Window Units or Mini-Split?

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rockncountry101
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Joined: Sun Mar 11, 2012 3:56 pm

Sun May 11, 2014 1:15 pm

I have decided today to shut down my central unit completely. I have had such an issue with it and after two years have decided there is no solution to the problem. Up to one hour after the a/c kicks off I hear loud knocking and popping underneath the air handler and in the ducts. My question is would a mini split be a good alternative to window units? I have heard about them but I have never seen one in operation. I see many good reviews and few bad ones.


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Greg
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Sun May 11, 2014 2:43 pm

just googled mini split systems. I have seen them in a few offices that we clean and they seem to do a good job for rooms. I am not sure about a whole home. I would question if the price for a large enough BTU unit would be worth it. We have 3 window units (2 8K & 1 12K) That do a good job in the summer.
I guess you will have to do some homework and get some prices.

Greg
"If I can't fix it, I can screw it up so bad no one else can either."

rockncountry101
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Sun May 11, 2014 3:03 pm

What do you do for heat Greg?

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Greg
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Sun May 11, 2014 4:25 pm

Pellet stove, just over 2 tons last year at $270/ton. I only use the furnace if it is sub zero just to keep the pipes warm.

Greg
"If I can't fix it, I can screw it up so bad no one else can either."

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thatswhoiam
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Sun May 11, 2014 6:34 pm

have you been under the house and really looked at the system?


you say the knocking and popping starts one hour after the a/c kicks off......do you mean one hour after it has been running? ?

are there any other noises?

what does it sound like when it first turns on ?

any noises from your outside unit ?

how well does it cool? for how long?



mini splits are a fine alternative, but you already have central air, so unless you have tried EVERYTHING.....keep trying. if the system functions at least mediocre for at least some of the time, then more than likely there's still some life in that thing.


could be a number of things.... the shaft of the motor out of line in fan....if that shaft isn't put just through the fan just right, it will make a lot of noise....the set screw has to go in on the flat side of the shaft. could be a loose fan blade.......that fan can cause a lot of problems....and that is just one of several things it could be . just throwin ideas at ya buddy !


http://inspectapedia.com/aircond/HVAC_N ... ions_2.htm


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Greg
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Sun May 11, 2014 7:27 pm

Where did you find that link??? Talk about a lot of information!

Greg
"If I can't fix it, I can screw it up so bad no one else can either."

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thatswhoiam
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Sun May 11, 2014 11:54 pm

Greg wrote:Where did you find that link??? Talk about a lot of information!

Greg
I know, right? it does have a little bit of everything.

Rockncountry, you should make a video of your a/c unit when it makes that noise. it would be preferable if you could video the blower wheel and get a shot of your whole system including the outside unit, and ducts while the thing is operating....just put everything in it. post it on youtube...then subscribe to some of the HVAC guys on there ...and there are plenty.....perhaps one of them will help you out.

there's one guy in particular that really knows his HVAC:

https://www.youtube.com/user/grayfurnaceman/featured

put your problem in his channel inbox and he will try to help you.

He also has a couple of websites with troubleshooting guides:
http://www.graycoolingman.com/troublesh ... ioner.html


www.grayfurnaceman.com

he has an insane number of hvac vids on his channel. he's the man

AND..... do a search on youtube and google with the keywords of your problem...."hvac, air conditioner, mobile home, noise, loud, bumping, knocking, a/c" I'm pretty sure that whatever your problem is, at least 1000 others have had the same problem.

ALSO.....Type out a description of your problem with all of the symptoms in simple terms.....save it to notepad or somewhere on your computer.....then go to all of the hvac websites you can find and post that information in the hopes that someone will be able to identify your problem.

rockncountry101
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Mon May 12, 2014 3:55 pm

Wow...that's a great deal of info! Thanks! However, what makes the noise are the ducts. I just happen to hear a pop in the air handler at the same time frequently. Someone had suggested that it was expansion/contraction, but it continues for an hour or longer. The ducts just keep popping and popping. I have tried everything. I can't get to them to work on them because of the underbelly. No one else wants to either.

