Broken A/C - upgrades!

Guys left a bit ago, having finished day 2 worth of work. Installing the second unit required some more work on the ducting so they didn't get that finished, but they got it blowing upstairs. Much, much better on this 92 degree day with not a cloud in the sky. They didn't get the mini-split done but I didn't expect that to get finished.

They'd said I might want to consider removing the zoning on the first floor, or at least disabling it for now. Having the two thermostats does cause a lot of extra cycling. Need to look at that some more and see.
They had to separate out the ductwork so one AC blows downstairs and the other AC blows upstairs? What about cold air returns? How did all that work?

I'm curious because I've thought about that for our house. Probably will never do it, but I've wondered how we'd have to retrofit the existing ductwork.
 
They had to separate out the ductwork so one AC blows downstairs and the other AC blows upstairs? What about cold air returns? How did all that work?

I'm curious because I've thought about that for our house. Probably will never do it, but I've wondered how we'd have to retrofit the existing ductwork.

The upstairs was easy as there was a single duct going up. They basically just unhooked it and then ran it straight down to the new air handler. Simple there. The returns I don't think were ever isolated to upstairs vs. downstairs (and the system was zoned) so I think they're just going to go into the existing returns and work that.

Then the mini-split is its own deal.
 
The upstairs was easy as there was a single duct going up. They basically just unhooked it and then ran it straight down to the new air handler. Simple there. The returns I don't think were ever isolated to upstairs vs. downstairs (and the system was zoned) so I think they're just going to go into the existing returns and work that.

I also have a single duct that feeds upstairs. But there would have to be a lot of sheetmetal work to get it separated from the existing work and branched out to a new HVAC system. I'm not sure how my returns are ducted. There may be ways to get it separated, but I'd have to take a close look at how it's all put together in my house. I'm not sure if the returns from upstairs are shared with downstairs, fire codes may dictate that.
 
I also have a single duct that feeds upstairs. But there would have to be a lot of sheetmetal work to get it separated from the existing work and branched out to a new HVAC system. I'm not sure how my returns are ducted. There may be ways to get it separated, but I'd have to take a close look at how it's all put together in my house. I'm not sure if the returns from upstairs are shared with downstairs, fire codes may dictate that.

Every house is different and the two-unit thing is something that's only come about in semi-recent years. So that may be harder to do. I've always thought it makes far more sense. And while zoning is good, it has its limits unless you're running a variable speed since it screws up airflow, as existed in our previous setup.

I can highly recommend these people.
 
I also have a single duct that feeds upstairs. But there would have to be a lot of sheetmetal work to get it separated from the existing work and branched out to a new HVAC system. I'm not sure how my returns are ducted. There may be ways to get it separated, but I'd have to take a close look at how it's all put together in my house. I'm not sure if the returns from upstairs are shared with downstairs, fire codes may dictate that.

We were single-zone two-story until we replaced it this spring. They basically built two 14" manifolds out of duct - one for upstairs and one for downstairs. They connected each of the manifolds to a single output from the baffle'd controller. Then they connected each piece of existing duct to each manifold appropriately. It's actually a pretty clean install. If I wasn't such a bum, I would go up in the attic and take a pic, but I just got un-sweaty from baseball practice, so I'll not re-sweaty myself at this time. :)

We were easily 10+ degrees difference once you made the turn on the stairs coming upstairs. Now you can barely tell a difference between up and down. Still TBD on if there are any savings on the utility bill though.
 
We just replaced ours last week. A 16 year old 5 ton is now replaced with a 17 SEER 5 ton. The cost sucked but you can't put a price on it when your house is 95 degrees.
 
and it was against the law (at the time) to sign the documents with anything other than black ink.

I have closed about $1.5 billion of commercial mortgages as mortgagee and we ALWAYS insisted on blue ink for the note. A black signature is too easily duplicated (xeroxed). As I am sure you know, the borrower should never sign more than one note. Although in 1988 on a home mortgage transaction, the lender tried to get me to sign multiple notes, I asked him why. And he said it was common practice to sell the mortgage on the secondary market. I refused and the attorney for the bank soon caved. -Skip
 
Just got back from the final inspection on things. I am very, very happy. The mini-split is silent and after 30-45 minutes of running was already cooling and dehumidifying the garage a noticeable amount. Paid the guys, gave them a tip for great service, and off they went.

The Mitsubishi mini-split is amazingly silent. Standing next to it, you still can't hear it operate. I'm very happy, can't wait to use it in the garage. After operating for 30 minutes it'd already cooled off the garage 5 degrees or so, with a huge reduction in humidity. I'm sure the winter will be better, too, in part because we now will have two whole-house humidifiers and the single was not keeping up.

