Reengineering an air conditioning unit to “marine” use. Purists should cover their e

[REBrueckner]

"It's good to know that all the other HVAC design variables mean nothing as long as you have SEER or EER."


I did not say that....As Mario and his buddy exemplified, you need installations that allow the equipment to perform as designed. Otherwise EER and SEER are the broadest measures of operating efficiency. As discussed previously, first costs and maintenance costs are also part of total operating costs.

What do YOU suggest??

[Boatsb]

"It's good to know that all the other HVAC design variables mean nothing as long as you have SEER or EER."


I did not say that....As Mario and his buddy exemplified, you need installations that allow the equipment to perform as designed. Otherwise EER and SEER are the broadest measures of operating efficiency. As discussed previously, first costs and maintenance costs are also part of total operating costs.

What do YOU suggest??

For those considering the possibility of such a change, you don't need to worry about whether water or air or anything else is "better", just use the SEER or EER of equipment for overall efficiency comparisons and the common sense approach these guys used in placing the compressor for proper cooling air flow.

Sounds like SEER and EER are only real considerations here to me.


It's not as easy as you seem to think. Google did not tell you everything you need to know. I'm sure you mean well but there are too many other factors that have not been worked through to make SEER and EER a slam dunk.

In Florida we use the air almost daily and a well installed unit properly maintained can and will last 10 + years.a 1 day or less install and I get 10 years of service. My time is valuable so I consider that in the equation too. Considering the high air temp and the constantly beating sun, water cooled units have an advantage especially with the R410A which has a major performance drop as the temperature rises. Also the wet bulb (humidity) has a big effect on the system and the amount of water it removes from the air. Add to that the stainless and copper used for Marine being a better quality and the resale value of a frankenboat and I see no real savings.

By the way did anyone calculate the heat load, Air flow requirement or filter requirements for the area? Things work better when they are properly designed for the space. By the way the use of the space under the bridge is a great idea. Insulated ducts and an air handler under there is a great idea. Even a self contained unit with a water feed like I have installed on some flybridges would work well.

[spcoolin]

Hello All~

Been reading this thread with much interest...Back in the beginning, I believe it was Dennis that asked for my comments...And Frankly Dennis...I have not known where to start...

First I would like to commend Mario & his friend Hector for all the thought & effort they have put into this re-design & retrofit...I'm sure it was quite a task & I'm also glad you are happy with the outcome...

But...I'd also like to point out some things before others consider doing similar...Please understand it's not my intention to pick this apart (and that's why I have not commented until now) but I feel it's only fair to point things out as I see them and to also state that I have seen this type of installation before...Though it's a cheap way...It may not be the best option for several reasons I intend to address here...

I have done a multi copy of several of your posts to keep my memory straight as I write this, and to also address each as it came up...This I'm sure will be a long post & please excuse it if I make many edits as I review it...

I also had to edit/remove some of Mario's text because the post was to long & the editor would not let me save it.
Geeze...Now I have to delete some images...It limits me to 4 so here go's...

