Installing exchanger and inside plumbing w/pics

[iCreek]

I am getting so close to firing up my outdoor stove. We are doing everything ourselves so it is taking a little longer than if I hired it out, but much cheaper.

Monday evening we cut open the duct work above the propane furnace and inserted the water to air heat exchanger and mounted my water to water heat exchanger for domestic water. My brother in law used to do some HVAC work so he had all the snipes and benders. We still have to move the humidifier up about 3 inches on the right side above the air exchanger, I think we are doing that later in the week.

He had a buddy that does good tin work, and they fabricated all the brackets for the exchanger to hang on, and built a nice removable insulated cover (5$) as you can see by the below picture.

We then sweated on some ball valves for the soft water and water heater so I can go back to 'non wood heat' mode very easily in the Spring and Summer. We are 'T'ing off the soft water into the water to water heat exchanger and running a line to the outdoor stove to top off water levels at the stove, Hardy has a water valve to turn on/off this water feed. (blue line at head level).

Everything ended up looking like the below two pictures, I still have to insulate the lines and do some cleanup work. Blue line left side is soft water going to water to water heat exchanger, and to outdoor stove for fill. One of the orange lines, top right, is the hot water line coming from the stove, going into the water to water heat exchanger. The cold water and hot water cross the plates and one hot water orange goes into the my water heater, and the other goes into the water to air heat exchanger. Then the other orange line from the air heat exchanger goes back to the outdoor stove to create the loop.

Also had time this last weekend to install a new White Rodgers thermostate so I can control the outdoor wood stove from my hallway upstairs. I am using the new White Rodgers 1277 programable for my AC and Propane heat, and the older White Rodgers above it for the Hardy outdoor stove. Flash kind of dis-colored, but you get the idea.

 

[rx7145]

Nice clean install. Wish mine looked that good.

So you are pe-heating the water that goes into the hotwater tank?

 

[iCreek]

Thanks TreeCo. Yes rx7145 the plan is to heat the water and pipe it into my water heater tank, then since it is already hot water, my propane should not have to ignite the water heater element to heat the water. The Hardy stoves have a domestic water coil at the stove, but I did not want to run the extra lines to the stove so I bought a AIC water to water heat plate exchanger and hoping this works : )

According to a few people that I talked to and some research, this should work. If the cold water is 40-50 degrees (not sure) and the hot water coming into the other side (from the stove) is around 180, I think the heater water will be around 150, which is plenty hot for a water heater. I will have some loss of heat in the hot water side of the water exchanger that goes to the water to air exchanger in the furnance, hoping it will be around 170. I have a handheld IR temp reader that I will use once we get it going, them I will monitor it with a PC and thermocouple type sensor.

I just hope this concept works as I only sleeved a 4" line to the stove with 3 ea 3/4 pex insulated tubing, thermostat wire, 12-2 electric wire for the pump and fan outlet, and a 14-3 wire for a light or other, no room to add two more lines. I guess I will know real soon !!!! Anyone else have any comments?

 

[rx7145]

That will work good, I also pre-heat the water as well as have a side arm to keep the water hot. Works very well the longer you use the water the hotter it gets.

 

[timbrjackrussel]

The blue return line to outdoor heater should of come straight through the T on the water to water exchanger to reduce flow restriction and put the make up water on the side of the T.

 

[iCreek]

timbrjackrussel - The blue line to outdoor heater is a soft water supply line for filling the stove water level when needed, not a return line. This line is currently coming out of the T (side) like you noticed. The hot water return loop (orange line) is coming out of the water to air heat exchanger, left side. So saying that, should I still come straight out of the T for the fill supply line to stove, instead of using that as the inlet from my cold soft water (inlet to water to water heat exchanger) and move the inlet of cold water to the side of the T? Basically switch the two blue water lines? I ain't no plumber and respect your opinion, but want to make sure I am clear.

The blue return line to outdoor heater should of come straight through the T on the water to water exchanger to reduce flow restriction and put the make up water on the side of the T.

