Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 12-12-2016, 20:08   #1
Marine Service Provider
 
FutureStories's Avatar

Cruisers Forum Supporter

Join Date: Dec 2016
Location: Cape Coral, FL/Annapolis, MD
Boat: Too many and they’re all for sale
Posts: 150
Closed circuit hot water heat? Anyone tried it?

I just bought a 32" Irwin. It had brand new sails and canvas so I couldn't say no!

This is a 1970 boat with no shore power, the head was replaced with a port-a-pot (hate this thing! 5gal bucket is more practical!)

Living aboard last winter I hated the heating issue. Space heaters would pull too much power and flip the breaker whenever the refrigerator compressor kicked on. Or I had to turn them off to use the stove blah blah blah.

My Irwin had like 6'4+" headroom and I'm already putting in all new electric/plumbing and I've got to replace the floors. So I can lose 2-4" headroom and be fine. I've known people to heat houses, additions and driveways by just pushing water through a series of floor pipes.

I want to put an instant hot water unit and compressed under the dinette for the shower. So I figured that would play easy into radiant heat from a closed water system.

I'll only run that on shore power. But it should keep everything nice and toasty. Just wondering if there's any flaws in my plan or if anyone here has tried it
__________________
PM me for a free SoldBoat report! I am happy to run sold comps for you for your next sale or purchase.

Feel free to ask me about actual full service brokerage for only 7% with Knot 10 Yacht Sales - find me on our crew page, Spencer Kent
FutureStories is offline   Reply With Quote
Old 12-12-2016, 20:38   #2
Registered User
 
mikemenza's Avatar

Join Date: Oct 2015
Location: Susquehanna
Boat: hydrostream
Posts: 66
Re: Closed circuit hot water heat??? Anyone tried it?

I would think a hot water fin and tube coil with a blower would be alot easier..
Hard part is instant heaters need a continuous flow usually requiring a main loop with secondary heating loops.. two circs.. Kinda the new norm with all these low mass boilers and water heaters coming out..
__________________
mike
mikemenza is offline   Reply With Quote
Old 12-12-2016, 23:31   #3
Registered User
 
GILow's Avatar

Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,127
Re: Closed circuit hot water heat??? Anyone tried it?

Have you read Typhoon's thread on hydronic heating for his boat? His system is diesel fired, not electric, but I think a lot of the info in that thread would be useful for what you are considering.


Sent from my iPhone using Cruisers Sailing Forum
__________________
Refitting… again.
GILow is online now   Reply With Quote
Old 13-12-2016, 02:23   #4
Moderator
 
Dockhead's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Denmark (Winter), Helsinki (Summer); Cruising the Baltic Sea this year!
Boat: Cutter-Rigged Moody 54
Posts: 33,764
Re: Closed circuit hot water heat??? Anyone tried it?

You're going to change the level of the soles just to fit hot water pipes underneath? Do you realize how much is involved in changing the levels?

It could work but you will need to run numbers on how much heat will be radiated from the pipes and how much of that will work its way through the floors -- wood is an insulator.

Surely far cheaper and more practical to just install a Webasto or Espar diesel heater. A hydronic one will make hot water as well as heat the boat. An air one will be easier to install. And the really big bonus is you don't have to be on shore power to use it.


I heat with electricity when I'm on shore power. I'm really lucky to spend winters in a marina with unmetered electrical power supply. I just use a couple of fan heaters. About $25 each and Bob's your uncle. I have an Eberspacher (Espar) hydronic system which I use when off shore power. I could add an electric heating element to it for use on shore power, but why bother when fan heaters work fine? So I really can't imagine installing a whole system and even raising floor levels (!) just to have quasi-hydronic heat which runs only on shore power.
Dockhead is offline   Reply With Quote
Old 13-12-2016, 09:04   #5
cruiser

Join Date: Jan 2012
Location: Lake Ontario
Boat: Ontario 38 / Douglas 32 Mk II
Posts: 3,250
Re: Closed circuit hot water heat??? Anyone tried it?

