You can do that but other concerns such as proper sub cooling temps remain at coils, compressor slugging, cold weather operation and others.
Since you have to generate heat to offset the cooling effects of dehumidification, your much better off using a central ducted dehumidifier..

I have one like this mounted in the attic connected with 14" ducts with an intake and exhaust on open second floor. Mines a desertaire, but same type.

http://www.aprilaire.com/index.php?znfAction=ProductsCat&category=dehumid

Here is a link that might be useful: Central dehumidifier

"In commercial and manufacturing situations, overcooling and reheating is done all the time as some of you know. "

At a large increase in operating costs and maintenance complexity.

Large commercial installations have a full time building engineer available to keep things running.

Can you really afford that?

"You can do that but other concerns such as proper sub cooling temps remain at coils, compressor slugging, cold weather operation and others. "

Would that be so hard to avoid with the correct electronic controls?

"At a large increase in operating costs and maintenance complexity."

Already covered, really. How would it be more expensive than a new, separate refrigeration system with both hot and cold coils in the air stream? Cost of operation would be extra gas and electricity on humid days rather than just electricity on a dedicated dehumidifier. We all know that gas is cheap right now.

The question is, what is so technically difficult about running both heat and cooling at the same time for short periods?

"Would that be so hard to avoid with the correct electronic controls? "

The typical controls do not measure or take into account the problems you will encounter.
Ever seen a residential system with a pressure sender?

"How would it be more expensive than a new, separate refrigeration system with both hot and cold coils in the air stream?"

Typical residential cooling systems are not designed to operate below about 50F outside temperature.

If liquid coolant returns to the compressor it can be instantly destroyed.
Liquids do not compress well, and if you are lucky all that happens is the compressor locks up, and then the electrical thermal overload shuts it down.
Many times they simply have mechanical failures of rods, seals, and motor shafts.

An often significant difference between these larger systems is the presence of an accumulator tank for liquid refrigerant, and a separate control loop to keep that tank filled.
Variable metering is then used to allow only the required amount of refrigerant into the evaporator based on humidity.
Temperature is also sensed to prevent inadvertent freeze up.

Industrial air systems are far more complicated than just cascading two separate systems together.

Thanks for looking.

"If liquid coolant returns to the compressor it can be instantly destroyed.â¨"
How are daisy-chained heating and cooling process going to cause liquid to return to the compressor?

"The typical controls do not measure or take into account the problems you will encounter. â¨Ever seen a residential system with a pressure sender?"

What problems? Why would I need a pressure sender?

"Typical residential cooling systems are not designed to operate below about 50F outside temperature."

Then it can't do what I want below 50F, or maybe 55 so shut it off/lock it out. Won't likely need dehumidification at that temp anyway because that is heating weather.

"An often significant ... freeze up.

Industrial air systems are far more complicated than just cascading two separate systems together."

I'd like to try again. Lets ignore the complexities of industrial and commercial HVAC systems which is irrelevant to the question. I can ask this in two ways.

Why can't I run a residential HVAC system, that is conventional beyond some minor control changes, with both the mechanical cooling and the gas furnace running at the same time? I obviously can not do that with a conventional thermostat because they won't heat and cool at the same time.

To make the question even simpler, why shouldn't I "hot wire" my furnace to run while the thermostat is in the cooling mode and the cooling part of the system is operating normally?

""If liquid coolant returns to the compressor it can be instantly destroyed.â¨"
How are daisy-chained heating and cooling process going to cause liquid to return to the compressor? "

If the entering air is not warm enough to evaporate the refrigerant in the evaporator you can 'slug' the compressor.

You can do whatever you want.

It is your money and your time.

It is NOT done the way you describe for the reasons given and plenty more.

But you are obviously better than all the HVAC engineers that create these systems.

Let us know how it works out after a compete set of seasons.

LOL!
@ brickeyee

ionized might be that deadly combination
of an engineer with a lot of curiosity.

the heater is physically in the wrong place.
you reheating the air after the cooling coil.
presently heaters are installed
before the cooling coils so they
don't rust out.

this makes my head hurt just to
think about it.

keep pondering ionized!

Brickeye, I know that there are a lot of people that know more about HVAC design than I do so I ask for help in understanding. Up to now, I have only seen hand-waving and no reasons why it can not be done. Why not explain why it can not or should not be done?