Finally, after taking a hammer to the P.I.T.A. aft salon air conditioner for the last time, I sat down and cooled off with a beer. I started to rethink this whole “marine” a/c theory and the way it is used in our application. Truth be told, this idea was thrown around last year with my good friend Hector. Hector, like me is gear head and we both share the same pastime of fixing or reengineering anything. Not being afraid of failure and with time on my hands we set out to rethink this “Marine” A/C system. Specifically how we can redesign a system conveniently and affordably with the added advantage of lower maintenance. Our old system for our salon cooling consisted of a 16K btu aft salon A/C and a 14K btu forward salon A/C that is also ducted into the galley. On a good day with both salon units working, it could barely keep up with the blistering heat and humidity down here in south FLA. especially when having a large amount of family and friends aboard. Both units were clearly showing their age and were starting to be a maintenance headache. The cost to replace both units with a substantially larger unit was through the roof which also required me to run larger Freon lines and change to 220V. This would have required me to remove the port side sofa and remove the original teak wall paneling to run new lines. Something that I wasn’t in the mood for. Another problem with the OEM units was that both A/C’s while operating were very loud due to blowers located inside it’s cabinets. Also it is poorly designed in that the a/c cabinet is located at knee level and blows cold air up to the ceiling instead of from the ceiling down which is more efficient use of cold A/C. After several months of searching we came to the conclusion that a departure from a “Marine” system was needed. Domestic systems were readily available and with a large variety and styles around, it opened up possibilities. So we created a short list of what was needed and what goal we were shooting for. The list consisted of cost, ease of maintenance, simplicity of reengineering, low amp draw, minimal/ low impact to factory (Hatteras) interior structures, cosmetically conservative. We looked and studied split systems, mini split systems, window shakers and wall units. All having their pros and cons. But after a thorough study and crunching numbers over and over we came to the conclusion that the unit that best fit our criteria for this redesign experiment was a LG 24,800btu Mod: LW2510ER window unit. After initially scoffing at the idea and the thoughts of the Beverly Hill Billy’s running through my mind, I put on my thinking hat and focused on the task at hand.

FYI, I always had a back -up plan incase this experiment failed miserably or did not live up to my strict expectations. I was fully prepared to junk this project, bite the bullet and install a “marine unit”. With this in mind I started with the duct work. Wanting to use a more efficient method of ducting, we chose to access the interior of our fly bridge to install A/C vents using insulated 8” and 16” ducting. Having a large fly bridge interior made this a fairly easy task. First I cut three holes into the fly bridge floor/salon ceiling with a router and after removing the balsa coring and epoxied the remaining exposed balsa around the circumference of the opening, I fiber glassed in two 8” galvanized ducting collars and a 16” ducting collar for the return air.

First...Let me start out by saying lets be fair...

Many of your Hatteras A/C systems (including Mario's) on the boats built before say 1990, have Jere Crews designed equipment, that the design & efficiency factors date back as far as 1959/1960...
They were also built small (as the technology of the time would allow) to fit in the small spaces available on "Yachts" of the day...

So comparing performance to a unit of any kind built today is not apples to apples.
Blow Through air handlers with propeller fans are not the way of today...They make noise & don't move much air...But I might also add that Mario's old system may have given what...Almost 40 years of service ???...You may want to compare original cost of that equipment (which was not much more than a residential split system of the day) & service calls, To how many of those Window units would have been replaced over that time ???

Note: Mario...In your second pic above...Sheet metal duct collars & salt air don't mix...Since you have glassed those in...Hope you don't start getting rust pellets coming out of your discharges soon...Plastic collars with mounting flanges that could screw down with a bead of 5200 or the like are available...But I'm also concerned about your other metal adapters...Could provide some nasty stains inside the cabin...

While Hector worked his electronic engineering magic on the control panel wire harness and plugs. This unit has many advantages which made customizing a snap. First the condenser fan is shrouded like the radiator fan in your car.

This is a very important consideration because for the unit to work properly outside of its cabinet the condenser must have fresh air directed into one side of the condenser (fan side) then out the other side at a much hotter air temperature. For our purpose, the fan shroud meant that I only had to isolate expelled hot air from mixing with the fresh “cooler” air that entered it, i.e. not circling back around into it. Secondly, the construction materials of the unit is mainly composed of copper, plastic and power coated components. Very little to corrode. Thirdly the front of the unit where the conditioned air discharge vent is located can easily be adapted to accommodate two Home Dpt off the shelf vent-to-duct tin 8” collars where the insulated ducting will attach to. Thirdly, this unit has the most btu’s for its overall dimensions.

For simplicity and efficiency pop rivet both vents together and tape the inside wall of the vents together. Complete the same vent box procedure with the condenser. Two very important notes at this point, first, all fitted vent components MUST NOT be permanently installed yet! because fully assembled the unit is much harder to maneuver into the fly bridge. All components will be permanently installed once the unit is in its final location. Basically you are pre fabricating the parts for installation later. Secondly, once you have constructed the boxes and vents, they may feel flimsy at first but this will go away once you apply aluminum ducting tape and rivets. This stage of the project, rated on the difficulty scale is about a 5. At this point you are 80% complete.

