Spa R-Ratings, more better?

[TrueGrit]

Hi, considering our first spa, have learned quite a bit from this site already (thank you!)  I won't mention brands because I don't want anyone to think I'm a mole for a specific brand trying to stir things up.

Interested in quality but also cost of ownership, focusing on efficiency.  I live in CA costal range on a tier rate, 14 cents is first tier and by the end of the month we're in the 3rd tier in 45c KWH ~ 200/mo electric bill (excludes heating!).  Cooler months lasts 6 months and average temp is 30Lo/50Hi.  The spa sits in the damp during that time with no direct sun.

I see big difference R-Value in the tubs from CEC ratings in the excel, is more better?
http://www.energy.ca.gov/appliances/database/excel_based_files/Pool_Products/.  The file is 'Portable Elcectric Spas.zip'

If you PM I'll receive your response in email and happy to discuss offline as to not start anything here.
Thanks,
TrueGrit

[stuart]

I would not even begin to base my decision on the CEC ratings...

In order to post those numbers the only proof is the manufacture had to sign an affidavit claiming that it was tested at a certified lab and that what they've supplied is true and correct.

We all know that no manufacture would fudge the numbers for their benefit regardless of an affidavit.

There are so many variables here like how much water the spa is rated at and how much is actually in it at the time of testing.

Again, they don't police it in any way so it's kinda hard to trust the numbers.

Your best bet is to research out some forums and other online sites to see what other owners say.

This site is a bit top heavy towards HotSpring and Watkins so it shouldn't be your only research but there are others. Remember, many of the sites are salespeople touting their brand so you have to weed those out but take your time and educate yourself.

My best advice is find a dealer that really makes you feel comfortable personally because that's where you'll have the relationship...not with the manufacture. A good dealer can make even a mediocre spa a great purchase.

[TrueGrit]

Thanks Stuart.  I spoke to a rep in town sells a couple of brands that I was considering.

[hottubdan]

One more post and you can send PMs.

[TrueGrit]

Not trying to question the expertise and help/advice, thank you! This seems to point to some legit testing via Cal Poly, yes?

http://apsp.org/APSPWeeklye-ad/April30-08/hottub-testing-begins.pdf

I know at least one of the Mfg. I'm looking at did mention they sent 3 of their units to Cal Poly for the testing.  Also in the Excel they were not the top of the R Values but were pretty near the top of the Ratings.

[Zep]

would an in-ground tub generally have better r-value?

[hottubdan]

negative.  the ground is much colder than 102.  it acts as a heat sink.

[Zep]

"negative.  the ground is much colder than 102.  it acts as a heat sink"

yeah but so is the outside during the winter

wouldn't there be almost zero wind chill factor for an in-ground?

I've always heard thats why snow sometimes doesn't stick
because the ground or earth is warmer...retains heat...ect....?

if it was 18 degrees would you rather be standing up in the wind
with your coat on or down in a foxhole with your coat on?

but Dan you probably know alot more about these things than I do,
so i'll trust you are right.

[D.P. Roberts]

"negative.  the ground is much colder than 102.  it acts as a heat sink"

yeah but so is the outside during the winter

wouldn't there be almost zero wind chill factor for an in-ground?

No wind chill, but consider two things:

1) Air does not transfer heat as efficiently as solids do. The ground is always 50 degrees or so; all your hot tub pipes are constantly being cooled to that temperature. In a hot tub, it's actually all the "air" (i.e. bubbles) in the insulation that are keeping the warmth in the pipes.

2) The cold ground will be fighting your in-ground hot tub all year round. The cold air in winter only fights your hot tub for a few months (depending on where you live). Plus, all that insulated air (in the cover & the tub insulation) are fighting against that cold.

[Zep]

but to me it's better in the winter because the ground is warmer thus
the tub/water is surrounded by a warmer environment and in the summer
my tub is empty.

[Dr. Spa™ Ret.]

Simple test for you Zep. Which cools your hand faster, sticking it in the freezer (in cold air), or holding on to ice cubes (a large heat sink)?

[Zep]

simple question for you doc...

if you were out in the cold would you rather be
standing out in the open or down in a fox hole?

[Dr. Spa™ Ret.]

You're not comparing apples to apples. The key here is CONTACT. Your body is in relatively complete contact with the air around it, it is NOT in complete contact with the ground when in a fox hole. An inground spa on the other hand, IS in complete contact with the ground.

While the ground may be warmer than the surrounding air (and lets not forget about "frost lines), the greater an objects mass the more heat it will extract (or more quickly it will extract) from a contacting substance.

A more correct comparison would be, "if you were out in the cold would you rather be
standing out in the open or buried in dirt?"  

Especially in a wind-breaker "suit" with no air infiltration  

simple question for you doc...

if you were out in the cold would you rather be
standing out in the open or down in a fox hole?

[Zep]

ok doc we'll agree to disagree!

[D.P. Roberts]

Here's another question for you - if it's 50 degrees outside and you put your hands in 50 degree water, does it feel warmer, colder, or about the same?

It feels colder. Much colder.

In many areas of the country right now, you can try that experiment for yourself right now. Just drain and refill your tub. I just tried this the hard way a few days ago. I was refilling my tub, and the water temp & outdoor temp were about the same - 50 or so. I was fine outside in a t-shirt, but the new tub water was FREEZING cold. I was trying to reinstall the filter, and had to pull my hands out every few seconds to warm up.

On a hot day, going into a cold, air-conditioned room cools you off fairly quickly. Jumping into a cold pool cools you off INSTANTLY.

Lastly, have you noticed that almost everyone's favorite hot tub temperature is within 5 degrees or so of body temperature? If it was a lot different we wouldn't be able to stand it for very long, but most people can handle air temperatures in a much broader range.