First of all, thanks to those of you who responded to my questions back in Dec 2013 regarding radiant ceilings.
Well, the house in question is under construction and I am finally designing the radiant heating/cooling system. I am working with dsdesignconsultants.net to provide the actual mechanical design of the system, but am personally responsible for designing the radiant panels re placement, size, and construction.
I am utilizing 90% radiant ceilings with a little bit of wall and some floor. My current plan is to utilize 1/2" PEX-AL-PEX (to reduce thermal movement) snapped into ThermoFin U transfer plates, and building panels similar to the ones shown in John's Modern Hydronic Heating except at 6" spacings.
For some areas where I just do not have enough ceiling space for the expected Btu output of the system, I am looking at Ray Magic Panels
I have asked Daniel (DS Design) and Robert Bean (via his Radiant Based HVAC group
) for information on how hydronic heating acts in a vaulted space. Both provided some good insight. Daniel provided an excellent report from Frenger Systems in the UK (attached) that discuss high ceiling radiant performance.
Prior to reading the Frenger report, I was concentrating all of the radiant cooling and heating required, at the 'pedestrian' level in the house so the people could 'feel' the radiant efforts. But after the report, I instead started thinking of the panels as just another type of 'insulation', in that they can be utilized to stop the heat loss or gain at the sources (see pg 19 & 27). SO for instance, this report talked about having the panels located where their rays can help keep the inside face of the window warmer which increases the occupants average experienced temperature.
I believe this makes a lot of sense (no pun intended), and I am wondering how many agree or disagree with this approach as I do not have ANY actual practical experience designing or living in a radiant dwelling (just a moderate amount of schooling).
With this new (for me) concept of how to treat radiant, I now think that for my three separate areas with vaulted ceilings
that instead of trying to overcome the loads, inserted by the surface areas and windows of those vaulted spaces, down at the pedestrian level, I should instead install wall and ceiling panels in the vaulted part of these spaces to handle the loads imparted by these spaces. I would still have lower panels to deal with the general losses and gains from those rooms, but they would be smaller panels now that they do not have the added loads from above.
Does this sound like a reasonable path forward?
Many thanks for all insight!