full foam vs thermopannels

[Hillbilly Hot Tub]

I was wrong, Clearwater does not spray, nor do they use bubblewrap. It is a 2 inch thick foam that they use for floating islands, and in construction. It has borates infused into the foam to eliminate bugs and rodents. It is foiled on both sides. It is placed on the floor and on all 4 walls of the cabinet, All 5 pieces touching tightly together. We brought it to an insulation guy(not a spa industry guy) and he stated it had an R 50 factor.....now that does not mean the tub as a whole is R 50, so lets not start down that road.

My point I guess is that a dead air space...a tight one with no gaps....with a high quality high R factor insulation works great. Add a 5 inch 2 pound quality cover.... My tub is very effcient. Why waste the heat pumps produce. I have 5 pumps and the other night, 50 degrees outside and all pumps going, my tub heated up 2 degrees in less than an hour from the heat produced by the pumps, heater never came on.

I had a full foam tub, a hawkeye and it cost me much more to run. The cabinet was always warm to the touch. Once you heat the foam up till it reaches the outside of the cabinet it starts "leaking out, kind of like a coffee cup. Now if the cabinet was lined with the foil to reflect the heat back, then filled with foam I think it would be great for insulation purposes.

Still have my gripes about repairs, I guess we have been the unlucky ones that have worked on all the full foam tubs with leaks other than in the control box. We have done a ton of them, multiple brands.

A quality tub is a quality tub....the high end tubs all seem to cost about the same to run, full foam or not, it just depends on how they are built

[Tom]

My point I guess is that a dead air space...a tight one with no gaps....with a high quality high R factor insulation works great. Add a 5 inch 2 pound quality cover....  Why waste the heat pumps produce. (My emphasis - TG)  

An excellent brief summary of the benefits of perimeter insulation.  Conserving energy from the pumps has been part of our system since 1997 (we call it "Free Heat(tm)")  

[BauerN]

I always tell myself:  "I'm just gonna look at BADH, I won't post, I won't post, I..."

I can't resist pointing this out though.  (Even though I sell and service FF spas).

The reason (IMO), that Arctic is doing a much better job than any others (which I'm aware of), was stated earlier, sort of.

Heat will, like many things, follow the path of least resistance.  So, by putting the high R-value foam on the cabinet, and not much on the shell, the least resistance is toward the plumbing and shell (where your water is).  This will effectively recycle the heat from pumps.

Other TP brands I have worked on put more insulation on the shell than the cabinet, therefore making the recycling aspect less effective (least resistance becomes outside of the spa).

I hope I don't ruffle too many feathers with this part:

I live in Montana, it gets kinda cold here (if you've never visited).  The ONLY TP spa I would consider at this point is Arctic.  

[Hillbilly Hot Tub]

Clearwater does not put insulation on the shell either. My point is there are a few good TP companies which have their other advantages.

It still all comes down to quality building and service. Not all in how many can we sell, but how many customers are completely happy.

I live in NH, also very cold as with Washington where Clearwater is made, and Canada for Artic who has all of us beat on "coldness" (I went on vacation to the coast of Canada in August and froze my butt off!)

[BauerN]

Clearwater does not put insulation on the shell either. My point is there are a few good TP companies which have their other advantages.

It still all comes down to quality building and service. Not all in how many can we sell, but how many customers are completely happy.

I'm in complete agreement with both of these points.

I have zero exposure to Clearwater, please pardon me for leaving them out.

[Gary]

Forget about insulation value, I see way more leaks with TP spas than FF spas and when I do fix FF leaks it is no big deal as some try to preach.

I am only a service person and from what I have seen through the years FF is how I prefer a spa to be.

[Tom]

Forget about insulation value, I see way more leaks with TP spas than FF spas and when I do fix FF leaks it is no big deal as some try to preach.

I am only a service person and from what I have seen through the years FF is how I prefer a spa to be.

This is turning into a good discussion.  Since Arctic uses access and ease of repair as a sales argument, I'm interested in comments of this type.  

