mini split purchase and diy install

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Old 09-29-18, 01:30 PM
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mini split purchase and diy install

Hi all, would appreciate feedback and any input on this.

I have been researching Mini Split systems for about a year now and am close to pulling the trigger on purchasing a Senville 9000 BTU unit. I've gone around the block about 1000 times, and keep ending up here. For background, I've done a lot of stuff myself, flipped 9 houses doing all the work myself, restored 4 Historical homes. When i started learning how to do things, I'd do the work, then hire a pro to come in and check me out and point out any issues, so it's important to me not to remuddle vs remodel. I believe the diy doesn't mean one cannot do the job meticulously and correct just because they are not professional level. I.e., my putting in my own system is about saving money and learning vs cutting corners and slapping stuff together.

With that caveat, I have arrived at the above system for several reasons.
One, Senville is a Canadian company and sells a lot of units in Canada. I've found that of all the Chinese relabels, they are one of the least expensive, well established makers offering units with higher HSPF ratings. I'm guessing that's because of their market, but US companies seem to emphasize SEER. I live in OR and my bigger expense is heating, not cooling, so HSPF is more important to me. Though you'd think the two numbers would run fairly parallel, i have not always found that to be the case.

Two, price. I plan on eventually having two units to condition my whole house. I'm starting with the 9000BTU Energy Star rated unit to see how that goes. I currently have central gas heat that is old and could fail any time, but still works. I'm putting the split in my bedroom, farthest from the central system, it's a cold spot. The unit is $900.
One of the things i have gone back and forth on is whether to buy a Chinese make from a reputable company that has some quality controls in place, or go with a (Japanese) 'name' brand like Daikin or Mitsubishi at almost twice the cost? Since i plan on diy, warranty will not factor in (unfortunately), so there is that gamble. I have been unable to find an HVAC company that will let me do the install and register the product doing the pressure, vacuum and line hook up, without gouging me. I get it, they want to make their money, but my thinking is I diy because of the money savings and paying someone hundreds of dollars to put their name on a piece of paper defeats the purpose. So, yes, i am gambling that if i do the job right, my unit will last as long as it would if someone else did it. I am leaning towards the Seniville vs Daikin because the better warranty doesn't factor in for me. On the other hand, i think, better warranty may be because it's a superior product, but is it worth 2x the price while still not having the warranty in either case?

All in (including all my tool costs, buying vacuum pump, gauges, etc.), my cost installing the 2 Senville units (eventually) will cost me about $2400. If i installed similar Daikin, the cost would be about $3600. Price for the same Daikin units installed by a local HVAC company was $6700. I figure the $4300 difference will pay for a to of repair, if even needed, or outright replacement.

Thoughts?
 
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Old 10-01-18, 08:05 AM
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I thought may of these mini-split systems had sealed, pre-charged tubing that is pierced by the connectors at each end so they CAN be installed DIY without vacuum pumps, manifolds, special knowledge, etc...?
 
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Old 10-01-18, 12:06 PM
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guy48065,
Thanks for your reply, i was getting very lonely.

Every mini split that i know of comes pre charged, but the charge is in the outdoor unit. There are valves built into the low/high end connects that are backed out, once the lines are connected, to release the refrigerant into the lines connecting the evaporator and condenser coils. The only lines i know of that come sealed (i.e., not requiring a vacuum) are the Mr Cool diy units. They come with 25 feet of line, so if you have a run half that long, you either cut and re-flare the tubing, or coil the left over and leave it behind the unit (or somewhere, which is kinda ugly). Of course, if you cut and re-flare, you gotta pull a vacuum because the tubes are no longer dry inside.
Almost all split systems, except Mr Cool, require line hook up to be done by a licensed HVAC contractor, otherwise the warranty is void.
I say that, but then just read that Daikin warranty is good for 5 years on unregistered equipment, so it is less, but does still apply, but am finding the unit cost is almost double comparable (specs rating wise) Chinese mini's.
 
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Old 10-01-18, 12:50 PM
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btu sizing/configuration for mini split system

Since i have gotten so many responses from my other post on this topic, lol, figured i'd post another pressing question. Trying to figure my sizing/configuration. I have a small, 1165 sq ft., 1941 ranch style house that has been retro insulated and energy efficient windows, i.e., the house is relatively tight. It's a three bedroom house, 20' hall with three bedrooms and two baths off of it. The living room and kitchen are pretty open and connected, and two of the bedroom doors open off of the passage between the living room and hall (i.e., the airspace is pretty open to the living room. The master and two bathrooms are at the end of the 20' hall with a similar openness of air space between the master and two bathrooms as the front half. The master is 11x15, 165sqft, the bathrooms don't add much to that, so really talking about 250sq ft for the back half of the house. I live alone and live mostly in the living area and the master bedroom.

