1. DanWildenhaus
   Member
   

   This is from a friend of mine. It started a VERY lively email chain. Thought I'd see what the HPW crowd thought. Consider it a challenge to see if our conversation can match the email chain (David Vollan, Tom Balderston and Jason Lear know what I am talking about)

   Hi-
   Has anyone heard of, or used the Matrix by NY Thermal (NTI), which integrates space and water heating with ventilation (heat recovery ventilation) and air conditioning, all in one?:

   http://www.ntimatrix.com/

   Jim Burton

   Posted 8 months ago #

2. Charlie_Rogers
   Board Secretary
   

   Hooray! The magical black box that does everything and solves all of our problems for us. What more could we ask for?

   I don't have any experience with this product, but it sounds like more box-specific thinking. What about the ducts...? Air sealing or insulation...? I'll guess it has lots of quirks and limitations too. I'll take a look at the technical specs and let you know what I find.

   Posted 8 months ago #

3. Charlie_Rogers
   Board Secretary
   

   So I'm guessing the recent conversation was sparked by Environmental Building News' February 1 article about the Matrix. You have to pay to play, but you can read the full article here:

   http://www.buildinggreen.com/auth/article.cfm/2009/1/29/Matrix-Total-Home-System-Offers-All-in-One-Efficiency/

   The article flat out says the $7,000 to $9,000 sticker price is not cost effective in homes using only forced air heating. And in the May 2007 Energy Design Update issue, Rob Alexander--a representative of the manufacturer--admits the Matrix does not make economical sense for houses that heat their whole house with hydronic. He says it would be better to get a stand alone boiler and HRV. So, basically the Matrix is designed for high end homes that use both forced air and hydronic heat (or have a heated pool). That pretty much rules out all the houses I have audited (and the vast majority of American homes).

   I would imagine something like this would be hard to install in an existing home. You would have to get all the water pipes, hydronic pipes, air handler, plenums and HRV ducts in the same room. Sounds like a nightmare. And what if one of those existing systems--say a water heater--is efficient and not near it's end of service? Would you just scrap it?

   OK, so say you're doing a deep retrofit and gutting the place. Or maybe it's new construction. So you have plenty of room to configure the system. Even then, why not just pay careful attention to detail when air sealing and super-insulate the house? Then you won't hardly even need a heating system!

   The HRV is only 65% efficient. Better than nothing, but for $7-9,000 I would expect a gold-plated heat exchanger.

   Also: The domestic hot water output is only 4.2 gpm. And when hot water and heat compete for output, the system gives the water priority. So what happens when someone does a load of laundry or runs the Energy Star dishwasher? No space heating and no hot showers?

   The 4.2 gpm also assumes a water temperature rise of 55F to 120F. So if your incoming tap is colder than that (my city water is coming in at a cool 49F), the performance will drop further.

   There will be long wait times for hot water (and the wasted cold water down the drain and customer complaints that come with it) because from a dead stop it takes the Matrix 15 sec to start providing heat and a total of 25 to deliver the heat. (I'm not sure what pipe diameter and distance is assumed for this math, but in a high end home with long pipe runs I imagine these times could increase significantly).

   It gets worse: if you momentarily turn off the water, it takes the Matrix another 45 to 75 seconds to redeliver hot water (and wastes cold water down the drain the entire time).

   So then you might want to install a holding tank of hot water and a demand actuated recirculating pump, right? Well then you would have heat loss from the tank and...well, defeat the purpose of the all-in-one dream machine...

   Posted 8 months ago #

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