In the Pictures above...Well I had to delete them but they are in your first post on page 1

You could have saved some room (big 16" duct) by cutting the return hole (240 square inches) just below the evaporator coil & built (out of plywood or starboard) a ski-ramp looking box that would attach to the unit & the deck (with a glassed in raised flange on deck to keep water out)
This would also facilitate a filter on the coil that could be accessed from below by removing the return grill & reaching the coil...It would also give you a way to clean that coil if needed from below without removing your metal plenum & crawling into the flybridge to do so....If there is still room.

As mentioned earlier by others...I'm concerned with getting rid of the heat from the condenser coil, and if you have sufficient flow (not to mention what salt air will do to that aluminum coil) those propeller fans are not meant to be ducted and don't handle back pressure well at all....Remember...You are not in So Fl summer yet where the temp under that flybridge brow is likely to climb up over 100 degrees during the day....All things considered...I'm sure it may work fairly well now as new, but what happens when that coil starts to corrode from salt and the temps go up ?
Then how do you clean that coil ???

Also remember that with that unit it only has one fan motor that spins both fans at the same time...So slowing the fan on the control to reduce noise inside...Is also slowing the fan outside that removes the heat from the condenser & the refrigerant.

Finally firmly attach brackets and clips to avoid movement during rolling and pitching. Now you can permanently install the vent boxes and air vents. Do not skimp on tape at this critical point not only will it give it structure but more importantly the unit must be sealed well to avoid outside air from being suctioned into the return air. A tight seal is important for efficiency. Take your time. Install your insulated ducting to all the collars. Tape, zip tie, then tape again the ducting to the unit.


Install the plastic barb drain fitting with fast dry 3M 5200 to the back of the unit drain pan through the hole that you cut into the vent box you made, don’t mess this up or it will drip water. Attach drain hose. This stage of the project rated on the difficulty was a 7. Finally, plug in the control panel wire harness and 220v power but make sure the breaker is off. Back in the salon all that is left is to plug in the other end of the wire harness to the control panel.

At this point you can turn the breaker and start the unit.
Results:
The salon now has plenty of conditioned air! From a performance standpoint, the unit has a wide range of cooling temperatures while properly cycling on and off. In fact, the salon can easily maintain 68 degrees during the day and 70 at night. Humidity is noticeability way lower. But where the real added advantage is that the factory aft salon a/c and the forward salon a/c is no longer needed! Not only did it cut down on the noise but the power savings is huge. As an example, with the master room, guest room, forward salon and aft salon A/Cs operating I was pushing close to 50 amps. Now I’m drawing about 28 amps total! As far as noise and vibration from the new unit, all that is perceptible is the quiet flow of air coming from the vents. No rumbling, no vibration. When the compressor kicks in it sounds like it’s very far away.
The only structural modifications that were made besides installing the A/C vents overhead in the salon was to the fly bridge access door. I did have to cut approximately 1” of the opening once the door frame was removed to accommodate the unit. It is now being replaced with a louvered door to aid in unit cooling. The other modification was to the starboard aft section vent of the fly bridge. Normally this vent was to keep the inside of the fly bridge dry with airflow. Now the vent was enlarged to allow warm air to escape and not return or flow back around to the unit. A new custom made louver is being fabricated.
Final thoughts,
My total investment in this project is about $800 or so. It took me about two weeks to prepare, engineer and install. From an esthetics view, it is clever design that looks quite good. With what I have learned I believe that this project can be done in about a week to 10 days as a DIY project. This project is totally practical from an application standpoint and has exceeded my expectations. Clearly one needs to get over the whole “marine” label that only serves to cost us substantially more. Also a willingness to think outside the box is a must. This project is totally doable and very gratifying.
Enjoy! Mario

I never understood why bubba had to make it such a complicated system either... Especially these days with way higher EERs and quiet rotary compressors you barely here them run. Hell, even a member here has central heat (forced air) on his 58 TC... why not ad air to that?? ws



Maybe not the prettiest install but form does follow function...