For anyone in the KC area, I can highly recommend these folks. The house has never been so comfortable, and the service was prompt, friendly, and reasonably priced. The installation is clean and professional.

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that's fantastic! honestly.

Now, throw them in the MU-2 and bring them out to Seattle when it comes time to do my place, will you?
 
That extra climate control in the garage will help your upstairs bedroom, too.
 
That extra climate control in the garage will help your upstairs bedroom, too.

Yes. We also think that it's going to result in more even upstairs cooling and heating. Right now the girls' room (which is above the garage) is always much hotter or colder than the rest of the 2nd floor. This should help to fix that.
 
....and your electric bill....will no doubt go up. ;)

We'll see. SEER went up from 13 to 14 (which is essentially negligible), but we eliminated some inefficiencies in how the previous setup was (poorly) installed and the garage unit is 22 SEER, and will reduce the heat/cooling demand on the upstairs thermostat.

I doubt it will change much one way or the other.
 
The temperatures have been dropping some the past few days, so I've changed up my mini-split a bit. I set it onto the "dehumidify" setting rather than setting a temperature setting. I'm not sure what humidification it sets for, but it's a slightly different mode where it runs the fan at a lower speed but the compressor at a higher/max speed to focus on getting as much humidity out of the air as possible. This does, of course, also produce some level of cooling. It's doing a nice job of making the garage very comfortable, and I haven't turned the temp down when going in there to work since.

I'm waiting for the next electric bill to see if there's any noticeable difference. But I also need to call the insulation people.
 
The temperatures have been dropping some the past few days

The thermostat for my swamp cooler didn't turn it off last night. They are not very accurate.

I woke up at 5:30a and it was 48 degrees in the house...
 
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About 3-1/2 years ago, we replaced a furnace that was way too big and blew like a gale with a better sized Bryant HVAC system. We also added solar at about the same time. There was a rebate to go to higher efficiency that was bigger than the cost of upgrading, so that was a no-brainer. It has an DC fan, so it draws minimal current when running, so during the summer, we have continuous circulation, which helps even out the house temperature, and filters the air. We have a couple of rooms that get hot in the afternoon, and each has room for another vent. That'll help keep the kitchen, and the living room cool.

My YF has severe allergies, so the continuous running fan helps keep the air clean, and reduces her dependence on Zyrtec.

We also moved the HVAC from the furnace closet to the attic, which opened up a closet for more storage.

Shortly after we put the HVAC in, we had solar installed. I wanted just to do peak shedding, but the salesman convinced us to try to replace our entire electricity usage. So, I don't know how much the new heater saved us, nor the A/C is costing us, but the reduction in gas and electricity costs for heating alone more than pays the interest for solar plus the new HVAC HELOC loan.

Used to be, you only really needed A/C for a couple weeks each August, but it's gotten hotter here. Probably because all the trees and grass have been paved over for roads, parking lots, and new buildings. Think Apple, Google, Microsoft, and Facebook.
 
Got my electric bill. This wasn't the first full month with the new units, but most of it had the new units, and it was a hot month.

End result: bill is about $10 cheaper for having much better cooling in both the house and the garage.

The setup will never pay for itself like that, of course, but it will mean we're more comfortable.
 
just got mine for last month....very hot here in a 3,000 sqft home and it was one of the lowest I've had in a long time. After changing out all my recessed cans with LEDs (bout 40 of them) and changed out the AC compressor with a newer.....there are 6 of us each with laptops, desktops, and phones....and it was $209.
2500 sq ft but 900 of that is the basement, so I close the vents down there but it still gets chilly in the summer and warm in the winter! On really hot summer days (Denver either met or beat the former record high of 98F - this is why I live here, not in Phoenix) I might sleep in the basement. New compressor installed 4 yrs ago, computers run 24/7. Like others, I changed out many of the lights for LEDs but not in my basement office - don't like the LED light. Old washer and dryer (30+ years and they just keep going!) Furnace and fireplace are gas. Monthly average electricity + gas is about $100/month.
 
Of course, I post on this thread that my Mitsubishi mini-split is working fine and then it dies.

Might be due to a power outage the other day, might just have felt like time to fail. Pulled the boards, fuses all fine, couple Zener diodes are charred, can't read the part number on them(and no idea if they're the problem or a symptom) so I punted and called the HVAC guys. We'll see how much this will cost.
 
So far so good on mine.

I'd been running mine on the "dehumidify" mode, and what was happening on that with the somewhat cooler temps was the garage was cooler than the rest of the house. So while nice, I figured that was probably using more power than ideal. For cooling for now I've set the garage to same temperature as the house. I'll see what works for heating and play with that as it gets cooler.
 
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