Has anyone tried a tent air conditioner?

[windblown]

Installing A/C is probably in our future, but it’s not as pressing as some other projects. However, when this unit popped up on sale, I couldn’t resist it as a short-term solution for $289:
Waykar portable tent AC

The unit arrived today, and the manual says it’s for tents, RVs, and “event tents.” They say it’s ok to put it inside or outside a tent, but it isn’t waterproof and shouldn’t get wet, to avoid shocking experiences.

I’m curious about why none of these portable units say they can be used on a boat. I’ve deduced it’s because they need a stable surface for operation. We would only use it at the dock, so I think we can provide a pretty stable surface. Although it’s not marinized, it would be stored somewhere indoors for 10 months of the year.

It also says to “Ensure the air conditioner is always kept in an upright position, whether in transit or stationary, to avoid internal damage.” We can strap it down well, but “upright” can be rather relative on a sailboat.

SO, here’s the big question for those who know about such matters: is it dangerous or foolish to take this portable unit with its flammable R290 refrigerant onto our sailboat?

 

[ConchyDug]

On their specs list the voltage, amps, and watts don't agree. 400w/110vac=3.6amps but they say 4.5amps on the spec sheet. The portable units are interesting though I wonder if the energy requirements are what they claim.

I think Dometic is using the new flammable refrigerant in some of their new units so it's not unheard of. I think I'd rather see how it works for other people before I use it though. Compressed flammable gas in a heat exchange sounds pretty uhhh sketchy.

The entire J105 fleet here uses companionway mounted window units to cool the boats and dry them out, seems like a cheaper option with less infrastructure involved than a ducted tent unit. The units last like 5+yrs before the salt air kills them.

 

[peaman]

Propane, in practical terms, is just another compound which can exist as both liquid and gas at reasonable temperatures and pressure, and so can be made to change phase under controlled conditions in order to "move heat" from one coil to another.

Propane vapor is both flammable and heavier than air, so just as in propane heaters or stoves on boats, one or more vapor detectors (sniffers) should be in place to alert to the presence of a dangerous accumulation of the gas at any (low) location that it is likely to accumulate.

Because the refrigerant can exist as both liquid and vapor at the same "normal" temperature and pressure, one must be careful about tipping or inverting the unit. If it is tipped or inverted, it should be allowed to "rest" in an upright condition for some time prior to normal operation in order for the refrigerant to "equalize", so that liquid and vapor may both migrate to their respective quarters. This is the case for any other appliance which uses conventional refrigerants, including AC units and refrigerators.

The Waykar unit is obviously not designed for use in the marine environment, so care should be taken to keep the unit dry and protected from high humidity. And it should be periodically inspected for any signs of corrosion either in the electrical components or in any refrigerant-containment components.

 

[gabriel]

I wouldn’t be any more concerned about it than having a bottle of propane or butane on board. Unless it has been physically damaged, it will never leak.

 

[Bolo]

To be honest, the Waykar AC almost seems to good to be true. I’d have to see one running before id make a purchase. As a temporary solution to summer heat I’d tend to go with a cheap window ac adapted to fit in the companionway, as mentioned before. You can buy one from Home Depot as cheap as $160. I’ve even seen them adapted to work with a deck hatch.

Here on the Chesapeake Bay AC is almost a must in the summer. On our first boat, a Hunter 285, we used a Cruiseair hatch AC which was described as “portable“ because it had two handles on it. In reality it was heavy and a bit unwieldy to move and store but we managed. I think you can still find them on eBay used for about $500 and they are made for marine use.

On Vesper, our E32-3, we have a Webasto AC/unit that lives under the the v-birth where the water tank use to be and that can turn the boat into a freezer if we let it. Of course it doesn’t work at anchor but after a hot summer day sail it comes at a great relief back at the dock.

UPDATE: I also found this - https://www.westmarine.com/west-marine-carry-on-air-conditioner-7000-btu-12025763.html

 

[Prairie Schooner]

My buddy keeps a small household dehumidifier on board his J/105. It's perched on the little galley counter draining to the sink. He's an electrical engineer and it doesn't bother him. It's mostly to dry sails and the interior after a race. We take it off board for the race.
There are other similar a/c units for even a little cheaper on Amazon. As it's only an interim solution and since you've already got it, try it. Just make sure it's securely placed.

