DIY Minisplits: Which side are you on?

 Recently, Friedrich has modeled and sold in limited markets their DIY Mini-Split Heat Pump, Breeze.  Just a few days ago, they scaled back their rollout in order to meet customer demand by limiting sales to New York and South Florida.  I am torn between two very valid arguments on this product, the HVAC Professional and the Energy Geek in me have compelling points.  Please, read both before you provide a comment!

HVAC Professional

Proper Sizing  -  In order to properly size the equipment, and meet current building code in most of New England, an ACCA Manual J v8 Load Calculation should be performed.  Although this equipment is variable capacity, installing the larger option could be a waste of money, materials, and energy.

Equipment Installation  -  Every HVAC professional knows during installation that vacuuming of the refrigerant lines are required.  Moisture can wreak havoc in an HFC refrigerant cycle like R-410A.  Non-condensables will artificially raise liquid line pressures, decrease capacity, and raise compressor amperage.  Fortunately, the engineers at Friedrich thought of this and provide pre-charged flexible line sets that have quick connect fittings.  How long before that check valve hangs up, or wears out?

System Efficiency  -  A 115V mini-split will almost always use more watts than the same size 208/230V counterpart.  This is why a professionally installed system sport SEER Ratings from 22-27!  If disconnected following a heating or cooling season, it is guaranteed small amounts of refrigerant will leak out.  How long before the unit will not operate, or efficiencies are so low the window unit would have been the better option?  Never thought I would have said that…

EPA Clean Air Act, Section 608 – Unfortunately, this ruling that changed our industry for the better almost 20 years ago does not include the restriction of equipment sales including HFC refrigerants, like R-410A.  Although sales are not restricted, it is illegal to vent HFC refrigerants into the air. 

Energy Geek

Energy Savings  -  For a homeowner, competent enough to install this on their own, this could mean significant energy savings in both the Summer and mild parts of Winter.  Imagine how many window units that historically are operating at 7 or 8 SEER would be removed and hopefully scrapped!

Technology Advancement  -  Flexible linesets, precharged, and counted on not to leak is a far cry from some of the poor installs completed by less than competent technicians out there.  Don’t get me wrong, it is much less than 10% that falls into this category.  Maybe this is the one thing the HVAC Industry can take away from this attempt of cutting them out of a booming industry?  Gone may be the days of bad flare fittings, leaking or kinked line sets, and ripped pipe insulation.

Window Sill Accessory  -  This goes against everything I can think of as a Building Analyst.  Let us offer an accessory that can be installed in a window, already the weakest point in an insulated wall, to which a line set can pass through?  What kind of leakage would this cause, moisture pouring in, and offsetting any savings you may have had with the new product?  But, in retrospect, how leaky was it with the window shaker in there all last Summer, oh and Winter since we were too lazy to take it out!

  Can it be possible to put all of the negative factors aside and trust everyone will be installing this equipment correctly?  I can see it now, big box stores renting out DIY install kits and the product being front and center on all of those network television shows.  Maybe the idea of making these systems affordable by cutting out installation labor costs could make sense for some parts of the world.  Please, I do not want to see them in parts of our country that have power problems and Efficiency Rebate Programs to promote the proper design and installation of systems that can save significant electricity!  I would hate to be a Friedrich Dealer in these areas where sales have already begun; I guess things could always be worse…

Views: 2802


You need to be a member of Home Energy Pros Forum to add comments!

Join Home Energy Pros Forum

Comment by Franco Oyuela on February 11, 2019 at 7:16pm


Some of the many benefits include:

Small Size
Energy Efficient
Cost Efficient
Easy to Install
Flexible Applications
Maximum Comfort

Comment by Walter Ahlgrim on June 29, 2014 at 6:54pm

The following quote does not ring true to me

“System Efficiency
  -  A 115V mini-split will almost always use more watts than the same size 208/230V counterpart.”

If you can support this statement with independent research I would like to see it.

When I studied electronics we were taught all watts are equal and do the same amount of work regardless of the voltage that delivered them.

The Friedrich units you linked to have the same SEER ratings with different voltages.

I could agree that larger systems may be slightly more efficient than smaller ones.

I could agree that lower voltages systems cost more to install as the larger gage wires required to move the same number of watts costs more.

I could agree that sometimes low cost systems are designed around less efficient parts to hold down costs.

I wanted to send this question a as a private message but I can’t without Christopher’s permission

I guess I will make a fool of myself in public with my first post.


Comment by Bob Blanchette on May 24, 2014 at 9:14am

Let them sell however they like, homeowners will find a way to buy what they want. Manufacturers could void warranty for DIY install, but they would have to analize how many sales they would loose to competitors who do warranty DIY installs.

Government needs to stay out of the whole thing !!!

Comment by Dennis Heidner on May 24, 2014 at 4:25am

I meant to add that Friedrich's engineering, marketing and sales also blew it.. they also still use the old 115Vac/230Vac for line voltage... sort of makes you wonder what else they missed.

ANSI stuff:

The standard process started back in 1954... pretty much went nation wide in the 70's... very few 115/230 electrical islands should still exist... except perhaps on a geological island...

Comment by Dennis Heidner on May 24, 2014 at 4:15am

Minor corrections,   115Vac/230Vac,  was phased out years ago when ANSI C84.x was adopted.  US wide standard line voltage is 120Vac/240Vac... although many of us still think 115Vac... its been perhaps 20 years.

While there might be a slight increase in the watts between 120Vac/240Vac,  that is likely to be minimal or almost nothing in future years.  The line current may double, but the total watts is likely to be nearly the same.  The reason is that many of the units are going to inverter based technology - and are likely to be using brushless permanent motors in the future.  The days of the permanent split capacitor motors (PSC) are likely to be numbered.

