AC Issues

[PhilPB]

I'm not sure what ac unit I have and have tried to find info on the web but have come up empty.
The ac panel is Aqua Temp and looks a bit old. Near the compressor is a hand-done info plaque, but not sure of its validity. Assuming the info is correct, does this look familiar? I'm also trying to figure out if it was to be replaced, what is a good option?

 

[tiltrider1]

I am guessing by the model number that you have a 16,000 btu heat pump with a reversing valve to give you both heat and cooling options.

I can’t tell from the photos if it is a self contained unit or a split unit. If you were on the west coast I would send you to Sure Marine. Hopefully those more knowledgeable about the Florida area can give you a recommendation.

 

[SIBERNUT]

I got no idea, but whoever made the tag can't spell

 

[PhilPB]

I got no idea, but whoever made the tag can't spell

I noticed that, not that it matters much

 

[PhilPB]

I am guessing by the model number that you have a 16,000 btu heat pump with a reversing valve to give you both heat and cooling options.

I can’t tell from the photos if it is a self contained unit or a split unit. If you were on the west coast I would send you to Sure Marine. Hopefully those more knowledgeable about the Florida area can give you a recommendation.

I assume it's considered a split unit. The blower/(evaporator?) is about 1 foot away on the other side of the bulkhead. The compressor is in the engine room and evaporator in a galley cabinet.

 

[tiltrider1]

Yes, that would be a split system.

 

[PhilPB]

I was also wondering if I could go with one of the self contained units (e.g. Dometic Envirocomfort retrofit, Webasto, etc). Ductwork isn't an issue. Not sure if they are reasonably easy to install.

 

[Action]

R417a is a replacement refrigerant for R22.

Likely that is an older system that has been converted during some service. Maybe because of a compressor replacement.

 

[tiltrider1]

I was also wondering if I could go with one of the self contained units (e.g. Dometic Envirocomfort retrofit, Webasto, etc). Ductwork isn't an issue. Not sure if they are reasonably easy to install.

Self contained are very easy to install if you have the space. You will need to connect the water, Electrical and Ducking to the unit.

 

[PhilPB]

R417a is a replacement refrigerant for R22.

Likely that is an older system that has been converted during some service. Maybe because of a compressor replacement.

I was wondering about that. The control panel looks rather old and possibly original (no picture of it at the moment). After looking up the tag on the compressor with a date of 2013 seems to cross reference to a Tecumseh, I assumed that part wasn't original.

It still cools, but doesn't makes the cabin cold. I understand being in Florida inside a virtual hotbox with very limited insulation, I can't expect perfect comfort.

 

[PM]

It really doesn't matter who made it or when. If it is broken, fix it. If you can't get parts, replace it.

If it is running and doing its job, leave it alone.

pete

 

[Action]

Based on what you posted, likely the charge is low.
At least that would be the first guess I would have in an automotive system. (Which I am very familiar) Getting a gauge set onto the system would confirm that.
The air should be very cold coming out of the evaporator. in the 30s f. By the time the air comes out of the venting it will have picked up heat and in an ideal setting the temp will be in the 40s if the duct work is not too long. (couple of feet)
The system will feel very nice if chilled dry air is 20 or 30 degrees cooler than ambient. Not always achievable and that is the goal for the interior space.

Florida is very humid. The system should pull out a fair amount of water and discharge that somewhere. That water comes off of the evaporator as well and drips to the bottom of a case or a pan.
In a moving platform there are a number of flexible hoses. Leaks happen. In a stationary platform (I know boats move however the AC system is fixed) there are metal lines with less possibility of leaks. If the system is low it is because of a leak. And a rather slow leak. The other possibilities of system performance issues are:

Compressor is wearing out.
Debris from compressor causing a restriction in expansion valve.
Or air flow is restricted across the evaporator or condenser.

I believe a fixed system may have a diagnosis of how many amps of current the compressor pulls. Versus using gauges. I am very familiar with auto AC systems (I live in Phoenix. I have to be or hire that out) and while the system principals are the same. Execution may be different.

BTW Tecumseh is a very old AC company going back to before WWII for fixed systems and to the 1950s for automotive systems

The system may be old, however there are few parts that wear. The compressor is it. Things that you can do to make improvements.
Make sure any moisture/water (called condensate) is drained away from the evaporator or system enclosure. If that water stays on the evaporator, the system is not as efficient.
A marine environment does not have much dust in the air. This is a concern with a land based system and that system has filters. Clean filters if used are a must for the evaporator. Cleaning both the evaporator and condenser will help the efficiency.
Duct work, the goal is zero leaks. Leaking duct work means the chilled air picks up heat along the way to the areas that are to be cooled.
Insulate the duct work if at all possible. The boat may be poorly insulated. However the air getting to the poorly insulated living areas does not have to be. Sure feels a lot nicer even if just the air coming out the venting is cold.

 

[PhilPB]

R417a is a replacement refrigerant for R22.

