Anyone Have a Winter Pool Dome - Ameridome or Others?

Swampwoman

TFP Expert
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Apr 27, 2012
3,845
Grand Rapids, MI
It was more like engineer-trained hubby said this can work and cranky boiler engineer said if he didn't think of it it won't work ;)
I understand that the impact on the system would be to some extent chiller-like, but I felt this could likely be handled with zoning (we already have 3 but there's no reason we can't add a fourth,) a bump out, and boxed in thermax insulation with accessible shut off valves. I am always willing to be told it doesn't make fiscal sense, or physics sense, but I prefer the "no" comes after a modicum of consideration ;)

With that said, sometimes the simplest method is best, and using the already hot pool water is normally simple ;)
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
STARLOG Trouble Bubble Update:

Well it's been quite a week in the Tundra Dome and I'm quite happy to report that my marriage has survived ;) SwampHubby has been super easy going with the great gobs o cash I've consumed on my quest for yearround hot water.

So after buying a new air warmer the week prior due to my not thinking through low flow on my vsp, last Sunday night brought us the heater flame rollout condition that for some reason stymied 3 different pool techs and hvac guys.

Of course, if I weren't running in winter, this would not have been the cliff-hanger it was. For posterity, it should be said that if you plan to run a dome in northern winter climes, learn a lot about heaters first because you'll be on the clock when a crisis arises ;) Might be worth owning a manometer.

I may reserve a complete report until I talk to Hayward again to do some analysis but here's the short strokes and a pic that ultimately tells some kind of story.

By way of background, heater is in a heated pool house with a un-powered draft stack that connects to 7" type b flue that runs a good 29' through 2 stories. The heater is an 18-mo old Raypak 266k btu Cupronickle exchanger running off a 1" gas line on a 400k btu service.

My life is governed by the law of unintended consequences, so I'm pretty sure this developing story does not reflect on Raypak in any way, just so you know.

- Monday I begged to get regular heater pool tech out...skeleton staff and booked up so they suggested having hvac guy out

- Said hvac guy came, changed the sensor, tested gas which was 3.96 (in other words, perfect) and then left saying his co didn't want him taking apart the heater. I wondered what the heck I'd just paid for, since the flame rollout sensor is merely a safety fuse. Heck I could have changed that part myself or jumpered it. The point was to correct the CONDITION causing the flame rollout. Tip: never let someone leave the property until you're satisfied that the repair is logical ;)

- So 20 min after hvac guy leaves, new sensor blows and heater remains down

- Next pool hvac tech comes later that afternoon, pulls out burner and cleans it, says they think the exchanger looks fine and since the company cleaned it 2 mos. ago, doesn't do this. We note condensation on heater floor. tech is convinced it cant be a leaking exchanger. Puts in a new switch and leaves. Tip: Never let a tech leave the property if there is an unexplained phenomenon that you know should not exist ;)

- 5 hours later, flame rolls out and blows switch. At this point we can rule out odds of ad hoc backdraft.

- I jumper the switch to observe burner. Something is clearly wrong as to me it looks like its burning too dirty. I do match test to see if there's a good draft on flu. No obstruction to makeup air vents. Etc. Calculate 1 square inch oer btu, check. Get it into my head that a powered vent might help. By morning, I've sent urgent message to pool guy, who stops by on route to another job. I beg him to clean the exchanger. He's sure that isn't it but thinks a powered vent will work, gives me a different hvac guy's number.

About six calls later, there is still no hvac co in town who can come for a week or two, by which time dome land would be dead unless I blow out the lines. I've convinced local wholesaler to overnight the powered vent hood that at retail costs almost as much as the heater did, not to mention having to swap out 20+ feet of flue to 4" vent...

-By this time, I have a direct line to Raypak guy via the pool co. He's convinced the exchanger HAS to be sooted and blocking/condensing combustion. He gives me name of another authorized tech - thank ye gods because the next one dug deeper.

- New tech comes out and goes to work. Pulls out the heat exchanger, which is a hot mess. Pinhole leaks all over the place. This guys theory is that drips from pinhole leaks may have caused incorrect combustion and sooting, which exacerbated corrosion due to condensate. This pretty much happened somewhere between Sept 11 when it was cleaned for phosphate scale and the rollout event on Dec. 17. He had checked my flue and found no obstruction or sooting that suggested any drafting problems, though we may expand out intake vents propholaptically.

- Another overnight shipping charge later, new exchanger is in, pool is heating, and so far so good. Fingers cross as temps are to drop right when were headed to Canada for Xmas.

