2 Split House (Evaporating) Units on 1 Compressor of the Size of 1 Match

I don't know any other way then solenoid valves to isolate unused evap coil.....

Was just thinking:

The active one gets rid of the cool and will work, because you sent air through it with the fan.

The other one will get to cool freon too, but has no way to get rid of it and not cool the room.

Eventually, maybe it could freeze and clog, however? Is that a problem?

Once we start that one up again, it will work after a while? Valves of course is one, but it complicates the switching sequence and adds more wires.

And does it need valves in both the pressure and suction line?

Automatically with 2 same units they are calculated for the same job and don't care which compressor feeds them.

The lines are also about the same length. Problem is that the fan is speed controlled, however I can get the power on the flap switch. (opens when switched on).

I have also the impression that perhaps the evaporator has a high pressure valve

(firing valve) instead of a capillary tube. Maybe this can hold up the liquid too, while it is sent to the other one? (how else do they get different settings - the compressor runs always at the same speed with my units)

no

Hi Fredski,

Your answer is short today. Can you elaborate:

1. No to what question?

2. What can possibly or surely will happen?

They do it in multi split systems probably.

Thanks

Fredski, Thank you

What about just a switching valve only in the pressure line, so that only one gets the high pressure and just a T in the return?

The valve could be activated with the house unit. (kind of bi- stable flip flop)

If I fill enough refrigerant after vacuuming the lines, he environment should work, because the not working in house unit also send nothing throught the evapoartor anymore.

Unless? I am not a specialist in this matter. Just don't want to put my walls full of

not used condenser units. The central A/C time will be past soon because too expensive to cool the whole house. Remember before people were heating also only the rooms they occupied?

Central heating came because diesel was dirt cheap, less than $0.20 per gallon. Now $4.00 per gallon. It all depends on what you want to spend your money.

I have over 30 years experience in commercial AC, I'm a licensed contractor......just trust me on this one.

My understanding is that some/many/most of the new, high-efficiency units have a solenoid built into the expansion valve which prevents the system from equalizing when it shuts down. If your units have this, you should be set in that department. My concern would be with lubrication - you want to make sure the lube oil doesn't have any place to fall out and not be returned to the compressor.

All piping is downstream towards the compressor unit. The extension is supposed to go up to the second floor.

traps?????

???

the refrigerant needs to maintain a specific velocity to hold the oil in suspension or the oil falls out and collects in low points. if the oil isn't all returned to the compressor it will fry. this thing is just such a bad idea!

Where do you see a drop in velocity ? ....all you're doing is switching coils with the solenoid valves....I assume the coils are the same size and only one at a time is being used....should be no problem

he said they'd be on 2 different floors of the house, sorry but trying to hammer the square peg into a round hole always makes a mess and this "after engineering" of marrying 2 systems together that were never intended to work this way is just a poor idea. hammer away I'm done with this thread for now

just get a thermostically controlled duct diverter which is build like a Y and can divert cold air to either of two main supply lines and use your one compressor and air handler unit.

http://www.hvaccomfort.com/sys2/sys2.htm

Whoa, major ductwork, no no....

not really if the two existing air handlers are the same size, then you only have to run a supply line from the diverter to the main trunk line of the system you removed the air handler from.

good thinking..but, the idea of air conditioning is less about delivering cool air, its more about moving heat from an area you don't want that heat in to a place that's less objectionable. he needs to remove heat not add colder air to a hot room. the whole idea is filled with problems, oil return, leakage of shut-off valves,superheat/charging, airflow and fan speedcontrol, etc, BAD IDEA get a system designed for the application

I did some research on the Sanyo website now. They sell those systems with a choice of compressors.

The in house units are the same as I have. Only the compressor units are different:

Have multiple outlets and perhaps a special manifold.

They have a inverter built in. Perhaps to adapt the speed and pressure the way you describe.(what makes good sense) I will call them on Monday and promise to come back with the results ASAP. Thank you all for the help. D.

I had my hearing checked the other day - said I am not hard of hearing, I am hard of listening. A lot of people seem to have that problem, too. I don't do much A/C, mostly small to medium refrig and freez. Look like a good money saving idea that is going to cost way more than it will save. I'm with you on this one. Just put the 2 systems in as designed and turn off the one you are not using. Anything else is just going to lead from one problem to another, to another ... -- JHF P.S. GA on your earlier comment!

Hi,

This is what I do not have: Air handler. And this is what I don't want to have: ducts.

The floor is 8" concrete, no plenums.

My house is full of ducts in which a army can hide. Have thought of filling big plastic bags with cold air downstairs and bringing them to the bedroom. But when can I sleep then? I'll check the link. Thanks.D.

This is what I have now. Only monster ducts, slow speed air, with controlled damper and shut-offs.

Good when the apartments are rented out, but... not for me alone.

I like to switch between the 2 systems. Central air of poor man's air.

The idle evaporator (air unit) will have small amounts of refrigerant and oil hung up in it, even if equipped with a liquid solenoid valve for pump-down type operation. If the evaporators are above the compressor/condenser, this is not likely to be a big problem. You might need slightly greater charges of refrigerant and oil.

Dvmdsc,

I believe such units have been around for about 15+ years--one compressor and 2-4 independent evaporator units (without ducts but with drip pans and condensate drains. My mind says Panasonic, but I don't remember the brand. Memory says the cost was fairly steep. Therefore, your concept should work. Of course, the attention to detail is a must and Fredski has some very valid points regarding trapping oil, etc.

--JMM

FYeyes,

This is the only split I have in mind.

I needed a lot of persuasive power to convince my wife that this was a good place to install the condenser unit. For the next one, who will service the room(s) above, I have only the balcony floor that has no hiding space.

Sanyo hasn't responded yet.

Here the situation pics:

In the walls the concrete is recessed by 2 to 4 inches, thus

very difficult to attach heavy things.

The floor are 8" 3000 psi concrete with negative and positive

3/4" rebar. (concrete structure goes up higher)

pictures!! great I feel for anyone in the future that needs to work on that hanging condenser! so why cant the outdoor unit be located on the roof, ground, or side of the bldg? what length run of lines are we talking about?

Dvmdsc

Looks to me like a very well-done very efficient home. I read into your words that the walls are ICF construction, with the upper story cantilevered out on a structural slab. I applaud your work.

--JMM

For the Bahamas, being known as a touristic destination and no hotbed for .......

This is the solution, chosen and implemented. Thanks to Fredski

Thank you all for your input.