ac / heat unit recommendation

[Brankulo]

in process of building my square drop and this is me planning a bit ahead, but just wandering how people handle heating and cooling during their trips. I live in Colorado and i am not planning to do winter trips, but it can get pretty cold here in the mountains even in the summer and it does get pretty hot as well. am i overthinking it thinking i will need actual ac/heat? or will i be fine with maxfan and maybe elecrtic blanket. i have power bank that i plan to use in the camper so i could power small roof unit such as this one.
is anyone using something like this? is it overkill?

image of my build so far below

 

[Tony Latham]

For cooling, I think you're fine with a roof-top fan. I live in Idaho, and I doubt Colorado is much different.

For heating, I highly recommend a Propex H2000 propane heater. They use a tiny bit of electricity, put out 180º dry heat, have a thermostat, and are quiet.

Here's a thread I did on how I installed mine:

My Propex Heater installation

The downside is that they are quite expensive. You can occasionally find them at a reduced price on eBay.

If I were building another teardrop and told my wife I wasn't going to install a Propex, my ass would be grass.

Tony

 

[Brumasterm01]

If you are inclined to install an AC, you may want to consider a 5000 BTU window AC. These are surprisingly efficient and sips about 400 watts at max power. More than enough cooling to quickly cool down these little trailers. Being mounted on the sides, frees up the roof for awnings, racks and solar panels. One drawback is that you do need a stout inverter to handle the inrush current when the compressor kicks in. I have a 1500 watt inverter and this seems to handle it.

 

[Brumasterm01]

By the way, the specs for that rooftop air that was posted look to be impressive from an efficiency standpoint. Seems that people are posting 300-550 watts of power usage depending on settings. Also, running off 12V or 24V DC directly is a plus as this eliminates the need for an inverter and the power inefficiencies that go along with it.

Just be prepared to run seriously thick copper cables to the unit if you choose to go with a 12V set up. Think thumb size pure copper cables.

 

[Tom&Shelly]

If you are inclined to install an AC, you may want to consider a 5000 BTU window AC. These are surprisingly efficient and sips about 400 watts at max power.

So, 400 watts/12 volts = 33.3 amps not counting the inverter inefficiency. My lead-acid 150 Ahr battery would be run down to the safety point in about 2 hours 15 minutes. A lithium battery could be run down all the way in 4.5 hours. Just saying, you're not going to run an AC unit all night on a typical teardrop sized battery. Then, of course, if you are staying in a non-electric site for several days, you will need to recharge each day from solar or generator.

We have a 5000 BTU AC unit that we use when we have shore power. Otherwise, we just use the roof fan. The roof fan is fine for most of Colorado most of the time, but we stayed at Colorado National Monument (non-electric) near Grand Junction for a few days last August and it was brutal!

Our AC unit also has an electric heater, again, for shore power only. We've camped in 20 degree temperature comfortably with that. If we made a habit of winter camping at non-electric sites, we'd probably get the Propex heater Tony mentioned.

Tom

 

[Brumasterm01]

I guess 400 watts relative to you build. Sure it would be a problem with lead acid, but why would put lead acid in a new build? Having owned RVs in the past with 1500 watt roof units, 400 watts seemed to me to be relatively low wattage usage. I have 300 watts of solar on my roof little 4x8 square drop and 300 Amp hours of lithium batteries in my battery box. So, I absolutely could run my window AC through the night, if I was so inclined. Remember, the unit is cycling on and off once the little space is cooled down so you not pulling 400 watts all the time.

Living in the southwest, most my time is dry camping in the high desert and mountains. Tends to be low humidity and cools off at night. It's nice to be able to run the AC for an hour or so to cool down trailer. Then the sun shines the next day and your solar tops them back off.

If are still building your unit and you think you might want window or roof AC, best to build it in now so that you can plan your electrical system around it. Chances are that once you size your batteries around your AC, you'll have plenty of battery to run a small space heater for a few hours and electric blankets through the night.

BTW Brankulo that's an awesome build so far. You have mad welding skills!

 

[Tony Latham]

am i overthinking it thinking i will need actual ac

So... in Idaho, when it's smoking hot, we camp at 8'000' or higher. I suspect you have the same option in Colorado.