Likely that is an older system that has been converted during some service. Maybe because of a compressor replacement.

Thanks for all the info. Would you know if R417a is available for the consumer to purchase similar to a recharge kit for a car?

 

[Action]

R417a was designed as a no-oil replacement to R22.
I cannot find it for sale easily. (I can find R22 which is likely recycled)
Other replacements are R422D, R427A, R438A.
Which means other gas types from the above may work and will require an oil change. (Done by flushing) Oil changes are necessary because the old oil does not play well with the new gas. Typically causing damage to compressors.

And all of that requires a license. So not available to a regular consumer.

In addition, there are no recharge kits with this kind of gas. A gauge set might be a way to introduce a gas. You are looking for fittings in the lines or on an accumulator.

Making a system change may be a good choice at this point. (based on long term cost) Especially if the current system is all in one. (Not split) Which may make a user install possible. I am writing this because I have no idea of what a marine AC tech or marine AC parts would cost and/or avilability. And it seems you have a 40 year old system that is not working well. And has been worked on or modified at least once about 20 years ago.

Something comparable or at least similar that I have experience.
HVAC systems in residential applications in the Phoenix area have about that long of a service life. Most are heat pumps (versus just AC) so get use most of the year. (I have 2) These systems are fixed platform with an expansion valve. The one component that will wear out is the compressor. Compressor replacement is a good way to continue the service life of a system. However, over time technology is improved and at some point the improvement out weighs the repair cost.

You may be there and part of that decision will be based on use. In a residential HVAC system the use is continuous. A yacht is a recreational vehicle that does not have that kind of use. May only be used for a couple of weeks a year. Or may be a live aboard and have far greater use. You need to make that decision.

 

[PhilPB]

R417a was designed as a no-oil replacement to R22.
I cannot find it for sale easily. (I can find R22 which is likely recycled)
Other replacements are R422D, R427A, R438A.
Which means other gas types from the above may work and will require an oil change. (Done by flushing) Oil changes are necessary because the old oil does not play well with the new gas. Typically causing damage to compressors.

And all of that requires a license. So not available to a regular consumer.

In addition, there are no recharge kits with this kind of gas. A gauge set might be a way to introduce a gas. You are looking for fittings in the lines or on an accumulator.

Making a system change may be a good choice at this point. (based on long term cost) Especially if the current system is all in one. (Not split) Which may make a user install possible. I am writing this because I have no idea of what a marine AC tech or marine AC parts would cost and/or avilability. And it seems you have a 40 year old system that is not working well. And has been worked on or modified at least once about 20 years ago.

Something comparable or at least similar that I have experience.
HVAC systems in residential applications in the Phoenix area have about that long of a service life. Most are heat pumps (versus just AC) so get use most of the year. (I have 2) These systems are fixed platform with an expansion valve. The one component that will wear out is the compressor. Compressor replacement is a good way to continue the service life of a system. However, over time technology is improved and at some point the improvement out weighs the repair cost.

You may be there and part of that decision will be based on use. In a residential HVAC system the use is continuous. A yacht is a recreational vehicle that does not have that kind of use. May only be used for a couple of weeks a year. Or may be a live aboard and have far greater use. You need to make that decision.

It is currently a split unit. Aside from an available space perspective, why would an all-in-one package unit be difficult to use as a replacement?

 

[Action]

An all in one unit by design is easier to install because by definition it is ..... well, all in one! However, making changes from original design is nearly always more difficult. The difficultly is in necessary modifications needed to make the new system work in the old space that was designed.

Space and connecting the system to the yacht are the considerations. IMO every install of that nature is a unique thing. Hard for me to say as I have no idea of the space and layout of old versus the proposed systems. If you do make a system change there are some system choices you can make.

Increase capacity of HVAC system. Many times OE pieces are used at the lowest cost available. The best step is making a calculation of what has to be cooled and match the system with a margin. Both too little and too much are a problem.
Current system efficiencies may make the choice to stay with current capacity. I did this in my home because the new systems were far better than what I was taking out. I stuck with the old system capacities. Both of mine are roof top all in one units. They draw far less power than the old units. Down side is they had to be craned onto the house.

HVAC versus only AC (if that is the case)

Upgrade attaching pieces. Electrical line gauge. Insulation to any duct work. Or?? (This is called job creep and in vehicle restoration happens a lot. "Oh look, because I am here I can also do this unplanned restoration.")

Good Luck.

 

[CaptTom]

Is that the only cooling unit in the boat? I'm not convinced it's not working as designed. One 16,000 BTU unit for a boat that size in Florida in the Summer just isn't going to cool the boat.

Adding a second unit, about the same size, might be the better solution. And of course going with a drop-in, all-in-one type would be the easiest.

 

[PhilPB]

Is that the only cooling unit in the boat? I'm not convinced it's not working as designed. One 16,000 BTU unit for a boat that size in Florida in the Summer just isn't going to cool the boat.

