Teardrops n Tiny Travel Trailers

The fans....
http://www.amazon.com/gp/product/B004SB ... UTF8&psc=1


The pump....
http://www.ebay.com/itm/New-Top-DC-12V- ... 5b0abfbe70

The hoses are faucet connection hoses with 1/2" pipe thread fittings.

Way to go Don.

Bruce

Don,

How quiet is the pump?

Rob

The pump is very quiet. The fans are nearly inaudible. 19.1 dB for one fan. The pump is rated at <45 dB. Maybe tomorrow I'll get the dB meter out and see what it indicates.

MtnDon, as Bruce said....way to go.
My gut tells me it will work.
I say this because I just went out to turn the 72W work light bulb off in my trailer. It has been 32 degrees for an hour or so outside. It is 27 now. The inside of the CT was 42 degrees and I have no ceiling insulation, just 1 1/2" of foam in the walls and floor. I think I will go back and turn it on to see what the temps are in the AM after being on all night.

I will be interested in your results.
I was working on trying to come up with a frame for the heater core since it will not be in a fixed position. The core is 71/2 X 83/4 X 2 and a single 120mm fan will fit nicely. The pump has shipped http://www.ebay.com/itm/290934852826

One of my ideas is to box in the core and fans; locate that in front of the shower stall lip/ledge. That can be seen behind the fans in photo #2. Use an expanded metal grill on the front to prevent toe kicks from damaging the fins. The height will work and the backside could have air inlets from both ends.

MtnDon,
Do you see using a thermostat which would engage a relay at selected settings? Without doing much research, that was my thinking.

You may want to measure the inlet and outlet temps to see if there is room to slow down the pump.
Tom

lrrowe wrote:MtnDon,
Do you see using a thermostat which would engage a relay at selected settings? Without doing much research, that was my thinking.

I plan on using a 12 volt temperature controller, similar to the 120 VAC version I used on the slow cooker hack. My plan is to simply turn the pump and fans on and off together, at the same time. It contains a relay switch good for 10 amps. More than enough. I don't see a lot of benefit to having the fan turn on and off via its own snap switch or whatever. The system is so small I feel that is unnecessary and just another complication.

Socal Tom wrote:You may want to measure the inlet and outlet temps to see if there is room to slow down the pump.
Tom

I'll decide if that merits more thought after the initial trials are over. I do have a PWM controller around here someplace doing nothing.

MtnDon wrote:

Socal Tom wrote:You may want to measure the inlet and outlet temps to see if there is room to slow down the pump.
Tom

I'll decide if that merits more thought after the initial trials are over. I do have a PWM controller around here someplace doing nothing.

I actually meant installing a flow control valve to reduce the water flow. It will also reduce the amperage draw since the pump will be moving less water.
Tom

Yes restricting the flow for an impeller pump does make it work less hard, as hard as that may be to grasp. However, I am also aware that works best for cool water. When restricting the flow of hot water, too much restriction can cause pump damage. And I have no idea how one figures where the limit is. In any event, at 0.66 amp as it is, I could run the pump and fans 24 hours a day for a week (a literal 24/7) and still have 50% of my battery capacity available. The KISS principle might indicate that valves or whatever might be an extra expense / complication we don't really need. We'll make many decisions as the test progresses. Thanks.

But then it is a simple enough job to place a valve inline when using the flexy hoses and measure the current change and see what happens to heat output of the radiator. Or I could use a restriction disc placed in one of the hose end connections.

MtnDon wrote:Yes restricting the flow for an impeller pump does make it work less hard, as hard as that may be to grasp. However, I am also aware that works best for cool water. When restricting the flow of hot water, too much restriction can cause pump damage. And I have no idea how one figures where the limit is. In any event, at 0.66 amp as it is, I could run the pump and fans 24 hours a day for a week (a literal 24/7) and still have 50% of my battery capacity available. The KISS principle might indicate that valves or whatever might be an extra expense / complication we don't really need. We'll make many decisions as the test progresses. Thanks.

But then it is a simple enough job to place a valve inline when using the flexy hoses and measure the current change and see what happens to heat output of the radiator. Or I could use a restriction disc placed in one of the hose end connections.

That's why I recommend measuring the in and out temps. There will be a flow rate that optimizes the "cooling" of the water. It maybe just fine at full speed, but if you don't like the temp drop, it might be worth experimenting a little.

MtnDon wrote:

lrrowe wrote:MtnDon,
Do you see using a thermostat which would engage a relay at selected settings? Without doing much research, that was my thinking.

I plan on using a 12 volt temperature controller, similar to the 120 VAC version I used on the slow cooker hack. My plan is to simply turn the pump and fans on and off together, at the same time. It contains a relay switch good for 10 amps. More than enough. I don't see a lot of benefit to having the fan turn on and off via its own snap switch or whatever. The system is so small I feel that is unnecessary and just another complication.

I need to go back and study up on your slow cooker temp module. Especially if it a success. Why reinvent the wheel?