ductless mini split air conditioning

Questions and answers relating to houses built in the 1800s and before.

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rodpaine
Posts: 131
Joined: Thu May 28, 2009 9:41 am
Location: Purcellville, VA
Contact:

Re: ductless mini split air conditioning

Post by rodpaine »

Mitsubishi Performance Update No. 2
Our August 2010 electric bill is $94.14, we used 216kWh less then last year (882kWh vs. 1098kWh) and it was as hot as last August. This is almost a 20% savings even dealing with keeping our house much cooler at 72F maximum, compared to last August with 78F settings on the window air conditioners. The Mitsubishi systems certainly do the job, based on my personal experience with them for the past three months.
FWIW,
-Rod

rodpaine
Posts: 131
Joined: Thu May 28, 2009 9:41 am
Location: Purcellville, VA
Contact:

Re: ductless mini split air conditioning

Post by rodpaine »

Mitsubishi Plumbing Update
Following up on my continuing work on our two Mitsubishi Mr. Slim systems, I have used a different method to minimize their external plumbing appearance, other then the earlier idea of using plastic down spout rain pipe plumbing. What I did is shown here.
FWIW,
-Rod

Barbara001
Posts: 205
Joined: Tue Aug 04, 2009 11:35 pm
Location: Kitchener, Ontario

Re: ductless mini split air conditioning

Post by Barbara001 »

That looks good Rod. I have had one quote on a mini split system and am trying to get one more (not many installers in my area). Do you know anything about the Carrier mini-split system?

I am limited to having it installed at the rear, even though I am in a rowhouse at the end, I am in a historical district and anything visible from the street has to be approved by the Historical Committee. I just received an email from them advising the unit should go in the back.
Barbara
Image

1889 Rowhouse
Victoria Park Heritage District
Kitchener, Ontario

www.365daysofcenturyhomes.com

rodpaine
Posts: 131
Joined: Thu May 28, 2009 9:41 am
Location: Purcellville, VA
Contact:

Re: ductless mini split air conditioning

Post by rodpaine »

Barbara001 wrote:That looks good Rod. I have had one quote on a mini split system and am trying to get one more (not many installers in my area). Do you know anything about the Carrier mini-split system?.
Barbara,
Thanks. No, I don't have any user info about the Carrier ductless system. The bulk of the feedback I got was for the Mitsubishi, Fujitsu and Samsung units, with most recommending I spend the money on the Mitsubishi, based on their performance and service experience with Mitsubishi Mr. Slim units. If your external compressor unit has to be located in less then an ideal location, make sure the unit is within the maximum allowable plumbing distance from the interior air handler unit, which in my case with the Mitsubishi was 50 feet. My longest run was 35 feet.

While the dealers said outside unit placement and distance was of no real concern, users I talked to said placing the unit in the sun wasn't ideal, nor was a maximum length black insulation plumbing run, both of which had to deal with losses caused by the sun heating these surfaces. As I mention on my web site, I saw this very problem with plumbing on my west side installation, where adding additional plumbing insulation and painting it white improved interior unit cold air output. Let us know how your project goes... there is significant interest in this type of system. I had a gentleman come to my house yesterday and asked to talk about my installation and experience with it, during the past very hot months.
-Rod

rodpaine
Posts: 131
Joined: Thu May 28, 2009 9:41 am
Location: Purcellville, VA
Contact:

Re: ductless mini split air conditioning

Post by rodpaine »

Hmmm, it appears that the additional pipe insulation that I installed as an exterior cover and painted, has contributed several more degrees of colder air to the upstairs interior unit. It was 97F yesterday, but I noticed that the unit was calling for compressor action less frequently and the exterior fan was running at the slow rate, most all of the day. Perhaps a quirk? I had not originally given any thought to the potential effect of additional insulation, as I was only thinking about covering and minimizing the exterior plumbing appearance. Interesting.
FWIW,
-Rod

Barbara001
Posts: 205
Joined: Tue Aug 04, 2009 11:35 pm
Location: Kitchener, Ontario

Re: ductless mini split air conditioning

Post by Barbara001 »

Hi Rod,

That's not good...what we do for esthetics!

I have a heat/air contractor coming this week who carries the brands you previously mentioned. He did mention that heat pumps are only good for temperatures to 0 degrees, any lower than that and they do not function? Does that sound right? Living in Canada heating below 0 is mandatory. So it may be necessary to keep my baseboards as a supplemental heat source.
Barbara
Image

1889 Rowhouse
Victoria Park Heritage District
Kitchener, Ontario

www.365daysofcenturyhomes.com

rodpaine
Posts: 131
Joined: Thu May 28, 2009 9:41 am
Location: Purcellville, VA
Contact:

Re: ductless mini split air conditioning

Post by rodpaine »

Barbara,
My Mitsubishi systems are cooling only, replacing the old widow air conditioners, so I did not do any research on their combination cooling and heating units. We heat with wood (past 27 years), using electric baseboard heaters as backup, when we are not at home to feed the wood stove.

However, a quick look at the Mitsubishi catalog shows that their combination heating and cooling systems using what they call their 'Hyper-Heating Inverter (H2i) P-Series' units can deliver 75% of their rated btu heat output down to -13F. So, I suspect competitive systems would have models that can deal effectivly with sub-zero temperatures, too.

I hope you can find a quality firm that has products that can meet all your specific needs, including quality installation and care when working in your old house. I've recently seen a split system installation that looked like it was installed by several monkies using rocks for tools. What a mess. Please don't hesitate to get referrals that you can talk to, who have had a split system(s) installed, by your potential installer(s).
-Rod

rodpaine
Posts: 131
Joined: Thu May 28, 2009 9:41 am
Location: Purcellville, VA
Contact:

Re: ductless mini split air conditioning

Post by rodpaine »

Mitsubishi Performance Update No. 3 (final)
For the past three months, I have been carefully monitoring the performance of our two Mitsubishi Mr. Slim cooling units (12k btu and 15k btu), reporting my experience and relevant data here. Our Sept. 2010 electric bill is $75.97, we used 97kWh less then last year (700kWh vs. 797kWh) and it was much hotter this year than last Sept., with the monthly average temp being 84.6F versus 77.9F last year. Again, this is almost a 20% savings even with keeping our house much cooler at 72F maximum, compared to last Sept. with 78F settings on the window air conditioners, as we did all last summer. The Mitsubishi systems we installed are certainly saving us money and providing a much cooler and quieter environment, based on this summers performance and its very hot days.
FWIW,
-Rod

rodpaine
Posts: 131
Joined: Thu May 28, 2009 9:41 am
Location: Purcellville, VA
Contact:

Re: ductless mini split air conditioning

Post by rodpaine »

Sept 2019

Had a leak occur in the coils in the upstairs unit and had to buy a new unit as the existing unit was now out of warranty. Still very happy with our two Mitsubishi units, which at this time (July 7, 2021) are maintaining interior house temp at 72F with 91-94F outside noon temps. Electric bill at $89 last month (June) and included cost associated with running old window units in upstairs office and minimal cooling in garage after vehicle useage. Both garage areas have been heavily insullated included garage door with 2.5-inch foam panel on interior side.
-Rod

Bell20
Posts: 6
Joined: Tue Apr 20, 2021 10:19 am

Re: ductless mini split air conditioning

Post by Bell20 »

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