Quote:
Originally Posted by Dockhead View Post
You're going to change the level of the soles just to fit hot water pipes underneath? Do you realize how much is involved in changing the levels?

It could work but you will need to run numbers on how much heat will be radiated from the pipes and how much of that will work its way through the floors -- wood is an insulator.

Surely far cheaper and more practical to just install a Webasto or Espar diesel heater. A hydronic one will make hot water as well as heat the boat. An air one will be easier to install. And the really big bonus is you don't have to be on shore power to use it.


I heat with electricity when I'm on shore power. I'm really lucky to spend winters in a marina with unmetered electrical power supply. I just use a couple of fan heaters. About $25 each and Bob's your uncle. I have an Eberspacher (Espar) hydronic system which I use when off shore power. I could add an electric heating element to it for use on shore power, but why bother when fan heaters work fine? So I really can't imagine installing a whole system and even raising floor levels (!) just to have quasi-hydronic heat which runs only on shore power.
Unattanded portable heaters are often a violation of marina regs and insurance policy terms and conditions.
ramblinrod is offline   Reply With Quote
Old 13-12-2016, 09:12   #6
Registered User
 
Cheechako's Avatar

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 25,483
Re: Closed circuit hot water heat? Anyone tried it?

I had one boat with water heat radiators built in. It's a complicated mess, hoses inside every storage are etc etc. You still need a lot of btu to heat the water and huge losses in the piping, so insulate well. All in all I think it's a boondoggle.
Far easier to add another shore power outlet and cord. Run with two 30 amp ones for the mini electric heaters. Or on a bigger budget get a small webasto heater.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 13-12-2016, 09:29   #7
Moderator Emeritus
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Jacksonville/ out cruising
Boat: Island Packet 38
Posts: 31,351
Re: Closed circuit hot water heat? Anyone tried it?

It won't work and I'll explain why in a minute.
First the most efficient way to heat electrically is a heat pump, reason is your not creating heat, your moving existing heat.
You don't say where you are, so I'm going to assume the water is too cold for a heat pump to work.
This leaves us with resistance heating as the only other option I know of, its equally efficient, but the ways of transferring it may induce inefficiency and that is the problem with your plan, you don't have the electrical capacity now, and when you add the more inefficient floor heat, you will need either more capacity, or you will be colder.
You see you will lose considerable heat through the hull.
Best plan as has been said is to increase electrical capacity with another 30 amp shorepower connection and use it to run your heaters.
But, get only heaters that cannot catch fire or cause a fire, my favorite is the ones that are oil filled and look like old fashioned steam radiators, they simply don't get hot enough to catch anything on fire, yet the do heat as well as a heater that does.
a64pilot is offline   Reply With Quote
Old 13-12-2016, 12:10   #8
Registered User

Join Date: Dec 2016
Posts: 142
Re: Closed circuit hot water heat? Anyone tried it?

Espar heaters, webasto heaters, and will give you ideas.
Sidney777 is offline   Reply With Quote
Old 13-12-2016, 12:26   #9
Registered User
 
appick's Avatar

Join Date: Nov 2011
Location: Grand Rapids MI
Boat: 1973 Easterly 36
Posts: 458
Re: Closed circuit hot water heat? Anyone tried it?

Oil filled electric radiators are your best bet. Safe no fire risk most usually have two switches and a resistor/ thermostat knob that allow you to turn it down so you might be able to run the stove at the same time. I'd say upgrade to a shore power connection first (you said the boat doesn't have one). You need a properly sized cable from the dock post to your boat. If you're using an extension cord (to small a gauge for high resistance heater fans) to try and run heaters pulling high amps you are a huge fire risk to the marina!