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thatswhoiam
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Mon May 12, 2014 5:49 pm

your problem is more than likely not that difficult to repair, possibly by yourself if you're physically able to get under there. you dont have to be an olympic hopeful to crawl under a mobile home and make some repairs.... get some good lighting under there, not just some puny flashlights.

as far as the underbelly is concerned you can cut it away by slitting a seam through it and patch it up later. there are kits you can purchase for that, or just patch the area with some tarpaulin and adhesive. you can worry about that when you get done.

like I said, at least make a recording of the noise its making, and put all the info about your system such as the model numbers if possible, and include whether or not the thing is cooling, and is there excessive condensate going on.

so put your nikes on and just do it !!

jpingram5
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Mon May 12, 2014 7:33 pm

Mini-Split Heat Pumps are really good alternative if you have the change to spare. They can run just as much as a central air system if not more. They tend to usually run at higher SEER ratings like most start around 15 SEER and can reach up to 27 SEER. Are you looking to do a multi-zone setup like one in the living room and one in your master bedroom?

I've done several of these mini-splits before and most commonly are used in addition spaces, basements and offices. I did do a 2 zone system in a mobile a while back. No complaints from them so far but they also went with top of the line Fujitsu units for $4,000+. There are some lower end brands out there that are all right. The only thing that would concern me is that if underneath isn't insulated enough I'd worry about pipes freezing if you live in an area that gets extreme colds. Any questions on them feel free to ask.
2009 Skyline Sunwood Premier 14 x 80

rockncountry101
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Tue May 13, 2014 1:09 pm

jpingram5...thanks for the info. I live in SE Texas and my underbelly is WELL intact. That's why I can't get under there to repair/replace the ductwork. My house is a 16x60. (828 square feet) I was considering a 2-ton split unit. I would put one in my living room/kitchen that is 322 square feet. I would then want one in my master bedroom which is 166 square feet. If they're reliable then I don't mind spending the money.

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thatswhoiam
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Tue May 13, 2014 3:08 pm

you can't get under there and repair the ductwork because the underbelly is intact???

its tarp....not the great wall of china :evil:



http://www.ductworkinstallation.com/noi ... fault.aspx

UmpJJ
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Location: Brazil, IN

Tue May 13, 2014 8:31 pm

I've got a 16 X 80 single wide and I stopped using central air and furnace a couple of years ago. I've got a 5000 btu window unit in the bedroom and a 10,000 in the living room/kitchen. Two bedrooms are only used for storage and those doors stay closed. Our 20 rooftop solar panels generate plenty of electricity to run the window units (110v vs 220 for the central a/c) as well as most of the household outlets. Grid power runs the furnace when it's used as well as the electric stove and water heater.
I use a vented propane heater for the living room/kitchen in the winter, and like Greg only turn on the furnace when temps drop to single digits. An oil-filled space heater does a great job in the bedroom, and can be set on a timer so it won't run all night. Propane is a bit pricey, but it's a nice alternative to grid electric and was installed as a "just in case electric goes out".
The window units were less than $500 total, and the propane heater was $500. I'm money ahead.

UmpJJ

Asphaltcowboy
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Tue May 13, 2014 9:09 pm

How much were the 20 rooftop solar panels though?

jpingram5
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Location: Orefield, PA
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Sun May 18, 2014 8:10 pm

I never heard complaints from customers we put them in for. Only heard of issues when they are not installed correctly. What I might recommend for you be a 2 zone mini-split. Instead of using 2 outdoor unit, you only need 1 that will feed 2 indoor heads. 1.5 ton in the living room/kitchen and .5 ton in your master bedroom. So basically it'll be a 2 Ton outdoor condenser but the heads inside are split up and add up to 2 tons.

http://www.thermospace.com/ductless_spl ... -12+12.php

That link is just to give you an idea of what I mean. That unit there has 2 indoor heads but their both at 12,000 BTU (1 Ton).
2009 Skyline Sunwood Premier 14 x 80

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