Bill..."Bubba" din't make yer install compicated...But that's what dem fancy pants folks wanted on there yachets...They wanted control in every room & dint want dem lady friends to be too hot or too cold...Dey might go home & den nobody has any fun...Les'n dey hire some dancing girls ana don't git caught by momma....

To be honest...One of the systems on your boat is no more complicated than a home system...It's just you have 5 or 6 of them and they didn't want to take up much living/storage space with air handlers so they used more than one on some systems to total that Btu...BTW your big system was a total of 36,000 Btu (I re-looked at your pictures)

One other question/comment Mario...Is there any space left over in there to work on anything else such as gauges etc ?

In closing...It looks pretty good...I have seen much worse...I know it's cheaper initially but your time is worth something too...Will it work out in the long run ?...Hope So...Really I do for you...One more thing though...What about re-sale of your Yacht ?...What about a fire ?...I'm sure that unit is not built to ABYC or USCG standards for Ignition Protection...What will your insurance company say ?...Maybe nothing since where it's installed, but it is a thought...

You might find out, or think about that in your charter business Angela...

Steve~

[REBrueckner]

Mario, Hector:
To be sure I understand, you guys did not modify any components of the LG window air conditioner, right?

I mean you used the factory compressor, evaporator, etc as provided..... You did not change any guts within the unit?"? You described all the ducting work and the photos show that....and I guess extended the controls..just wondering about the "innards"...

spcoolin:

regarding air filters, do newer boats use electronic air cleaners??? Any recommendations on brands??? if not, do you have a preferred type traditional filter???

[spcoolin]

Mario, Hector:
To be sure I understand, you guys did not modify any components of the LG window air conditioner, right?

I mean you used the factory compressor, evaporator, etc as provided..... You did not change any guts within the unit?"? You described all the ducting work and the photos show that....and I guess extended the controls..just wondering about the "innards"...

spcoolin:

regarding air filters, do newer boats use electronic air cleaners??? Any recommendations on brands??? if not, do you have a preferred type traditional filter???

Yes...Dometic offers these...Just put 3 in a 110' Broward that had a bad diesel smell...Got rid of that, and I never smelled a boat so fresh...

http://www.dometic.com/enus/Americas...ctdataid=94755

I use the plastic plastic mesh filter material that Dometic installs on new units...It's washable & does a good job...Not that expensive either...It now comes as precut sizes to fit particular units but that's not to say you can't take snips (it cuts very easily) to a piece that was meant for a larger unit (I used to be able to buy it in bulk from them) now it's only the pieces, but you can ask any local Dometic dealer about it.

Otherwise Home Cheapo has foam type material for window units...Cut it to size...

Steve~

[sgharford]

Great job detailing the installation -thanks for a Great read (been a while since a fun thread like this started).

I am surprised the propeller type fan has enough oomph to overcome static losses in ductwork. Normally it's a squirrel cage (centrifugal) fan for these purposes. Looks like your ductwork is well oversized by standard duct sizing conventions which must be making all the difference since you sound very happy with results of project. Next cold one is for you!

As aside, I use to sell commercial A/C units. We had a problem with a contractor installing a couple of commercial grade split systems for a new casino boat leaving south shore of Long Island (it was actually a brand new boat). Well, the standard condensate drain pans are not very deep, certainly not enough to compensate for the rocking motion of the boat. Ruined ceiling tiles, made puddles, etc. Not enough room in unit to make pans any deeper. Got into a pissing match with the engineer who spec'd it. Anyway - glad to see yours on top of fly bridge.

Just remembered something else we use to do for seaside units and/or units in corrosive enviroments. We'd send the entire unit to a speciality shop in Tennessee who'd remove condenser coils and apply a Phenolic Coating. This supposedly increase standard coil life in these enviroments from 5 years to 10. Probably a bit a snake oil involved, hard to say. They would put stainless steel drain pans in as well if you couldn't get that option from factory.