 

[nukey99]

My buddy keeps a small household dehumidifier on board his J/105. It's perched on the little galley counter draining to the sink. He's an electrical engineer and it doesn't bother him. It's mostly to dry sails and the interior after a race. We take it off board for the race.
There are other similar a/c units for even a little cheaper on Amazon. As it's only an interim solution and since you've already got it, try it. Just make sure it's securely placed.

On our express cruiser in Tampa FL, we kept a household dehumidifier on board. Kept the humidity around 45%. When we came aboard, we would kick on the AC units and it would be very comfortable inside of 30 minutes. I think if you need AC, the solution Bob S has on Vesper seems the way to go.

 

[jtsai]

On Vesper, our E32-3, we have a Webasto AC/unit that lives under the the v-birth where the water tank use to be and that can turn the boat into a freezer if we let it. Of course it doesn’t work at anchor but after a hot summer day sail it comes at a great relief back at the dock.

Bob, what btu is your AC and how is it ducted from under the v berth to cool the saloon area? I assume it is ducted through the hanging locker?

 

[Bolo]

Bob, what btu is your AC and how is it ducted from under the v berth to cool the saloon area? I assume it is ducted through the hanging locker?

A Wabsto FCF5,000 BTU and, yes, it runs through the hanging locker. It replaced an old unit (the band name I can’t recall) that broke a few months after we bought the boat about 19 years ago. The previous duct work and control location was used. This included the vents for the return air located in the wall of the seat area in the v-berth. I did not install it myself.

 

[bsangs]

No experience with a tent AC, but last year we started using this when needed for the dog days of July and August - Portable AC Unit. Run the hose through a porthole and it chills the cabin down quickly. Obviously only works on shore power, and has to be either removed from the boat, or locked down like Hannibal Lecter when underway. Does its job well.

 

[David Vaughn]

No experience with a tent AC, but last year we started using this when needed for the dog days of July and August - Portable AC Unit. Run the hose through a porthole and it chills the cabin down quickly. Obviously only works on shore power, and has to be either removed from the boat, or locked down like Hannibal Lecter when underway. Does its job well.

We used one of these for our first full summer aboard. They will provide a lot of cold air. In addition to what bsangs mentioned, there are a couple of downsides to be considered, depending on the model, and how often you use it.

First the exhaust hose will get hot if run for any length of time, and unless you’ve insulated that hose, the area where the hose runs will be noticeably warmer than the rest of the cabin.

Second, they can create negative pressure as the exhaust air is forced out. The air it’s trying to pull in to replace it has to come from somewhere, so any opening in your companionway, any dorades, even air leaks from cockpit lockers, hot outside air will be pulled in. The better ones have two hoses that lead outside, one for exhaust and one for intake.

We just finished installing a Webasto FCF9000 that we found used. The difference in it and the portable one we had is significant. As live-aboards at the time, we found the portable one often in the way and we always had issues with outside air leaks. For a hot humid Alabama summer, it was adequate but just barely. I would not have expected such a difference with a “marine AC” but I’m a believer now.

 

[jtsai]

Interesting that Bob is happy with 7,000 btu in a 32-3 and David is happy with 9,000 btu in a 31. Both boats are located in a warm climate. My aging but deceased Mermaid on the 32-3 is 12,000 btu that lives under the settee adjoining the navigation table. I have been eyeing sales on a replacement and the manufacturers' online calculators state I need 12,000 btu at a minimum.

 

[bsangs]

We used one of these for our first full summer aboard. They will provide a lot of cold air. In addition to what bsangs mentioned, there are a couple of downsides to be considered, depending on the model, and how often you use it.

First the exhaust hose will get hot if run for any length of time, and unless you’ve insulated that hose, the area where the hose runs will be noticeably warmer than the rest of the cabin.

Second, they can create negative pressure as the exhaust air is forced out. The air it’s trying to pull in to replace it has to come from somewhere, so any opening in your companionway, any dorades, even air leaks from cockpit lockers, hot outside air will be pulled in. The better ones have two hoses that lead outside, one for exhaust and one for intake.

