Ventilation systems

Does anyone know if energy recovery ventilators or heat recovery ventilators are made for dc power on boats? Small ones?

I want to make an air exchanger for my boat cabin if I can't buy a commercial version.

I would use two ip67 rated cpu enclosure fans and build a small corrugated plastic exchanger.

I'm a little uncertain about how to control it. Obviously, an on/off manual switch, but then I also wondered about using a temperature controller. When the cabin temperature rises to say above 80F; the thing would kick in automatically.

But then, another issue would be how to change cabin air just now and then; so perhaps some interval control.

Anyhow, I did some googling and came up with nothing; so wondering if this is only done on super high end yachts and full sized house systems or if I'm missing some product.

 

Delta t systems makes some fans that might be in the vein your asking about. Installed a set of fans on a 79 footer, and know they made much smaller systems.

I will warn that the price was staggering for a fan.

 

I seem to recall that there are diesel and pellet heaters with one inch air supplies and concentric exhausts that have powered feed air. Try Webasto or Dickinson.

 

I'm going to build an air exchanger because I cannot find one.

The incoming air will be from outside and then be temperature tempered via a plastic air exchanger. There will be condensation; so it needs a drain pan.

The only thing I'm a little unsure about is the control. An on/off control is the simplest, but it would be nice to have it kick in if the cabin temp reaches say 80F, and to run a bit automatically for better air.

I used a little temperature controller for exhausting heat from behind the console.

I even wondered about humidity as I am going to run a humidity system in the lockers and bilges.

 

I would think that a plastic heat exchanger will not be as efficient as something made out of metal due to the heat conductivity factor

A question: It appears that you want to reduce the temperature of the cabin but use the outgoing heat to increase the temp of the incoming air?
I must have this wrong

 

The cabin tends to get a lot of solar heat gain. So, in general, an air exchanger would be reducing the temperature. I'm less concerned about tempering than air change.

I will use extruded plastic as the exchanger because if someday encounter salty environment; won't hurt it.

I also want fresh air in the cabin with windows closed. If two people are inside a 600 cuft area; it tends to get pretty steamy, even if only sleeping!

I think for starters, I'll skip worrying about humidity and just control for heat and air changes.

The fan I am using is this one: Coolerguys 140mm (140x140x25) 24vDC 4Pin IP67 Variable Speed PWM Fan 2000 RPM https://www.coolerguys.com/collections/dc-24-volt-fans/products/coolerguys-140mm-140x140x25-24v-2000-rpm-ip67-pwm-fan

At about 60 cfm or the fans midrange; I can move 3600 cf/hr which is 6 air changes of the cabin.

Not sure about power consumption, but there will be two fans; one in and one out and a small controller...maybe 2.5 wattsx2, call it 5 watts..

It is basically going to be a fresh air unit for cuddy cabins.

 

As to your question; the most common application of fresh air systems assume controlled environment. So the tempering is done to maintain the current inside temps. So, you are not wrong. If I was merely wanting to get to outside temps; I'd just run a fan in and exhaust out.

I also need to determine where to install the exchanger and the intake and exhaust...

Lunos makes a nice system for dwellings that intakes and exhausts at the same outlet by going out sideways two different ways. I imagine similar inside..but it reduces ducting a lot