Gary, have you had the opportunity to work on an Arctic Spa?  We really don't follow the usual TP construction, and other technicians report the reverse, that they prefer to work on an Arctic to FF types.  Perhaps this is just a variation in individual experience?    I do know that in our factory service training courses, we have techs with a lot of experience with other brands who comment on how easy it is to service our spas by comparison.  At that point, though, they wouldn't have much experience about relative frequency of repairs.

Would this vary with location or climate, do you suppose?  I remember one tech from Alaska, who makes a good living fixing frozen spas, saying that Arctic was the only one that made sense from his perspective.

[Gary]

Have never worked on an Artic nor see one up close, not much a dealer base in the deep south.

If and when a spa does leak a non full foam spa is easier but as I stated fixing a full foam is not a big deal either.

If they are sealed up tight and it appears Artic does then I would think it would be insulated just fine.

The other thing that bothers me though is the heat, to lower the life and any electronics just add heat or moisture or a combination of the both. If you seal it up tight the pumps, circuit board will all run much hotter than they were intended. That is why some manufactures of TP add vents that the owner can open if it gets too hot in there. The pumps themselves have fans built into the to remove heat, so if it is a sealed environment it will just recycle the hot air. All kinds of electronics have built in fans, they are not doing it for no reason.

For this reason alone I would never recommend a TP style spa to someone.

[Tom]

Have never worked on an Artic nor see one up close, not much a dealer base in the deep south....The other thing that bothers me though is the heat, to lower the life and any electronics just add heat or moisture or a combination of the both. If you seal it up tight the pumps, circuit board will all run much hotter than they were intended.

Your being in the deep south does indicate a regional influence.   As their name implies, Arctic Spas were engineered for cold climates, and a lot of that engineering is redundant in your service area.  Many who think we are an ordinary TP-type spa are not really familiar with our product.  I invite you to check www.arcticspas.com (and oh, how I hope our new site gets finished soon!)
  
Obviously, we've considered the heat issue, and our components are spec'd for the required internal operating conditions.  Our pump motors, for example, are IP55 (sealed against moisture and air infiltration) and use an aluminum housing with an external fan driving air over cooling vanes.   Electronics are spec'd appropriately as well.

Although we have few dealers in the American south, we have dealers in Australia, the Canary Islands, and Cyprus, to name a few hotspots.  For warm climates like that, in what I consider a monumental irony, we remove two of the insulated doors and replace them with screened, louvered doors to permit cross airflow, or we install our patented Chiller to help keep the interior cold.  The irony is, of course, that we devoted a lot of R&D time to keeping the heat in during a Canadian winter, only to have to find ways to keep it out in more southern latitudes.  

Often mentioned in this context is the myth that "In a TP tub, the unsupported hoses flop around, which causes them to work loose and leak."  Could be true in some, not so in ours.  The simple answer is to remove a couple of the access panels and point out that the hosing is spot-tacked where necessary so it is hardly "unsupported".  A more fun answer  is to hand the person a three-foot piece of the heavy hose used in our products and say, "Here you go, flop it around."  It takes real effort to bend the stuff; it doesn't need a lot of support.

I hope that addresses some of the concerns you raised in your post.

[Hillbilly Hot Tub]

Very well explained Tom. Funny how different our experiences are in different climates on the repair aspect. I will also add that for us, in the cold weather, digging in foam for a leak sucks when it is zero outside. I will also add with Clearwater we have never had to address a leak in the plumbing(keeping fingers crossed!) We have had to replace many light lenses last year(light lens manufacturer issues), very glad it was not a full foam tub for those! Clearwater also spot glues the plumbing where needed and uses decremeted clips for the plumbing to the jets. It still comes down to a quality built spa with a company and dealer that back it!

As well as my tub is insulated, we are having serious heat creep here right now, but only have to deal with it for a month. I can see in the south how this would be a disadvantage. I have the tub set for 98, it wont go below 100 and creeps to 102 when we use it. We have to take 2 doors off to let the heat out this time of year.

