one pipe

jamie_2

My friend just bought a module home and we're doing the heating system hook up in it. He has 60 ft of 3/4" fin tube radiation and 750ft of 1/2 pex in floor in basement. We also want to hook up a boiler mate. The home manf. recommends a Weil Mclain ag4 boiler but didn't give a btu size. Also if we go with a one pipe system what size of line should we run to tie in the baseboards with. I know we'll have to do primary/secondary piping for the in floor. Your help would be appreciated. Thanks.

ScottMP

Please tell us

The 750 1/2" pex is Not One loop ???

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Ken_8

You may be refering to a

Weil McLain CGa-4 ?

If so, the CGa-4 seems like gross overkill on a modular contemporary (implying well insulated) home, but would have an input of 105MBTU's and a net I=B=R output of 77MBTU's.



To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Jim Erhardt

Heat loss calc

The only way to properly size the boiler is to do a heat loss calculation. Based on what you have told us, a 105,000 BTU boiler would in all probability be overkill. Avoid over-sizing the boiler.

If you connect the baseboard as a series loop, one zone with 3/4" copper, you will need a pump with a slightly higher head capacity, such as a Taco 008 or Grundfos 15-42. If you go with two zones and zone valves, a Taco 007 should be just fine.

Your 750' feet of 1/2" PEX in the basement slab should be divided into two loops, and piped as a separate zone with its own circ and mixing valve.

Your indirect would be yet another zone, preferably with its own circ for maximum output. Consider using a priority relay.

Please feel free to download our latest heat loss software to be sure you are sizing the boiler correctly. You can download our Hydronic Explorer 2 software (for free) from here - www.slantfin.com/he2

Good luck!

Weezbo

how many square ft is the modular?

does it have 6 foot sliding doors,are there cathedral ceilings,is the pex in 1 2 3 4 loops what you have with a package home is a variety of vagarities.you need actual carpenter ,electrician,plumbing heating guys on the job. a guy with a hammer another with some linemans and another with a wrench isnt going to do right by you. sight unseen,advise is apt to be a case of too many chickens spoils the broth:)) I have no reason to lie. I am telling you the truth.

jamie_2

one pipe

The module home is 55x25 and the upstairs has 60 ft of 3/4" fintube radiation. The basement has 750ft of 1/2 pex in four circuits. He wants a 40gl indirect water heater also. You say i'll have to go to a Taco 008 pump for the radiation if i go one pipe 3/4 inch. What would you recommend for a boiler if not a cg4 as stated by the home manufacturer. Would i be better off with a cg-3.Thanks for your input.