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I thought about adding this to Jason Wise’s question about mixing a pex IFR bath system with rads, but the replies lead me to think it’s different enough to need its own discussion. I “inverted” my house a few years back, locating the living space on the second floor and the bedrooms on the first, to make use of a great view. I’m about to replace the boiler on an old two-pipe rad system and would like to use copper fin baseboard on the second floor, but leave the rads on the first. The reason is that while the first floor is a traditional arrangement of separate rooms, the second is now basically one big space where the furniture sits well away from the walls. I also built a mostly-glass addition (7×17) to that large space, and it needs more heat. The connections to the existing feeds would be easy, and I’d love to get rid of these big rads that look odd in their positions now that walls have been eliminated. I spent a good bit of time on Don Holohan’s site, but his Q&A doesn’t address two-pipe systems at all, and I couldn’t find anything about a “mixed” system like the one I’m considering. ALSO, if anyone knows of a really competent hydronic heating contractor in Pittsburgh, please let me know. Forced-air pretty much rules here, and I actually had one guy say, “Sure, we do hydraulic heat.” Thanks. John
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Replies
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John,
My understanding is that you shouldn't mix the two, based on the differing needs for temp and flow (rad's need low temp, high flow, fins high/low or maybe the other way around.)
I know a good HVAC contractor in Pgh (I learned the above from "Chuck") but I'm damned if I can remember his last name. It may come. He's an independent, mainly does repair/maintenance, also does good plumbing work (and is reasonably priced!)
I'll e-mail you if it comes to me.
*A thermostatic radiator valve fitted to each unit will allow for balanced hat in a mixed system, or a house with mixed envelope performance. It may be the only way. To do it right, the boiler should be controlled a little differently but satisfactory results can be had with a traditional thermostat turning the heat on and off.
*
I thought about adding this to Jason Wise's question about mixing a pex IFR bath system with rads, but the replies lead me to think it's different enough to need its own discussion. I "inverted" my house a few years back, locating the living space on the second floor and the bedrooms on the first, to make use of a great view. I'm about to replace the boiler on an old two-pipe rad system and would like to use copper fin baseboard on the second floor, but leave the rads on the first. The reason is that while the first floor is a traditional arrangement of separate rooms, the second is now basically one big space where the furniture sits well away from the walls. I also built a mostly-glass addition (7x17) to that large space, and it needs more heat. The connections to the existing feeds would be easy, and I'd love to get rid of these big rads that look odd in their positions now that walls have been eliminated. I spent a good bit of time on Don Holohan's site, but his Q&A doesn't address two-pipe systems at all, and I couldn't find anything about a "mixed" system like the one I'm considering. ALSO, if anyone knows of a really competent hydronic heating contractor in Pittsburgh, please let me know. Forced-air pretty much rules here, and I actually had one guy say, "Sure, we do hydraulic heat." Thanks. John