[spa_newb]

The war is about to start again.  You can look at some of the older pages and fine whole threads on this.  In a nutshell the dealers that sell thermopane will say they are better and the dealers that sell full foam will say that they are better.  As I am not a dealer or a energy expert (nor do I want to spark the war again) I will refrain from adding my opinion to this question.

Dave

Is it any indication as to what the better solution is when I have not visited a single dealer that sells anything other than Full Foam?

[Tom]

 The pumps would have to bring the cabinet air temperature up to a level "above" the temperature of the thin foam, plumbing, vessel shell, and water for the heat to travel through the air by convection, transfer to the thin foam and plumbing  and on through the shell and into the water by conduction. I would venture to guess that, especially in colder climates, the pump or pumps heat energy input would be hard pressed to reach and/or maintain a temperature high enough for this theory to work.

I point out again that an Arctic has NO foam on the shell.  A temperature gradient of only one degree is sufficient to transfer energy from the cabinet air into the water through the uninsulated shell. Some heat is transferred by radiation, I expect. Provided the cabinet is sufficiently insulated to prevent heat loss, energy will transfer into the water, reducing (but not eliminating) the time the heater is required to run.

[Engineer wants hot tub]

Anybody out there?  Is this thread still alive?

Anyways, I am struggling with the question of FF vs TP question.  The consensus of the thread seems to be FF offers more advantages at higher cost.  Does a third method of insulation exist where TP is used with fully sealed air cavity between shell and skirt?

I would like to have a hot tub with the highest R-value.  I have not seen any published R-value information.  Has any research institute or public agency attempted to assemble this data?

I am particularly interested in the R-value of the sides between the shell and the skirt.  I have already settled in my mind that the top is where approximately 70% of heat would be lost (with no insulation whatsoever).  Any cover that forms a full contact seal with the rim and provides several inches of foam insulation over the top will prevent most heat loss from this source.  The heat loss from the bottom is solved by resting on a thermopane panel.

This leaves the sides for which I have not resolved the question of the "ideal" insulation method.

I accept that FF may result in higher repair cost if a leak occurs (which is less likely to occur since additional pipe support is provided by FF and longer time to freeze pipes during periods of no power).

It seems to me that a third option may exist where the air cavity between the shell and the skirt is fully sealed.  The air serves as the insulation with some TP under the skirt.

Does anyone know if it is reasonable to expect a fully sealed air cavity between the shell and the skirt?  If this method was relied upon for a superior R-value then no leaks in the air cavity could be tolerated since any cold air intrusion would significantly reduce the effectiveness. 

If I am allowed to wish, then I would like to see comparisons of infrared thermography scans using various techniques of insulation (to go along with my wish of tabulated R-values for each model).

I may just give up and design-build my own hot tub.

[Tman122]

The dilemma would be cooling of the pump motors. I purchased a partially foamed tub (Great Lakes) and actually removed some foam from beneath the entry step (the pump motor was located right under it.) Then fully sealed the cabinet walls with reflextics 2 inch insulation. Shiny silver side facing the vessel. My thoughts here were it would reflect any warmth back to the vessel. Then I designed and installed a thermostatically controlled 110V actuated 2 damper and fan system for incoming vent air and out going waste air. The dampers were ducted so the incoming air went across the pump motor down low and the outgoing air was drawn from the top on the opposite side. The fan was on the outgoing duct/damper to create a positive flow in and across the motor. It was set for 115 degrees which was slightly lower than the motor manufactures maximum safe operating range. I live in Northern Minnesota so the system seemed to save on some dimes. The funny thing is all the components and labor added up to about a 10 year ROI with the minimal cost to operate savings that was realized. Instead of a 50 dollar bill to operate on a particular cold month it was a 40 dollar bill. I have all the KWH data to prove the savings as the spa was metered. I believe the pumps running at max temp may cause premature failure. Never kept the tub long enough to know. The new owners lived far enough away that they never called me for service. I do know it is or was still running about a year ago which would make the tub about 9 years old. Not sure if a new pump was ever put in it but their life expectancy on that value brand was likely only 5-6 years anyway.

Any way just some thoughts for you.