Tony

 

[Brankulo]

Thanks guys. Any idea if my battery would even handle the unit i linked. This is the battery i have Battery. I can build anything but when it comes to electrics, i am total basket case. I really like the low profile of the unit and that it provides both heat and ac. I cant imagine runing the unit all night, just to warm up or cool down the space here and there. I am thinking to just get the fan first and pre wire for this unit to the battery in case i decide to go with it later.

 

[Tony Latham]

Any idea if my battery would even handle the unit i linked. This is the battery i have Battery.

If yours is a 1500, it has a 125 amp battery.

This is what I read on the page about the unit:

'Enjoy 8–9 hours of max cooling with a 12V 480Ah or 24V 240Ah battery, and up to 10–11 hours with a 12V 600Ah or 24V 300Ah battery—ideal for off-grid comfort.'

And then there's the issue of recovering that amount of energy.

Tony

 

[Brankulo]

yes its 1500x. does that mean that my bank would not run it at all or would just last roughly 1/4 of 8-9 hours?
i would assume all i need is maybe 15minutes to cool such a small volume in the evening before we go to bed.
i am looking in the specs but dont see 125amp figure anywhere. where should i be looking?
i can get the energy back via solar or stop by starbucks and charge it there as we move from spot to spot.

 

[Tony Latham]

i am looking in the specs but dont see 125amp figure anywhere. where should i be looking?

I used Ohm's law. 1500/12 = 125.

The unit uses 50-60 amps for an hour of run time. That's a huge draw. If you only use it for an hour, you still need to figure out how you'd recover the 50 or so amps. Since you live in Colorado, I assume you'll boondock.

We seldom turn our rooftop fan on. In fact, this year, we never did. While the lid and side windows are open, the convection is constantly pulling in outside air.

What's missing from the specs on their web page is the amp draw for the heater. I suspect it, too, is 50 amps.

Tony

 

[Brumasterm01]

That DC rooftop air unit is likely not the best fit for you power station. It seems to be better suited for a rv with a medium sized lithium battery bank. Perfect for direct DC connection to a 12v or better yet 24v battery without the need an inverter.
Your power station is great and solves the needs of many campers by delivering lower amperage DC power for things like lights, usb and refrigerators and also higer power AC for appliances like microwaves, space heaters and induction cook tops. However it is not made to deliver high amp low voltage DC. The Aircond website goes so far in recommending using an AC to DC inverter for a power station.

If you didn't already have a power station and were looking to build a battery box, then a DC airconditioner might a good option.

 

[Tom&Shelly]

i would assume all i need is maybe 15minutes to cool such a small volume in the evening before we go to bed.

I don't want to sound negative, but I think that's a bad assumption. You need ventilation in a teardrop, so you'll want an open vent in the roof and/or windows, or another way to circulate air. If not, it will get very stuffy, very fast. If you need AC in the first place, that implies it is hot outside.

When we do run our AC (on shore power) we keep the fan vent cracked. We tried not doing that and taking the AC return from the cabin and the AC froze up (another problem not yet discussed in this thread), so we crack the vent and bring in outside warm air to the AC unit. It doesn't run constantly all night, but it does run much of it.

I agree with what Brumasterm01 said this morning, the numbers quoted for battery requirements are pretty large for a small RV like yours. (Frame looks good, BTW!)

I'll just add that, if you plan on using solar to recharge, remember the power rating is valid the first day out of the box, with no clouds, and with the panel pointing right at the Sun around noon. You won't get that rated power all day, every day, particularly if you are camping in trees and are out and about (not constantly repositioning the panel).

One thing I haven't tried (yet) but have seen in Youtube videos and a thread on this forum somewhere: Folks have made their own swamp coolers, which draw less power and work in dry climates. That would likely work in Colorado, but would take some skill and craftsmenship, not to mention some experimentation.

Tom

 

[Tom&Shelly]

What's missing from the specs on their web page is the amp draw for the heater. I suspect it, too, is 50 amps.

Tony

FWIW, on our 5000 BTU Climaterite, the power draw for the AC is 700 watts and the heater is 1300 watts. And yes, that is more heat than we need. That, we usually run for awhile before bed and often don't need after that, with the fan vent cracked. (Along with a wool blanket.)

Tom