Join Early Retirement Today
Reply
 
Thread Tools Search this Thread Display Modes
Under-Sink Mini-Tank Water Heater
Old 11-04-2013, 12:49 PM   #1
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
TromboneAl's Avatar
 
Join Date: Jun 2006
Posts: 11,197
Under-Sink Mini-Tank Water Heater

Having a mini-tank water heater under the sink looks like it will be a perfect solution to the problem of waiting for hot water. I've calculated that I must run 1.5 gallons of water before it reaches full heat. If I have a mini-tank heater, then that will supply the hot water in the interim. Also, that tank will then receive the hot water from whole-house heater, and be ready to go again at any time.

However, the problem I see is fitting one in there. Here is my undersink area:



And this product is 11x14x14.

Is there some way to make this fit (reroute plumbing), or should I try to find a smaller model? Note that I will be getting a single bowl sink, with the drain on the left.
__________________

__________________
TromboneAl is offline   Reply With Quote
Join the #1 Early Retirement and Financial Independence Forum Today - It's Totally Free!

Are you planning to be financially independent as early as possible so you can live life on your own terms? Discuss successful investing strategies, asset allocation models, tax strategies and other related topics in our online forum community. Our members range from young folks just starting their journey to financial independence, military retirees and even multimillionaires. No matter where you fit in you'll find that Early-Retirement.org is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with our members, see fewer ads, upload photographs, create a retirement blog, send private messages and so much, much more!

Old 11-04-2013, 01:16 PM   #2
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
pb4uski's Avatar
 
Join Date: Nov 2010
Location: Vermont & Sarasota, FL
Posts: 16,411
This would fit better in the space and is tankless. But will your undersink 120 service support it (It requires 20 amp with 12 ga wire)?

I think your best bet would be mini-tank or tankless units that will fit better in your cabinet. I'll be going through the same process soon. I'm sick of waiting for hot water to get to the sink from the utility room.
__________________

__________________
If something cannot endure laughter.... it cannot endure.
Patience is the art of concealing your impatience.
Slow and steady wins the race.
pb4uski is offline   Reply With Quote
Old 11-04-2013, 01:24 PM   #3
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
HFWR's Avatar
 
Join Date: May 2005
Location: Lawn chair in Texas
Posts: 12,964
When you say single bowl, do you mean one sink as wide as the two you have now? If the single bowl is the size of one side now, why not install on the right side, get rid of the disposal (use it's power for the heater), since your p-trap and drain are already on the right. Should leave plenty of room, assuming your sink base is 36".
Attached Images
File Type: jpg sink base.jpg (51.0 KB, 12 views)
__________________
Have Funds, Will Retire

...not doing anything of true substance...
HFWR is offline   Reply With Quote
Old 11-04-2013, 01:28 PM   #4
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
pb4uski's Avatar
 
Join Date: Nov 2010
Location: Vermont & Sarasota, FL
Posts: 16,411
Quote:
Originally Posted by TromboneAl View Post
Would it fit along the left wall of the cabinet? or would it conflict with the disposal?

Or could you reconfigure the disposal to be on the right sink to free up some room on the left side of the cabinet for the HW unit?

I just saw your note that your are going to a single bowl sink. If you could concentrate the drain and disposal on the right side of the cabinet then you would free upspace on the left side for the HW heater.

The constraint is the location where the drain enters the wall.
__________________
If something cannot endure laughter.... it cannot endure.
Patience is the art of concealing your impatience.
Slow and steady wins the race.
pb4uski is offline   Reply With Quote
Old 11-04-2013, 01:37 PM   #5
Thinks s/he gets paid by the post
martyb's Avatar
 
Join Date: Nov 2006
Location: Bossier City
Posts: 2,182
Do I see six beers under your sink?

