View Single Post
Old 05-05-17, 11:43 AM   #19
buffalobillpatrick
Master EcoRenovator
 
Join Date: Mar 2014
Location: Florissant, Colorado
Posts: 599
Thanks: 814
Thanked 59 Times in 55 Posts
Default

Geo, I will run the pex under the tub and under the shower.

I will keep the master bath warmer than the master bedroom, possibly 10-15*F or so.

The thermostats are Tekmar PWM type that learn about and correct overshoot & undershoot.

They have air & slab sensors, which I have never used before.

Micro zones like this can be a big problem with standard boiler installs & even mod-con boilers.

Think about this, the boiler must be sized to be able to keep every room at 70*F at "Design Temperature" (2*F here)

With multiple zones (4 this house) & say it is 50*F outside, then the smallest heat loss zone calls for heat, this could only a few % of the boilers required capacity, and any boiler would "short cycle" leading to lower efficency & early death.

My system has a buffer tank (79 gal.) between the heat source and the radiant zones.
My boiler will always have long efficient burn cycles
(79gal x 8.5# x 30* aquastat Delta) = 20,145 BTU's about 30 minutes minimum for my boiler, and possibly much longer when system is calling for heat.
buffalobillpatrick is offline   Reply With Quote