Through-The-Wall Air Conditioner That Can Use An External Thermostat

[apostolakisl]

Lou,
 
Question:  Unrelated to OP.
 
I have a very old (~15-20 years old) Gibson dehumidifier in the basement which I use during the summer months here in the midwest.
 
For many years now I have had to "adjust" the control such that the coils wouldn't freeze up.  I did replace the only controller on the device about 3 years ago.  Doesn't the dehumidifier have some checks and balances mechanism such that it prevents the coils from icing up?  (like some sort of shut off?).
 
Is there any way to do diagnostics on the switch or is there some adjustment such that the coils do not freeze up?
 
I have the old controller and it appears to be a "Ranco" with a two HV terminals switch and metal lever on it which can be adjusted. 
 
That said it is acting like I didn't change the controller; freezing up the coils if I set it just a notch too high.
 
Any suggestions relating to diagnostics of the controller such that I can fix this Gibson Dehumidifier?
 
Basement temperature is below 70 and above 60.  The dehumidifier is sitting next to the furnace elevated some 10 inches or so and configured such that it drains to a drain nearby.

 
 
The coils ice up most likely because you have a micro leak.  When the freon. . er I mean refrigerant level drops, the compressor pulls a vacuum over the evaporator coil which drops the boiling temp of the refrigerant to below freezing and thus the evaporator coil freezes.  A dehumidifier's coil should never drop below freezing in a 65 degree room, so this is almost certainly the problem.
 
To fix this you need to add more refrigerant.  As old as it is there is a chance that it actually has Freon in it.  Which means you can't get any more of it (like R-12).  Look at the specs on the unit and it should say.  It should also list the charge in pounds (ounces probably on something this small)
 
If it has the old stuff, you can't fix it . .. at least not at a reasonable price.  R-12 is like a $2,000 a can if you can even find it.
 
It might have r-410a.  This you can fix. . . but only with the right tools.  And if you don't have the tools, you will probably spend more paying someone else to do it than a new one costs.
 
I doubt you have the tools, but the basic steps just as an fyi are as follows:
 
First try to find the leak.  This may be hard, you need a "sniffer".  These can detect pretty small leaks.  Once you find the leak, you'll need to decide if it is in a location that can be sealed or if the whole part needs to be replaced.  Depending on what needs to be done and the cost, you may quit right now and buy a new one.  If you can't find the leak, it may be that you just recharge it.  It may take another 10 years before it leaks enough to freeze up.
 
Usually these things do not have a fill valve (Schrader valve).  If yours does, you could potentially just top it off and forget about the micro-leak.  But the odds of that are like 1 in a million on a portable dehumidifier.  
 
The compressor will have a stubbed off copper pipe that is welded shut.  This is where the factory filled it.  You would need to first take the charge off (which would require putting a side stab into the pipe with a valve if you were going to try to recover it. . . it is the law, but you can do what you will.  Then you cut off the end of the copper fill tube and weld in a schrader valve with silver and an oxy-acetlyene torch.. . or MAP gas works too.  Then you fix your leak. . . perhaps just by brazing a little silver over the spot.  Then you vacuum down the unit, then you refill it measuring out the refrigerant by weight.  If you didn't blow out the oil inside the unit then you don't need to add any more.  Also, once you open a system in the field, you should consider a drier.
 
So that is the basic jist of it.

 

[pete_c]

Thanks Lou.
 
Yup; if I tweak it just right the coils will get cold but not freeze up.  Turning the controller up a notch will always freeze the coils.  I've only taken it apart once maybe in 15-20 something years.  Will take it to the garage compressor and blow out the coils and clean out the sponge like filter in the front.
 
If that doesn't do anything will just replace it .  Just looking at the manual; looks to be older than 20 years; purchased it maybe in the 90's.
 
 

 

[apostolakisl]

Thanks Lou.
 
Yup; if I tweak it just right the coils will get cold but not freeze up.  Turning the controller up a notch will always freeze the coils.  I've only taken it apart once maybe in 15-20 something years.  Will take it to the garage compressor and blow out the coils and clean out the sponge like filter in the front.
 
If that doesn't do anything will just replace it .  Just looking at the manual; looks to be older than 20 years; purchased it maybe in the 90's.