Possible and as-yet undetermined lessons:

1. Phosphate scale may indeed be corrosive as Matt dug up in a research paper I now need to locate and read more thoroughly ;) Next week, I'm going to see if Raypak will analyse it after my endoscope comes in and I take picture. This is not for warranty purposes as online warranty is only 1 year. This is for my own understanding.

2. When you look at pic from sept 11 cleaning to removal, the speed of degradation is profound. Have a hunch that cleaning was a mistake insofar as it was also improperly executed. Won't get into all that now as there's nothing to be done about it, but have learned a few things along the way.

All I want for Xmas is to swim ;) Hi ho.

Sept 11 Heat Exchanger
image.jpg

Dec 21 Heat Exchanger
image.jpg
 

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Swampwoman

TFP Expert
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Apr 27, 2012
3,845
Grand Rapids, MI
^yes, literally and figuratively a hot mess.

In other news, dome has reached temp and after dinner hubby, guest and I are going for a dip to pretend we're vacationing on the Riviera since we probably could have for about what we're into on the various Dec. fixes ;)

We have a very nice Madeira-cased Glenmorangie ready for the celebration.

And I just finished putting together the other Santa stocking stuffer for the dome: a baby dome to protect the new air warmer exchanger from high cold winds ;)

image.jpg
 

JoyfulNoise

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May 23, 2015
14,515
Tucson, AZ
There are two possible failure modes that need to be determined - did the heat exchanger "rot" from the inside-out OR the outside-in ?

If I'm remembering the discussion we had correctly, phosphate removal does not cause enhanced corrosion but rather it's the use of phosphate based metal sequestrants that can enhance corrosion because they increase the solubility of metal ions above their normal equilibrium value. This would be the "inside-out" rotting problem.

However, you have been running a zinc anode attached to your bonding wire (which eventually connects to the heat exchanger) and you've been running a heater in the winter with potentially cold water and cold air exposure. Correct me if I'm wrong, but combustion exhaust can get quite corrosive when it is incomplete (formation of nitric acid by-products) and cold air can exacerbate the formation of condensation that can lead to rotting of the exchanger. That would be the "outside-in" rotting scenario.

So, perhaps your endoscope will give you a good idea of the interior health of the exchanger. One would have to carefully cut apart the exchanger to examine the outside surface of the cupronickel coils and fins to see what kind of damage may have occurred.

Sorry to hear about your troubles....that bottle of Glenmorangie should be put to immediate use....
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
Lol, indeed. Live n learn ;)

The outside/inside or "combo" is what I'm hoping to find out but its a bit "chicken or egg" because a pinhole leak could cause the condensate condition, which, left long enough, causes improper combustion.

Condensate is incredibly corrosive as I understand it.

The water that is heated has never been colder than 90 this year as we heat continually (until this week) and the heater itself is in a heated poolhouse. So those two sources of operational combustion interferences aren't in play...but the stack itself is subject to freezing above the roofline, so I can't rule condensation out since the heater has only been run approx 8 hrs a day and sits idle the rest of the 24-hr period.

Another complicating/confusing aspect is that I've not added phosphate since Sept 11 as I've weaned from sequestrant since I've gotten my metal zeroed out and phosphates down. If the initial damage was prior (there was some soot as you see in Seot 11th pic, which was after 15-16 mos of operation) then my new exchanger should suffer less. But if the damage was subsequent then it would have me wonder if I wasn't better off with protection from sequestrant.

Raypak also says high TDS can wear on the exchanger...which between salt, phosphate, metal, well water-to-softened water etc., I possibly have (their guideline is if its up around 6000-7000, of which salt would be 3200.)

I plan to use my endoscope to periodically get a glimpse of the underside of the exchanger during non-heating times to try to gauge if I have any combustion issues via condensation/soot.
 

Swampwoman

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Apr 27, 2012
3,845
Grand Rapids, MI
Star Log update (for my records)

Dome was buckling when we left for Canada in a fast snow storm Xmas am, but stayed up and was up on our return this aft, despite prior 40 mph winds together with heavy snow ;)

1 F degrees right now...turned heater on at 6 pm just to recover some heat before am (it was down to 89 in pool) - gained back 3 degrees in 2 hrs.

Air temp inside dome had dropped to 37 - ice on inside walls may have contributed to its staying up ;) now heading upwards of 38 after opening small portion of cover near stairs to increase heat capacity via increased avail moisture to retain heat.

Vsp is running at 2600 rpm for a flow of about 43 gpm...good flow through air xchanger and returns. Heater flame field is predominantly blue, burning clean, with good draft. Will leave it running overnight and let it just thermostat to be at right temps for imminent -0 temps predicted.
 