We just bought our retirement home, and our kitchen sink is a long way from the water heater (in the attic). I haven't thought about checking to see how many gallons of water we're wasting before the hot water gets to the tap, but I'll do that. I've considered doing what you're talking about.
__________________
martyb is online now   Reply With Quote
Old 11-04-2013, 01:38 PM   #6
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
HFWR's Avatar
 
Join Date: May 2005
Location: Lawn chair in Texas
Posts: 12,964
Quote:
Originally Posted by martyb View Post
Do I see six beers under your sink?
They stay colder in the fridge...
__________________
Have Funds, Will Retire

...not doing anything of true substance...
HFWR is offline   Reply With Quote
Old 11-04-2013, 02:18 PM   #7
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
travelover's Avatar
 
Join Date: Mar 2007
Posts: 9,878
I don't recall if you have a basement, so this might not be practical. I have a hot water return line from my farthest faucet T'd into the drain valve on the water heater. I get instant hot water at the small cost of the constantly circulating water's heat loss. Seems like Pex would be great for a retrofit.
__________________
Yes, I have achieved work / life balance.
travelover is offline   Reply With Quote
Old 11-04-2013, 03:04 PM   #8
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
TromboneAl's Avatar
 
Join Date: Jun 2006
Posts: 11,197
A tankless would probably require rewiring, and doesn't have the nice plays-well-with-other-heater attributes. I could do that if necessary.

Yes, the single-bowl sink is as wide as the current sink, and has the drain on the left, and I have no choice there (unless I want the faucet in the front).

Quote:
Do I see six beers under your sink?
Those are actually emergency seltzer water cans. If someone spills wine on the carpet, I grab one and empty the entire contents onto the spill.
__________________
TromboneAl is offline   Reply With Quote
Old 11-04-2013, 03:12 PM   #9
Dryer sheet wannabe
Bob Adams's Avatar
 
Join Date: Feb 2012
Location: Omaha
Posts: 22
Grundfos has a slick product available that you might not have ran across before. Works well and Grundfos is a top notch manufacturer. Minimal space required and the only electrical connection required is for the circulation pump, and that's just 115VAC.

Grundfos Comfort System | Grundfos

Good luck!
__________________
Bob Adams is offline   Reply With Quote
Old 11-04-2013, 03:24 PM   #10
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
pb4uski's Avatar
 
Join Date: Nov 2010
Location: Vermont & Sarasota, FL
Posts: 16,411
These look interesting. Small size.

Mini Tank | Waiwela

Also this one would seem to fit your space - it may be the leading contender for my application.

http://www.amazon.com/Rheem-81VP2S-E...productDetails
__________________
If something cannot endure laughter.... it cannot endure.
Patience is the art of concealing your impatience.
Slow and steady wins the race.
pb4uski is offline   Reply With Quote
Old 11-04-2013, 07:59 PM   #11
Dryer sheet aficionado
 
Join Date: May 2012
Posts: 48
Reroute the plastic drains within the cabinet would be the easiest solution to gain the needed space. With a few fittings you could move the trap parallel to the back of the cabinet and route the drain from the right hand sink right out of the basket to the back of the cabinet to gain the needed space on the right hand side of the cabinet. When you put your new sink in you can change and pretty up the drain installation permanently.
__________________
painterbill is online now   Reply With Quote
Old 11-05-2013, 01:05 AM   #12
Thinks s/he gets paid by the post
Telly's Avatar
 
Join Date: Feb 2003
Posts: 1,448
Quote:
Originally Posted by TromboneAl View Post
Having a mini-tank water heater under the sink looks like it will be a perfect solution to the problem of waiting for hot water. I've calculated that I must run 1.5 gallons of water before it reaches full heat. If I have a mini-tank heater, then that will supply the hot water in the interim. Also, that tank will then receive the hot water from whole-house heater, and be ready to go again at any time............
It will be interesting to see how this works out. After first turning on the faucet, hot water will come out, as it is heated water off of the top of the mini-tank. As the hot water continues to be taken out of the top of the tank, cool water from sitting in the pipes will be filling into the bottom of the mini-tank, eventually going out the faucet. As the inlet water into the mini-tank rises in temperature due to the main water heater, the water in the minitank will increase in temp. Then all the water coming out of the faucet will be hot, from the main water heater.