Adding a second unit, about the same size, might be the better solution. And of course going with a drop-in, all-in-one type would be the easiest.

I figure that I have about 1000 cubic feet of cabin space, It's a relatively small space. Running the current ac it takes a while to make it semi-comfortable as long as the sliding door stays shut.

 

[The Brockerts]

Does the unit call for cold?, You should hear a click and see the cold on the thermostat. If so, I would check both the capacitors(start and run). Easy to check on a meter. I've got 4 units and have over the last 3 years replaced one or both capacitors in each unit, even one of the new units. They just don't make capacitors like the old days.

The Brockerts

 

[Action]

I have had capacitors fail on my HVAC units on my home.
When that occurred, there was no cooling. Just air movement.

 

[PhilPB]

The compressor comes on and is running. With my limited knowledge I suspect there is not a capacitor issue. The unit just doesn't cool as well as I want and it is old. Granted the heat index is over 100°f

 

[Action]

Going a lil off topic, the predicted high today in the Valley of the Sun.
110f.
The duration of the week the high is predicted to be between 106 and 110 with lows between 75 and 78. Zero chance of rain and humidity levels under 25%.

The two weeks after the summer solstice are typically the hottest. This summer so far has been cooler than some years in the past.

 

[CharlieO.]

What is your output temperature? On hot days my unit only blows out about 20 degree cooler air than ambient.

 

[Turtle Blues]

Look at a dometic 16k btu turbo or similar, the entire unit should fit in the footprint of your existing evaporator / blower cabinet. Adding all the modernization, motor inside blower, airflow over exchanger coil, soft start and digital controller, it is money well spent. you will need to run your heavier condenser circuit and the cooling water to the new location.
At 34' 16k btu and a single unit is borderline for keeping the main salon cool during the day and then the state room at night. Do you have any means of diverting air from one to the other? Adjustable grills etc?

 

[Deckape]

Measure the temp of the air leaving the unit and then the air returning near the return . Best will be 20* + . If less , your unit is not large enough for the hot space or could be undercharged . Covering all windows , putting shade over forward deck and leaving back sliders close will help with heat/sun load . Anything you can do to lower heat load will help . You will need to get a tech to add freon as R-22 and it's replacements are not availble to owners . With the age of your unit might be best to invest in a new unit . Mermaid Air has a self install unit and are great in support .

 

[CaptTom]

Running the current ac it takes a while to make it semi-comfortable as long as the sliding door stays shut.

That's about what I'd expect in Florida this time of year. I'm only going by boats I've been on. Maybe someone with the same boat in a similar climate can chime in.

 

[Turtle Blues]

marine ac load calculator
https://www.marinaire.com/category-s/28.htm

 

[PhilPB]

Look at a dometic 16k btu turbo or similar, the entire unit should fit in the footprint of your existing evaporator / blower cabinet. Adding all the modernization, motor inside blower, airflow over exchanger coil, soft start and digital controller, it is money well spent. you will need to run your heavier condenser circuit and the cooling water to the new location.
At 34' 16k btu and a single unit is borderline for keeping the main salon cool during the day and then the state room at night. Do you have any means of diverting air from one to the other? Adjustable grills etc?

I'm going to take some measurements but I think one of those package units may fit where the evaporator is now.

In the current configuration there are vents in the salon and state room/v-berth. The state room gets nice and cool especially since adding Seagrass carpet to the sides which gave some insulation value. When I redid the salon I insulated the space between the cabin wall and then added 1/4" teak plywood which is also helping some.

 

[Turtle Blues]

That's what they are designed to do.
Being able to redirect air is a big energy saver. I find that I can do a lot during the day directing most of the cooling to the salon which has the major heat load and as other have said anything you can do to lessen it is worthwhile. I have a canvas cover for the front that goes over the sunscreen and that is huge. No wonder most sport-fishing boats have gone to solid fronts instead of glass.
Full disclosure from the department of redundancy department, I have installed 3 completely independent systems. Most days only 1 is in operation as it can be adjusted between the salon and rear cabin as desired.

 

[Action]

marine ac load calculator
https://www.marinaire.com/category-s/28.htm

Thanks for the link.

Regarding replacement system features, I prefer some of these features
A non-metal drip pan. (Even over stainless)
A sound cover. (I just want the cool, not the sound of cool.)
A reverse cycle - Heat pump. Winter in FLA may not need heat and ....
Lower starting amps and lower running amps

If it were me and a few hunded dollars was the difference between a base model and a model that was quieter, more efficient and may last longer, I am gonna write that bigger check. With the assumption I would be boating for at least another 5 years. But I am playing with your money!

In the Dometic choices, some Turbo choices are no longer available.
Here is a comparison of Turbo to Envirocomfort from 2019 & 2020.
https://citimarinestore.com/citiguide/dometic-turbo-unit-dtu-vs-envirocomfort-unit-ecd/
There are other comparisons too.
And for what it's worth the article is from a dealer in Miami.