retro

don_205

You left out the head.You made get 15 gpm out of it if the pump was only seeing 5 feet of head.

Personally as a service tech I would love to see more differential by-pass valves when using zone valves.Nothing like walking up on a zones system with one huge pump and hearing a noise thru out the house when only one zone is calling.

Oh no...its got type m copper and short radius ells too.

Unknown

what would you do ?

I'm still learning this stuff. I don't have much problem when designing from scratch. I run into issues with retrofits. This is for a simple boiler replacement that I'm choosing to over think. here is my situation:

I have 3 zones that are high temp baseboard. I figured all gpm to be 2 fps

Zone 1 - heat load is 37,259 btu

Supply & return common pipe is 1" that splits into two 3/4" loops

@ 5.5 gpm my DT is 13.5

Zone 2- load @14,688

3/4" loop

@ 3.2 gpm DT is 9.18

zone 3- load @ 16,660

3/4" loop

@ 3.2 gpm DT is 10

A 007 can pump up to 15 gpm so I'm thinking that zone valves may be good. However (if I remember correct) Robert Bean stated that the threshold for using circs over valves is when the zone is over 4 gpm.



Should I zone w/ valves or pumps ?

If I piped both supply & returns into a common header would I make that 1 1/2" ?

Alan(OnVacationInOregon)Forbes

At 12 gpm,

a 007 will push a max. of 7 ft. of head; a 0010 will push a max. 0f just less than 10 ft. of head. Baseboard has a low pressure drop, but since this is a retrofit and you really don't know what's out there in terms of pipe and fitting, I'd go with circs. to play it safe.

Steve M_2

one pump

To take the guess work out of it I would use a Wilo-Stratos ECO and use zone valves or ideally TRV's and do constant flow. The Wilo is a little little pricey but well worth it especially if you did zone pumping.