EcoRenovator  

Go Back   EcoRenovator > Improvements > Conservation
Advanced Search
 


Blog Register 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read


Reply
 
LinkBack Thread Tools Display Modes
Old 08-25-16, 12:17 PM   #1
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 907
Thanks: 11
Thanked 105 Times in 89 Posts
Default Hot tub insulation improvement

I got this little gallon hot tub for my wife.
It holds around 280 gallons of water and has a 1,000 watt heater and it sits outside.
I figure if it gets cold enough and the heater runs all the time that could increase the power bill by up to $75 a month. That is really bad.
Then I remembered I own a FlirI7 thermal camera this should be easy.

This picture is the cover to the hot tub. You see the one line of heat escaping, that is where the cover folds. As you can see about 99% of the rest of the covers surface area is doing a very good job.


This is not a very good image of the side. As you can see some heat is getting away. It was 64'F that night.


The most obvious place for improvement. The filter housing. Just wrapping some insulation around it should take care of it. The water in the hot tub is 99'F that housing is pretty close to 99'F.

The filtering assembly will likely get a foam box built around it.

Turning the hot tubs temperature way down then back up to save power really is not an option right now. I figure with the 1,000w heater it will only be able to raise the temperature 3'F every 2 hours assuming no losses, so I got an 240 volt powered industrial grade 500w fish tank heater to help. It looks dangerous and is not GFI protected so it wont be on while anyone is in the tub.
The fish tank heater and the built in heater could bring the temperature up 2'F every hour.
If it works well I may order another one or 2.
I think what I can do on her last night off turn the temperature down, so the heater maintains a much lower temperature the 3 nights she works then turn it back up the morning she starts her 3 days off.
With the outside temperature being between 65 and 70 at night the tub can lose up to 5'F per hour while the cover is off. Only opening half the cover cuts losses to between 1'F to 2'F per hour.

Attached Thumbnails
ir_0184-jpg   ir_0185-jpg   ir_0186-jpg  
oil pan 4 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following User Says Thank You to oil pan 4 For This Useful Post:
JimiQ (08-26-16)
Old 08-26-16, 08:21 AM   #2
Administrator
 
Daox's Avatar
 
Join Date: Aug 2008
Location: Germantown, WI
Posts: 5,247
Thanks: 906
Thanked 338 Times in 273 Posts
Default

Sounds like a good plan. What is the plan with insulating the tub itself?
__________________
Current project -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Daox is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 08-26-16, 08:30 AM   #3
Supreme EcoRenovator
 
Join Date: Sep 2012
Location: Vancouver Island,Canada.
Posts: 1,036
Thanks: 116
Thanked 99 Times in 86 Posts
Default

I'd probably add a rigid foam skirt with a ceder surround or whatever.
For an similar effect as the slow cooker Pot cozy.

My insulated bathtub is keeping the water hot/warm for 2.5 hrs at a time
__________________

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
ecomodded is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 08-26-16, 02:47 PM   #4
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 907
Thanks: 11
Thanked 105 Times in 89 Posts
Default

The vertical sections are insulated by about a half inch of wood and about an inch of Styrofoam. I do not know what the cover has inside it, but it appears to be working very well.
oil pan 4 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-03-17, 03:29 PM   #5
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 907
Thanks: 11
Thanked 105 Times in 89 Posts
Default

Opened it up this year but before I put the liner on the in the frame I took a bunch of 1/4 inch thick high density floor under layment cut it to fit my hot tub corners and layed it down layer by layer until it was at least an inch thick. Then put 1 layer around the inside.
So now instead of just sitting in the ground it's sitting on an inch of Styrofoam.
The flir is showing less heat loss, I just need to wait for another 64F night to check it's heat loss again. For consistency and to make a good comparison.
oil pan 4 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
The Following User Says Thank You to oil pan 4 For This Useful Post:
ecomodded (07-06-17)
Old 07-06-17, 06:19 PM   #6
Supreme EcoRenovator
 
Join Date: Sep 2012
Location: Vancouver Island,Canada.
Posts: 1,036
Thanks: 116
Thanked 99 Times in 86 Posts
Default

I was thinking insulating the base would give good gains
__________________

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
ecomodded is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 07-07-17, 08:07 AM   #7
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 907
Thanks: 11
Thanked 105 Times in 89 Posts
Default

You see the ring of heat around the base in the original post pic, it's not there anymore.
That's the main difference.
Next I'm going to spray foam the inside walls, I could add 1 to 2 inches of foam, there is an air gap where the liner doesn't even touch the side most of the way down the sides.
oil pan 4 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-13-18, 06:19 PM   #8
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 907
Thanks: 11
Thanked 105 Times in 89 Posts
Default

I sprayed about $200 worth of 2 canister AB foam in the hot tub this year, it can still go on a little thicker in a few spots.
oil pan 4 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-15-18, 08:21 AM   #9
Administrator
 
Daox's Avatar
 
Join Date: Aug 2008
Location: Germantown, WI
Posts: 5,247
Thanks: 906
Thanked 338 Times in 273 Posts
Default

How thick did that get you?
__________________
Current project -
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
&
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Daox is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Old 05-15-18, 08:30 AM   #10
Land owner
 
Join Date: Nov 2012
Location: NM
Posts: 907
Thanks: 11
Thanked 105 Times in 89 Posts
Default

1 to inches on the bottom and sides.

oil pan 4 is offline  
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiTweet this Post!
Reply With Quote
Reply


Tags
flir, hot tub, insulation, spa

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 03:38 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO
Ad Management by RedTyger
Inactive Reminders By Icora Web Design