Replies

1. 
   Perry525 | Mar 06, 2013 07:39am | #1

   Radiant hot water is good for out of sight heating

   especially where the rooms are wide with high

   ceilings.

   Most people lay 4 inch thick concrete with the

   pex pipe held in place tied to the reinforcing

   mesh.

   There is another way where the pipe is laid in the

   top of sheets of polystyrene.

   The concrete method is slow to warm and very

   slow to cool, if you have a building with large

   windows facing south, the sun can quickly make it

   impossible to stay in the room as it is so hot.

   The light weight system, where the pex is laid in

   the top of polystyrene sheet with t&;g OSB laid

   directly on top is quicker to warm and cool.

   As both radiation and conduction both travel

   through 360 degrees half your heat input goes

   downwards, you need at least 4 inches of

   polystyrene insulation below the pipes to keep the

   heat in the rooms.

   I find that the best way to deal with the slow heat

   up, is to have the heating on 24/365. The level of

   heat is very low, it is silent in operation and after

   a short while you completely forget it there.

   One advantage, is that the floor area is usually

   divided into heating areas, this means you can

   have more heat in front of large windows and low

   or no heat further away.

   The concrete based system works well with clay

   or porcelain tiles.

   Both systems are not so good with thick underlay

   and thick carpet if the users are going to turn the

   heating off - makes heating up even slower, but

   its good once warm.

   UFH is good for basements, make sure you

   have a thermostat and motorized valve in every

   area to control the heat, if the basement is damp

   you can add a humidistat to the control, this will

   raise the temperature and lower the humidity

   when required.

   I find it best to raise the door frames as a well

   installed, insulated  system is raising the floor 5 or

   more inches.

   A radiant system is easier to live with and is cheaper

   to run than warm air.

1. 
   DanH | Mar 06, 2013 07:53am | #2

   I'm guessing you posted that from your pad??

2. 
   calvin | Mar 06, 2013 09:00am | #3

   Perry

   I find that the best way to deal with the slow heat

   up, is to have the heating on 24/365. The level of

   heat is very low, it is silent in operation and after

   a short while you completely forget it there.

   One advantage, is that the floor area is usually

   divided into heating areas, this means you can

   have more heat in front of large windows and low

   or no heat further away.

   You write quite a bit about radiant heat and the use and benefits of foam.  What's your background with these?

   thanks.