Reply
 
Thread Tools Display Modes
 
Old 01-09-2020, 01:28 PM   #1
Mini-Skoolie
 
Join Date: Jul 2019
Location: Houston
Posts: 62
Year: 1997
Engine: Cummins 8.3
Webasto to Radiant Floors - How to transfer the heat between systems

Hi all.

We are looking for a method of using the Scholastic Webasto to heat radiant floors in our bus. I saw on some past forums that, since the Webasto often reaches temperatures too high to heat radiant floors, that you should buy a compatible water heater with a heat exchanger inside to transfer the heat from the Webasto to the water heater. And then a separate heat exchanger to transfer the heat from the water heater to the glycol in the heated floors.

Is there a very specific variety of water heater that is capable of this type of heat exchange? (i.e. transfer heat From Webasto Heated Coolent, to Potable Water, to Glycol) What kind of key words should I be looking for? Is this system rarely discussed because of some other problem that I have not recognized yet?

Note: This general topic seems to have been brought up in the past, but I haven't found any answers that still have working links. Sorry if this is redundant.
Truffles is offline   Reply With Quote
Old 01-09-2020, 04:54 PM   #2
Bus Crazy
 
somewhereinusa's Avatar
 
Join Date: Nov 2010
Location: Andrews,Indiana
Posts: 2,154
Year: 1991
Coachwork: Bluebird
Chassis: AARE
Engine: 3116 Cat 250hp
Rated Cap: Just the two of us.
Quote:
Originally Posted by Truffles View Post
Hi all.


Is there a very specific variety of water heater that is capable of this type of heat exchange? (i.e. transfer heat From Webasto Heated Coolent, to Potable Water, to Glycol) What kind of key words should I be looking for? Is this system rarely discussed because of some other problem that I have not recognized yet?
I can't answer your specific questions, perhaps I can help with what I have and works for me. I don't have a Webasto, I have an Espar.
I would think the heater would make water somewhere around 170 or so which is lower than what your engine makes. I used a heat exchanger similar to this. NOT this one in particular I think mine is 20 plate but, don't remember for sure. Do your own math.

https://www.amazon.com/Brazetek-Exch.../dp/B00401AIX4

It goes in the water lines from the engine that would normally go to the heater, the other end goes in the loop that your heater is in. It works both ways if heater is on engine is warm, if engine is running and warm heater loop is warm. I also have a marine hot water heater, in the heater loop, that has an internal heat exchanger.

I have been using this for over 5 years with no problems although some will say that engine temp is over recommended for pex.

There are some pictures here.

Heat
somewhereinusa is offline   Reply With Quote
Old 01-09-2020, 04:59 PM   #3
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,851
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
My webasto is rated to turn off at 170 and back on at 158.. a heat exchanger like the one somewhereinusa listed is exactly perfect for floor loops.. you can turn the pump on and off if your loop temp gets too high and the webasto will simply cycle out when it reaches 170 in the heat exchanger...
cadillackid is offline   Reply With Quote
Old 01-10-2020, 03:36 AM   #4
Bus Geek
 
Join Date: May 2016
Location: Eastern WA
Posts: 6,318
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
I have only seen one RV water heater that had a coolant heat exchanger built in. And I bought it....

There are a number of marina water heaters that have that feature.
PNW_Steve is offline   Reply With Quote
Old 01-10-2020, 09:54 AM   #5
Bus Crazy
 
Drew Bru's Avatar
 
Join Date: May 2016
Location: Minnehaha Co., SD
Posts: 1,026
Year: 1996
Coachwork: Amtran
Chassis: International
Engine: DT466
Rated Cap: 65
Quote:
Originally Posted by PNW_Steve View Post
I have only seen one RV water heater that had a coolant heat exchanger built in. And I bought it....

There are a number of marina water heaters that have that feature.

Yup, Suburban makes one. https://www.dyersonline.com/suburban...d-sw10dem.html


I think Atwood might have one too.
__________________
Our Build: https://dazzlingbluebus.wordpress.com/
Drew Bru is online now   Reply With Quote
Old 01-12-2020, 05:01 AM   #6
Bus Geek
 
Join Date: May 2016
Location: Eastern WA
Posts: 6,318
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
Quote:
Originally Posted by Drew Bru View Post
Yup, Suburban makes one. https://www.dyersonline.com/suburban...d-sw10dem.html


I think Atwood might have one too.
Thank you. I stumbled onto the one I bought for my first build at a surplus store. When I went looking for another one I couldn't find it.
PNW_Steve is offline   Reply With Quote
Reply

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 Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 10:18 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×