[MarioG]

Hello All~

first...Let me start out by saying lets be fair...

Many of your Hatteras A/C systems (including Mario's) on the boats built before say 1990, have Jere Crews designed equipment, that the design & efficiency factors date back as far as 1959/1960...
They were also built small (as the technology of the time would allow) to fit in the small spaces available on "Yachts" of the day...

So comparing performance to a unit of any kind built today is not apples to apples.
Blow Through air handlers with propeller fans are not the way of today...They make noise & don't move much air...But I might also add that Mario's old system may have given what...Almost 40 years of service ???...You may want to compare original cost of that equipment (which was not much more than a residential split system of the day) & service calls, To how many of those Window units would have been replaced over that time ???~

Hi Scott! Thanks for comments and well wishes!
I agree that this is not an apples to apples compairson. I did say that part of my problem was having to deal with very old systems. The difference is that except for the fact that the end product that is coming out of the vents was obtained at a very low cost compaired to the substantully larger upfront cost that a traditional marine would have cost. I agree that some day this unit will fail and will have to be replaced. but lets take into consideration a small/cheaper window unit that is located all around the coastal areas. these newer designed units are lasting north of 3-5 years before being replaced. in our marina there are several units installed is areas that are directly exposed to the eviroment and salt water. they show their wear from exposure to the elements but are still operating. Our aplication is installed in a reletively clean and protected eviroment. As far as noise, bottom line this unit is very quiet, and hardly noticable. Also, this unit moves a large amount of air in our application.

Note: Mario...In your second pic above...Sheet metal duct collars & salt air don't mix...Since you have glassed those in...Hope you don't start getting rust pellets coming out of your discharges soon...Plastic collars with mounting flanges that could screw down with a bead of 5200 or the like are available...But I'm also concerned about your other metal adapters...Could provide some nasty stains inside the cabin...~

We also thought about this. But I couldent find the plastic collars. at this point, IF any collar shows signs of corrosion I will fully encapsulate them in glass.

You could have saved some room (big 16" duct) by cutting the return hole (240 square inches) just below the evaporator coil & built (out of plywood or starboard) a ski-ramp looking box that would attach to the unit & the deck (with a glassed in raised flange on deck to keep water out)
This would also facilitate a filter on the coil that could be accessed from below by removing the return grill & reaching the coil...It would also give you a way to clean that coil if needed from below without removing your metal plenum & crawling into the flybridge to do so....If there is still room.~

Yep, we also thought about this one too. our decition was two fold, 1. the insulated ducting was a fast and adaquate solution do to the fact that if this experiment failed I could switch to a marine unit with little trouble. 2. If I would have hard enclosed the return air with a ramp type of box, that would have really been cumbersome come maintance time and would have taken up a lot of space. Asa far a filters, a good quality filter fits nicely right behind the return air grill in the salon.

As mentioned earlier by others...I'm concerned with getting rid of the heat from the condenser coil, and if you have sufficient flow (not to mention what salt air will do to that aluminum coil) those propeller fans are not meant to be ducted and don't handle back pressure well at all....Remember...You are not in So Fl summer yet where the temp under that flybridge brow is likely to climb up over 100 degrees during the day....All things considered...I'm sure it may work fairly well now as new, but what happens when that coil starts to corrode from salt and the temps go up ?
Then how do you clean that coil ???~

I agree with you. One of the top prioritys of ours was to efficently expell the hot air from the condensor. we feel that our solution is good. infact, if you think about it, any unit of this type in a normal application takes into consideration that the unit may unavoidably intake some of the expelled hot air back into the fan/condensor side. In our aplication, we have compleatly isolated the expelled hot air away from the condensor air intake. We also thought about back pressure but there is plently of unrestricted flow of expelled air exiting the enlarged vent at the back of the bridge wall. as far as corrosion and the temperatures going up, this all remains to be seen and will be reported.

