Drama of having a new A/C installed

[meierlde]

Indeed. If you can find a good independent small HVAC service company, they will offer the best service and price.



Hmmm. They developed largely as an answer to a European/Asian situation (a large stock of existing homes built with no forced air ducting and no good way to retrofit that ducting). Mini-spilts can be a good answer to some niche situations in the US, but it is generally impractical to use them to supply conditioned air to every habitable room in a home, as is commonly done with a ducted system. Having a home with 8-15 separate evap coils, control units, fans, drains, plus the outside condenser would be very expensive and a full employment program for HVAC service folks. The single outside condenser and singe inside air handler (maybe two in a 2 story home) of a typical ducted system is a good, serviceable, practical approach for the vast majority of present homes and new construction.

Mini splits make sense in homes that had hot water or steam heat, with there for no duct work and no chases to install it. For example the house I grew up with in MI had hot water heat, and to cool it its either mini splits or window units. (not that you need cooling that much of the time near Detroit).

 

[Breedlove]

They are starting to put mini splits in new homes in College Station . One compressor with multi heads . The old line A/C guys hate the mini splits . They want to force the package units

 

[homestead]

I probably know more about Mini splits then most people would ever want to know . I Know about the Mr Cool , out of Kentucky it is a DIY unit and is gaining popularity but remember any mistake by me as the installer and I am screwed . The lines are charged and it looks very simple to hook up . I was not brand sensitive I was even looking at Chigo a very very cheap import . As I said I am finding out there are over 50 brand names of A/C units manufactured by no more than 8 manufactures . I have heard about people not even purging the system with a vacuum pump , but Freon and water make acid and we all know what acid does to steel . These new inverter heat pump systems are incredible.
My Rant is that A/C is a controlled business . I hope more companies like Mr. Cool come about.

I installed two of the Mr Cool units on our house. I think the base unit is made by Pioneer. Pretty easy to install. They have been working great for a couple years now. I like the phone app where I can control units from internet. If you do have an install problem you can call Ingrams or any local heating/cooling company to help with the install.

 

[Texas Proud]

OK, wasn't considering an evaporator in the hot attic, since that just seems wrong in so many ways!



Or just have a mechanical closet for the evaporator and air handler on the first floor, in conditioned space, and ducts in the conditioned space. Like you say, if you have a furnace as well, that can got there too.

For me, floor space isn't at such a premium that I would want all this stuff in the attic. I've lived in places w/o a basement, and a closet for this stuff (plus water heater) isn't all that large, plus there enough extra space for a few small shelves for storage of misc stuff.

-ERD50

You have not seen my 5 ton AC unit... the inside part covers at minimum 10 ft when you add the air intake and exhaust (to and from the house)... and the duct work is also huge... I have one line that is either 14 or 16 inches and a few 12 inch...


My house is zoned at the plenum.... so have dampers controlling where the air goes...


It would take my DDs bedroom to hold all the stuff that is up there....

 

[meierlde]

They are starting to put mini splits in new homes in College Station . One compressor with multi heads . The old line A/C guys hate the mini splits . They want to force the package units

Because the minisplits eliminate the need for ductwork with (in the south at least) several square foot taken up by the return duct which is near the floor, as well as adding a lot of clutter to the attic, (as well as compared to the traditional systems being as efficient as the top of the line systems for far less money) it makes sense to use them in new construction. Also you far better zoning in the house unless you do to putting power dampers in the ducts. (Also each room can have its own thermostat)

 

[Breedlove]

How big were your Mr. Cool's . Were they the 220v or the 110

 

[homestead]

How big were your Mr. Cool's . Were they the 220v or the 110

12k btu @110v and 36k btu @ 220V

 

[Breedlove]

I am probably going to put a 12K BTU / 110 in our guest house . I can do that myself . keep us posted how the Mr. Cool holds up . My installer did not say a word bad about them .

 

[ERD50]

You have not seen my 5 ton AC unit... the inside part covers at minimum 10 ft when you add the air intake and exhaust (to and from the house)... and the duct work is also huge... I have one line that is either 14 or 16 inches and a few 12 inch...

My house is zoned at the plenum.... so have dampers controlling where the air goes...

It would take my DDs bedroom to hold all the stuff that is up there....

My new A/C is 4 ton, high efficiency and variable speed - so not so different in size from yours (it gets hot here, just not for a long time or as hot as Texas, but we still need a big unit for the hot days we do get). The evaporator fits right inside the plenum above the furnace - it's not huge.