JoyfulNoise

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May 23, 2015
14,515
Tucson, AZ
Did you keep the old heat exchanger or did you send it back? Anyone planning to do the post-mortem ?

Less than 0F eh.....I had no idea thermometers went that low ... at least around here they never do :scratch: I suggest lighting smudge pots around the property. The smoldering diesel flame will produce a nice, dense cloud of particulates and sulfurous compounds. The blanket of smog will keep everything nice and warm :deal:
 

Swampwoman

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Apr 27, 2012
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Grand Rapids, MI
^I thought maybe the exhaust from the heater would do that but apparently the carbon footprint isn't quite big enough ;)

I've kept the heat exchanger to first collect some images. Then i was thinking about asking Raypak to take a look.
Step 1 will be getting the endoscope organized. (it arrived Sun but with Xmas wasn't around to putter.)

This am its -6...my water got up to temp no prob but the air inside dome is down to 34 degrees. Getting in may be interesting ;)
 

Kitana

Bronze Supporter
Aug 28, 2017
31
Sterling Virginia
Happy New Year!
Just catching up...holy moly...I wont even pretend to understand all you have been through with the heater. I may need to take an HVAC course. :confused:
Crazy holiday for us with each family member getting a nasty cold virus that left our desire to swim a little low the last two weeks. However pool is ready to go with air temps at 54 degrees and pool 91. It is 25 degrees right now but will drop the next 2 days to the single digits. Thank you for the heads up on the dome heater.
 

Kitana

Bronze Supporter
Aug 28, 2017
31
Sterling Virginia
We held up fine. Only a couple inches of snow but the cold temps were brutal. Dome is doing good. We had 70 degree temps on Friday so our water hose thawed out to add more water to pool. (Forgot to bring the hose in.) Back in the 20's now, dome air is around 50 and pool still 91. We swam last night when it was 18 outside felt like 5, dome was 47 and we felt the chill so I can imagine how 36 must feel.
 

Swampwoman

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Apr 27, 2012
3,845
Grand Rapids, MI
Glad to hear! I just had a lovely dip...pool is 95, dome air now 57 and outside air got up to 24 after being in single digits overnight and low teens this morning ;)

For top ups, I use NOT regular or the retractable flex hoses, but a new kind of soft but not retracting type. Easy to carry inside, store, keep warm and flexible til needed.

Here's a link if you're interested...note that a few reviewers complain about developing leaks...these are lighter weight, not to be dragged through sharp gravel etc. IMHO, but for my purposes, work great. Eg. I run regular heavy duty hose up the terrace or thru stone to the bed at te far end of the pool, and in summer, use this one for walking around to water the patio planters. Never kinds, easy to carry, etc. and for winter, is perfect for running out to the pool.

https://www.amazon.com/4001-50-Lightweight-Flexible-Durable-Kink-Free/dp/B014M9PEXC/ref=sr_1_1?ie=UTF8&qid=1515953688&sr=8-1&keywords=zero+g+50+ft+hose
 

Kitana

Bronze Supporter
Aug 28, 2017
31
Sterling Virginia
Glad to hear! I just had a lovely dip...pool is 95, dome air now 57 and outside air got up to 24 after being in single digits overnight and low teens this morning ;)

For top ups, I use NOT regular or the retractable flex hoses, but a new kind of soft but not retracting type. Easy to carry inside, store, keep warm and flexible til needed.

Here's a link if you're interested...note that a few reviewers complain about developing leaks...these are lighter weight, not to be dragged through sharp gravel etc. IMHO, but for my purposes, work great. Eg. I run regular heavy duty hose up the terrace or thru stone to the bed at te far end of the pool, and in summer, use this one for walking around to water the patio planters. Never kinds, easy to carry, etc. and for winter, is perfect for running out to the pool.

https://www.amazon.com/4001-50-Ligh...=1515953688&sr=8-1&keywords=zero+g+50+ft+hose
Excellent, will purchase.
 

Swampwoman

TFP Expert
LifeTime Supporter
Apr 27, 2012
3,845
Grand Rapids, MI
Lol. I can relate.
Btw, I was supposed to thermostat for you when my friends came down to compare gas usage. They'd cancelled previously due to weather but were down this weekend. Like an idjit, though, I forgot to read the meter. I'm not sure f I'll be able to read the day as gas co changed its online interface. I will check though to see.

I've left mine running 9 hrs overnight throughout winter so far...didn't need it for the last few warm days. So that should be about 18 CCF per day in adverse temps to a top temp of 95 and then potentially dropping as low as 89 before the next scheduled heat run. Maybe we can compare notes on consumption to help figure out what's most economical.