Also remember that with that unit it only has one fan motor that spins both fans at the same time...So slowing the fan on the control to reduce noise inside...Is also slowing the fan outside that removes the heat from the condenser & the refrigerant. ~

Again,noise is not a factor. but I have slowed the fan to it's minimum speed and have not noticed any change in vent temperature. I dont think I'll be changing fan speeds much in my application.

One other question/comment Mario...Is there any space left over in there to work on anything else such as gauges etc ?

What about re-sale of your Yacht ?

Steve~

Yes! infact that is why I explained that the unit had to be installed as far forward as practicable. Not only because of unit installation but also because of access to the gauges and electronics of the console. I am 5'10" and weigh 205 lbs, I can enter into the flybridge and lay flat on my side in front of the unit or I can kind of sit just to starboard of the unit. tight but works. If I release its tie down braces the unit can be slid around on the mount.

As far as resale of our yacht which I hope will never be needed. We designed this system to be replaced with a marine unit at any given moment with little extra costs/labor aside from purchasing the marine unit.

Steve, again thanks for your constructive input, keep them coming and I'll keep reporting my findings.

[MarioG]

Mario, Hector:
To be sure I understand, you guys did not modify any components of the LG window air conditioner, right?

I mean you used the factory compressor, evaporator, etc as provided..... You did not change any guts within the unit?"? You described all the ducting work and the photos show that....and I guess extended the controls..just wondering about the "innards"...

No we did not change anything in this unit other than Hector creating a long wire harness for the control panel. Some soldering required in this.

[spcoolin]

Hi Scott! Thanks for comments and well wishes!
I agree that this is not an apples to apples compairson. I did say that part of my problem was having to deal with very old systems. The difference is that except for the fact that the end product that is coming out of the vents was obtained at a very low cost compaired to the substantully larger upfront cost that a traditional marine would have cost. I agree that some day this unit will fail and will have to be replaced. but lets take into consideration a small/cheaper window unit that is located all around the coastal areas. these newer designed units are lasting north of 3-5 years before being replaced. in our marina there are several units installed is areas that are directly exposed to the eviroment and salt water. they show their wear from exposure to the elements but are still operating. Our aplication is installed in a reletively clean and protected eviroment. As far as noise, bottom line this unit is very quiet, and hardly noticable. Also, this unit moves a large amount of air in our application.


We also thought about this. But I couldent find the plastic collars. at this point, IF any collar shows signs of corrosion I will fully encapsulate them in glass.


Yep, we also thought about this one too. our decition was two fold, 1. the insulated ducting was a fast and adaquate solution do to the fact that if this experiment failed I could switch to a marine unit with little trouble. 2. If I would have hard enclosed the return air with a ramp type of box, that would have really been cumbersome come maintance time and would have taken up a lot of space. Asa far a filters, a good quality filter fits nicely right behind the return air grill in the salon.


I agree with you. One of the top prioritys of ours was to efficently expell the hot air from the condensor. we feel that our solution is good. infact, if you think about it, any unit of this type in a normal application takes into consideration that the unit may unavoidably intake some of the expelled hot air back into the fan/condensor side. In our aplication, we have compleatly isolated the expelled hot air away from the condensor air intake. We also thought about back pressure but there is plently of unrestricted flow of expelled air exiting the enlarged vent at the back of the bridge wall. as far as corrosion and the temperatures going up, this all remains to be seen and will be reported.



Again,noise is not a factor. but I have slowed the fan to it's minimum speed and have not noticed any change in vent temperature. I dont think I'll be changing fan speeds much in my application.




Yes! infact that is why I explained that the unit had to be installed as far forward as practicable. Not only because of unit installation but also because of access to the gauges and electronics of the console. I am 5'10" and weigh 205 lbs, I can enter into the flybridge and lay flat on my side in front of the unit or I can kind of sit just to starboard of the unit. tight but works. If I release its tie down braces the unit can be slid around on the mount.

As far as resale of our yacht which I hope will never be needed. We designed this system to be replaced with a marine unit at any given moment with little extra costs/labor aside from purchasing the marine unit.

Steve, again thanks for your constructive input, keep them coming and I'll keep reporting my findings.

Mario~

You asked...So here we go...

