air conditiong rear of ac unit in galley or that pet cool

[Socal Tom]

I still think this idea chokes the ac down on return and supply 4" -5" isn't big enough 4"=40cfm and 5"=60 cfm
im thinking more like 6"=100 cfm and an 7"=150 cfm not shure how much cfm these little units blow but it has to be atleast more than 40cfm and 50cfm and return the bigger the better but not that close together

The CFM is dependent on the length of the tubing, and the pressure of the air. I used this chart as guidance when I went with 4"
https://resaveguide.lbl.gov/step-6-duct-design

I searched on line, and on high, the A/C unit should put out about 120CFM. The 5 inch hose is capable of 125CFM if the run is under 20ft long ( an elbow =15 ft) 4 inch won't get above 80 cfm and that's only a 3 ft run). After my testing, I think a 4 inch supply and a 5 inch return would have been fine. But as I stated previously, I think a cross flow design will do better at preventing icing.
The straight flow design will point water vapor straight at the cooling coils, and the majority of the water will hit that one spot, eventually that spot ices over, and the block of ice continues to grow and cover the whole face of the cooling coil.
With cross flow, the return air, and moisture would be spread further accross the face, and the momentum of the water would tend to throw it past the cooling cool ( heavy water won't make the turn as well as dry air), so less moisture makes it onto the coil, and when it does its not as thick, so when the cooling cycle is over, the air passing over the coils has a better chance to thaw it out.
Tom

[Socal Tom]

I still think this idea chokes the ac down on return and supply 4" -5" isn't big enough 4"=40cfm and 5"=60 cfm
im thinking more like 6"=100 cfm and an 7"=150 cfm not shure how much cfm these little units blow but it has to be atleast more than 40cfm and 50cfm and return the bigger the better but not that close together

The CFM is dependent on the length of the tubing, and the pressure of the air. I used this chart as guidance when I went with 4"
https://resaveguide.lbl.gov/step-6-duct-design

I searched on line, and on high, the A/C unit should put out about 120CFM. The 5 inch hose is capable of 125CFM if the run is under 20ft long ( an elbow =15 ft) 4 inch won't get above 80 cfm and that's only a 3 ft run). After my testing, I think a 4 inch supply and a 5 inch return would have been fine. But as I stated previously, I think a cross flow design will do better at preventing icing.
The straight flow design will point water vapor straight at the cooling coils, and the majority of the water will hit that one spot, eventually that spot ices over, and the block of ice continues to grow and cover the whole face of the cooling coil.
With cross flow, the return air, and moisture would be spread further accross the face, and the momentum of the water would tend to throw it past the cooling cool ( heavy water won't make the turn as well as dry air), so less moisture makes it onto the coil, and when it does its not as thick, so when the cooling cycle is over, the air passing over the coils has a better chance to thaw it out.
Tom

I can tell you mine kept the TD at 72F on a 90F+ day just fine.

[dms2871]

I still think this idea chokes the ac down on return and supply 4" -5" isn't big enough 4"=40cfm and 5"=60 cfm
im thinking more like 6"=100 cfm and an 7"=150 cfm not shure how much cfm these little units blow but it has to be atleast more than 40cfm and 50cfm and return the bigger the better but not that close together

The CFM is dependent on the length of the tubing, and the pressure of the air. I used this chart as guidance when I went with 4"
https://resaveguide.lbl.gov/step-6-duct-design

I searched on line, and on high, the A/C unit should put out about 120CFM. The 5 inch hose is capable of 125CFM if the run is under 20ft long ( an elbow =15 ft) 4 inch won't get above 80 cfm and that's only a 3 ft run). After my testing, I think a 4 inch supply and a 5 inch return would have been fine. But as I stated previously, I think a cross flow design will do better at preventing icing.
The straight flow design will point water vapor straight at the cooling coils, and the majority of the water will hit that one spot, eventually that spot ices over, and the block of ice continues to grow and cover the whole face of the cooling coil.
With cross flow, the return air, and moisture would be spread further accross the face, and the momentum of the water would tend to throw it past the cooling cool ( heavy water won't make the turn as well as dry air), so less moisture makes it onto the coil, and when it does its not as thick, so when the cooling cycle is over, the air passing over the coils has a better chance to thaw it out.
Tom

I can tell you mine kept the TD at 72F on a 90F+ day just fine.

that's fine if your happy with that 18deg difference does it run constantly or does it ever get satisfied and shut down I think im going to a split system inverter type not a bad price

