plug in Master Unit and Sensor Pod system is easy to set up. Place up to 16 Sensor Pods in areas susceptible to water leaks such as water heaters, washers, and under sinks. • Visual...

shop.us.dlink.com

But a simpler approach would be something like a float switch which is found on AC condensate lines -

GAGALOR SS2 Condensate Float Switch Clear PVC Overflow Safety Level Sensor for HVAC Drain Pan with 3/4 Adaptor
https://a.co/d/fhlUc1f

That could be used to close a contact on a relay that would kill the power. The basin of the glacier chiller had to two drain ports, one high and one low. A float switch would be place on the high port to sense when water gets too high up. But you’d need the electrical skills to run that contact closure back to your automation panel that controls the relay for the Glacier.

 

[jark87]

The basin of the glacier chiller had to two drain ports, one high and one low.

If so, I don’t know where the high drain port is. I’ve never noticed one and I’ve been all around my chiller. But I could have overlooked it, I guess. I’ll check when I get home. Regardless, I could install a sensor that’s above the pump float but below the rim of the basin (or upper drain port.)

But you’d need the electrical skills to run that contact closure back to your automation panel that controls the relay for the Glacier.

While I wouldn’t say I have electrical skills, I’ve wired plenty of things, like ceiling fans, lights and electrical outlets. I know how to shut off the correct breaker and test for current and I can certainly attach wires. I just don’t know what to attach them to and what to do with the controller once they’re attached.

 

[jark87]

That could be used to close a contact on a relay that would kill the power.

And if killing power is the same thing as turning it off at the control panel, that might work and perhaps eliminate the need for any programming. I differentiate killing power and turning off because when I turn the chiller off, that also closes the 2 actuators. If killing power does the same thing - bingo!