Teardrops n Tiny Travel Trailers

I haven't seen these mentioned on the board. I ordered my Haulmark 5x8 cargo trailer with an unpowered vent thinking I would spring for a Fantastic fan later but I ventured across this conversion kit for $50.00 and thought I would give it try:

http://www.pplmotorhomes.com/parts/rv-vents/vent-fan-replacement.htm?source=froogle_p



I ran 14 ga. wiring for a possible vent fan before I installed my insulation and ceiling so the installation was quick and easy. Just remove the interior trim on the vent (4 screws), crank handle (1 screw) and the screen assembly (2 screws). Connect wires. Install fan assembly (2 screws). Install crank knob (1 screw). Reattach interior trim.

This thing moves a lot of air. Only has one speed, which is pretty fast. Is not reversible and is a little noisy when running, but is worth the money if you are just trying to add a fan to an existing vent...

...nice find ..........................................................

not sure, but don't see a thermostat on it. Last thing a tear needs is a high powered fan for such a small volume.

I understand the price thing, but many of us have added resistors to slow down the fantastic fans.. and they have thermostats and are reversible.

Keep in mind, this is just my opinion. I like the fact the fan turns slowly and shuts off when the temp gets right.

Yes, but in a bigger Cargo trailer convertion there is more volume. So in a Cargo convertion they may be great.

I wonder how much current it draws? I don't know the details of this particular fan, but the most inexpensive fans have less efficient motors that draw more current, a consideration if the fan will be running off the house battery. Since it is only a single speed, it's probably set to run at full speed for maximum effect, and would then draw the most current.

Perhaps you can mount a resistor across the load similarly to the way the Fantastic Vent can be slowed down, with the same effect. It wouldn't cut into the voltage drop (save electricity), but it would give you a quieter fan speed.

I was going to do a fantastic fan, but the idea of not having to remove my existing vent sounds so much easier.
I ordered the single speed fan, but I plan on wiring in a DPDT switch so I can reverse polarity and draw in air if I so choose.

That could work well in a shower/bathroom situation where you might only need it for a short period.
McDave

mikesova wrote:I was going to do a fantastic fan, but the idea of not having to remove my existing vent sounds so much easier.
I ordered the single speed fan, but I plan on wiring in a DPDT switch so I can reverse polarity and draw in air if I so choose.

Be careful on the reversing the polarity and expecting the rotation to reverse. It depends on the type of DC Motor. Some will do that for sure, but some will not. Some of the newer high efficiency DC motors may not. They just wont turn. I am not familiar with the design, but they must not be the typical fixed magnet DC motor.

It came in today and I stuck it in. My DPDT switch didn't yet, so I'll leave it as is for now and re-evaluate. So far it seems to be great. I don't think it's TOO noisy and it pulls a decent amount of air.

Untitled by mikesova, on Flickr

mikesova wrote:It came in today and I stuck it in. My DPDT switch didn't yet, so I'll leave it as is for now and re-evaluate. So far it seems to be great. I don't think it's TOO noisy and it pulls a decent amount of air.

The fan looks real nice! Did you reverse the wires to see if it will run backwards? If it does not, it really doesn't get you much in any case. The same amount of air will be exchanged. You just need to make sure there is a window or something cracked open to pull in the Fresh Air. You'd need to do the same if it was running in reverse to push the air out.

flboy wrote:

mikesova wrote:It came in today and I stuck it in. My DPDT switch didn't yet, so I'll leave it as is for now and re-evaluate. So far it seems to be great. I don't think it's TOO noisy and it pulls a decent amount of air.

The fan looks real nice! Did you reverse the wires to see if it will run backwards? If it does not, it really doesn't get you much in any case. The same amount of air will be exchanged. You just need to make sure there is a window or something cracked open to pull in the Fresh Air. You'd need to do the same if it was running in reverse to push the air out.

I admit to being tempted by this too but so far in 7 different trailers I have only used the Fantastic to bring air into the trailer a couple of times.
Every other time it is used to exhaust hot air only and usually is running all the time while camping.

There is more to these fans than seems obvious from just the descriptions or theory ?
I also don't want to get on the roof and r&R my vent with a FF but am about to too!

YMMV as they say but I can not remember ever talking to anyone who has upgraded to a Fantastic who did not love it.

