DIY Hydronic Floor Heating - Page 44

buffalobillpatrick · 03-31-14, 12:01 PM

Yes, more thermal conduction is goal.

AC_Hacker · 04-01-14, 12:48 PM

Quote:

Originally Posted by buffalobillpatrick

Yes, more thermal conduction is goal.

I found THIS paper about additives to concrete to improve thermal conductivity.

-AC

Drake · 09-09-14, 12:55 PM

As I have been searching for a control panel system to match a simple 2 or 3 loop one zone radiant layout I have been asked by suppliers "what is the hot water source?" Are control systems that specific to method of hot water? I want to stay as generic as possible to be able to switch "sources" as availability, knowledge of DIY and economics change. The manifold and loops are constant if designed properly what are the components that are specific to water source? Is their a design that gives you the most options? Are the requirements based on on-demand or storage sources? Or high temp vs low temp supply?

buffalobillpatrick · 09-09-14, 01:32 PM

Drake, Will your loops be in a slab that is properly insulated with FOAM R10 or more underneath, or in heat transfer plates, or suspended under subfloor?

The water temp. required for each method is quite different, say aprox. 25*F Delta up with each.

Gain in efficiency is pretty large with minimizing water temp.

No boiler is made small enough for a small heat load, thus a buffer tank would be required.

The PEX loops & manifold could stay the same regardless of heat source, mine have.

Drake · 09-09-14, 06:05 PM

Yes, two loops will be in a high mass(4") slab with 1 1'2' thermax below. And a third loop in a thin slab(1 1/2") in a lofted bedroom. 600 sq ' new space will be built to "passive house" standards. Am favoring off peak heating a 120 gallon DHWH tank as storage and incorporating a mixing valve to lower loop temps as slab are said to work best supplied with lower temp fluid. Tank and loops a dedicated system, another DHWH sperate for potable use. But in the future I would like to go Geo or something when I have the time after completing the build(4-5 yrs) as a heat source with as little retrofit as possible.

AC_Hacker · 09-09-14, 07:43 PM

Quote:

Originally Posted by Drake

Yes, two loops will be in a high mass(4") slab with 1 1'2' thermax below. And a third loop in a thin slab(1 1/2") in a lofted bedroom. 600 sq ' new space will be built to "passive house" standards. Am favoring off peak heating a 120 gallon DHWH tank as storage and incorporating a mixing valve to lower loop temps as slab are said to work best supplied with lower temp fluid. Tank and loops a dedicated system, another DHWH sperate for potable use. But in the future I would like to go Geo or something when I have the time after completing the build(4-5 yrs) as a heat source with as little retrofit as possible.

If you think you will want to 'go geo', be sure you design your floors for geo now... it'll make your conventional heating cheaper too, in the meantime..

-AC

buffalobillpatrick · 09-09-14, 11:56 PM

Drake, I would make it 2 zones with seperate thermostats, 2 zone valves & 1 pump.
With different slab thickness & bedrooms are usually set at lower temp.
I like the Grundfos Alpha, low electricity use & automatically sets its own speed to match backpressure.
Use O2 barrier 1/2" PEX spaced at 8" OC, limit each loop to 250'
Get a Taco Outdoor Reset Thermal mixing valve (ODR TMV). It will minimize water temp. to zones based on outdoor temp.

Drake · 09-10-14, 08:51 AM

AC, to the best of my research high mass(concrete) floors are the best design for low temp hydronic radiant heating I have come across. It also is the best for solar passive gain storage. I have gotten a consensus that this floor design will function equally well with any source of hot fluid run thru it. From your comment am I missing an alternative design?

BBP, all your recommendation are now in my folder on hydronics for when I get to that part of my new construction. Am I correct that all these components would be part of what is considered the "control panel" portion of a hydronics system?

Ormston · 09-10-14, 09:18 AM

Quote:

Originally Posted by buffalobillpatrick

Use O2 barrier 1/2" PEX spaced at 8" OC, limit each loop to 250'

Why limit to only 250' ?
I have 2 zones of 800-850' (240-260m) each as well as 6 other zones all fed from a a single grundfos alpha 2.
This is through 17mm PEX, the pump usually draws 21w so is not struggling at all.

Steve

buffalobillpatrick · 09-10-14, 09:49 AM

Drake, yes control components. What does your " 1 1'2' " mean? 1.5" not nearly enough.