 

[timbrjackrussel]

Sorry, I got it now. I use a 50 foot .5 inch copper coil in the plenum of my hot air wood furnace (Surefire in the basement) that is in series with a small pump and a coil of copper tubing inside of a 30 gallon insulated tank. This tank has my domestic cold water fed in at the bottom and the preheated water outputs at the top and then feeds into my domestic gas water heater. A differential temperature control turns on the pump when the coil in the plenum is hotter than the preheat tank. I use a coolant that won't freeze and in the April to October months close one valve and open another and send the coolant out to my solar water heating panels. I have to switch in a sensor on the solar panels instead of the sensor on the plenum coil. The preheat tank temp. can reach 167 F.on a sunny July day! Wood furnace seems to max out about 140F. I am amazed at how much power the sun has in the summer months. It great when you can heat your house and domestic water too.

 

[Brooklyn Plumbi]

Cool! Thanks for sharing the pictures and method. When I had my shop installed in Brooklyn, I asked an expert plumber to do it for me and so far I am not having problems with it. Thanks for posting. I learned something new today.

 

[Stihl310]

Just for clarification, you are running your water through a plate exchanger and then into your hot water heater, correct? What size BTU is the exchanger? and will this only preheat the water as you use it? Or do you have it in a loop with some sort of circulator to push the water through the tank? I'm very interested in your design, just not sure I'm seeing it all correctly.

I have thrown the idea around of installing a small plate exchanger to heat my hot water, and then just running a small circulator to push it through... I'm aware of the side arm type exchangers, but was just thinking of something along the lines of what it appears you did.

 

[Mister Twister]

I would like to know how this works for you also. How many plate exchanger did you use for this application? After the water sits in the heater overnight without any use how long does it take to get hot water in the morning? Do you still have the gas heater working and this only preheats?

I have a sidearm on my direct vent gas heater. I keep it unplugged when I am using the OWB during the heating season but after a couple of showers the water starts to cool down because the sidearm has a rather slow recovery without a circulator pump to assist.(But the goal is to conserve energy.) Also as the cold water comes into the tank if I have it plugged in the hot water tank will turn on because the make-up water is piped down towards the thermostat.(There again burning gas which I don't want to do.)

I have to replace my hot water tank it is starting to leak so I am very interested in how your application works.

 

[Stihl310]

After the water sits in the heater overnight without any use how long does it take to get hot water in the morning?

Just for this reason, I'm interested in knowing whether or not I could just isolate my hot water tank, install a plate exchanger of "x" BTU rating and run it just as an "on demand" hot water system, that way when I called for hot water, boom it would be hot, and I would be heating no more or no less than what I was using. Then in the summer time I would just open the hot water tank back up and use it.

Make any sense??? If I could just figure out what size exchanger I would need to take water frm 50 degrees F to 120-125 F in short order... I'll have to snoop aound the internets and see if I can't find some info on this..

 

[robsco]

5x12 10 plate exchanger will spit out 120-130 degree water as fast as I can use it. I have a shower with two heads and four body jets, no problems.

 

[mbergeon]

I would like to know how this works for you also. How many plate exchanger did you use for this application? After the water sits in the heater overnight without any use how long does it take to get hot water in the morning? Do you still have the gas heater working and this only preheats?

I have a sidearm on my direct vent gas heater. I keep it unplugged when I am using the OWB during the heating season but after a couple of showers the water starts to cool down because the sidearm has a rather slow recovery without a circulator pump to assist.(But the goal is to conserve energy.) Also as the cold water comes into the tank if I have it plugged in the hot water tank will turn on because the make-up water is piped down towards the thermostat.(There again burning gas which I don't want to do.)

I have to replace my hot water tank it is starting to leak so I am very interested in how your application works.

I don't have any pictures, but I ran a 30 plate 5x12 similar to the original poster preheating the water going into my gas water heater. I had to put a mixing valve on the outlet as the water got too hot. The gas is now shut off to the heater. If we are gone for the weekend, the water is still warm, and quickly reheats with a little use.