[Socal Tom]

I still think this idea chokes the ac down on return and supply 4" -5" isn't big enough 4"=40cfm and 5"=60 cfm
im thinking more like 6"=100 cfm and an 7"=150 cfm not shure how much cfm these little units blow but it has to be atleast more than 40cfm and 50cfm and return the bigger the better but not that close together

The CFM is dependent on the length of the tubing, and the pressure of the air. I used this chart as guidance when I went with 4"
https://resaveguide.lbl.gov/step-6-duct-design

I searched on line, and on high, the A/C unit should put out about 120CFM. The 5 inch hose is capable of 125CFM if the run is under 20ft long ( an elbow =15 ft) 4 inch won't get above 80 cfm and that's only a 3 ft run). After my testing, I think a 4 inch supply and a 5 inch return would have been fine. But as I stated previously, I think a cross flow design will do better at preventing icing.
The straight flow design will point water vapor straight at the cooling coils, and the majority of the water will hit that one spot, eventually that spot ices over, and the block of ice continues to grow and cover the whole face of the cooling coil.
With cross flow, the return air, and moisture would be spread further accross the face, and the momentum of the water would tend to throw it past the cooling cool ( heavy water won't make the turn as well as dry air), so less moisture makes it onto the coil, and when it does its not as thick, so when the cooling cycle is over, the air passing over the coils has a better chance to thaw it out.
Tom

I can tell you mine kept the TD at 72F on a 90F+ day just fine.

that's fine if your happy with that 18deg difference does it run constantly or does it ever get satisfied and shut down I think im going to a split system inverter type not a bad price

I wasn't asking it to do more than that. When it was mounted in the bulk head it spent more time with the compressor off than on, and it worked, but not as well as it does now. The space its cooling is so small that they tend to short cycle. WIth the hose setup I haven't had that problem, even when it was only 80ish outside. I suspect the extra heat load from being outside, and the tubing help it run just a little longer. I did some calculations a while back, and it should only take about 3000 BTU to change the temp inside by 30F. According to the calculator below, with a 5K BTU unit I should be able to get a 50F temp difference . I have camped in 122F weather before, its not fun.
Here is a simple BTU load calculator
http://www.calculator.net/btu-calculato ... t&x=69&y=4

Tom

The split systems are great if you can find one at the right price. The AC unit cost $105, and I probably have $50 in the other parts for the external plenum.

[dms2871]

I still think this idea chokes the ac down on return and supply 4" -5" isn't big enough 4"=40cfm and 5"=60 cfm
im thinking more like 6"=100 cfm and an 7"=150 cfm not shure how much cfm these little units blow but it has to be atleast more than 40cfm and 50cfm and return the bigger the better but not that close together

The CFM is dependent on the length of the tubing, and the pressure of the air. I used this chart as guidance when I went with 4"
https://resaveguide.lbl.gov/step-6-duct-design

I searched on line, and on high, the A/C unit should put out about 120CFM. The 5 inch hose is capable of 125CFM if the run is under 20ft long ( an elbow =15 ft) 4 inch won't get above 80 cfm and that's only a 3 ft run). After my testing, I think a 4 inch supply and a 5 inch return would have been fine. But as I stated previously, I think a cross flow design will do better at preventing icing.
The straight flow design will point water vapor straight at the cooling coils, and the majority of the water will hit that one spot, eventually that spot ices over, and the block of ice continues to grow and cover the whole face of the cooling coil.
With cross flow, the return air, and moisture would be spread further accross the face, and the momentum of the water would tend to throw it past the cooling cool ( heavy water won't make the turn as well as dry air), so less moisture makes it onto the coil, and when it does its not as thick, so when the cooling cycle is over, the air passing over the coils has a better chance to thaw it out.
Tom

I can tell you mine kept the TD at 72F on a 90F+ day just fine.

that's fine if your happy with that 18deg difference does it run constantly or does it ever get satisfied and shut down I think im going to a split system inverter type not a bad price

I wasn't asking it to do more than that. When it was mounted in the bulk head it spent more time with the compressor off than on, and it worked, but not as well as it does now. The space its cooling is so small that they tend to short cycle. WIth the hose setup I haven't had that problem, even when it was only 80ish outside. I suspect the extra heat load from being outside, and the tubing help it run just a little longer. I did some calculations a while back, and it should only take about 3000 BTU to change the temp inside by 30F. According to the calculator below, with a 5K BTU unit I should be able to get a 50F temp difference . I have camped in 122F weather before, its not fun.
Here is a simple BTU load calculator
http://www.calculator.net/btu-calculato ... t&x=69&y=4

Tom

The split systems are great if you can find one at the right price. The AC unit cost $105, and I probably have $50 in the other parts for the external plenum.