It's hard to argue equipment price with you...There really is no argument to make since you have a Home window/wall unit and those are cheap...

Comparing a Home Split system might be a better (a more fair) comparison...I frequently hear quotes of over 3-4 grand in just the equipment nowadays for the new 410a high efficiency systems...None of which would be ABYC or USCG approved for ignition protection...

Your return duct idea/application would not lend itself well to the installation of one of these Marine Air handlers that are rated, and would take up much less space...But you have already cut your hole thru the overhead for the grill...Question: Did you frame it so the a pan overflow might not enter the cabin ?

http://www.dometic.com/0752f0f0-b5d3...1f1accbd.fodoc

They already have the return plenum made for you and provide dual blower outlets...Maybe you weren't aware of them ???

I also don't see any advantage to your unit with sheet metal plenum's attached with rivets & silver tape in a very damp environment...Service to any of that as I see it would be an issue...Keeping it sealed may be another...Silver tape is good in an attic, but in my experience does not hold up in salt air, or much moisture...It won't stay inside a cold air plenum or duct either...There is some that will (it has a gummy backing instead of just glue) but what I see you have won't...Be prepared to redo all of that shortly...Remember, anytime you are running that unit you are drawing in salty, humid air...

As far as running new copper...Yes you would need to do that if you went with a 24K air handler like I linked...But running up the chase in the picture of your new control, or maybe the one on the other side of the boat would have not been much of an issue ??? Just remove the chase off the bulkhead, or open it up...most have provision for that...and I believe they both go to the engine room ???

Also a new Cruisair condensing unit with that air handler would give you the same savings in power that you realize now...

Just for everyone's knowledge...Cruisair equipment costs for both units would be around $5500...Before I discount it to you (so similar to home equipment pricing which I can't quote on-line, it's a Dometic no-no) For top of the line Marine equipment....

Labor does have to figure in here...Whether it's done by the DIY guy, or by a Pro...Either way the easiest job is the best one for all involved...I've been the Pro guy for many years, but now also cater to the DIY guys with my help if they buy from me (or like this & on my forum...even if not buying from me)

I certainly can't compete with a Wall or Window unit pricing...But as already mentioned...That's what you are getting, and the labor Mario & Hector went thru would have been quite costly if paying for two talented guys (such as themselves) even at reduced rates.

I can't help but believe that installing the Marine equipment might not be similar, or less work than what was done here...

Please keep reporting Mario...I'm only voicing here what I see, and what I know from my experience (and I have been wrong before)

Steve~

[REBrueckner]

spcoolin:
very generous of you to share your knowledge and experience with us. Thanks.

Any idea what the EER/or SEER is for a typical modern marine (water cooled) unit?

Can you provide any insight into how much AC system efficiency typically improves over say five or ten years? Is the efficiency change rather minimal, in which case long lived (expensive) equipment might be preferable (to save on labor removal and installation costs), or does it typically improve several percent annually, meaning after five or ten years, upgrading would yield significant operating savings?? For the last several (maybe 5??) years, Home Depot, Lowes, and Walmart AC window units seem to have stayed at 10.6 or so....

All I know is my circa 1972, 1985 Cruisair systems were still working when I sold my 48 YF 2 years ago..at 37 and 24 years old, but I know from the high current draw they were very inefficient. I only ran them to exercise the units so the operating cost was minimal for me.


For those interested, wikipedia has interesting information and clear explanations under the heading SEER....or EER....here is one tidbit:

"Maximum SEER RatingsToday
there are residential AC units available with SEER ratings up to 26. [4] There are a variety of technologies that will allow SEER and EER ratings to increase further in the near future.[5] Some of these technologies include rotary compressors, inverters, DC brushless motors, variable-speed drives and integrated systems.[5]"

26??? Holy cow?? That's news to me......I never have seen anything close to THAT. Likely NOT window units. The reason this is so potentially interesting is that electricity costs for Mario's system, for example, would be roughly 7.5/26 or about 29% of the LG unit he used....of course such a unit may cost big upfront $$$.