THERMAX? Sheathing

Thermax is polyisocyanurate foam, this type should NEVER be used under a slab, it will waterlog & loose most all of its R-value.

In Mn. I would use 4" minimum or MORE of XPS (blueboard) or EPS type2 or 3

To push 1gpm through 800' takes 3.2X energy vs. 1gpm through 250'
Read: Modern Hydronic Heating by John Siegenthaler, P.E.

09-09-14, 11:56 PM	#437
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Drake, I would make it 2 zones with seperate thermostats, 2 zone valves & 1 pump. With different slab thickness & bedrooms are usually set at lower temp. I like the Grundfos Alpha, low electricity use & automatically sets its own speed to match backpressure. Use O2 barrier 1/2" PEX spaced at 8" OC, limit each loop to 250' Get a Taco Outdoor Reset Thermal mixing valve (ODR TMV). It will minimize water temp. to zones based on outdoor temp. Last edited by buffalobillpatrick; 09-10-14 at 12:48 AM..

09-10-14, 09:49 AM	#440
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Drake, yes control components. What does your " 1 1'2' " mean? 1.5" not nearly enough. THERMAX? Sheathing Thermax is polyisocyanurate foam, this type should NEVER be used under a slab, it will waterlog & loose most all of its R-value. In Mn. I would use 4" minimum or MORE of XPS (blueboard) or EPS type2 or 3 To push 1gpm through 800' takes 3.2X energy vs. 1gpm through 250' Read: Modern Hydronic Heating by John Siegenthaler, P.E. Last edited by buffalobillpatrick; 09-10-14 at 09:53 AM..

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03-31-14, 12:01 PM	#431
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Yes, more thermal conduction is goal.

09-09-14, 12:55 PM	#433
Drake DIY Guy Join Date: Jan 2011 Location: Mpls,MN Posts: 315 Thanks: 2 Thanked 17 Times in 17 Posts	As I have been searching for a control panel system to match a simple 2 or 3 loop one zone radiant layout I have been asked by suppliers "what is the hot water source?" Are control systems that specific to method of hot water? I want to stay as generic as possible to be able to switch "sources" as availability, knowledge of DIY and economics change. The manifold and loops are constant if designed properly what are the components that are specific to water source? Is their a design that gives you the most options? Are the requirements based on on-demand or storage sources? Or high temp vs low temp supply?

09-09-14, 01:32 PM	#434
buffalobillpatrick Master EcoRenovator Join Date: Mar 2014 Location: Florissant, Colorado Posts: 599 Thanks: 814 Thanked 59 Times in 55 Posts	Drake, Will your loops be in a slab that is properly insulated with FOAM R10 or more underneath, or in heat transfer plates, or suspended under subfloor? The water temp. required for each method is quite different, say aprox. 25*F Delta up with each. Gain in efficiency is pretty large with minimizing water temp. No boiler is made small enough for a small heat load, thus a buffer tank would be required. The PEX loops & manifold could stay the same regardless of heat source, mine have.

09-09-14, 06:05 PM	#435
Drake DIY Guy Join Date: Jan 2011 Location: Mpls,MN Posts: 315 Thanks: 2 Thanked 17 Times in 17 Posts	Yes, two loops will be in a high mass(4") slab with 1 1'2' thermax below. And a third loop in a thin slab(1 1/2") in a lofted bedroom. 600 sq ' new space will be built to "passive house" standards. Am favoring off peak heating a 120 gallon DHWH tank as storage and incorporating a mixing valve to lower loop temps as slab are said to work best supplied with lower temp fluid. Tank and loops a dedicated system, another DHWH sperate for potable use. But in the future I would like to go Geo or something when I have the time after completing the build(4-5 yrs) as a heat source with as little retrofit as possible.

09-10-14, 08:51 AM	#438
Drake DIY Guy Join Date: Jan 2011 Location: Mpls,MN Posts: 315 Thanks: 2 Thanked 17 Times in 17 Posts	AC, to the best of my research high mass(concrete) floors are the best design for low temp hydronic radiant heating I have come across. It also is the best for solar passive gain storage. I have gotten a consensus that this floor design will function equally well with any source of hot fluid run thru it. From your comment am I missing an alternative design? BBP, all your recommendation are now in my folder on hydronics for when I get to that part of my new construction. Am I correct that all these components would be part of what is considered the "control panel" portion of a hydronics system?