The plan is to locate a 9000 btu in the master and a 12000 btu in the living room, which would give me 1/3/4 tons. For my climate, the heating is more important (read: "more expensive") than the cooling, which is why i am looking more at HSPF than SEER rating. The quote i got from an HVAC company thought the set up was good, even suggested that 9000 btu would be adequate for the back vs 2 12000 btu units. Am supposing if circulation becomes an issue, i can always switch on the old ducted heating fan. Since i rarely use the other two rooms, not inclined to include them in the split set up with their own separate air handlers.
 
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Old 10-01-18, 02:06 PM
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Real hard to answer this but first a heat load has to be done. Without that you know nothing. 2nd all bedrooms will need a head, bathrooms could use a ducted model and catch both of them. If the kitchen is that open one unit could do it. If the set up is good id rather see a ceiling cassette for the bigger areas. do a heat load per room then we can talk more. If heat is needed then brands will 100% matter.
 
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Old 10-01-18, 02:26 PM
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You didn't post your location but if you live in a climate that gets colder than 32 you might get cold.
 
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Old 10-01-18, 03:30 PM
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Similar topic..... threads combined.
 
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Old 10-01-18, 04:38 PM
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Hi airman,
Thanks for taking the time to reply.
I haven't done an 'official' heat load analysis, but then, neither did the HVAC company that wanted to charge me $6700 for a comparable system. I've also restored a lot of houses (4 historical and very old) so i do have a sense of leaky vs non leaky houses. I live in Oregon in Albany, a fairly moderate climate, zone 4.

During the summer when the days were getting over 95 and the nights down to 60, i could throw the windows open, bring the temp of the inside of the house to 70 degrees, close everything in the morning and, at worst, the temp would get to 80 degrees inside before i could open the windows again. So, a 10 degree gain in 8-10 hours. I have a gas vented central heater, works fine except my back bathroom and master bedroom are kinda chilly, usually a couple of degrees difference. I could just put in one mini in the back bedroom and call it done, but i like the efficiency of the the split systems and would love to realize that at both ends of my house. Yes, i do realize that putting in ceiling vents and more "heads" would make this system wonderfully adapted to my situation and efficient... and expensive.
I see you are in VA. My four historical restorations where in VA. Two on the Elizabeth River, one in Charlotte County (out in the sticks) and one in Louisa County. I put vented 2 zone systems in all of those, they worked and were very expensive, but the houses were much bigger too. Then, there are the very humid Mid-Atlantic conditions (there's no such thing as summer humidity in OR, you can actually open windows at night and cool off lol). The winters are pretty moderate as well

I 'live' in the living room and master bedroom, thinking the set up would work. I remember as a kid growing up in So Cal all we had was a standing gas flame heater in the center of a similar sized house, it worked.
 
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Old 10-01-18, 05:44 PM
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In August I posted this regarding mini-splits:

A few years ago I went through decision making over whether to buy Chinese or Japanese mini-split.

My professional life is centered on the global electronics industry not HVAC, but have long experience with AC's. Also have extensive travel in China.

In China endless forests of hi rise residential buildings have mini-splits. There are zillions of them. Most are made by a handful of billion dollar Chinese companies. Those sold in the US are often re-branded with obscure names.

Because of high Japanese manufacturing costs their units often have significant Chinese made content. I finally concluded there was nothing to justify the 100% price differential of Japanese mini-splits. Installed a 9000 BTU Chinese cooling/heating unit for total cost of $700.

If a Chinese unit was to develop problems the 50% savings could be used to pay for service or new unit.

Because of added complexity of heat pump mini-split refrigerant systems I installed a bidirectional filter/dryer and sight glass. The system has run flawlessly for five years.
 
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Old 10-02-18, 09:59 AM
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Guy48065: I thought may of these mini-split systems had sealed, pre-charged tubing that is pierced by the connectors at each end so they CAN be installed DIY without vacuum pumps, manifolds, special knowledge, etc...?
Some mini-splits are pre-charged and have valve that can be opened after connecting lines are evacuated.

My tubing set was not pre-charged. The mini-split came with overcharge so additional refrigerant was not needed.