 
The dials on those things work by cycling the compressor.  By turning it to do less dehumidifying  the compressor is spending less time on, which allows the freezing that just started to occur to thaw. But as I mentioned before, a dehumidifier compressor should be able to run 100% of the time and not freeze up because the evaporator coil is never supposed to drop below freezing.
 
If the evaporator coil has no air going over it, it can freeze up.  But with a system like a dehumidifier where the same air goes over the condenser coil then directly to the evaporator coil, it is unlikely to be the reason for a freeze. Since it is the same air flow, for both, if one stops, the other stops.  When no air is going over either coil, the entire system gets hotter.

 

[pete_c]

Thank-you Lou.
 
Then its time for another dehumidifier.
 
Yeah the basement is tight relating to total air flow but during the summer months when I have the HVAC on it gets a bit more humid. 
 
That and due to WAF the temps are kept at 68 F for the other two floors in the house.  Wondering now if an open return would even out the flow a bit in the basement.

 

[Del91574]

I'm curious, exactly how many HVAC systems have you installed?  Repaired any?  Have you ever replaced a compressor?  Have you ever installed any refrigeration system?  Ever even opened a system?  Do you have any HVAC licenses?  Do you own a set of gauges?  Vacuum pump?  Acetylene torch?  It may be a hobby for me but at least I have done it, for you I speculate it is just a musing.  But you seem to be implying that this is your profession since you work for a company that also does this.  Or perhaps you are the first professional alarm system installer I have met who is also a professional hvac installer/designer.  I suppose I could go to work for GE in their finance division and claim expertise in jet engine design.  Maybe you have done some of this stuff, but I don't see where that puts your level of authority above mine.  It does appear that your understanding of the evaporation/condensation cycle is lacking, and that really is the most fundamental concept in all of HVAC.
 
So yeah it is a hobby, but one I don't take lightly.  I do the research and have a licensed friend who provides me advice and materials.  I have to this point in my life installed a split system wine room from scratch. I did 100% of the engineering and construction, all of it, from the vapor barrier, insulation, line sets, compressor, evaporator, etc.  I even built the raised panel arch top mahogany door to the room.  My math was perfect, the wine room compressor runs roughly 50% of the time, cycles the temp at 57-59, and holds the humidity at 52% plus.minus 2.  I did a volunteer replacement of an HVAC compressor for a non-profit I work with which is now in its 10th year post repair and going strong.  I even recycled the R-22 just to be nice to mother nature.  I replaced the compressor on a small fridge, and 2 cars back in the day.  I did all the engineering on my office HVAC and subbed out the actual installation to a free-lance guy.  I even fixed the glycol system at my friend's restaurant when it went out one weekend and the beer got warm.  I learn the physics, not just the "how to hook it ups".  But I learn that to.  And I have fun doing it.
 
But back to the hotel room HVAC. .. that is what this is all about.
Check it out.
 
http://cgproducts.johnsoncontrols.com/MET_PDF/1201430.pdf
 
Thermostats for hotel rooms.  Appears to be what I described.  I've been in at least 100 hotels with this style of thermostat with numerous make/model.  Never been in a hotel with a slider, have you?

Lou,
 
I'm in the building efficency industry, specifically the controls side of the business and my specialty is fire and security. You read into that what you choose to. I deal with building engineering functionality, life safety and security as my trade. I don't find the need to get into my licenses, certifications and other qualifications at this point, or what tools I take out of the truck to work with.  I have more than enough to work legally within my state and others, both as a contractor and a journeyman, not to mention as an OEM in other states (supercedes licensing). I install, service and do engineering on systems that I work on and with. I'll let you read the next paragraph and you can digest what is said there.
 
It's very amusing that you chose to put a link of my employer's hardware as your example (and from 2006, to boot, from someone that was complaining about an article I linked to) as specific hardware that you've stated as being in or similar to what is installed at the 100's of hotels you've stayed in. Hopefully I understand how the hardware works, how it is connected, what it is connected to, and then the BAS it's supposed to be attached to, then I might have a slight clue of what's going on and what is involved with basic system architecture, let alone extended system architecture. 
 
