Longest run ?

Unknown

Does anyone know the longest run of 1/2" copper that can be installed before a heating element. Or the temp drop per ft. on 1/2" copper.

Brad White_9

Depends on Flow Rate

What is the load and delta-T?

Unknown

I calculated 2.2 gpm & 6' of head for the serving space. I already prepared a plan for it. I'm stuck with the 1/2". So because 1/2" copper is 1.5 gpm I'm concerned with the undersized pipe helping to satisfy the load once I correct the baseboard.

This guy hired his neighbor to install radiant heat. After the tile was installed the guy said,"he forgot" to install the pex. He only buried 1/2" copper in an uninsulated slab. His neighbor ripped him off $80'000. He stole the guys documents and took off to florida. So the guy wound up installing baseboard. The guy's boiler runs non-stop beacause his neighbor undersized the boiler by 8000 btu's and installed 37' of 1/2" base board. 1/2" is only good for 25' of element.

Brad White_9

I normally

limit flow in a 1/2" pipe to between 1.0 and 1.5 GPM.

At those flow rates and with Type L copper, the head loss per 100 feet of pipe would be 2.45 and 4.93 feet respectively to the flow rates. Corresponding velocities would be 1.38 to 2.06 FPS, not bad for fitting losses.

Brad White_28

Ouch

(Not sure when you posted this KC- seemed to be later in real time than your date stamp suggests. Hope I did not hold you up)

Anyway, why limit your self to baseboard? Use panel types like Runtal, Myson or Buderus and get lots of radiant heat which will thrive on lower water temperatures. At a 30 degree delta-T you can get 22.5 MBH, at 40 degrees, 30 MBH out of 1.5 GPM. At 2.2 GPM proportionately more.

JimGPE_17

Rats!

I thought this was going to be a thread about Joey Porter....

Unknown

We will give him that option, however he just got beat for so much $ he'll probobly go for whatever is cheaper.