So it would seem if the mini-tank's capacity is less than some X times of the amount of the "slug" of cold water due to sitting in the pipes cooling off from the main heater, then the faucet water temperature profile versus time will be:
Hot -> Cold-> Hot

If the mini-tank's capacity was many times the amount of the slug, then it would seem that even with cold pipe water mixing in for the short while, there would be enough hot water stored in the mini-tank to mix in with and minimize the cooling effect of the input slug.

I'm just thinking as I'm typing...
__________________
-- Telly, the D-I-Y guy --
Two fools dancing on the hands of time
Telly is offline   Reply With Quote
Old 11-05-2013, 08:20 AM   #13
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
pb4uski's Avatar
 
Join Date: Nov 2010
Location: Vermont & Sarasota, FL
Posts: 16,411
Quote:
Originally Posted by Telly View Post
It will be interesting to see how this works out. After first turning on the faucet, hot water will come out, as it is heated water off of the top of the mini-tank. As the hot water continues to be taken out of the top of the tank, cool water from sitting in the pipes will be filling into the bottom of the mini-tank, eventually going out the faucet. As the inlet water into the mini-tank rises in temperature due to the main water heater, the water in the minitank will increase in temp. Then all the water coming out of the faucet will be hot, from the main water heater.

So it would seem if the mini-tank's capacity is less than some X times of the amount of the "slug" of cold water due to sitting in the pipes cooling off from the main heater, then the faucet water temperature profile versus time will be:
Hot -> Cold-> Hot

If the mini-tank's capacity was many times the amount of the slug, then it would seem that even with cold pipe water mixing in for the short while, there would be enough hot water stored in the mini-tank to mix in with and minimize the cooling effect of the input slug.

I'm just thinking as I'm typing...
Interesting thought. I think you may be right in that once one turns on the faucet the water would probably go hot then cold or warm and then hot so it may not "solve" the problem but rather just defer the problem. The question would be what "x" needs to allow the mix of hot water from the mini and water from the main heater to not become too cool.

I've heard of tankless HW heaters being used in such situations and it is clear that those would work and then would turn off once hot water from the main heater reaches the tankless.
__________________
If something cannot endure laughter.... it cannot endure.
Patience is the art of concealing your impatience.
Slow and steady wins the race.
pb4uski is offline   Reply With Quote
Old 11-05-2013, 08:29 AM   #14
Thinks s/he gets paid by the post
zinger1457's Avatar
 
Join Date: Jul 2007
Posts: 1,452
Are you doing this to conserve water or save money? If it's to save money I doubt you'll ever re-coop the cost of whatever system you choose. As a water conservation measure recirculation pumps are now part of the building code for new home construction where I live in Arizona.
__________________
zinger1457 is offline   Reply With Quote
Old 11-05-2013, 08:34 AM   #15
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
calmloki's Avatar
 
Join Date: Jan 2007
Location: Independence
Posts: 5,459
Quote:
Originally Posted by Bob Adams View Post
Grundfos has a slick product available that you might not have ran across before. Works well and Grundfos is a top notch manufacturer. Minimal space required and the only electrical connection required is for the circulation pump, and that's just 115VAC.

Grundfos Comfort System | Grundfos

Good luck!