I found the whole thing on amazon for 580$ inverter does heating cooling and dehumidifies 110v also 9000 btu is the smallest

[dms2871]

I still think this idea chokes the ac down on return and supply 4" -5" isn't big enough 4"=40cfm and 5"=60 cfm
im thinking more like 6"=100 cfm and an 7"=150 cfm not shure how much cfm these little units blow but it has to be atleast more than 40cfm and 50cfm and return the bigger the better but not that close together

The CFM is dependent on the length of the tubing, and the pressure of the air. I used this chart as guidance when I went with 4"
https://resaveguide.lbl.gov/step-6-duct-design

I searched on line, and on high, the A/C unit should put out about 120CFM. The 5 inch hose is capable of 125CFM if the run is under 20ft long ( an elbow =15 ft) 4 inch won't get above 80 cfm and that's only a 3 ft run). After my testing, I think a 4 inch supply and a 5 inch return would have been fine. But as I stated previously, I think a cross flow design will do better at preventing icing.
The straight flow design will point water vapor straight at the cooling coils, and the majority of the water will hit that one spot, eventually that spot ices over, and the block of ice continues to grow and cover the whole face of the cooling coil.
With cross flow, the return air, and moisture would be spread further accross the face, and the momentum of the water would tend to throw it past the cooling cool ( heavy water won't make the turn as well as dry air), so less moisture makes it onto the coil, and when it does its not as thick, so when the cooling cycle is over, the air passing over the coils has a better chance to thaw it out.
Tom

I can tell you mine kept the TD at 72F on a 90F+ day just fine.

that's fine if your happy with that 18deg difference does it run constantly or does it ever get satisfied and shut down I think im going to a split system inverter type not a bad price

I wasn't asking it to do more than that. When it was mounted in the bulk head it spent more time with the compressor off than on, and it worked, but not as well as it does now. The space its cooling is so small that they tend to short cycle. WIth the hose setup I haven't had that problem, even when it was only 80ish outside. I suspect the extra heat load from being outside, and the tubing help it run just a little longer. I did some calculations a while back, and it should only take about 3000 BTU to change the temp inside by 30F. According to the calculator below, with a 5K BTU unit I should be able to get a 50F temp difference . I have camped in 122F weather before, its not fun.
Here is a simple BTU load calculator
http://www.calculator.net/btu-calculato ... t&x=69&y=4

Tom

The split systems are great if you can find one at the right price. The AC unit cost $105, and I probably have $50 in the other parts for the external plenum.

I found the whole thing on amazon for 580$ inverter does heating cooling and dehumidifies 110v also 9000 btu is the smallest

it has a good rating from other consumers and a guy put one on his camper too

[Shadow Catcher]

The interior of our tear is about 400 cubic feet, more than most tears and yes it sweats a bit and I could insulate but one of the big problems with too much coolth is that you do not adequately dehumidify. So far we have been in situations with 90% humidity at about 90 F and the interior of the tear is 70 F, and not humid. The bilge blower is at about half speed and the computer case fans in our roof vent are at half speed.

[Socal Tom]

I still think this idea chokes the ac down on return and supply 4" -5" isn't big enough 4"=40cfm and 5"=60 cfm
im thinking more like 6"=100 cfm and an 7"=150 cfm not shure how much cfm these little units blow but it has to be atleast more than 40cfm and 50cfm and return the bigger the better but not that close together

The CFM is dependent on the length of the tubing, and the pressure of the air. I used this chart as guidance when I went with 4"
https://resaveguide.lbl.gov/step-6-duct-design

I searched on line, and on high, the A/C unit should put out about 120CFM. The 5 inch hose is capable of 125CFM if the run is under 20ft long ( an elbow =15 ft) 4 inch won't get above 80 cfm and that's only a 3 ft run). After my testing, I think a 4 inch supply and a 5 inch return would have been fine. But as I stated previously, I think a cross flow design will do better at preventing icing.
The straight flow design will point water vapor straight at the cooling coils, and the majority of the water will hit that one spot, eventually that spot ices over, and the block of ice continues to grow and cover the whole face of the cooling coil.
With cross flow, the return air, and moisture would be spread further accross the face, and the momentum of the water would tend to throw it past the cooling cool ( heavy water won't make the turn as well as dry air), so less moisture makes it onto the coil, and when it does its not as thick, so when the cooling cycle is over, the air passing over the coils has a better chance to thaw it out.
Tom

