09-08-14, 04:47 PM | #1 |
DIY Guy
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fluid xfer in passive solar mass floor??
I am installing a high mass concrete floor 16x40 that will have hydro radiant tubing in it for heating but the floor also will have large exposure to southern windows for passive solar gains. Direct sunlight will hit about 1/3 of the 16' depth of the room on sunny days. About the first 3' will be shaded by low knee wall under windows, the next 6-7' in direct light and the last 5' or so again shade. I am exploring the possible advantage of using fluid in tube to xfr solar heat gain throughout the whole floor not in direct light. Anyone know of any this?? Possible that the direct light hitting is not far off center of the fairly narrow/long floor and with diffuse light might already store heat pretty evenly. Can an existing radiant loop be used without adding more heat to make it flow?? Maybe a second loop of tubing? Floor surface will be a dark ceramic tile(shaded in summer). Curious of anyones experiences.
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09-18-14, 02:42 PM | #2 |
Master EcoRenovator
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Yes, a radiant floor system can be used to move solar gained heat from one area to other areas of a floor or even other rooms of a house. We did this in a large log home for my neighbor. I designed this system with constant circulation with zone valve heat injection. Large window area to West view heats up floor in that side of house & heat is moved by circulation to cooler areas.
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09-23-14, 06:29 AM | #3 |
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I do this with all my passive home installs. The simplistic method is to just have the circ pump run when there is a call for heat and have the boiler run on return water temp. That way it will come on less, or modulate down further, because the average water temp has been increased slightly.
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The Following User Says Thank You to Mikesolar For This Useful Post: | buffalobillpatrick (09-23-14) |
09-23-14, 03:18 PM | #4 |
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Any boiler that can keep a house warm at design temp, even a 5:1 turndown ModCon, will be too powerful when 1 zone calls for heat & it's 50*F outside. That's why I like buffer tanks.
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09-24-14, 11:41 AM | #5 |
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"Most people understand that oversized equipment has a higher first-cost. However, oversized equipment also costs more to operate due to increased cycling losses. Short run-times are like stop-and-go driving: system efficiency drops off as cycles become shorter. "
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09-24-14, 05:25 PM | #6 |
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5:1 turndown is soon a thing of the past. It was only limited to that for testing reasons but they have been resolved so look to see some 20:1 turn down coming soon.
That said, if a house has a design heat loss of less than 50Mbtu, it is better to use a vertex or polaris HE tank, if you want to use gas. Still put them in but getting away from boilers, more and more. |
09-24-14, 05:45 PM | #7 |
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Still have a bad taste in my mouth from 10 years with a HTP Voyager on LP at high altitude.
Have they fixed the howling blowers? |
09-24-14, 05:49 PM | #8 |
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Way quieter now. The early Polaris/Integra were kind of noisy but not any more.
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