I think this is the hot ticket - hot water pretty much instantly at ALL points for the cost of keeping hot water in the pipes and some minimal pumping. Wonder if the cost isn't equal to the cost of having a couple gallons of hot sitting under the sink in a poorly insulated container. It was suggested to me when we did our place a dozen years ago - didn't do it, I just adjust what I'm doing to match the temperature changes.
__________________
calmloki is offline   Reply With Quote
Old 11-05-2013, 08:50 AM   #16
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
pb4uski's Avatar
 
Join Date: Nov 2010
Location: Vermont & Sarasota, FL
Posts: 16,411
Just thinking some more. I wonder if one could solve the hot>cold>hot problem of a mini-tank by plumbing the mini-tank and the hot water line from the main hot water heater into some sort of valve that would mix the hot mini-tank water with the room temperature lag water until the main hot water reaches the sink. Any plumbers out there?
__________________
If something cannot endure laughter.... it cannot endure.
Patience is the art of concealing your impatience.
Slow and steady wins the race.
pb4uski is offline   Reply With Quote
Old 11-05-2013, 08:51 AM   #17
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
pb4uski's Avatar
 
Join Date: Nov 2010
Location: Vermont & Sarasota, FL
Posts: 16,411
Quote:
Originally Posted by calmloki View Post
I think this is the hot ticket - hot water pretty much instantly at ALL points for the cost of keeping hot water in the pipes and some minimal pumping. Wonder if the cost isn't equal to the cost of having a couple gallons of hot sitting under the sink in a poorly insulated container. It was suggested to me when we did our place a dozen years ago - didn't do it, I just adjust what I'm doing to match the temperature changes.
I agree but my main system is a propane fired tankless so a recirculation solution wouldn't work for me as the tankless would be running all the time.
__________________
If something cannot endure laughter.... it cannot endure.
Patience is the art of concealing your impatience.
Slow and steady wins the race.
pb4uski is offline   Reply With Quote
Old 11-05-2013, 09:06 AM   #18
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
calmloki's Avatar
 
Join Date: Jan 2007
Location: Independence
Posts: 5,459
Quote:
Originally Posted by pb4uski View Post
I agree but my main system is a propane fired tankless so a recirculation solution wouldn't work for me as the tankless would be running all the time.
Ahh. We've nat gas water heater in a remote location - even have a 110V outlet right there by the top of the tank waiting for me. Don't recall if T-Al is tankless - don't think so if I recall a thread from long ago about running pipes from a garage location and floor joists....
__________________
calmloki is offline   Reply With Quote
Old 11-05-2013, 09:13 AM   #19
Give me a museum and I'll fill it. (Picasso)
Give me a forum ...
 
Join Date: May 2005
Posts: 13,263
Quote:
Originally Posted by TromboneAl View Post
A tankless would probably require rewiring, and doesn't have the nice plays-well-with-other-heater attributes. I could do that if necessary.

Yes, the single-bowl sink is as wide as the current sink, and has the drain on the left, and I have no choice there (unless I want the faucet in the front).



Those are actually emergency seltzer water cans. If someone spills wine on the carpet, I grab one and empty the entire contents onto the spill.

If you go to the 'insta-hot' (tankless), you can close off the hot water line and just split the cold... no need to draw any hot water from the big tank....
__________________
Texas Proud is offline   Reply With Quote
Old 11-05-2013, 09:47 AM   #20
Thinks s/he gets paid by the post
walkinwood's Avatar
 
Join Date: Jul 2006
Location: Denver
Posts: 2,676
We have the grundfos comfort system, but to back-fit it into an existing home, you'll need to make a change to your piping - something called a direct return.

I've seen other hot water circulators that only need a minor modification under the sink - the hot water is dumped into the cold water pipe when the circulator is on. These also have a switch at the sink so you can turn it on just when you need it.

Our hot water cirulator has a timer so it can be set to turn on at certain times. That doesn't work well for us since we don't have a fixed schedule. I'm thinking of buying a remote controlled switch so we can turn it on/off when we need it. Still looking for the ideal switch - remote on/off with a timer in case we forget to turn it off. I've seen one by NuGiant that looks interesting.
__________________

__________________
walkinwood is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are Off
Refbacks are Off


 

 
All times are GMT -6. The time now is 05:14 AM.
 
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.