DIY Hydronic Floor Heating

[buffalobillpatrick]

Hey Stevehull, that's pretty rare to have radiant heat floors + A/C isn't it?

I figured that anyone with A/C ductwork would pick cheaper FANG

[Mobile Master Tech]

I have hydronic floors and A/C too. I wanted the floors to be the heat source for efficiency, comfort and the ability to use solar heat stored geothermally. You can't cool building surfaces for AC this way because of the condensation. Vapor compression is the easiest efficient way to get cooling. Wanted air filtration too, so this means forced air. Since the heatpump version of my equipment is 20 SEER instead of 23 for the straight cool and I wanted the bulk of heat to come from the floors, I chose the cheaper straight cool version.

[stevehull]

BBP,

Here in central Oklahoma we have about 3600 heating degree days and 1800 cooling degree days. Low low heat design temp is about 0 F and 100 is the high cool limit.

So we need both. Too humid to cool floors as condensation issues when dewpoint > air temp.

Pollen is also real high here (almost year round) so pleated high efficiency (98% arrestance at 10 microns) filters on a low CFM air handler do a great job on that.

Steve


Steve

[Mobile Master Tech]

HERE is a description of a lot of my system and house. The more detailed thread about annualized storage of heat for floors and DHW is HERE.

The updated controller improves SEER to 23, and I have decided to go with a 330gal IBC tote with 234 gallons of phase change material in it instead of the 2000 gallon tank I described to buffer the floor and DHW.

That bag filter is way oversized: 96sqft (16 24x36" surfaces) of filter area-no significant restriction there! It hangs down vertically so it works at ultra low flows. Any other orientation and it would just collapse on itself. It is MERV 14 as recommended for hospital general operating rooms as well as pollen, but I haven't changed it in 4 years because the MERV 4 prefilters catch the lion's share of contaminants. Having so much surface area plus longer life due to the prefilters allows ultra filtration without overwhelming the head capacity of the blower.

[buffalobillpatrick]

MMT,
On the tote tank, I recommend the HDPE food grade, tough stable stuff.
I'm interested on how the phase change works out, I hope great.

[Mobile Master Tech]

Yep, those are good for 230F instead of the usual LLDPE at 150F. Any pointers on how to tell one from the other on quick visual inspection?

[buffalobillpatrick]

They will be stamped Food Grade and/or PEH

Have U seen these threads?

http://ecorenovator.org/forum/solar-...affin-wax.html

http://ecorenovator.org/forum/geothe...hp-source.html

http://ecorenovator.org/forum/solar-...e-storage.html

[buffalobillpatrick]

When I build my next house, I will use active solar, I got the panels & BIG 1,000gal tank cheap off craigs list.






I got a new Vie$$man dual coil 79gal indirect DHW SS tank off Ebay, $1000

My small Burnham RV3 boiler / solar system will add heat to tank via the bottom coil.
If solar tank is hot enough it will provide heat to Vie$$man tank.

The 79gal water contained in the tank will provide DHW (with TMV tempering it down to 134*F) with recirculation to fixtures.

The top coil will provide low temperature ODR controlled heat to the pex in concrete floors, continuous circulation with 3-way zone valves.

An Erie Boiler Boss 3000 Outdoor Reset Controller (another Ebay steal $160) will control the speed of a Taco 007

ECM pump can't be used here as Erie BB3000 unit uses PWM to control the variable speed of standard PSC motor pumps:

Note:
permanent-split capacitor (or PSC) motor also known as a capacitor-run motor, Power Factor typically from around 0.85 or 0.90 at full load to as low as 0.12 at no-load

[buffalobillpatrick]

My DIY Hydraulic Seperator / Mixer

Goes between top coil in Vie$$man tank and pex heat distribution system.

Main body is 2.5" cast iron fittings.

I copied this design from Caleffi $$$, it has rolled up fine mesh SS screen inside to remove air in system, Watts air vent on top.

Bottom has a drain valve, junk in system naturally settles there as water velocity slows down inside body, it has a strong heat proof magnet contained in drain.

IMPORTANT: Any system that has any steel or cast iron components with ECM pumps, needs magnets to capture the generated Magnetite, which would build up on PM rotors.

Heat input on upper left & return on lower left, the Vie$$man top coil is connected here.

System heat output on upper right (to zones) & system return on lower right.

Heat input pump from Vie$$man tank is a Taco 007, which is speed controlled by Erie BB3000 with it's feedback temp. sensor on right (output) after Alpha

[motoguy128]

Originally Posted by stevehull

BBP,

Here in central Oklahoma we have about 3600 heating degree days and 1800 cooling degree days. Low low heat design temp is about 0 F and 100 is the high cool limit.

So we need both. Too humid to cool floors as condensation issues when dewpoint > air temp.

Pollen is also real high here (almost year round) so pleated high efficiency (98% arrestance at 10 microns) filters on a low CFM air handler do a great job on that.

Steve


Steve

You can get some sensible cooling with radiant floor. You take the return water off a 3 row coil with a low approach temp, and run it to the radiant. If needed, you can still add a mixing valve to make sure the water stays over 55-60F, especially in kitchen and bathrooms. It will only be a fraction of your capacity, but it reduces drafts.

But then you can save but reducing air handler and ductwork size to a minimum, mainly just for fresh air and air movement. A high velocity system might work well for this.

Further, the best set-up for water to water geo, is ideally to have a single loop between hot water, chilled water and ground loop. Then you simply pump to each loop as needed. But I'm not aware of any residential companies that are doing this. The advantage is precise humidity control and if combined with a small fluid cooler and solar, you don't need nearly as much ground loop capacity.