1 Condenser & 2 Air Handlers? Possible?

JayPoorJay

Hello all. Don't yell at me, I just thought I needed to ask, as it COULD make my life a whole lot easier.

Also, I'm a DIY dude. Have to be as I ain't got a lot of money. In that, perfection to an EXTREME isn't the goal. Something that works and works good (as good as I can get it) is the goal. 

I've read about this a little (been trying) and what I saw suggested here and there is that there are some controls that could be put into a system that would allow one condenser to supply two separate air handlers? Is that a thing?

I have a balloon framed old craftsman style house in Staten Island. 2 floors with a large walkable attic, and basement. Over the winter I would like to install (DIY) an air handler in the basement and one in the attic, lay out duct work, and feed them BOTH with one 3.5 ton condenser/compressor on the ground. Is that possible?

I figure if I placed a 1.5 handler in the attic and one in the basement it could/would make life so much easier when it comes to running duct work. 

Please advise.
I am super open to ideas.
Even if it means telling me I'm a big dummy 😂

Hot_water_fan

Yup! This is called a multi-split. Plenty of brands offer these. For DIY, look to Mr Cool.

pecmsg

Hot_water_fan said:

Yup! This is called a multi-split. Plenty of brands offer these. For DIY, look to Mr Cool.

And buy a extra system so you have the spare parts!

jumper

If both evaps are well above compressor than oil returns to where it is needed. Otherwise....

pecmsg

jumper said:

If both evaps are well above compressor than oil returns to where it is needed. Otherwise....

Probably sized
Properly installed
YES

JUGHNE

Are you considering a standard fixed speed compressor/condenser?

JayPoorJay

Thanks to all of y'all... Ok, so I'll just take that (all the responses) as a yes... except the spare parts comment.

So, one evaporator will be above the condenser/compressor and one just below. Where will that leave me? Q: I've watched ppl (YouTube) install compressors in basements where the handler/evaporator was way/well below the compressor. Is there a difference when there are or just because there are 2 evaporators? I thought that the oils kinda vaporized and were "carried" by the gas...? Is this wrong?

I'm not sure I know the difference between a fix speed compressor and what other... I guess, as the plan unfolds and while prices are a little lower (season) I'll do what's best in that regard.

Multi Split!? I need to know more about that AND, who the heck is Mr Cool. I wanna meet him. 

JayPoorJay

I'm thinking 2 stage/speed might be the right thing. I'm not in Florida,,, we are enviro conscious people (and bill conscious too) but we don't use AC all year round and we don't use it unless it gets uncomfortably hot.

Also, I understand variable systems are quite complicated on installation, maintenance and for repairs and as a do it yourself kinda guy, simple-er is better-er...

I swear, I will be priming (begging) y'all for the info I'm going to be needing, the things I'm going to be buying and the WAY this thing gets set up. Beware 🤣

What about numbers of thermostats? 

HVACNUT

Sounds like you're looking for ducted mini splits.
You can also do a combination of ducted and ductless if needed.
Do your research as some have extreme limits on allowable ductwork, while others offer better velocity and more trunk and branch ducts.
Service access is key as well. 
No comment on Mr
Cool.

pecmsg

HVACNUT said:

Sounds like you're looking for ducted mini splits.
You can also do a combination of ducted and ductless if needed.
Do your research as some have extreme limits on allowable ductwork, while others offer better velocity and more trunk and branch ducts.
Service access is key as well. 
No comment on Mr
Cool.

I’ll comment
1step lower than NEST!

Hot_water_fan

Also, I understand variable systems are quite complicated on installation, maintenance and for repairs and as a do it yourself kinda guy, simple-er is better-er...

eh, not really more complicated. Maintenance and installation will not be different at all. Repairs might be, but if something is beyond your capabilities, if it’s a little beyond or a lot beyond it doesn’t matter a whole lot. Cheaper for fixed speed though. 

I'm thinking 2 stage/speed might be the right thing. I'm not in Florida,,, we are enviro conscious people (and bill conscious too) but we don't use AC all year round and we don't use it unless it gets uncomfortably hot.

In terms of environmentally conscious, just make sure the system can both heat and cool. It’ll cost about the same to install and delivers huge environmental bang for your buck. 

EdTheHeaterMan

JayPoorJay said:

Hello all. Don't yell at me, I just thought I needed to ask, as it COULD make my life a whole lot easier.

Also, I'm a DIY dude. Have to be as I ain't got a lot of money. In that, perfection to an EXTREME isn't the goal. Something that works and works good (as good as I can get it) is the goal. 

