While pvc can be used to carry cold water and air all day long there are maximum temperature ratings for the material.
Solar heat with pvc pipe in attic.
The pipes would get covered in condensation and drip into the attic but yes it would work during the day.
This could limit some heating applications if temperatures are expected to be near or above this range.
Baseboard hydronic heating requires higher temperatures typically 180 f 82 c to be effective as does a water to air heat exchanger located in the plenum of a forced air system.
When gluing the flex pipe to the ldr unions use the best pvc primer and cement you can locate.
Use transition cement to connect the abs to the pvc elbows extending them up to approximately 4 6 below the roof line.
Risk of leakage is greater with parallel pipes.
Use two inch pipe to reduce friction loss.
The idea with the sand was to both store heat for use at midnight and to avoid forming puddles in the attic.
Medium temperature solar systems.
Pvc pipe makes good outlet tubes.
Pipes in the solar panel can be arranged in a serpentine s like pattern or put in as a set of parallel pipes.
On the roof these are covered with lead flashing to prevent water from getting inside the house.
I have been doing a lot of.
Add 90 degree elbows and run the pipes to approximately 4 6 past the roof edge.
You will use 2 abs pipe now as it is less expensive and it is black to attract the sun and heat.
Simply break into the pvc line after the filter and run a couple of flex hoses or pvc if you prefer to the solar collector panel which you can lay out on the ground or set against a hill to achieve some tilt toward the sun.
The universal maximum temperature for pvc is 140 f.
Flex pvc pipe can be used in the attic to avoid cementing joints in a closed and confined area.
This would be important in northern climates for winterizing the heat exchanger coil.
All external pvc piping should be painted to avoid deteriation from sunlight.
For these reasons many radiant heating systems installed today use solar collectors as the primary heating source.
Newer solar water heating systems use mostly propylene glycol as a heat transfer liquid but in some early solar panels ethylene glycol a toxic substance was used.
If excessive heat is a local concern cpvc pipe can be used instead of pvc pipe.
Constructing the box the size of the heater is determined by the plywood back and it should be long enough to accommodate a whole number of cans.
In my house attic i have several 4 inch white pvc vent stacks which are simply white pvc drain pipe extending from the wall headers through the attic and the roof.