I can tell you mine kept the TD at 72F on a 90F+ day just fine.

that's fine if your happy with that 18deg difference does it run constantly or does it ever get satisfied and shut down I think im going to a split system inverter type not a bad price

I wasn't asking it to do more than that. When it was mounted in the bulk head it spent more time with the compressor off than on, and it worked, but not as well as it does now. The space its cooling is so small that they tend to short cycle. WIth the hose setup I haven't had that problem, even when it was only 80ish outside. I suspect the extra heat load from being outside, and the tubing help it run just a little longer. I did some calculations a while back, and it should only take about 3000 BTU to change the temp inside by 30F. According to the calculator below, with a 5K BTU unit I should be able to get a 50F temp difference . I have camped in 122F weather before, its not fun.
Here is a simple BTU load calculator
http://www.calculator.net/btu-calculato ... t&x=69&y=4

Tom

The split systems are great if you can find one at the right price. The AC unit cost $105, and I probably have $50 in the other parts for the external plenum.

I found the whole thing on amazon for 580$ inverter does heating cooling and dehumidifies 110v also 9000 btu is the smallest

That's awfully big for a TD. Another reason I like my little unit is that it runs off of my Honda 10000eu generator.
It does look like a nice system though.
Tom

[dms2871]

I still think this idea chokes the ac down on return and supply 4" -5" isn't big enough 4"=40cfm and 5"=60 cfm
im thinking more like 6"=100 cfm and an 7"=150 cfm not shure how much cfm these little units blow but it has to be atleast more than 40cfm and 50cfm and return the bigger the better but not that close together

The CFM is dependent on the length of the tubing, and the pressure of the air. I used this chart as guidance when I went with 4"
https://resaveguide.lbl.gov/step-6-duct-design

I searched on line, and on high, the A/C unit should put out about 120CFM. The 5 inch hose is capable of 125CFM if the run is under 20ft long ( an elbow =15 ft) 4 inch won't get above 80 cfm and that's only a 3 ft run). After my testing, I think a 4 inch supply and a 5 inch return would have been fine. But as I stated previously, I think a cross flow design will do better at preventing icing.
The straight flow design will point water vapor straight at the cooling coils, and the majority of the water will hit that one spot, eventually that spot ices over, and the block of ice continues to grow and cover the whole face of the cooling coil.
With cross flow, the return air, and moisture would be spread further accross the face, and the momentum of the water would tend to throw it past the cooling cool ( heavy water won't make the turn as well as dry air), so less moisture makes it onto the coil, and when it does its not as thick, so when the cooling cycle is over, the air passing over the coils has a better chance to thaw it out.
Tom

I can tell you mine kept the TD at 72F on a 90F+ day just fine.

that's fine if your happy with that 18deg difference does it run constantly or does it ever get satisfied and shut down I think im going to a split system inverter type not a bad price

I wasn't asking it to do more than that. When it was mounted in the bulk head it spent more time with the compressor off than on, and it worked, but not as well as it does now. The space its cooling is so small that they tend to short cycle. WIth the hose setup I haven't had that problem, even when it was only 80ish outside. I suspect the extra heat load from being outside, and the tubing help it run just a little longer. I did some calculations a while back, and it should only take about 3000 BTU to change the temp inside by 30F. According to the calculator below, with a 5K BTU unit I should be able to get a 50F temp difference . I have camped in 122F weather before, its not fun.
Here is a simple BTU load calculator
http://www.calculator.net/btu-calculato ... t&x=69&y=4

Tom

The split systems are great if you can find one at the right price. The AC unit cost $105, and I probably have $50 in the other parts for the external plenum.

I found the whole thing on amazon for 580$ inverter does heating cooling and dehumidifies 110v also 9000 btu is the smallest

That's awfully big for a TD. Another reason I like my little unit is that it runs off of my Honda 10000eu generator.
It does look like a nice system though.
Tom

yeah I know its pretty big, im just guessing mybe if its really hot and humid out it would work pretty decent, I had a pop up camper once and put a regular window unit in it and it didn't work that well for that, I don't think it was big enough either and also it was a cavvas tent so