hydronic in Texas

Brandon_4

Contact these guys and see what they can offer you.
www.hpscontrols.com

Jim Sargent

hydronic heating in Texas

I have a custom home (4957 heated and cooled sf) to build in the Dallas area. It is one story slab on grade. The first run or two on heating loads show that I will expend 11196 Million kWh. A little unusual as my Cooling load is only 4410 Million kWh.
There is very little information about hydronic heating in our area and the usual response is that the slab will hold the heat too long as we might start off with a cool morning and be at 80 by 2:00 pm in the winter.
Almost all the information I find is written for areas where the outside temp and ground temp is somewhat cooler than ours.
My gut feel is that it would take very little additional hydronic heat to keep the house comfortable in the winter and that might allow a different layout of the pex tubing.
The design of the house has eliminated the ability to have any passive solar gain in the the winter and I am trying to determine if a hydronic system will help me.
I'm looking for a consult and then possible design work. I would suggest a short conversation where I lay out my thoughts and concerns and you can tell me if you can be of help and how we would structure a fee.
If you want to know a little more about us, you might google AndersonSargent.
Jim Sargent
AndersonSargent Custom Builder LP

jp_2

numbers are way off here

at a cost of 1 cent per KWh your 4410 million KWh would cost $44 million dollars.

Jim Sargent

Yes,
You are right forget the Million part of both numbers
Jim Sgt

Home Depot Employee

Texas Radiant

Jim,

While Texas doesn’t see a lot of radiant installed, I wouldn't be discouraged to do it if that’s what you desire. Radiant still has its benefits regardless of the climate, but in your case you would benefit from it less. Being me, and most southern build has the diffusers located high, I would take the warm hardwoods, ceramic or marble tile any day.

With regards to design and layout, it is just as important to maintain standard principles of layouts that most importantly include the distance between loops and lengths. While your load requirements may allow smaller tubing, you do not wish to fall prey of the notion that you can increase the spacing which would result in thermal differences in the floor temp.

Most importantly, an outdoor reset system, injection or modulating is needed to eliminate the possibility of overshooting the temp in the house. Your concern of overshooting the room temp as the floors have some residual heat is valid yet, being in a semi-humid environment, this could be a benefit. Perhaps the AC load would be increased by 5-10% annually but, this could be considered as a plus for the dehumidification benefits in the home.

Home Depot Employee

Your loads are closer to:
110,000 net heat
7-8 tons cooling

GLENN_14

radiant cooling?

You may want to also look at radiant cooling. It is starting to be used more in the southwest. dry climate is a must. You could benefit by having cooler floors in the summer but be careful of dew point issues.....

Home Depot Employee

Not in Dallas

Besides not to advisable for residential-I haven't met a woman yet that enjoys cold feet.

Remember where your bread is buttered!

don_192

Sounds

Sounds more like a job for a geo system.Thats is if your electric rate are fairly close to gas.

tim smith

Regarding radiant in Texas

Due to the flywheel effect and the drastic changes in daily temps some days, maybe better off with warm board or quick track. This would allow for faster heat up times and faster cool down with still enjoying the warm floor aspect. Regarding radiant cooling, may be to high of humidity down there for that, just a thought. Tim
Geo sounds interesting also I would think for heating and cooling in there locale. Good luck

tim smith

Also they build green

Another reason for Geo I think.

[Deleted User]

It can be done...

But being Green comes with a price tag that generally shocks people into wanting to be maybe NOT so green, like maybe pale green...

So, we developed a pale green system.

Drill enough holes to cover your worse case cooling scenario, based upon your needs, (300' per ton here in Colorado, YMMV) then use that capacity to base load the radint heating system. I agree with the use of a fast reacting, low mass, ultra low mass (electric radiant surfaces) for the heating needs of the system. They can both be easily proportionally flowed to acheive near perfect thermal balance in nearly any envelope. Build the building, then install a system that meets the thermal comfort needs of the OCCUPANTS, not the building. Let the building do its thing. If you do your job right, the mass will reflect your work in human thermal comfort.

Set up a 2 stage control with full outdoor reset. Limit the first stage to 115 degrees F unless you're really in to replacing compressors, and potentially wasting energy. I guess the COP wold never get below 1, buh there are so many "DEPENDS" in the geo filed, you'd best back it up with something else. Electric units are the cheapest to install. But you can use whatever source YOU want for the 2nd stage. Preferably modcon. Just set the curve, and using non electric TRV's or equivelant electric radiant systems, the 2nd stage might never come on, 'cept maybe to finish topping off the DHW system for sanitization cycle (180 degrees?) so make sure your second stage has enough ooompf.

Then, using the hydronic capacity of the system, and a high velocity cooling system, you can stabalize the mass by maintaining a relatively low humidity, and 75 would be MORE than comfortable. Small individual multi zone multi speed AHU's with outdoor air injection from a ERV, and you got happy people :-)

But get ready to spend some green. Like 3 to 4 times as much green as it would cost for a "conventional" system...

But the bodies will thank you. And happy people tell other people, and the next thing you know, you're a hot commodity. With happy bodies.

Variable speed systems rule.

ME