BTW, the unit you are citing as a thermostat is no different than a slider unit, the BAS allows (among other things) a basic override based on occupancy as determined by other factors tied to the BAS that either allow or deny the host controller from actually controlling the package unit within either a predefined operating range or even at all. The unit is not direct wired back to the package unit for it to control, it gets wired to a DSC that is then in turn, wired via I/O and then programmed based on other factors that then allow or deny control of the package unit, or in a non-compartmentalized installation, control the VAV's and reheat for the room(s)....but then the argument is going to be that no BAS or head end exists at the hotels you've stayed at with the specific unit(s) you're citing, but then again, the hardware can be standalone and preprogrammed.
 
Irregardless of the make/model that is installed, I doubt many hotels are really going to consciously give carte blanche to their guests for HVAC control when energy usage cuts directly into their bottom line and is one of their highest expenditures as a line item....unless you're talking about the hotel/motels that have glorified window shakers installed with remote t-stats, but that's an entirely different conversation altogether.
 
 
 
 
.

 

[tmbrown97]

I was figuring either Honeywell or JCI...  Now we know.  I can't tell you how many JCI properties I've been in...
 
I stayed at a Doubletree last week in Phoenix and that thermostat seemed like it'd let me do whatever I wanted to the room and was very responsive - and when I requested 69°, it promptly obliged.  There were no "window shakers" involved - just an easy to use traditional-feeling thermostat on the wall... for whatever that's worth.

 

[Del91574]

Work,
 
I didn't bother to get into where I worked, it's irrelevant besides basic facts of knowing the systems, hardware, integration and automation in a very intimate manner.
 
Honeywell is essentially out of the security/FA business....they dabble but only as a necessity. That leaves Simplex/Tyco (ex-ADT), Siemens, and Chubb/UTC as the big players in the industry, however none are involved heavily in the BE/controls business or large scale integration....it's the cold, hard facts.
 
I'm also not sure how many people really know about how construction projects get bid and the design specifications that come with those sets of prints....it's not like building a small office building or a strip mall where you can say you're going to install a X ton AH unit and X T-stats, here's the calculations for them, pick the hardware that fits the budget and design criteria; there's design and engineering and many times, part of the spec calls for very specific hardware and software or a specific vendor as part of the engineering.
 
In your specific case/experience, if the programming and integration is done correctly, the end result is going to be seamless and invisible to the end user, they're never going to know there's a back end BAS that is involved and oversees the entire property, but in reality, the energy savings that are implemented are huge. Toss wireless and bluetooth on the equation, it's even more seamless for the end user and client that is installing the system.
 
Here's a favorite piece for DSM's in these sorts of applications http://www.grisk.com/specialty/concealed_hinged_door_positioning_switch.html.....they keep a lot of the public folk from messing with the BAS hardware.

 

[pete_c]

Lou,
 
Thank you for your insight relating to my dehumidifier.
 
Took apart the Gibson dehumidifier.  Used the compressor to clear out the coils a bit.  They were not really dusty.  Put it back together.  I did notice a bit of oil on one side of the compressor.  It is sealed with no means to recharge it.  I then plugged it in and turned it on about halfway such that it would kick on.  It ran about 25 minutes and started to ice over a bit then shut itself off.  Maybe I can get a bit more life out of it.  I am guessing though that the new ones are much more efficient.

 

[apostolakisl]

Lou,
 
I'm in the building efficency industry, specifically the controls side of the business and my specialty is fire and security. 
 
 
 
 
.

 
Great, so I'll take that as a "no", you don't have any hvac any of the various hvac/epa licenses that you would need to actually do hvac work.

 

[apostolakisl]

Lou,
 
Thank you for your insight relating to my dehumidifier.
 
Took apart the Gibson dehumidifier.  Used the compressor to clear out the coils a bit.  They were not really dusty.  Put it back together.  I did notice a bit of oil on one side of the compressor.  It is sealed with no means to recharge it.  I then plugged it in and turned it on about halfway such that it would kick on.  It ran about 25 minutes and started to ice over a bit then shut itself off.  Maybe I can get a bit more life out of it.  I am guessing though that the new ones are much more efficient.