While I'd hope manual J's are done for a house before HVAC is changed, or Manual D and S... those steps are often skipped even by HVAC companies that should know better.  Too much competition.  I've had friends in relatives that have been victim of the "we just upsize the HVAC" so it works right.  Bigger is better aways... until that "jet engine" turns on the first time it is used.

I certainly appreciate the concerns about R-410A,  and perhaps when propane and CO2 are used more frequently as the refrigerant -- the resulting accidents may result in tighter restrictions...

One last comment,  for many years the consumer electronics repair industry had certifications for repair techs.  The goal was to ensure that the consumers were not being ripped off by individuals that had absolutely no knowledge of what they were doing in the back of the TV set, stereo, or early computers.  There are not a lot of repair shops left... technology evolved and local neighborhood repair shops closed down.  We may not like it, but to be honest - how many on this forum have just recycled an appliance or piece of electronics and not frequented the repair shops?  It's a tough chicken and egg problem.  The little shops can't get parts,  customers buy new items...old units get tossed.  Same thing is happening in auto industry.  It has happened in the computer/PC industry.... and you are seeing the beginning of it in the residential HVAC industry.   

Comment by Tom Conlon on May 22, 2014 at 9:58pm

Consumers desperately need options cheaper than the status quo, so at a minimum the creativity of this DIY approach should be applauded. But John Proctor's right. The real issue is that this market isn't innovating fast enough (and to date the Feds have done little to change that). I keep waiting for a disruptor (like maybe a Fujitsu, Google/Nest, even NRG-Solar?)  to swoop in and shake things up, but that certainly hasn't happened yet. Friedrich is making this modestly incremental play, but I suspect the pull-back in their roll-out isn't entirely related to volume. Surely they must be nervous to find out what fraction of real world installations don't go as planned.

To answer your question, I lean toward the DIY advocates (I consider low cost to be that important). But before I decide, I'd like to see a pilot study with side-by-side life-cycle cost analysis of these three currently available ductless options: 

  • Professionally installed high EER/SEER PTHP (240v)
  • DIY moderate EER/SEER PTHP (120v) through the wall
  • DIY moderate EER/SEER PTHP (120v) window grill accessory

Then maybe add some form of third-party-verification on top of all three and run the analysis again.

A well-designed research study would go a long way toward settling this good debate you've raised.

Comment by John Proctor on May 22, 2014 at 12:05pm

Chris  I think it is way too risky to think these can be assembled on site by homeowners given the experience in other countries and with professionals in the US. On the other hand we need to fix the problem. There is no reason that "window shakers" have to shake or be inefficient. However the current rulemaking for PTACs and PTHPs is woefully inadequate to push the market. We could build window and wall units that do not have on site assembly with high EERs and SEERs and they are automatically zoned. The problem is that no one wants to push the market.

Submitting Public Comments

Comments may be submitted through, email, postal mail, or by hand delivery/courier. All comments must be received by May 27, 2014. Please follow the directions below. Also please see the Public Participation section of the notice for additional directions regarding submission format, campaign form letters, and confidential business information.

Any comments submitted must identify the packaged terminal air conditioners test procedure by rulemaking by name and provide its docket number EERE-2012-BT-TP-0032 and/or Regulation Identifier Number (RIN) 1904-AD19. Comments may be submitted using any of the following methods:

  1. Federal eRulemaking Portal: The rulemaking docket at Follow the instructions for submitting comments.

  2. Email: Include the docket number and/or RIN in the subject line of the message.

  3. Mail: Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Office, Mailstop EE–5B, 1000 Independence Avenue, SW., Washington, DC 20585–0121. Please submit one signed original paper copy.

  4. Hand Delivery/Courier: Ms. Brenda Edwards, U.S. Department of Energy, Building Technologies Office, 950 L’Enfant Plaza, SW., Suite 600, Washington, DC 20024. Telephone: (202) 586–2945. Please submit one signed original paper copy.

Comment by Glen Gallo on May 21, 2014 at 3:44pm

Nice Job Chris excellent breakdown. Regarding the snap refrigerant lines the might be ok. I can remember when faucets came out with the snap fittings. I thought really how long is this going last before it leaks. I have had a problem with a few but it was my fault. I must admit that ten plus years later I was wrong and they are fine. Lets hope it is the same with those pre charged lines. Also when you look at the picture they have the condenser right next to the window as well. Not the best idea.

I am considering one for my home as

1) our need for AC is light in my climate

2) initial cost is low

3) the slim condenser unit would be perfect as I can hide it from the wife and not have to hear about that big ugly thing

I have also seen jobs where there is no ducting in areas of discomfort and this would be a problem solver.

Latest Activity

David D Daher is now a member of Home Energy Pros Forum
10 hours ago
Eric Kjelshus replied to Dan Wise's discussion Convert BTU/hr in a Manual J to actual fuel usages
"I do a heat loss/gain each "bid"  some times 3 ways.   I like to use fuel…"
Dennis Heidner replied to Jacob Corvidae's discussion The problems with gas stoves
"One of the VERY first basic science principles that are taught is that "CORRELATION IS NOT…"
Emily Ambrose posted a blog post
Profile IconHannan Ahmad and Eryn Spellman joined Home Energy Pros Forum
David Byrnes's blog post was featured

Why Phoenix Is Called "The Land Of No Return"

 Maricopa County is the fastest growing county in the nation with the population expected to grow…See More
Roy Terry posted blog posts
Kent Browning replied to Jacob Corvidae's discussion The problems with gas stoves
"First - in answer to your question - I am not a PhD climatologist. I work with PhD's and they…"

© 2019   Created by Building Performance Association   Powered by

Badges  |  Report an Issue  |  Terms of Service