Yeah, I think i'll skip wiring up the dpdt switch for now. I didn't wire it in reverse to try it, but it's just a basic old school electric motor, so I don't know why it wouldn't. I went with the single speed because from what I could tell, the fan wouldn't use any less energy on the lower settings because it used resistors. If it is too much, I'll wire in a Pulse Width Modulator that I read about here (http://www.rv.net/forum/index.cfm/fusea ... page/1.cfm).

mikesova wrote:Yeah, I think i'll skip wiring up the dpdt switch for now. I didn't wire it in reverse to try it, but it's just a basic old school electric motor, so I don't know why it wouldn't. I went with the single speed because from what I could tell, the fan wouldn't use any less energy on the lower settings because it used resistors. If it is too much, I'll wire in a Pulse Width Modulator that I read about here (http://www.rv.net/forum/index.cfm/fusea ... page/1.cfm).

Now that's an idea! I can see that being very useful. My Maxxair runs a 900cfm on high and has only 4 speeds. You'd be able to get any speed on the continuum with that! I'll have to check to see if Maxxair is just dumping the power through a resistor and wasting power. I will be running off the grid on solar a lot, and I'd rather not waste power... I could retrofit the fan with the PWM.. I am sure it is not 100% efficient however, so I'll check to see if there is any real power savings... it may be a wash with the additional circuitry?

Do you think that would work to dim LED lighting without making it flicker? I'd like to have a dimmer on my main lighting possibly.

Most dimmer switches these days use a triac type device that actually turns the light on/off many times per second. They don't use resistors to "burn off" excess power anymore. This means that you don't use anymore juice than you want. It could really add up over time. The older dimmer switches are not as efficient in energy savings as newer ones, but by the very nature of Ohm’s law they do conserve. Some of the energy is converted to heat – that much is correct.
Ohm’s Law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship:
I=E/R. where I is current (amperage), E is voltage and R is resistance.
If you increase resistance, you reduce voltage and current. Some losses are present in the form of heat or electrical leakage due to inefficiency of components, but there is still a reduction.
With LED lights the effect of dimming compared to power use is fairly linear. However, dimming incandescent is actually less efficient than using a lower wattage of bulb.

McDave

P.S. @ flboy,
I don't know what size and type of LED main light you are using, but here is what I'm using to dim my strip lights that are used for general indirect lighting. Probably 80' (ft) or so @ 2amps or 24wt per 16ft (5m), so 10a or 120wt for 80 ft @ 100%. A lot of light for a small area, but it is indirect. I dim them all to less than 10% for normal use, so 1 amp or 12wt. http://www.ebay.com/itm/111792901741?_t ... EBIDX%3AIT

The remotes are handy and seem to be at the same RF, so I have 1 remote at front door and 1 at rear. Easy wiring and they remember the last setting when powered on/off.
For task or direct lighting I'm using 2 of these, 1 in galley area, 1 in cargo area. http://www.ebay.com/itm/LED-921-Dome-Li ... 33748fd6f3
They are VERY BRIGHT, and 2.5wt or .2amp @ 100% if you can tolerate that much light.

McDave

McDave wrote:Most dimmer switches these days use a triac type device that actually turns the light on/off many times per second. They don't use resistors to "burn off" excess power anymore. This means that you don't use anymore juice than you want. It could really add up over time. The older dimmer switches are not as efficient in energy savings as newer ones, but by the very nature of Ohm’s law they do conserve. Some of the energy is converted to heat – that much is correct.
Ohm’s Law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship:
I=E/R. where I is current (amperage), E is voltage and R is resistance.
If you increase resistance, you reduce voltage and current. Some losses are present in the form of heat or electrical leakage due to inefficiency of components, but there is still a reduction.
With LED lights the effect of dimming compared to power use is fairly linear. However, dimming incandescent is actually less efficient than using a lower wattage of bulb.

McDave

P.S. @ flboy,
I don't know what size and type of LED main light you are using, but here is what I'm using to dim my strip lights that are used for general indirect lighting. Probably 80' (ft) or so @ 2amps or 24wt per 16ft (5m), so 10a or 120wt for 80 ft @ 100%. A lot of light for a small area, but it is indirect. I dim them all to less than 10% for normal use, so 1 amp or 12wt. http://www.ebay.com/itm/111792901741?_t ... EBIDX%3AIT

The remotes are handy and seem to be at the same RF, so I have 1 remote at front door and 1 at rear. Easy wiring and they remember the last setting when powered on/off.
For task or direct lighting I'm using 2 of these, 1 in galley area, 1 in cargo area. http://www.ebay.com/itm/LED-921-Dome-Li ... 33748fd6f3
They are VERY BRIGHT, and 2.5wt or .2amp @ 100% if you can tolerate that much light.

McDave

McDave, Thanks for the link!! I am using three LED Dome light similar to what you have. The dimmer you linked to looks perfect for what I want. It is powered inline with the lights after the switch. At that price, I am going to order a few! :-)