As far as the duct work in/out - that's shared with the furnace, so it isn't anything extra. I just measured - the actual floor 'footprint', furnace & AC total is less than 2.5' by 4' - that includes space for the return duct coming down on the side (the treated air blows out the top), the gas pipes and electrical coming in on the other side - it could have been tighter if needed.

We don't have multi-zones, I guess that would add some to the duct work, 2 smaller sets versus one larger set. I'm guessing it looks so huge is that they had the empty space, so they did nothing to try to keep it together, it's all spread out? I think maybe you are counting ducts that would be there regardless of where the evaporator was installed?

-ERD50

 

[samclem]

The old line A/C guys hate the mini splits . They want to force the package units

They should >love< the mini-splits! They can charge customers more to install them (compared to a "regular" split system with a single condenser and a single evaporator), and the ongoing service and repair of 2-4 times as many fans, control boards, evaporator coils, refrigerant lines, etc is going to be a boon that lasts for decades.


In 2016 the US signed on to the Kigali agreement that calls for the phase-out of most HFC refrigerants, including those commonly used in residential split systems and mini-split systems. Different countries have different timeframes, and the exact phaseout of R-410A in the US hasn't been determined yet, as far as I know. Also, the replacement for R-410A hasn't been determined yet. But we know that when we transitioned from R-22 to R-410A, nearly every home evap coil and most of the refrigerant lines had to be replaced, too (largely due to incompatibilities of the lubricants each refrigerant used). There's a good chance that something similar will happen in a decade or so if/when R-410A goes away. And before it gets phased out entirely, it may get very expensive (as we've seen with R-22). If/when replacements of refrigerant lines, evap coils, etc are eventually required due to this new refrigerant, folks with mini-split systems-- 2-8 inside units and refrigerant lines run through the interior of their wall studs, etc, are going to be in a "different situation" than folks who have one inside unit located in a utility room or closet with one set of lines going directly to the condenser unit outside.

 

[Breedlove]

That sounds like a lot of Air conditioner !

 

[DAYDREAMER]

I've purchased and installed 15 mini-split systems purchased from GODUCTLESS.com for friends and family.

If you are somewhat mechanically enclined, they are very basic to install. The key to a successful install is to vacuum the system to 500 micron or less, using a Hvac quality vacuum pump, and measure with a micron guage. Example for DIY cost, an 18kbtu single inside head 22 seer inverter system costs about $2000 (LG Brand). Goductless.com sells many brands. You can buy a new vacuum pump online for $350, and a good quality micron guage for 200.

 

[Sunset]

I saw a bunch of those things on apartment balconies in Barcelona, now I know what they are and how they work.
Possibly they had them due to window A/C not being allowed or fitting windows, or people just didn't want to block off a lot of their windows.

 

[meierlde]

I saw a bunch of those things on apartment balconies in Barcelona, now I know what they are and how they work.
Possibly they had them due to window A/C not being allowed or fitting windows, or people just didn't want to block off a lot of their windows.

There was even one on the house where Osama Bin Laden was found. Note that compared to a window unit, the mini splits are also far more efficient.

 

[ncbill]

With their inverter compressors, mini-splits are efficient enough to be used in off-grid solar-powered homes.

As another poster notes, even the cheapest mini-splits have SEER ratings comparable to high-end traditional split units (here most installs are for the latter are the minimum SEER 13)

 

[Texas Proud]

There was even one on the house where Osama Bin Laden was found. Note that compared to a window unit, the mini splits are also far more efficient.

They are also much quieter than a window unit... at least all the ones I have seen...


I was in a place in Europe once and I did not hear any noises from the inside unit... it was quiet....

 

[NYEXPAT]

There was even one on the house where Osama Bin Laden was found. Note that compared to a window unit, the mini splits are also far more efficient.

Do you recall what "Brand"?

 

[jazz4cash]

Man, I am nearly lost trying to follow the discussion on the new HVAC technology wrt the mini split systems. It seems to me that the high efficiency is primarily due to the variable capacity inverter drive compressor. Seems like that type of compressor is not discussed/not available in a conventional split system. Why not, I wonder? The mini split is ideal for special situations like a room that has extra high heat load or a structure with no ducts. This reminds me of the top vs front load washer discussion. I am looking forward to replacing or 20 yo builder grade system and simultaneously hoping it'll last forever!

 

[Breedlove]

It is kind of neat with the inverter technology . I remember my old house had a package unit . When it came on it came on full blast . This thing works with the need .

