Getting hot water from the engine into the house

[jens]

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[oliver90owner]

Will it be a problem after first purge?  As long as the pump is flooded suction it should purge the line?  Just need somewhere in the system to remove any entrained air.  As long as pump is in outlet feed from the engine the pressure at the head gasket should not be greatly above the static head?

Should not really be a problem, I would have thought.  Copy Eadie's system?

Regards, RAB

[SteveU.]

Morning Jens,

My expereinces in automotive says most any cooling system is possible When Every Thing Is Working Properly. But in repair/service work I only got to work on the broke/fix it systems.  Example: in a vehicle the heater core and supply line are almost always HIGHER the engine/radiator/unpressurized expansion tank. Let alone the SUV/Bus?Vans systems with remote rear heaters. With no purge venting at these higher/remote spots the only ways to force the air out is a high volumn pressure pump or jucking the vehicle up at a 30-40 degree angle.

Since you will need heat in your down stairs office space anyhow drill through the concrete run your lines uninsulated through this space sloped for the least amount of problems. Put your regular expansion tank AND pressure fill cap in the basement at the at the high point of that coolant loop.

If you decide to go the other route: consider using a closed system with an air bladder pressure/surge tank like on a well or residential water system. This could have adjustale pressure (with the air) and be mounted below the highest point.

Good luck
SteveU.

[Tom]

Hi Jens,

A small 6 gal hot water heater from an RV would make a good expansion tank. Thinking outside the box, is there a place on the first floor you could tuck the tank away. That way it would be the highest point in the loop.

Or you may want to set it up like I plan to do my domestic solar hot water system, as a drain back. Just place the hot water heater/reservoir near the pump in the engine room. When the pump starts it will draw the water in the tank down until the line is filled. And when the pump shuts off the water will drain back into the reservoir. The only question is how high of a head the pump will handle.

[Tom]

I don't see why you can't disregard the air. It will either purge when the pump comes on or the fluid will flow under the air bubble. Any purged air bubbles will eventually end up in the reservoir. Also unless you are running 3" lines, the volume of drain back should be quite small so you could place the tank at about the same level as your pump. That would make it easier to fill.

Again reservoir location has more to do with how much head your pump can handle. Do you have the pump yet?

[Tom]

That pump is good for 8' of head, so it sounds like it will work fine, unless you have 12' ceilings.

[ronmar]

As long as the pump head will push up over the wall, you should be fine.  Flow thru the pipe up over the wall will either push the air on over, or flow thru/under it.  If it flows under, the flow may eventually break up the air pocket into bubbles and carry them off to some other high point in the system, hopefully the expansion tank and vent. You could also put a "T" with a valve to help bleed air from these high points when needed.  If the expansion tank is vented to the atmosphere, expansion tank placement will need to be such that the path of least resistance from pump outlet back to pump inlet, is thru the line comming back over the wall, and not out thru the top of the expansion tank:) 

Mixing in chemicals can be done with  a "T" fitting and 2 valves on the pump inlet.  One valve is on the main line before both the "T" and the pump inlet.  The other valve is on the open leg of the "T"..  You place a container like a funnel above this second valve, and to this you add your chemicals.  With the pump running, slowly close/throttle the upstream valve, and open the valve running up to the funnel/chemical container.  The restriction upstream will lower the pressure at the pump inlet and force the pump to draw fluid from the container.  Depending on valve position, and if the pump is running or not, you will be able to move system fluid into or out of the container/funnel to help mix/flush/clean the container.

[Sfene]

Jens,

Sounds like an interesting application. Any chance of you writing up a schematic?

Sfene

[Sfene]

Im curious to see what solution you end up using. I wasn't sure I understood what you were trying to do. I was thinking that your best and easiest bet was to put an expansion tank somewhere on the floor above. Thats why I asked for a drawing, I can be pretty dense at times.

Sfene

[oliver90owner]

C'mon Jens!

It is lower than the highest point ....................The system will run at atmospheric pressure

IF that is the case, what will happen as soon as you turn on your pump to raise this water, as you seemed to explain it, higher than the outlet ......which apparently is open to the atmosphere?

You will need a riser pipe (vent ) from your expansion tank higher than the maximum dynamic pressure will lift.  The water level will eventually settle at the static head, so it seems as though your expansion tank will be full, in short order?

Or have I misunderstood your description?

Regards, RAB

[Sfene]

Thats what my thought was, as long as there is coolant higher than a vented tank, it will poot out the vent. I think Rab has the answer, run the thin vent tube above the highest point of your system and you should be ok.

Something as simple as a coiled hose, if purged and the end higher that your highest point might give you enough excess capacity and also allow to run at atmospheric.

What do you think?

Sfene

[Geno]

According to a calculator on the web 10 gallons of water will expand a maximum of .445 gallons when hot.

As far as your design is concerned I suggest an expansion tank/vent at the highest point. That's what I did. I also isolated the engine coolant loop from the heating loop that goes to the house. No problems with excess pressure on the engine. Less possibility of leaks that could cause the engine to overheat. I tapped into the the loop that goes to the house to dump excess heat in summer or put some heat in the garage in winter. I thought about it long and carefully and asked many questions before putting it together and spending the $. There is no automation so I do have to watch things a bit. My system has been working perfectly for a year now. I have so much hot water in the summer I waste it on things I never would have before. In the winter, after a couple hours to heat things up, I can keep a large cast iron rad in the living room hot and have enough domestic hot water to take a shower, do the dishes or a load of laundry.

Plumbing diagram one. Outside the house.  http://www.genedevera.com/listeroid/cogen/diagram1.jpg

Plumbing diagram two. Inside the house.    http://www.genedevera.com/listeroid/cogen/diagram2.jpg

Other pics at the bottom of my webpage   http://www.genedevera.com/listeroid/

Thanks, Geno