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Old 08-10-12, 08:50 AM   #6
AC_Hacker
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I'm reading through your blog about your hydronic install...

How would you describe the length & severity of your heating season? Average information is important, but also the extremes that you have seen since you have lived in your house.

Does this average temperature chart seem to reflect your experience:


average temperature - Rohnert Park, CA

I also looked up your average Heating Degree Days for Rohnert Park, CA and the 5 year average, assuming that your base heating level is 65F, calculates out to 4172 heating degree days. This doesn't make any difference to you, but it might if someone was installing their own system, they could find out what the HDD was for their locale and compare it to your HDD and would have a rough idea if your design would work for them, too.

From what you have said so far, I assume that your house is built on a slab that has no insulation underneath, correct?

Regarding insulation, you said that your house was pretty well insulated...
  • What exactly do you mean by that?
  • Did you do the insulation yourself?
  • What is the thickness of your outside walls?
  • What kind of filling is in them?
  • Do you have single pane/double pane/triple pane windows?
  • Aluminum window sashes?
  • Vinyl sashes?
  • Wood sashes?
  • Did you do any kind of a heat load analysis (similar to Manual-J)?
  • Have you done a blower door test on your house?

In reading your blog, I saw that you didn't do any insulation UNDER your floor... and that you chose a thin foam underlayment to go OVER your floor, under your final flooring... Any thoughts on that?

I don't know if you looked at Vlad's hydronic install yet, but he built his own house (6" walls filled with mineral wool, 2x pane windows, highly effective infiltration prevention) and he did a similar install to yours, with just a few differences. His house is three stories tall, so it is somewhat more of a cube than your single level house (ranch I would assume). Since his 'cube-ish' would have lower surface area per unit volume, it would favor lower heat loss, too. Anyway his water feed temperatures are running about 95F to 100F, as I recall, which is astoundingly good, especially considering that he lives just outside Vancouver, Canada where his average HDD is about 5481 which is a fair bit higher than yours.

By the way, you haven't gone into any detail as to how you plan to get the heat into the water... and how you plan on regulating temperature/

I will be very interested to see how your system performs as winter comes to visit us. Please keep us posted!

Good work, Olaf... it's a big job that should last the rest of your life.

Best,

-AC_Hacker
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