I've read about this a little (been trying) and what I saw suggested here and there is that there are some controls that could be put into a system that would allow one condenser to supply two separate air handlers? Is that a thing?

I have a balloon framed old craftsman style house in Staten Island. 2 floors with a large walkable attic, and basement. Over the winter I would like to install (DIY) an air handler in the basement and one in the attic, lay out duct work, and feed them BOTH with one 3.5 ton condenser/compressor on the ground. Is that possible?

I figure if I placed a 1.5 handler in the attic and one in the basement it could/would make life so much easier when it comes to running duct work. 

Please advise.
I am super open to ideas.
Even if it means telling me I'm a big dummy 😂

Many will not believe this, but I did just that. It turns out that the home I lived in was not equipped with central air conditioning. It required 3 ton of AC and I had a crawl space and an attic to work with. I also had a 3 ton Whirlpool condensing unit left over from a Floor Plan deal I made with RE Michel. (How long ago was that?)

I purchased 2 First Company air handlers with Aqua Coils and R-22 coils. One was 2 ton the other was 1.5 ton. I installed two refrigerant rated solenoid valves at the outlet (high pressure line) of the condensing unit that were operated by the zone thermostat in order to separate the refrigerant to the unused air handler if only one zone called for cooling. It was not perfect because of the laws of physics, when the first and second floor called for cooling the weight of the refrigerant would cause more of the flow to the refrigerant to go to the bottom air handler. Only after the first floor was satisfied would the second floor get more liquid line pressure to cause the second floor coil to actually freeze up. I used a clip on coil temperature to stop the compressor if the coil started to freeze up. They were orifice type metering devices on the First Company AC coils.

This worked adequately for about 8 to 10 years before the condensing unit failed. At that time I replaced the Whirlpool with two separate outdoor units and the summer electric bill dropped noticeably.

So to answer your question, Yes it can be done. Would I do it today? Probably not with the variable speed condensers that are available. You may even find a mini split system that is designed to have multiple indoor units connected to them by design. Some of the indoor units can be ducted. Look into that before you try to reinvent the wheel (like I did so many years ago).

I have installed this for a customer, two indoor units that can handle a small amount of duct work attached to a single outdoor unit. Works quite well, but the ductwork must be kept to a minimum.
https://www.ecomfort.com/Fujitsu-F2L36D12240000/p85046.html

JayPoorJay

Thank you Ed, HCAVNUT, HWF and all...

I do love forums. I have several old jaguars and a Porsche 928, then I work on repairing old hand wound watches, then a bunch of other life's projects, and I would be lost in many many cases without forums. Yall are awesome! Forums are!

So, this is getting dense. I'd better add a couple of things.

No heat with this. We have a new boiler installed by PO that heats radiators and it works well. Gas fed. Then,

It's a beautiful old house and my wife would punch me in the snozzle for even suggesting mounting something on the exterior. Or, hangimg appliances off the walls inside... It might be possible to get her to allow me mount a 1.5 or 2 ton compressor outside behind a dormer on the 3rd floor. I even think I can place it so servicing it wouldn't be toooo painful but I wouldn't be able to get away with much more than that. In that, I would be moving towards two compressors, two handlers. If the idea of one compressor two handlers exhausts itself, I'll come back to that i guess.

I think mini splits are out of the question for us. unless a good argument can be made for going that way....?

I kind of urgently want to know/hear more about the idea that both evaporators MUST be over the condensers for oil supply. That would end this. It's a must that one be below and the other WAY above. Basement to attic with condenser on the ground. Please say more.

So yes. I've heard of solenoids closing off the refrigerant to the unused evap when not in use. I need to know more about that... I don't know anything about the sensor that would sense ice and shut things down.

Then there is the stage 1 or 2, or variable compressors and what would be best. Then, 1 thermostat or 2... Then, one big zone (whole house) or two zones???

Lots to begin zeroing in on here and I will take ALL the help I can get.
Deep bow,,, many thanks.

I'm all ears.
How can I make this work and not break the bank?

I

Hot_water_fan

I think mini splits are out of the question for us. unless a good argument can be made for going that way....?

“Minisplits” is a term that just causes confusion. They can be either ductless (the things hanging on walls) or ducted (your typical central system) or a combination of both. So rule out ductless, but keep ducted. They can heat too, so may as well install it. It costs the same, so even if you never use it, no downside. 