"If the entering air is not warm enough to evaporate the refrigerant in the evaporator you can 'slug' the compressor."

One reason that I can think of that would make it not practical with existing systems is that I think the air flows through the furnace first and then the cool coils. Although that would preclude slugging, it would make for very inefficient dehumidification.

If the system were turned around so the air were cooled first, it should work. Can the return air in a residence be too cool and cause slugging? If so, a simple control addition would prevent that by locking out the compressor if the temp a the return was below desired temperature.

I have been thinking about how to do this for a decade or more efficiently. I first saw that package units were becoming available with a (reheat panel) this would be a coil that was downstream in the air flow right before it went back into the living space. I thought when I built a new home with a duel fuel system of gas and heat pump, why could I not use a valve to send hot refrigerant to a downstream panel so I could temper the air and still dehumidify the home with the existing equipment. Why not the valves are available to do just this and HVAC being a hobby made me dangerous because I think too much. Well anyway I gave the X wife that home and have been thinking about building another so I have been dabbling on the internet here and there for my mechanicals along with other building ideas. What I found about a year ago is that Lennox is doing just what I imagined and I may seriously look into this type of equipment. http://www.lennox.com/products/indoor-air-quality/humidity-control/hd and this one too http://www.lennoxcommercial.com/pdfs/brochures/Lennox_Humiditrol_brochure.pdf

ionized, yes I understand a tight home as well as plant, I have built both. I always use an HRV for air exchange and insulate all concrete surfaces with one inch of blue or pink board. Long story, learned it from DuPont about 1988. Anyway the problem in Ohio is not excessive heat and humidity but there are many days when you AC will meet it's demand and yet the home will be humid because the outside temperature may be in the high 60's low 70's. If sized right the AC will do most of the work in the summer, we just need a seasonal changeover option. Buying another machine like a Honeywell dehumidifier is over $1000.00 for a little more that 65 pints a day. As for insulation there are a lot of good posts in the thread about (spray foam). [https://www.houzz.com/magazine/insulation-basics-what-to-know-about-spray-foam-stsetivw-vs~28163329[(https://www.houzz.com/magazine/insulation-basics-what-to-know-about-spray-foam-stsetivw-vs~28163329)

How about just adding electric reheat? some thermostats already have auxiliar outputs that can be set to dehumidification to make both the cooling and reheat contacts. why wouldn’t this work? The main problem would be sizing the electric heating coil properly.

HU, yes you can but the idea of reheat is to recapture the waste heat and funnel the refrigerant back to be used for that purpose. Like a home dehumidifier you have an evaporator removing the water through the cooling process and then the air passes over its own internal condenser to "reheat" the air. The air will come out a little warmer because the process is not 100% efficient.

But just as way of dehumidification, from all of the proposed solutions, it seems like a adding an electric reheat would be the most cost effective way. All it would take is adding the electric reheat coils and wire the thermostat or even a separate humidistat for controls. Instead of adding a hole other unit and duct work with additional filters grills or dampers.

HH, you do not need to add anything, the reheat concept comes from the concept of using a heat pump. When you use a heat pump to heat and cool a building you are reversing the refrigerant flow from one coil to another. Rather than purchasing another piece of equipment you are using your heat pump and only one extra coil panel, the reheat panel. In this manor you cool the air like you were air conditioning but because the interior air temperature is below the requested air temperature the hot liquid refrigerant is directed to the reheat panel the keep or bring the interior air temperature up or equal to the thermostat temperature setting. If the room is cooler than the thermostat setting the hot liquid refrigerant will be directed outside into the outside condenser. It is very efficient way to utilize the HVAC equipment to dehumidify in climates where high humidity and cooler temperatures exist, like here on Ohio, USA.

This thread popped up on me but it is a good one. For 20 years I wanted to do something like this, maybe harvesting the heat off the condenser outside and reheat the downstream air after an AC dehumidification. In Ohio we have days like today where it is 70 F outside with 91% humidity and the AC is not running. I know of one system on the market now by Lennox that uses a heat pump and a reheat panel, I would like to see more before I do it. If anyone knows of more please post, thanks. https://www.lennox.com/products/indoor-air-quality/humidity-control/hd