How to hook up a cast iron radiator

[bschwartz]

I have one of these heat exchangers from ebay
http://cgi.ebay.com/Stainless-Steel-Heat-Exchanger-1-2-Ports-Alfa-Laval-/350394163736?pt=LH_DefaultDomain_0&hash=item51951ea218

It has 1/2" ports.  Will putting this in line with my main radiator running 3/4 copper lines restrict it too much?

[LowGear]

Gosh I wish I could learn to read and look.  My wife says I don't look so good any more but I thought she was talking about my added weight.

Ronmar's is exactly the way I'd go if I had FPHEs.  And if I had radiator(s) in a living space; heat exchangers would be my dream.

Just running the engine coolant to the living space radiators would be a matter of test as to where I'd pull the coolant from.  Over the hills and through the dales then I'd start with directly off the engine.  Seven feet upstairs then I'd probably start pulling it off the bottom of the radiator.  When the boiler water I work with hits 120 degrees it shuts down until the temperature drops about 10 degrees.

I'm curious about the system that bschwartz has installed in his basement.  A person that has actually done it is miles ahead of this armchair coach.  Doesn't the "presence" of the engine running in the basement get to you?

Casey

[LowGear]

Hi Jens,

Covering the radiators may be good sense but these cast iron puppies were designed to be seen. 

The storage tank would really be handy especially if you are producing more heat than you could use in real time. 

As for the pumps; Being able to take a certain temperature and reaching maximum mean time between failures may not be the same value.

Well I guess I've shown how little I know about this subject.  I've learned a lot and had fun.  That's why I hang around. 

Thanks to you all,

Casey

[bschwartz]

Casey,

I don't have a basement.  I have my engine in a 1000 sf workshop which is 12 away from my house.
Engine noise is nonexistant.  Mild ground thumping is something else.

My engine is a part timer only run during the evenings from around 5-9 PM, and sometimes all day on weekends.  Do you think I'm really wasting that much heat by not using a storage tank?  I figured that by the time the storage tank got up to temperature (during the week days), it was time to shut the engine down for the night.  If the tank never got really hot, the the temperature differentials wouldn't be great enough to transfer a lot of heat to the house radiator.

I figured the 1/2" ports on the home radiator side would be OK, my concern was too much restriction to the main radiator next to the engine.  As the coolant would only have that one path, if the heat exchanger was turned off in the warmer weather, I'm concerned that the restriction would cause the engine to overheat.

Let me try to insert a picture...... http://s828.photobucket.com/albums/zz204/brettschwartz/?action-view&current=radiatorsystem.jpg

OK, insert didn't work, try the link..... grrrrr..

[vdubnut62]

Pardon me for asking, but what is the Hornet's nest looking thing above the ST head? Heat exchanger?
Ron.

Oops! Never mind!! Muffler, duh.

[bschwartz]

Yes, I have a thermostat on the engine.
I have the heat exchanger, I would just have to plumb it in to test.
I wanted opinions on port size before doing that, as it would be a pain to drain the system, solder in
new joints etc. just to have someone say after the fact that "don't do it, 1/2" won't flow enough to cool it"

I prefer expert opinion over my own trials when possible.

Hornet's nest   usually people say it looks like a big turkey being cooked.
It is a propane tank muffler/expansion chamber covered in fiberglass, and wrapped in aluminum foil.
It's ugly, but the glass keeps the heat and noise in, and the foil holds the glass in place.

[bschwartz]

This is what the muffler looked like naked....

[vdubnut62]

Oh boy. Woo Hoo. Just what I always wanted to see, a naked muffler. Now I can die happy.
A happy smartass!!
Ron

[bschwartz]

Listerporn.com 

[vdubnut62]

Somebody with some smarts PLEASE tell me how to size a FPHE for a Changfoid S-1100?
I have a tranny cooler from a Dodge/Cummins automatic that I think will make a dandy oil cooler.
I have no idea where to start, but I do have a 600-700 gallon storage tank planned, I'm also going to put a heat-X on the
flue of my woodburning furnace.
I plan on  PEX under the floor a little later if everything works out, for now a couple or three radiators hidden in tasteful wooden cabinets.
Well, tasteful by my standards anyway.
I just hate to crawl around under a 100 year old house(some places not enough room to turn over)and go to all the expense of a
full system until I get a "feel" for how it's going to work.
Ron

