Chiltrix Questions
I’m going to be building a 3000 sq. ft. superinsulated house near Rochester, NY, zone 5. It’s a single story with R-40 walls, R-70 roof, and R-20 under the slab. I’ve had a room-by-room manual J professionally done . The total load for the house is 27914 BTU/h heating at 7F and 18534 BTU/h cooling at 86C.
I’m considering a Chiltrix system. I like the idea of a centralized chiller with fan coils distributed where the loads are. There are hydronic contractors here, so I’m not too worried about the install. I actually ran into a local company with experience with Chiltrix systems.
The cooling capacity of a single chiller is sufficient for the entire house. However, the heating capacity is only 17-18kBTU/h at 7F. Two chillers would be 20-30% oversized for heating, but 3-4x oversized for cooling. I could turn one chiller off from April to November, but that seems wasteful.
My main question: Would it be overly optimistic and risky to simply install a single chiller and see if it’s enough for the winter? That’s around 60-65% of the manual J. I could wire and plumb to allow a second to be installed if found necessary.
Here are some side questions: Does anyone know the turndown ratio of a chiltrix unit? What insulation thickness is recommended for the outdoor pipes in a cold climate? Any new feedback or info on the units that hasn’t already been posted on GBA?
Thanks!
–John
P.S. A central minisplit design, though appealing, won’t cut it. Among many reasons, we close our doors to keep pets out of our bedrooms and offices, and the house doesn’t have central rooms that will allow heat to spread.
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Replies
John,
If you haven't read it yet, you should read this article: Air-to-Water Heat Pumps.
In your climate, I would definitely be worried about the outdoor pipes freezing. (I imagine that you can use a solution of antifreeze and water to lower the chance of freezing.) As noted in my article, very high levels of pipe insulation are essential.
If you have done a careful job on your Manual J, and it sounds as if you have, then a heating appliance that only handles 60% to 65% of the load won't work. (By the way, the turndown ratio for the Chilltrix appears to be 25%.) So if you want to install only one Chiltrix unit, you'll need to either (a) install a few electric resistance space heaters, or (b) install a Mitsubishi or Fujitsu ductless minisplit in your living room to provide supplemental heat during cold weather.
-- Martin Holladay
Hi John,
I don't know if you'll get a notification on this old question but I'm wondering what system you went with. If you went with Chiltrix or something unusual, it would be great if you shared your experience here.
Thanks.
Note that Chiltrix offers a backup heat option:
http://www.chiltrix.com/hydronic-backup-heater/
+1 on the request for an update from John
There are a few options, Aermec have been in North America for 12 years now and are not made in China
+1 on an update from the original post.
I am debating myself to install several mini splits vs chiltrix.