My 30amp shore power service will run my electric stove, water heater, battery charger all at the same time. You'll need the upgraded electrical panel if you put in the on demand water heater too. The plus to the radiators is you haven't permanently altered the boat that will make it worth less to the next buyer. Instead do it right with a proper circuit breaker and shore power hook up and make the boat worth (even if its just a little bit) more, because it's the proper equipment for a boat. If you want hot water buy a marine electric hot water heater, these can attach to the engine too so you get hot water from the running, which is nice when you pull in to anchor somewhere.
__________________
"If you want to build a ship, don't drum up people to collect wood and don't assign them tasks and work, but rather teach them to long for the endless immensity of the sea." Antoine de
appick is offline   Reply With Quote
Old 13-12-2016, 12:35   #10
Registered User

Join Date: Jan 2011
Location: Lake Macquarie
Boat: Farr 1020
Posts: 484
Re: Closed circuit hot water heat? Anyone tried it?

Heat from the pipes will travel downwards, as well as up.
The bilge will get toasty and as mentioned above, with the wood floor as a partial insulator, the greatest heat loss will be to the cold water below.
Insulation in the bilge is harder, as the bilge water will always try and lift it etc etc.
To use the false floor principle, lay insulation on existing floor then pipes, then a stiff but thin floor - no carpet.
Better results will be a finned tube in the cabin, perhaps at front of lockers, grille in face and top to allow cold air from floor level to be warmed and rise.
We change fin size, spacings, materials; tube size and materials, water temp and flow rate then balance the whole thing so we get the right heat in the right places. It is easy to loose all the heat quickly and not get it to where you want it at furthest point, so we also consider the way the loops run.
i.e. it is a heck of a lot more complex than first appearance. Doable, yes, but.....
Forced air is certainly easier, even if it is fed with heat by a reverse cycle unit either drawing from seawater or air.
Roger
Djarraluda is offline   Reply With Quote
Old 13-12-2016, 13:16   #11
Registered User

Join Date: Oct 2014
Posts: 303
Re: Closed circuit hot water heat? Anyone tried it?

Having installed several residential in floor hydronic heat systems, including my shop and garage floors, I thought installing one on a previous boat would be a piece of cake.

WRONG!!!!!!

The plan was to use the 5gal Seaward water heater for the heat source and use hydronic base board radiators for the disipators.

First problem was getting radiators that weren't 10' long. But this was a minor issue compared to the main problem.
The standard marine water heater doesn't produce enough BTU's to continuously supply hot water to the radiators.

Even bought some automotive heaters from J.C. Whitney.
The water heater struggled to even have one of them produce luke warm air.

I can see where using an "on demand" heater would solve the BTU problem, but most of them are 220V which causes new problems.

The new boat has a heat pump installed, and it does a very good job of both cooling and heating. I can't see where it's expense would be more than what would be involved in getting an operating hydronic system.

I really think that you need to backup and rethink other options.

Just my $0.02 worth.
missourisailor is offline   Reply With Quote
Old 13-12-2016, 14:20   #12
Marine Service Provider
 
Scott Berg's Avatar

Join Date: Jul 2011
Location: Aboard
Boat: Seaton 60' Ketch
Posts: 1,338
Re: Closed circuit hot water heat? Anyone tried it?

Sitting in a chilly anchorage, 40something outside, water 42f, but a toasty 74F below decks... webasto 2010 boiler and fan coil units... sips diesel, and the warm air coming out of the registers feels good compared to the reverse cycle chillers we just de-commissioned when the water hit 44F. I LOVE diesel heat (and, more important, so does my Co Captain!)
__________________
Scott Berg
WAØLSS
SV CHARDONNAY
Scott Berg is offline   Reply With Quote
Old 13-12-2016, 17:32   #13
Registered User

Join Date: Oct 2015
Location: Summerstown Ontario Canada
Posts: 457
Re: Closed circuit hot water heat? Anyone tried it?