Two air handlers = two zones = two thermostats. That’s an easy one

JayPoorJay

Hot_water_fan said:

I think mini splits are out of the question for us. unless a good argument can be made for going that way....?

“Minisplits” is a term that just causes confusion. They can be either ductless (the things hanging on walls) or ducted (your typical central system). So rule out ductless, but keep ducted. 

Two air handlers = two zones = two thermostats. That’s an easy one

I guess for me, at this stage, unless someone can completely help me invision how it would be done, in my house, with what I have and how these new AC designs would work (and maybe it's just a matter of what I am more familiar with),,, I am far far more comfortable with the idea of the more traditional big ol box (compressor/condenser) sitting on the ground outside, and an air handler/evaporator inside moving the air around.

I just can't (or am having a hard time) wrap my head around the split idea and how it works. I have 5 rooms on the second floor, 4 small, medium and large rooms on the first and don't want to hang a bunch of things off the house.

I have awesome amounts of room in the basement and attic,,, if I could just get a better sense of what is possible with what I have to work with...

Hot_water_fan

I am far far more comfortable with the idea of the more traditional big ol box (compressor/condenser) sitting on the ground outside, and an air handler/evaporator inside moving the air around. 

This is what a ducted minisplit is! They can be connected to 1 air handler or multiple depending on the model. I agree 100%, you’ll want ductwork based on what I’m hearing.

jumper

If basement evap is below condensing unit you need to pipe suction pipe in such a way so that oil will return to machine. DuckDuck "ladder piping". And you have to make sure that basement runs lots of time when attic is off. Otherwise oil will end up in that low evap.

Those modern VRF units are computer controlled to return oil to machine.

JayPoorJay

Thanks Jumper, thanks to All of y'all...

I've been thinking on this since getting replies from folks and I'm just going to lay out what I've been thinking.

This is the season to buy. Fall time here in the northeast so time is of the essence,,, as equipment is cheap-er, now. 

Hopefully, I can try and get a BETTER understanding of oil/lube flow and potential problems I'll have with 2 handlers on one compressor. It sounds like that is the most important piece here. Is there a electric PUMP that will solve a lubrication flow issue! At a low point or reservoir in the system? 

Then, being able to control refrigerant flow to two air handlers as demand changes floor to floor. One, or two thermostats? One or TWO stage compressor? I need to start zeroing in on my direction here.... 

To reiterate. I have a large walkable attic. A large walkable basement. I need to cool 2 floors, 1st and 2nd. This is a large colonial house made in the 20s.

My idea so far is an air handler in the basement. A handler in the attic. Refrigerant supplied by a compressor/condenser on the ground outside. When placed, the compressor will be just a bit (a bit more than a foot) above the level basement evaporator coil. The attic evaporator coil on the other hand, about 20 feet up. 

Once I have a PLAN and what is possible (or impossible) I can begin to give specs on the house, square footage, volume and what not. The layout of ducting and and and.

My wife is AFTER me 🤣
Please help. 
Open to ideas. 

ps all the modern and fancy HVAC stuff, the more tech advanced and split type stuff is too expensive right now,,, I think...? 

pecmsg

2 stories 2 systems

JUGHNE

IIWM, and you wanted HVAC, I would suggest as Pecmsg says.....2 stories.....2 systems.
I would go for the simple basic systems, less electronics maybe no PC boards.

You might succeed with one condenser and 2 evaps, but it sounds like you don't need AC for a long season.

IMO, you are proposing a Frankenstein system that someone in the future will not understand.

Your second floor system will run more than the first. 2 separate systems gives you redundancy in the
event of break down.

I think you are thinking of Mini Splits with Multiple inside heads.

EdTheHeaterMan

Here is an illustration of what you might be looking at with your home.
This might be the floor plan of the second floor with the duct in the attic and a central return in the hallway.

These mini systems that can handle two or three air handlers on the inside are limited as to what they can accomplish, however I was quite successful installing two of the mini duct units and one wall mount in the kitchen above the cabinets. That was a total of 3 indoor units connected to one outdoor unit. https://www.fujitsugeneral.com/us/products/multi/2-3-4rooms/index.html


Here is the web page for all the indoor units available https://www.fujitsu-general.com/us/products/multi/indoor.html

ratio

If you're expecting to save money, either install or operating, two systems or a muti-split. If SWMBO is getting involved, two systems or a multi-split. If you want a bada$$ system that you will be the only one capable of servicing, two evaps on one condenser, plus lots of learning and more than a touch of luck.