rooftop a/c

[jonb8]

I was just wondering why noone uses rooftop a/c like this small unit? It mounts in a standard 14x14 vent hole, I'm researching A/C and I see it's tough to get it were it's not in the way of something else. Thanks https://www.my12voltstore.com/ProductDe ... aQod138LEA

[KennethW]

This is my thoughts of that roof top unit. It would make the teardrop harder to tow(aerodynamics) . Would not look good on a teardrop. The weight on the roof would need to be supported. The weight on the roof may make the teardrop top heavy. Way to many btu for teardrop. A window unit can be removed when not needed.
That would be my reasons.

[lrrowe]

For me,
Cost, too many BTU's, height, wind resistance and did I say cost.

[jonb8]

Ok thanks, I just need to purchase/get an idea about how I'm gonna put a/c in before I start throwing sawdust. I hate to take up my front storage rack or have it hanging out of the front wall. Guess there's things I'm going to have to compromise on.

[2bits]

To define "overkill" it is actually counter to your best interests which is to condition your air. With a unit that big, it will hardly run, it will blast out the cold air and the compressor will turn off. This is a common topic, the trick with a teardrop even with the smallest 5k btu unit is to keep the compressor running long enough to cycle out the humidity, not just lower the temperature. Have you ever been in a room where you felt cool but it was clammy? That's cold humidity and gross. Dry is where it is at when it comes to air conditioning and a 13k unit not only will be inefficient for your needs and way too expensive but they are extremely loud. People have to fight to let outside air in with a 5k unit to keep the compressor running so aim for the smallest unit possible. Most people put them up front and some put them under their galley counter and suck fresh air from the sides and vent heat out the bottom. Pet cools are an option but are slightly under powered and hugely expensive, but you might try a window unit with custom duct work. You could even mount it on your roof if you engineered it right. I would worry about wind drag, you're just pulling a teardrop! I hope that helps.

[noseoil]

It's called "short-cycling" in the AC industry. Basically, the unit runs too often for a short amount of time, so its efficiency can't be utilized properly. A 2,000 or 3,000 BTU installation would be more than enough for most teardrops. Our 5K window unit keeps up with any heat load we have here in Tucson.

[KennethW]

Ok thanks, I just need to purchase/get an idea about how I'm gonna put a/c in before I start throwing sawdust. I hate to take up my front storage rack or have it hanging out of the front wall. Guess there's things I'm going to have to compromise on.

Maybe mounting by the galley wall on the shelf above your feet. Venting out the roof(two dryer vents?) and air in thru the floor or wall(if mounted on the left or right).

[jstrubberg]

There's a great post under the electrical section on using a wall mount AC unit with a custom duct on the front to allow the unit to sit on the ground and duct air into the teardrop. Keeps the mess and noise outside and the cool inside.

[m.colley]

As noseoil said the rooftop units are severe overkill, specially for a TD. Window units are cheap to use and available in smaller sizes. Other then that the ideal unit would be a small refrigeration unit similar to what they use on ice merchandisers ( bagged ice boxes ). The draw back is they aren't self contained and cost more than a window ac.

A window unit with a dump zone would work if a 5000btu unit were too big to cycle correctly. You can tell if its oversized by using a small hygrometer to keep up with your humidity %. If your humitidty stays consistently over 50% and your unit cycles off and on constantly its probably oversized. If it cycles normally but your humidity is consistently over 50% your TD is leaky, seal your leaks and you'll be much happier.


Martin

[Shadow Catcher]

Our 5,000 BTU works well with a 400 cubic foot tear