11-23-2019, 05:20 PM
You can insulate the tank more, it won’t hurt anything. But I personally don’t think that is the problem.
There is a known problem where the water in that outside loop can freeze and expand the copper in that loop. When it does, it pulls the loop away from the heat transfer mastic ever so slightly, but it wreaks havoc with the heat transfer. I suspect this has happened in my coach. I need to run the test of measuring incoming water temps, shower temps, and flow rates to see if the unit meets the AH specs which I think, don’t trust my memory, of 40 degree rise in temp at 1.5 gpm.
One more thing to be aware of, and this is a huge difference between using the AH for showers on electric vs diesel. On diesel, the bathroom loop pump is activated when the burner is running. The effect is to circulate the coolant inside the tank which tremendously improves the heat transfer to the hot water loop outside the tank. On electric, the coolant inside the tank is stagnant, and does not transfer heat nearly as well once the hot water starts flowing.
I have three concepts I am thinking about. The first is to add an additional coil to the hot water loop. It would require heat transfer mastic, and obviously the space inside the cover would have to have enough clearance.
The second is to simply fab a squarish tank to sit on top of the AH cover. The cold water would enter the tank first, and then into the hot water coil. The purpose of the tank would be to preheat the water.
The third idea is to add a insulated hot water tank to the bay. That idea would require a circulation pump and controller to make it work.
There are two things that make a big difference with the existing setup with regard to length of showers. First, measure you water output at the shower. If it is more that 1.5 gym, you will have really short showers. The second is to use water from the fresh water tank instead of 50ish degree ground water.
Based on your measurements, the hot water coils around the tank contain less than 2 gallons of water. What this tells me is that heat transfer is the key. The AH is NOT storing hot water of any significance.
There is a known problem where the water in that outside loop can freeze and expand the copper in that loop. When it does, it pulls the loop away from the heat transfer mastic ever so slightly, but it wreaks havoc with the heat transfer. I suspect this has happened in my coach. I need to run the test of measuring incoming water temps, shower temps, and flow rates to see if the unit meets the AH specs which I think, don’t trust my memory, of 40 degree rise in temp at 1.5 gpm.
One more thing to be aware of, and this is a huge difference between using the AH for showers on electric vs diesel. On diesel, the bathroom loop pump is activated when the burner is running. The effect is to circulate the coolant inside the tank which tremendously improves the heat transfer to the hot water loop outside the tank. On electric, the coolant inside the tank is stagnant, and does not transfer heat nearly as well once the hot water starts flowing.
I have three concepts I am thinking about. The first is to add an additional coil to the hot water loop. It would require heat transfer mastic, and obviously the space inside the cover would have to have enough clearance.
The second is to simply fab a squarish tank to sit on top of the AH cover. The cold water would enter the tank first, and then into the hot water coil. The purpose of the tank would be to preheat the water.
The third idea is to add a insulated hot water tank to the bay. That idea would require a circulation pump and controller to make it work.
There are two things that make a big difference with the existing setup with regard to length of showers. First, measure you water output at the shower. If it is more that 1.5 gym, you will have really short showers. The second is to use water from the fresh water tank instead of 50ish degree ground water.
Based on your measurements, the hot water coils around the tank contain less than 2 gallons of water. What this tells me is that heat transfer is the key. The AH is NOT storing hot water of any significance.
Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home
)