 

[meierlde]

Man, I am nearly lost trying to follow the discussion on the new HVAC technology wrt the mini split systems. It seems to me that the high efficiency is primarily due to the variable capacity inverter drive compressor. Seems like that type of compressor is not discussed/not available in a conventional split system. Why not, I wonder? The mini split is ideal for special situations like a room that has extra high heat load or a structure with no ducts. This reminds me of the top vs front load washer discussion. I am looking forward to replacing or 20 yo builder grade system and simultaneously hoping it'll last forever!

It is available in top of the line units in split systems For example lennox xp and xc 25 units have one and it appears the xp/xc 20 line does also. Look for variable speed models as this is one of the things an inverter compressor does. So you are far above the typical builder or consumer replacement at seer of 23.5 for example. It is that the manufacturers of the mini splits have driven inverter compressors further into their line, and because the minisplits are international products efficiency is more important due to the cost of electricity outside North America

 

[ERD50]

It is kind of neat with the inverter technology . I remember my old house had a package unit . When it came on it came on full blast . This thing works with the need .

But you are comparing new mini-splits to old 'packaged' units.

The modern whole-house HVAC have variable speed fans, so they don;t come on full blast. You can get variable compressors, we went with two-stage, which works well with the variable speed fan to optimize for temperature or humidity reduction as needed.

I really can't imagine that for a large-ish US style home, that the number of mini-splits required would end up cheaper/better than central HVAC. Especially in places where NG is available for heating - you've already got the ducts and air handler.

 

[Texas Proud]

But you are comparing new mini-splits to old 'packaged' units.

The modern whole-house HVAC have variable speed fans, so they don;t come on full blast. You can get variable compressors, we went with two-stage, which works well with the variable speed fan to optimize for temperature or humidity reduction as needed.

I really can't imagine that for a large-ish US style home, that the number of mini-splits required would end up cheaper/better than central HVAC. Especially in places where NG is available for heating - you've already got the ducts and air handler.

I was just counting in my head and I think I have 21 air registers... now a few are in a small room for a toilet, but I would not want to think about how many units I would need to cool the house properly...


The benefit would be that you could tailor the cooling to the room and its usage... and the sun of course... my DS's bedroom gets hot in the morning due to the sun even though we have two registers in his room... the sensor is around the corner in the living area and it is cooler there...

 

[jazz4cash]

But you are comparing new mini-splits to old 'packaged' units.

The modern whole-house HVAC have variable speed fans, so they don;t come on full blast. You can get variable compressors, we went with two-stage, which works well with the variable speed fan to optimize for temperature or humidity reduction as needed.

I really can't imagine that for a large-ish US style home, that the number of mini-splits required would end up cheaper/better than central HVAC. Especially in places where NG is available for heating - you've already got the ducts and air handler.

Yeah I think Breedlove responded to my comment about a packaged system with inverter compressor to upgrade my 20 yo forced air system. As I understand this a variable speed compressor is more capable than a two stage unit. Problem for me is I generally prefer a system that is a couple notches below top of the line so an 18 or 20 SEER would be in my target range. A variable speed fan is great but not at all comparable to variable compressor.

 

[Breedlove]

All I can say is my 22K unit so far does a jam up deal keeping my 1000sf home cool . I first had a hard time trying to set the temp and let it fly . I called the A/C guys they told me to put it on mode and scroll to automatic . Now what happened I can't explain the unit reads the last time I held the controller and also cools to the occupants in the house . The unit hardly runs and it really comfortable . Says 76 degrees but feels like 70. We keep all of the doors inside the house open so the A/C circulates pretty good . We also have 2" of closed cell foam in the ceiling and in the walls . It is hard to hear if it is running or not.

 

[meierlde]

I was just counting in my head and I think I have 21 air registers... now a few are in a small room for a toilet, but I would not want to think about how many units I would need to cool the house properly...


The benefit would be that you could tailor the cooling to the room and its usage... and the sun of course... my DS's bedroom gets hot in the morning due to the sun even though we have two registers in his room... the sensor is around the corner in the living area and it is cooler there...

Note that mini split systems outdoor units can drive mutliple indoor units up to 4 per outdoor unit.

And of course multiple indoor units mean lots of zoning of HVAC. I have seen youtube videos of split systems with multiple dampers and of course needing mutlispeed blowers as well (to handle the differing amounts of air to be handled.


Minisplits outdoor units seem to come to at least 24k btu in capacity. American standard has one that goes to 38 seer and 16 hspf which is better than any ducted split system.