Solar radiant Heat

[RichNJKubota]

AHH I was confused, (AS USUAL ) anyhow this is going to be more of a home made solar collector then or are the panels store bought as well?
Mark M

The evacuated glass tube collectors are factory made. They install rather quickly with little effort. The glass tubes plug into the manifold at the top.

 

[Squeak n Itch]

But I wonder why you think you'll need less heat if you go radiant vs. hot water baseboard? If your house needs, let's say 100,000 BTU per hour at 0F outside temp, then does it matter whether it's radiant or baseboard? Or am I missing something?

The answer is the decrease in the loss on the way to the 100,000BTU of usable heat:
First, heat transfer is partly a function of the temperature difference between the fire and the water. The higher the difference the faster the heat moves between the two. Admittedly, the difference here is a matter of only 100 degrees or so (100F for radiant and 200F for the finned radiators).

Second, the higher your system temperature the more losses you have through the walls and windows.

Finally I suspect, at least in my own house anyhow, there is considerable loss as the baseboard radiators are connected to the outside wall with the conduction loss that follows. When built I would have been smarter to have put at lease a 1/4" foam insulator between the wall and radiator.

 

[randydupree]

i lurk over here quite a bit.
i never post much but this thread is about the same kind of project i have in an old warehouse we are building a loft type home in.
i poured new floors with the pex tubing in the slab for the RH.
i have 9 solar panels that i have bought used that i;m going to use for heating the water.
this building is in SW ga.,near the fl. state line.

i'm also going to do a geo-thermal AC system,closed loop,buried pipe in the backyard.

a question i have for you guys,can i run cool water from the geo-thermal loop through the floor to help cool the building in the summer?
say,72 degree water?

Randy

 

[SpringHollow]

Running cold water in a radiant floor system can lead to sweating in humid areas.

I have radiant floor heat and love it. It is extremely comfortable. However, multiple real life studies have shown that the energy savings of such a system is hype. Even though one does not get the stratification, etc of other forms of heat and the water temperatures are lower, they did not find any noticeable savings. Their findings were contrary to their expectations. The studies had been intended to prove the savings.

We installed an evacuated tube system in Rochester, NY which has the honor of being one of the cloudiest cities in the country during winter. On days when it was in the 30s and raining, it would produce boiling water. It was truly an amazing system. They finally took it down after 23 years when they were reroofing, afraid they would fail soon. The system heated the insulated 40' lap pool we installed in the timber frame addition we built for them (doubled the size of their house), heated their house, and their domestic hot water as well. It did not heat their jacuuzi. It really was a great system. Solar tax credits made it affordable.

Ken

 

[philbuilt]

hey all,
I will post more but a tree by the house was hit by lighting and we won't have INTERNET till Friday. I'm on the porch wheezing from the neighbors.
With permission of coarse. keep posting it's all good.
Phil

 

[randydupree]

the radiant heat just feels good!
with my solar panels i think it will be cheap heat,of course i'm way down south.

 

[dmccarty]

Even though one does not get the stratification, etc of other forms of heat and the water temperatures are lower, they did not find any noticeable savings. Their findings were contrary to their expectations. The studies had been intended to prove the savings.

That is interesting and makes me happy about or decision to NOT install RH in the house. The house has a colored concrete slab as our finished floor. We did this for durability and ease of cleaning, much much much better than carpet, but also to use the mass to store heat. The house does use passive solar and it helps. We heat with a wood stove and we origionally wanted to use RH with solar collectors on the roof. The roof is angled just so to maximize solar collection. When it got down to finally deciding on RH or not we went with NOT. The RH and solar collectors would have cost as much as the heat pump system. I just could not justify that expense in our climate. We can put in a second wood stove if we really needed the extra heat.

Later,
Dan

 

[SpringHollow]

Radiant heat is particularly nice with concrete, tile, etc floors because they feel warm instead of cool. But an expensive retrograde if the tubing is not already in place.

Ken

 

[js5020]

So you guys are saying that a solar heat source will be able to produce heat even in cloudy weather,,, now I'm not talking a couple hours of clouds, I'm talking days or even a week without sun?? Is this ad hype or what?

 

[SpringHollow]

I do not sell solar systems so it is not add hype. The system worked great for many years. Check out the amount of solar energy for Rochester, NY.

Ken