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…

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