Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 12-09-2008, 12:50   #1
Registered User

Join Date: Jan 2006
Location: Rhode Island
Boat: C&C 38
Posts: 519
Images: 6
Doing something useful with heat dissipated from your fridge compressor

Hi, this might be more geared towards DIY tinkerers, but has anyone tried using a good quality heat exchanger and high side of the compressor to heat water for the shower? I was recenlty working on an old commercial espresso machine and was very impressed with the quaity of a copper boiler. It had a heat exchanger loop that heated the water for espresso.
Then i had a thought...
I still intend to keep the fan as the primary condesing element, but I would add the copper boiler before the condenser, and then cycle the water in the boiler as it got warm, into the 6gal waterheater tank.
Would the high side copper line be enough the heat the water in the copper boiler from espresso machine, its about 1/2 gal?

phorvati is online now   Reply With Quote
Old 13-09-2008, 06:13   #2
Registered User

Join Date: Jan 2007
Location: Fremantle Australia
Boat: Schioning 12.3 "Wilderness" Bi-Rig under construction
Posts: 558
Send a message via Skype™ to Whimsical
A refridgeration unit pumps a very small amout of heat and to heat 6 gal needs lots. Not worth the complication.


Whimsical is offline   Reply With Quote
Old 13-09-2008, 12:18   #3
Registered User
Nordic cat's Avatar

Join Date: Jan 2008
Location: Denmark
Boat: FP Tobago 35
Posts: 721
For energy efficiency, you want to keep the condenser temperature as low as possible. The higher the temperature at the condenser, the higher the pressure is that the compressor needs to pump up against, the lower the efficiency of the system. It has to do with compression ratios. The lower the fridge temperature the lower the pressure is that the compressor has to "suck", so if there is a big difference between suction and discharge pressure, the amount of gas the compressor can move for each stroke goes down. In industrial systems they try to keep the ratio below around 1:8. If you know what refrigerant you have, you can look up the temperatures and correlated pressures to give you an idea of where you are. Or else post here, and I can do it for you

You need to go the other way, use a salt water cooled condenser if sailing in warmer climates especially.


Nordic cat is offline   Reply With Quote
Old 15-09-2008, 17:40   #4
Registered User

Join Date: May 2008
Location: SW Florida
Boat: Bristol (Alden) 35 Sloop "Zephyr"
Posts: 494
Images: 2
I was on a 40 foot boat a fellow was building, and he had some very interesting inovations on the boat.
One of them was a clothes dryer, that used wasted heat from his refrigeration, to heat the drum. Not sure how well it worked, but was an interesting idea.
He had bought the bare hull, without a deck, and was almost done with the boat, when I met him.
Quite a project.
over40pirate is offline   Reply With Quote
Old 15-09-2008, 18:22   #5
Registered User

Join Date: Jun 2008
Posts: 69
I think he is talking about putting the hot part of the refrigeration inside the hot water heater and then going out to the cooling part or whatever it is called. I've taken engineering thermodynamics and forget many of the terms, processes and whatnot.
You could also attach a peltier to the hot side of the refrigeration and add a heatsink with cool lake/ocean water flowing through, in this sense you could make electricity from the wasted heat.
malovich is offline   Reply With Quote
Old 22-09-2008, 06:02   #6
Registered User

Join Date: Sep 2008
Location: Ft Walton Beach
Boat: Newport 28 - Aprianna
Posts: 9
Images: 1
Originally Posted by malovich View Post
... inside the hot water heater ...
Not that I have anything valuable to add but isn't it a cold water heater or just a water heater? If your already heating hot water doesn't that just defeat the purpose?
Josh H is offline   Reply With Quote
Old 22-09-2008, 07:03   #7
Registered User

Join Date: Jan 2006
Location: Rhode Island
Boat: C&C 38
Posts: 519
Images: 6
Josh, water heaters are well insulated and can store the hot water. I want the hot, high side copper line exiting the danfoss compressor, to go through the heat exchanger, and heat the fresh water. The hot fresh water would go into the water heater for storage of hot water.
You could do the same with black hose on deck during the hot summer day. Then just feed the hose water into the water heater.
I am trying to avoid running the engine every day for hot water. I also don't have the kind of AC capability to heat the water.

phorvati is online now   Reply With Quote


Thread Tools
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
Compressor on Board Gisle Fishing, Recreation & Fun 31 13-12-2010 09:15
Compressor gone bad Minitee Plumbing Systems and Fixtures 3 22-08-2007 02:14
Compressor for sailboat Strygaldwir Fishing, Recreation & Fun 16 14-08-2006 21:39
Dive compressor Talbot Fishing, Recreation & Fun 1 10-08-2004 20:17

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 15:02.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.