Ducted roof top A/C units

Zeroclearance · July 31, 2008, 10:03:22 AM

My first thread, be gentle

I have lurked for many months. I presently have 5 tons of basement A/C with full length ducting. I am looking to do a remodel and gain some of my basement storage (A/C is taking a full bay). I have noticed alot of the Pro conversions are using slim line rooftop units. I already have 2 domes on my roofline and am requesting info with folks that have the newer slimline roof top units. I am leaning toward the Carrier ducted unit. I have alot of ceiling height and can insulate the return air plenum/grille with ductboard to reduce the fan noise "I think" My question is, how is the Carrier unit vs the other manufactures. Do any of the manufactures offer a "economizer" or outside fresh air option?

Nick Badame Refrig/ACC · July 31, 2008, 10:29:33 AM

Hi Zeroclearance,

Welcome!

Both Carrier and Dometic's Penguins are good Low Profile units. However, Dometic offers the 3 speed fan that folks seem to like for a quiet sleep.

What are you thinking, 4/5 units?? I assume you have a large generator. As far as an economizer, none with roof tops... "windows open"

The only problem we have with the Carrier LP's is the fan grill on the top. Debree/twiggs will become lodged through the grill and stop the

condencer fan motor. If not caught in time, you could damage the compressor.

The Penguins, seems like if it's works when you first install it, it will work until they rott away.

Good Luck
Nick-

Zeroclearance · July 31, 2008, 04:01:59 PM

Nick, Thanks for the response. Yes, I am thinking 4 units. I surprised that no one makes a unit with the added make up air option. Pressurize the coach a little bit.

coachconverter · July 31, 2008, 04:21:51 PM

I've installed several Carrier units without problem, just did a low profile 13.5 on a Sprinter last week - no problems.

I agree with Nick that the fan on the top looks like it could cause problems down the road though.

I've had several retailers "warn" me against the Penguins, but I wouldn't doubt it's because they have a better markup on the Carriers.

I'm glad to hear Nick's view on the Penguins, its what I wanted to put on my Sprinter, think I'll go that route.

BTW, there was a guy on eBay with 4 or 5 new Penguin LP units (no inside kits) for something under 500 each.

hth,

Todd

Paladin · July 31, 2008, 04:35:12 PM

Quote from: Zeroclearance on July 31, 2008, 10:03:22 AM
I am looking to do a remodel and gain some of my basement storage (A/C is taking a full bay).

Lemme know if and when you sell the basement airs, I may be in the market.

-Dave

Zeroclearance · August 02, 2008, 06:33:32 PM

Paladin, please realize that the air handlers/coils are topside times two. For someone that wanted a split system basement A/C unit this would be it. But I need the space. If you have room to spare get ahold of me.

I like the fact the new Carrier units are 2" smaller in height. I guess the swing vote for the Duo-therms would be is they make the heat pump option in a low profile.

muddog16 · August 02, 2008, 06:54:52 PM

When I started my conversion, I thought basement units would be the best and keep the top clean, but once I started thinking about how much room I was losing, plus the price of replacement, and the new low profiles units starting coming out, I changed my mind! I've listened to a lot of information on here about ducted roof units, and the system I like best is doing a remote location for both supply and return ducts, when I say remote I mean moving the return further away from the supply registers. Ron Walkers duct work was really inovative, he has pictures of his finished ceiling in a topic here! The new penquins that I have are Heat Pumps, and they all tie together and have remote temperature senors in each area of the bus, there is only one digital thermostat, this system promises the best answers for me, I know everyone is different in their approach to air conditioning and heat, I chose the one that would work best for me, I wanted access if they needed to be replaced, and I wanted them quiet, plus this system can also run my hydronic heating system from the same controls......I'm sure mini splits and basement units will do the job just as well, the final line was did I have enough storage for my wife........this woman needs an 18 wheeler to travel in........

so I've made room for her!

Zeroclearance · August 02, 2008, 07:13:01 PM

Pat what is the height of your penguins (9.5") BTW, nice job with your conversion and webpage.

rv_safetyman · August 02, 2008, 10:24:16 PM

Pat, I tried several search options and can't find Ron Walkers post on his ducted system.

Can you (or someone else) give me the link?

Jim

dolson · August 03, 2008, 09:42:06 AM

I just installed three penguin model 630516 15K heat pumps and have the control system the same as muddog. I have the units temporarily wired and working. I think that they will do a good job but right now the bus has no ceiling insulation and at 100F in the sun they will only bring the temp down to the upper 70s. I am also going to duct the supply and return to quiet things down. These units only have a 2 speed fan.

jjrbus · August 03, 2008, 09:53:42 PM

I wish I would have thought to duct the supply, way too late for me!!!!!! On my Duo therms the installation manual gave specific specs for the discharge ducting, but nothing for the intake air. I would guess the noise could be dropped by 50%. When setting up intake ducting make sure yuou have acces to the bolts that hold it to the bus