I used old small refrigerator compressor with vacuum gauge. It is simple process so AC gauge set and special tools are not needed. But do add bidirectional filter/dryer and sight glass.
 
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Old 10-02-18, 10:21 AM
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Hey doughess,
Thanks for your reply. This has been a big wrestling point for me (i.e., Chinese vs Japanese). I've also noticed that some of the big Japanese brands are manufactured in China but tout "Japanese engineered."

I watch this youtube channel called ADVChina, a guy from the US and one from South Africa who immigrated to China a dozen years ago. They ride around the country on motorcycles discussing all sorts of aspects of Chinese culture. In a few of their videos they discuss the difference between stuff made in China for China and stuff made in China for export. Essentially, they note that, for a variety of reasons, quality control is not important to the Chinese market, that it has a throw away mentality. On the other hand, the Chinese are just as capable of making great stuff as anyone else. What it seems to come down to is quality control and whether or not the manufacturer has those controls in place and how well they police them.

I remember when Japanese cars started selling in the US. The Japanese revolutionized the car industry by forcing everyone else to increase their quality just to compete. I am guessing that the Chinese are running into similar challenges because their internal market is different from their export market when it comes to expectation.

The Senville units i am looking at are Chinese made and half the price of the Daikin i am comparing them to. Still, reading reviews, i find a lot more negative stuff about the Senville than i do the Daikin, so it seems the Senville would be more of a gamble to install, but at half the cost, how much of a gamble? As you note, the cost saving could pay for repair, or even replacement.
 
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Old 10-02-18, 10:31 AM
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After researching a lot more yesterday, i am finding myself leaning toward Daikin. I found that a slightly better SEER/HSPF rated Daikin system vs Senville would be $1350 vs $900, 50% cost difference. If i go the route of having an HVAC company do the line connect so i can get warranty, the Daikin is a 12/12 warranty vs Senville 3/7 (parts/compressor respectively). Daikin gives a 5/5 warranty on "unregistered" units and Senvile has no warranty on units unless installed by an HVAC company. Also, Daikin customer service seems better than Senville. The Senville brand apparently just has scripted phone answerers for customer service since they are just relabeling vs manufacturing, Daikin is a manufacturer and has a whole support system in place.
 
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Old 10-03-18, 08:23 AM
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Am not going into a lot of background about my long history with Chinese and Asia. I feel the only difference between Chinese made mini splits for use in China or the US is the 230 VAC or 120 VAC motors.

Chinese core instinct is to squeeze the costs out of everything. Chinese billion dollar companies have not even tried to develop their brands in the USA market. They sell to buyers who fill cargo containers full of them and resell them here.

A Japanese company would set up a bureaucratic corporate office here under the name Xxxx America.com then micro manage it from Tokyo. They call it “consensus management” but the consensus is dictated and controlled from Japan. USA customers then pay twice as much for the product.

See: Daikin North America

Daikin Industries, Ltd. is a Japanese multinational air conditioning manufacturing company headquartered in Osaka. It has operations in Japan, China, .......
 

Last edited by doughess; 10-03-18 at 08:59 AM.
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Old 10-15-18, 05:57 PM
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Okeedokee, for those remotely interested. Bought a system from a company out of Florida, took a week to get here, but shipping was included. Got here in great shape, well packaged, good price. I bought for the 12.5 HSPF since heating is more of a factor where i am than cooling (24.5 SEER).

I had previously checked for a HVAC co to hook the refrigeration lines, pressure and vacuum check the unit, and had been told yes by a company @ $100/ hour. Figured it would be a bout a 4 hour job. Then when it came down to it, they said it would cost $1400. Checked extensively and not able to find a company that will do any less than an install, guess that's where all the money is.

I have mounted the exterior unit, electrical is all run and passed inspection, mounted the indoor wall unit. All pretty straight forward. Today, i bought the Harbor Freight tube bender so as not to kink any tubing, works great. Also have the conduit to run the tubing and wire in, looks good, about a 25' run.

What's really interesting to me is the Daikin install specs, instructions. They are meticulous about the tubing flair and connections. Smart, me thinks. But then They state to vacuum for not <10 minutes for a run of <49' and and not <15 minutes for a run >49'. Then after vacuuming, they state to turn the refrigerant valve on for not more than 5 seconds, then off, to pressure check the system. Thought it was interesting that they use the system refrigerant to test for leaks vs nitrogen. Also, no mention of vacuuming down to x number of microns.
 
 

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