 
 
Yes, I am sure you are right to assume that oil is leakage from the sealed system.  It is fixable if you can find someone with the tools and if it uses a non-discontinued refrigerant.  But unless you have a friend with the tools, a pro-repair place will probably charge darn near what it costs to just buy a new one.
 
Depending on how slow the leak is, you might be able to get a little more use out of it by cycling it off long enough for ice to melt.  It tends to be though that leaks start slow and get faster as time goes by, so it sort of dies at an exponential pace.  Soon enough you won't have the freeze problem, however, because it won't do anything. 

 

[Del91574]

Great, so I'll take that as a "no", you don't have any hvac any of the various hvac/epa licenses that you would need to actually do hvac work.

I could send off a nice spreadsheet with certifications and licenses in addition to other qualifications if that would make you happy.  Would you like the NICET, LEED and OSHA certifications on there also? Let me know which ones you're going to not consider as valid, so that way I can keep the list conscise for your consideration.
 
As I stated prior, I do not see the need to get into the granular details as far as employer or certifications, I have more than enough to be legal in my state and surrounding states, as well as those with reciprocity across the country.
 
I stated where my specialty is and what systems I'm primarily working with most often. There's a difference between the dirty work, grunt work and the work I do most often....and it's not because of qualifications or licensing.

 

[apostolakisl]

Lou,
 
It's very amusing that you chose to put a link of my employer's hardware as your example (and from 2006, to boot, from someone that was complaining about an article I linked to) as specific hardware that you've stated as being in or similar to what is installed at the 100's of hotels you've stayed in. Hopefully I understand how the hardware works, how it is connected, what it is connected to, and then the BAS it's supposed to be attached to, then I might have a slight clue of what's going on and what is involved with basic system architecture, let alone extended system architecture. 

It is rather amusing Dell.  That thermostat is made by "your" company and you where quite adamant that I was full of hogwash when I described that very thing.  I guess they left you out of the design and construction of all of the hotels you have built, they just let you design the skyscrapers.
 
Furthermore,  those don't work like sliders.  Sliders adjust from a central set point up or down.  These don't do that at all.  They can have a max/min set by the building engineer and they can be set remotely by the engineer, but they up/down arrow sets a temperature, not an offset to the central control.
 

I could send off a nice spreadsheet with certifications and licenses in addition to other qualifications if that would make you happy.  Would you like the NICET, LEED and OSHA certifications on there also? Let me know which ones you're going to not consider as valid, so that way I can keep the list conscise for your consideration.
 
As I stated prior, I do not see the need to get into the granular details as far as employer or certifications, I have more than enough to be legal in my state and surrounding states, as well as those with reciprocity across the country.
 
I stated where my specialty is and what systems I'm primarily working with most often. There's a difference between the dirty work, grunt work and the work I do most often....and it's not because of qualifications or licensing.

 
Help me out here, which one of those is a license to buy/install HVAC equipment or refrigerant?  Maybe one of those comes with an engineering stamp for the HVAC page of the blueprints?  You know, the stamp that the inspector requires?

 

[Del91574]

Lou,
 
What you believe and described is not the host system and how it functions, so more power to you because you tinker and do X and Y...own a set of tools and have performed some aspect of the job
 
I carry licenses as a journeyman and contractor for multiple trades as a part of my employment. I could perform the dirty work that you deemed as valuable legally and qualifies one to know all about systems that are part of my core business, however as a specialist and technician, I do not need to do such. I have other contractors that perform that part of the job typically and my part is to make it work. I don't feel compelled to educate you on how a system is contracted and installed and what portion of the install is each trade's responsibility....
 
Give me an email address and I'll provide the spreadsheet with licenses and certifications for you to review at your leisure. I've got nothing to hide and have the qualifications from multiple independent examining boards to back up what I say, do you?

 

[tmbrown97]

The funny thing is, if what you say makes sense, nobody needs to dig into the licenses and qualifications.  Skip all that and talk about facts about how systems work and if you're right, nobody will call BS (or if they do you should be able to dig up facts that back your stance).

 

[Del91574]

As I said, the systems are not installed nor do they function as what was described.
 
Sending chilled process or heated loop is one thing, stating that refrigerant lines are installed and run back to compressors is definately not how it's done unless you're working with small package units, which is far from economical unless you have glorified window shakers or a retrofit.