We just finished installing a Webasto FCF9000 that we found used. The difference in it and the portable one we had is significant. As live-aboards at the time, we found the portable one often in the way and we always had issues with outside air leaks. For a hot humid Alabama summer, it was adequate but just barely. I would not have expected such a difference with a “marine AC” but I’m a believer now.

Yeah, if we were living aboard full time and in an area that was consistently hot and humid, would definitely seek an alternative. But for two months of sporadic use, it fits the bill. (Researched the two-hose models, but they just wouldn't work logistically.) That exhaust hose does get hot, but it runs through and over a port side settee area we don't really use much. Most of the air getting pulled in comes through the small porthole openings on the sides of the exhaust hose exit, so it doesn't really make its way back into the main cabin. What's funny is I wanted one of these the first year we owned "Radiance," but my wife said we didn't need it. So I got used to the humidity. Fast forward to last summer, as she was preparing to host a couple friends for a few forecasted VERY hot and humid days, guess who suddenly wanted an AC unit?

 

[windblown]

A Wabsto FCF5,000 BTU and, yes, it runs through the hanging locker. It replaced an old unit (the band name I can’t recall) that broke a few months after we bought the boat about 19 years ago. The previous duct work and control location was used. This included the vents for the return air located in the wall of the seat area in the v-berth. I did not install it myself.
View attachment 53206

View attachment 53207View attachment 53208View attachment 53209View attachment 53210

This is great, Bob. Thank you.
I think this is the direction we will investigate for the future. We haven’t used our forward water tank for several years, and I don’t think we’d miss it. Under the port settee, which is where AC is often installed, the original owner had a good set up for three house batteries, and I’d like to keep that option open (we just use 2 AGMs—one for starter and one for house now, since we cruise on weekends from dock to dock).
There’s some fine carpentry in this installation, which has some appeal as a future project. This time next year, I’ll be retired. . .
It’s already over 90 degrees today, which is pretty wretched for our area, so I’ll be putting the tent AC to the test today.

 

[windblown]

We used one of these for our first full summer aboard. They will provide a lot of cold air. In addition to what bsangs mentioned, there are a couple of downsides to be considered, depending on the model, and how often you use it.

First the exhaust hose will get hot if run for any length of time, and unless you’ve insulated that hose, the area where the hose runs will be noticeably warmer than the rest of the cabin.

Second, they can create negative pressure as the exhaust air is forced out. The air it’s trying to pull in to replace it has to come from somewhere, so any opening in your companionway, any dorades, even air leaks from cockpit lockers, hot outside air will be pulled in. The better ones have two hoses that lead outside, one for exhaust and one for intake.

We just finished installing a Webasto FCF9000 that we found used. The difference in it and the portable one we had is significant. As live-aboards at the time, we found the portable one often in the way and we always had issues with outside air leaks. For a hot humid Alabama summer, it was adequate but just barely. I would not have expected such a difference with a “marine AC” but I’m a believer now.

Thanks for this input. The unit did come with an exhaust hose and connection attachment.

 

[windblown]

No experience with a tent AC, but last year we started using this when needed for the dog days of July and August - Portable AC Unit. Run the hose through a porthole and it chills the cabin down quickly. Obviously only works on shore power, and has to be either removed from the boat, or locked down like Hannibal Lecter when underway. Does its job well.

Very helpful.

 

[windblown]

Propane, in practical terms, is just another compound which can exist as both liquid and gas at reasonable temperatures and pressure, and so can be made to change phase under controlled conditions in order to "move heat" from one coil to another.

Propane vapor is both flammable and heavier than air, so just as in propane heaters or stoves on boats, one or more vapor detectors (sniffers) should be in place to alert to the presence of a dangerous accumulation of the gas at any (low) location that it is likely to accumulate.

Because the refrigerant can exist as both liquid and vapor at the same "normal" temperature and pressure, one must be careful about tipping or inverting the unit. If it is tipped or inverted, it should be allowed to "rest" in an upright condition for some time prior to normal operation in order for the refrigerant to "equalize", so that liquid and vapor may both migrate to their respective quarters. This is the case for any other appliance which uses conventional refrigerants, including AC units and refrigerators.

The Waykar unit is obviously not designed for use in the marine environment, so care should be taken to keep the unit dry and protected from high humidity. And it should be periodically inspected for any signs of corrosion either in the electrical components or in any refrigerant-containment components.