Quote:
Originally Posted by Scott Berg View Post
Sitting in a chilly anchorage, 40something outside, water 42f, but a toasty 74F below decks... webasto 2010 boiler and fan coil units... sips diesel, and the warm air coming out of the registers feels good compared to the reverse cycle chillers we just de-commissioned when the water hit 44F. I LOVE diesel heat (and, more important, so does my Co Captain!)
This is the first time someone talks about temperature. I am wondering at what temperature is the output of the boiler? Boiler at 212 degrees? I often wondered about heating with hydronics. I heat my shop in floor hydronics and the temperature going to the floor is 130 degrees and since the heat is in the floor... it rises and all is very warm. The thermostat is set for 13 degrees and I work in there with short sleeve shirt and I feel the heat rise from the floor. Also very economical for me. Am I missing something that this will not work in a boat? Just curious...
seabreez is offline   Reply With Quote
Old 13-12-2016, 18:48   #14
Senior Cruiser

Cruisers Forum Supporter

Join Date: May 2013
Location: Oregon to Alaska
Boat: Wheeler Shipyard 83' ex USCG
Posts: 3,499
Re: Closed circuit hot water heat? Anyone tried it?

In a floor, usually it's a slab with tubes and with foam underneath. In a boat underneath is the bilge and hull drawing out much of your heat. Dirt is a good insulator, but water isn't.
My "boiler" runs under 15psi so temps up to 250° F are possible without producing steam. When the boat had baseboard radiators I had to run above 220° to get timely heat in Nanaimo in the winter. I switched to marine (car style) heaters and set the temps to 180° and cut the diesel bill in half. I also insulated all the lines. Now with a cold boat at about 40°F I can be comfortable in about a half hour. With the radiators it took about 4 hours.
I heat a big boat and found electricity the most expensive (paying 7¢/kwh in Oregon), diesel 2nd most. Now I have a pellet stove with a homemade water coil that heats the boiler. In really cold weather, 0-20°F, it cost about $10/day. Diesel would be 5+ gallons and electric about $20 a day.
Lepke is offline   Reply With Quote
Old 13-12-2016, 19:33   #15
Registered User

Join Date: Oct 2014
Posts: 303
Re: Closed circuit hot water heat? Anyone tried it?

Quote:
Originally Posted by seabreez View Post
This is the first time someone talks about temperature. I am wondering at what temperature is the output of the boiler? Boiler at 212 degrees? I often wondered about heating with hydronics. I heat my shop in floor hydronics and the temperature going to the floor is 130 degrees and since the heat is in the floor... it rises and all is very warm. The thermostat is set for 13 degrees and I work in there with short sleeve shirt and I feel the heat rise from the floor. I installed this myself. Very simple system, heat from a hot water tank. Also very economical for me. Am I missing something that this will not work in a boat? Just curious...
My shop and garage hydronic system are heated with the domestic hot water heater. Which is set to about 130F. But there is no way the hydronic system is running at that temp. The mixing valve, some call it a tempering valve, is set to 105F output. Which is the feed temp to the distribution manifolds. The return temp is around 80F with the stat set to 70F.

At 130F feed temp, it would be very uncomfortable to stand on for any length of time.

With a typical marine water heater, the 3k watt heating element does not provide enough BTU's to even maintain 60F feed temp. And this is for automotive style heaters. Which require less flow than an in-floor or baseboard style system.

Trust me. I tried. And failed!
missourisailor is offline   Reply With Quote
Reply

Tags
water

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
HOT HOT HOT! running AC on Honda generator sailorboy1 Plumbing Systems and Fixtures 79 27-06-2019 07:21
solar, 100w, open circuit ok, short circuit ok, no power to battery NotreVoyage Electrical: Batteries, Generators & Solar 3 26-04-2016 22:41
Hot Water System - Extra Hot Water Needed ? Harben Plumbing Systems and Fixtures 8 07-10-2010 16:20
Propane hose that shrinks closed when hot James S Construction, Maintenance & Refit 6 16-01-2009 06:39
Ohhhhh Hot! Hot! Hot! knottybuoyz Marine Electronics 6 01-06-2007 07:43

Advertise Here


All times are GMT -7. The time now is 04:56.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.