[Ronmar]

Brett
  That FPHE will work just fine since your primary loop is pumped.  that one is the same size as mine, but yours has 6 extra plates.  At the heat load a 6/1 creates, 195F coolant only needs to move about 1/2 GPM to remove the heat.  With that small and low head loop, your little taco pump and 1/2-3/4 plumbing will do that just fine.  Your thermosiphon probably didn't work because of the 3/4" line, but more probably because of the radiators horizontal distance from the engine, and that horizontal run with 2 elbows comming right out of the head.  Vertical is your friend with thermosiphon, horizontal, particularly with smaller diameter line is not...  If you had put the rad on the coolant port side of the engine and come off of the head outlet port with a 45 degree fitting pointing upward running at that angle or steeper up to the radiator it probably would have worked just fine.  But I don't know the makeup and restrictions of that fancoil heater you are using as a radiator.  If it flows OK, and it was relocated to the coolant port side of the engine and no more than say 12"-18" horizontally from the engine, I think you would have enough height to put the heatex on top of the radiator and still thermosiphon, but probably not with that 1/2" port FPHE.  Since you have the pump in place already, plumbing the heatex in as you pictured should work just fine.  A valve in that secondary circuit will allow you to adjust the flow and control what temp water gets delivered to the radiator in the house.  Is your fan on the radiator in the generator room thermostatically controlled?  You don't want to over cool the water returning to the engine.  Ideally, the cooling systm should match the heat generated so the engine thermostat opens and stays open making only small flow changes to maintain a steady op temp.

Casey.  I probably should have mentioned that I get 120F water out of my heatex secondary loop  because I have an automotive style thermostat out of a mercury mariner outboard motor right at the FPHE outlet that modulates the flow to deliver that outlet temp to feed my domestic hot water tank.  If I increase the flow, I can get just about any water temp below that out of the FPHE that I want...

Ron  How many HP is your 1100?  The BSFC's are not all that different, so you are burning about the same amount of fuel per HP/KWH that I am.  IF my 6/1 works fine using a 2.24 SQ/FT heatex, a 12HP engine should be able to get by with a 4.5 SQ/FT FPHE ECT.

[squarebob]

With a 195 Degree thermostat on the output side of a 6/1 feeding a heatex and/or radiator cooling loop, what would be the "ideal" temp for input water back into the head that one would want to shoot for?

Bob

[Ronmar]

For my 6/1 with heatex and thermosiphon, mine typically runs between 85F and 90F at the fitting at the cylinder coolant inlet...  When I was working the kinks out, I found that if I was running much over 95F back into the engine at full load,  the flow wasn't great enough to carry away enough engine heat with the inlet temp starting that high, so the outlet temp would creep into the 200's indicating the thermostat was wide open...

[Geno]

Storage tank
In the summer I throw out a lot of heat, which is why a thermal storage system is in the works. I should be able to get at least 5 days of hot water without running the engine. In the winter I use all the hot water I make unless the wood stove is running, which is a lot.

Pumps
My pumps, 1 Grundfos and 1 Taco, seldom see temps above 150°f and now have around 2000 hrs. on them.

Hot Radiators
Even when my rad in the living room is 145°f  it would be very hard to burn myself unless I duct taped my hand to it. A child might cry a little after touching it but it would be very hard to get even a small blister. It's just not the same as sticking your hand in a pot of 145°f water. My brothers old house has many steam radiators, some of which have been unprotected for decades.

Once things are warmed up my return to the engine is 120-150°f. That loop has ~4 gallons and plenty of height in it so thermosiphon works well.

Thanks, Geno

[vdubnut62]

Well here's the thing- I don't have a clue about fuel consumption but the engine is rated 16hp @ 2000rpm. I'm running it at 1800
direct driving a 12kw st head. I guess I'll have to get some sort of baseline on fuel consumption and do the math.
The temperature differential is only going to be 40 or 50 degrees.
Ron