Vacuum Exhaust Heat Exchanger

Jim Davisson

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Aug 23, 2016
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James Davisson
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#1
20181230_134409.jpg


This 8x8 finned tube heat exchanger while being a total challenge to implement doesn't add substantial solution temperature (only 10° with my insane flow wand, 15° with an 8 flow) however it has attenuated heat exiting the exhaust air and namely dampened sound. Exhaust temps are reduced 30° to 120° and it's 75 decibels next to it and a very tolerable 60 @ 15'.

The vac exhaust heat exchanger idea is nothing new for sure, but the sound and heat suppression is a pretty kickass side effect. Cfm's are reduced more by the muffler than the heat exchanger. Overall my system takes a 15 CFM penalty through the exchanger and muffler vs reading off the stack.

In an ETM situation a couple of these together would be very effective in preheating incoming water before the main heater and substantially quieting the exhaust noise especially when running on cord power.

Again, nothing new or groundbreaking, but worth the trouble for me. Cheers!
 

smart n kleen

Smart N Kleen
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Mar 12, 2010
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#2
View attachment 82012

This 8x8 finned tube heat exchanger while being a total challenge to implement doesn't add substantial solution temperature (only 10° with my insane flow wand, 15° with an 8 flow) however it has attenuated heat exiting the exhaust air and namely dampened sound. Exhaust temps are reduced 30° to 120° and it's 75 decibels next to it and a very tolerable 60 @ 15'.

The vac exhaust heat exchanger idea is nothing new for sure, but the sound and heat suppression is a pretty kickass side effect. Cfm's are reduced more by the muffler than the heat exchanger. Overall my system takes a 15 CFM penalty through the exchanger and muffler vs reading off the stack.

In an ETM situation a couple of these together would be very effective in preheating incoming water before the main heater and substantially quieting the exhaust noise especially when running on cord power.

Again, nothing new or groundbreaking, but worth the trouble for me. Cheers!
Looks nice.
 
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Jimsteam

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Apr 19, 2009
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#3
Awesome ! You must have a box truck or similar . I have no room for all the creations you come up with ~! LOL
 

Ymetimme

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Apr 27, 2018
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Tim yeater
#6
View attachment 82012

This 8x8 finned tube heat exchanger while being a total challenge to implement doesn't add substantial solution temperature (only 10° with my insane flow wand, 15° with an 8 flow) however it has attenuated heat exiting the exhaust air and namely dampened sound. Exhaust temps are reduced 30° to 120° and it's 75 decibels next to it and a very tolerable 60 @ 15'.

The vac exhaust heat exchanger idea is nothing new for sure, but the sound and heat suppression is a pretty kickass side effect. Cfm's are reduced more by the muffler than the heat exchanger. Overall my system takes a 15 CFM penalty through the exchanger and muffler vs reading off the stack.

In an ETM situation a couple of these together would be very effective in preheating incoming water before the main heater and substantially quieting the exhaust noise especially when running on cord power.

Again, nothing new or groundbreaking, but worth the trouble for me. Cheers!
That's weird I've been working on one as well it really does heat up the water pretty good. All things considered
Have you done the wrapping the vacuum motors in copper tubing yet you know the good old power flight trick.
I'm doing a combination of both for my preheat
I'm trying to get away from fuel fired
 

Jim Davisson

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Aug 23, 2016
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#7
I don't want any excess heat in the motor cabinet so I haven't looked at that route.

If you are going to keep everything on the van routing the coolant before the heater core to 50' of 1/2" copper tube into the freshwater tank is an awesome mod. Keeps the van warm all night here on 20° nights, no heater needed.
 

Ymetimme

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Apr 27, 2018
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Tim yeater
#8
I don't want any excess heat in the motor cabinet so I haven't looked that route.

If you are going to keep everything on the van routing the coolant before the heater core to 50' of 1/2" copper tube into the freshwater tank is an awesome mod. Keeps the van warm all night here on 20° nights, no heater needed.
Yeah I did notice your working with a really tight space. It lower my motor winding temperature by over 125 degrees f what's the cabinet temperature of the machine increased slightly about 20 degrees f

And man that's weird we have been doing the copper coil in the freshwater tank for like 15 years. I was always scared to mention it on this format due to the fact someone might scream. you'll get any freeze all over the place!!! It's never leaked a drop!!!

I'm currently working on a thermal Mass heater followed by an induction heater with pulmonary results are absolutely astounding we'll keep up with fuel fired for the most part.
The problem is it's very dangerous
A split-second of too much induction and boom!!! You got a pipe bomb in your van or clients home
I know I know pressure bypass!
 
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Jim Davisson

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Aug 23, 2016
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Serving the greater Charlotte area
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James Davisson
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United States
#9
Yeah I did notice your working with a really tight space. It lower my motor winding temperature by over 125 degrees f what's the cabinet temperature of the machine increased slightly about 20 degrees f

And man that's weird we have been doing the copper coil in the freshwater tank for like 15 years. I was always scared to mention it on this format due to the fact someone might scream. you'll get any freeze all over the place!!! It's never leaked a drop!!!

I'm currently working on a thermal Mass heater followed by an induction heater with pulmonary results are absolutely astounding we'll keep up with fuel fired for the most part.
The problem is it's very dangerous
A split-second of too much induction and boom!!! You got a pipe bomb in your van or clients home
I know I know pressure bypass!
I'm interested in seeing this setup. 160-170° is plenty of heat for me especially if it is consistent.
 

Ymetimme

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Apr 27, 2018
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Tim yeater
#10
I'm interested in seeing this setup. 160-170° is plenty of heat for me especially if it is consistent.
Oh man thermal mass will do that easily you don't even need induction
hit 240 if you include induction
Maintain 170 without induction
Once again hoping to hit market in the spring
 
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