This was a really helpful lesson.Thank you.

 

[windblown]

Review update. We had a heat advisory Sunday, with temps in the mid 90’s and pretty high humidity, so it was a good day to test the unit. After a great sail (gusty with 10 - 18 knots, but reasonably calm seas) and the 20-30 minutes of motoring it takes us to get upriver and into the basin, the saloon was plenty warm!
Unfortunately, I didn’t think to take a thermometer. It was very easy to attach the exhaust hose and run it out the companionway with the unit on the galley counter. I didn’t try to really seal the opening; I simply dropped the canvas companionway cover over the open companion way and exhaust duct. After about 10 minutes with the AC unit on, I went from dripping all over to being mildly sticky. After about 45 minutes, I was quite comfortable. Though I wouldn’t say it was cool in the cabin, I could have worked on a project or taken a nap without breaking a sweat.
Eventually, I moved the unit out into the cockpit and ran the cooling duct through the companionway. That was even more effective.
So, this little 4,000 btu unit would be way undersized for a long-term solution, but for now, it does what we hoped it would: it means we don’t have to be discouraged from hanging out or sleeping onboard dockside, even if the outside temps climb north of 90 Degrees.
We probably could achieve a better, cheaper result by putting an inexpensive window unit in the companionway (as others have suggested and done successfully). But we ruled that option out because: 1. The unit would block the companion way, 2. We find those units to be a bear to lift, move, and manage because: a. both of us have short arms (5’2” tall), and b. those units tend to be unwieldy and have sharp edges, and c. they don’t sit flat when not in a window.
We were quite tempted with the hatchway unit that is 70% off right now, but getting the unit in and out of the hatch opening and down the companionway seemed like too much for us.
So, we’ll see how long this non-marinized, undersized unit lasts, and report back if there’s anything newsworthy.

 

[Bolo]

Review update. We had a heat advisory Sunday, with temps in the mid 90’s and pretty high humidity, so it was a good day to test the unit. After a great sail (gusty with 10 - 18 knots, but reasonably calm seas) and the 20-30 minutes of motoring it takes us to get upriver and into the basin, the saloon was plenty warm!
Unfortunately, I didn’t think to take a thermometer. It was very easy to attach the exhaust hose and run it out the companionway with the unit on the galley counter. I didn’t try to really seal the opening; I simply dropped the canvas companionway cover over the open companion way and exhaust duct. After about 10 minutes with the AC unit on, I went from dripping all over to being mildly sticky. After about 45 minutes, I was quite comfortable. Though I wouldn’t say it was cool in the cabin, I could have worked on a project or taken a nap without breaking a sweat.
Eventually, I moved the unit out into the cockpit and ran the cooling duct through the companionway. That was even more effective.
So, this little 4,000 btu unit would be way undersized for a long-term solution, but for now, it does what we hoped it would: it means we don’t have to be discouraged from hanging out or sleeping onboard dockside, even if the outside temps climb north of 90 Degrees.
We probably could achieve a better, cheaper result by putting an inexpensive window unit in the companionway (as others have suggested and done successfully). But we ruled that option out because: 1. The unit would block the companion way, 2. We find those units to be a bear to lift, move, and manage because: a. both of us have short arms (5’2” tall), and b. those units tend to be unwieldy and have sharp edges, and c. they don’t sit flat when not in a window.
We were quite tempted with the hatchway unit that is 70% off right now, but getting the unit in and out of the hatch opening and down the companionway seemed like too much for us.
So, we’ll see how long this non-marinized, undersized unit lasts, and report back if there’s anything newsworthy.

“Human life is a series of compromises, and it is not always easy to achieve in practice what one has found to be true in theory.” - Mahatma Gandhi

 

[Chschaus]

A Wabsto FCF5,000 BTU and, yes, it runs through the hanging locker. It replaced an old unit (the band name I can’t recall) that broke a few months after we bought the boat about 19 years ago. The previous duct work and control location was used. This included the vents for the return air located in the wall of the seat area in the v-berth. I did not install it myself.
View attachment 53206

View attachment 53207View attachment 53208View attachment 53209View attachment 53210

Where does the unit exhaust through?