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[kc]

Trying to get my head around my plumbing design and the few I've talked to directly have given me different ideas.   Bottom line is I have a 3000 sf pretty well insulated home in northern KY and I want to plumb in my forced air furnace (20"x20" plenum), hot water, 250 gallon hot tub, and a small HE in my 20x25 garage for occasional heat if I work on something in there.   My question is can I plumb all of this off of a single 1" loop back to the OWF?   The first guy I talked to had me with one loop to the furnace only, another pair to a coil in the OWB for hot water, and a third loop for the hot tub / garage.   I have already decided to put in a heat exchanger at the hot water heater so I don't need that loop back to the OWB.   I feel pretty confident in one loop for furnace, HW, and garage but I am wondering if adding the hot tub would be too much.   Also if I can do all 4 on one loop should I consider a larger pump to push more water?   What about bumping up to 1.25" lines?   Some more specs which may be relevent is from my OWB to my garage and hot water is 60' or so, to the furnace is an added 50', and another 15' past to the hot tub so the total loop would be 125' or so.  Thanks in advance for your thoughts as I am set on doing as much of this as I can myself but want to make the right calls and not have to redo any work if possible...

kc

[Scott7m]

It's becoming a theme here on the forum, folks keep wantin to add more and more to a single loop.  Of course moving water faster means return temps are higher.  That's the concern, not whether it will "work or not"

With that many large applications, your return water could be coming back at 70 degrees at times, that would have your firebox sweating like a pig inside, hence ruining your boiler far before it's time.

It's just not feasible to go through that many things and keep flow up as needed, line size would help, but still, the coil restricts, the domestic water heater restricts, each item does. 

Personally, I would do one loop for the domestic water and hx.  One loop for garage and hot tub, hot tubs pull a lot of heat when they pull heat. 

You'll spend a bit more running 2 line sets, but the job will be done correctly. 

[willieG]

i do agree with scott that 2 runs and piped as he suggested is best. according to charts i find on the net it is possable on those one or two coldest days of the year you may require over 100,000 btu per hour to keep your home comfortable so for the house loop i would suggest 1.25 inch pex

for the hot tub and garage i think 1 inch would do but if the price difference doesn't scare you  i would go 1.25 for both

when you decide what way you are truly going to pipe your system then you can consider pumps, feet per second etc.

also i think you could run one loop of 2 inch pex and do everythng but i have never seen 2 inch insulated pex nor have i any idea of its cost. 2 inch pex in the distnance you supplied would have about 8 feet of head pressure in the pipe (you would still have what ever is created by your "appliances")and capable of over 25 gpm. that would let you deliver at (180 degrees) 250,000 btu per hour

[kc]

Thanks guys on the reality check.   I am forming my slab today pouring tomorrow and the next step will be the trench and burying the pex to the house and I wanted to be clear on doing one line or two before that step.   Two it is!   My first step will be hooking up the furnace and HW so I can expand to the hot tub and garage later...

kc

[Scott7m]

I've never saw 2" either, I'm sure it would be high dollar.

I carry 3/4 - 1 1/2"

For example.

1" 3 wrap is $5.39/ft
1" 5 wrap is $7.15/ft

1 1/4" 3 wrap is $7.32/ft
1 1/4" 5 wrap is $7.88/ft

1 1/2" 3 wrap is $7.88/ft
1 1/2" 5 wrap is $8.72/ft

Those are the prices I've been charging for online/phone orders.

[kc]

I saw somewhere (2) pair of 1" pex wrapped and a 12/2 or 12/3 electric line all put in a 4" black drain pipe.   Is that something common or is that putting too much together at once?   I already feel a little sqeamish about drilling a 4" hole in my foundation and thinking of running two separate pipes compounds that feeling.

Also I am going to have a 50' or so run of pex through my garage and crawl space back to the furnace.  I know it should be insulated but I am thinking the pex inside a  4" drain pipe might be overkill especially if I am going to hang it from the floor joists.  Any suggestions for that part of the run?   Would it be enough to use straight pex and use the tubular foam insulation?  This would be a single pex pair for the furnace (HW is in the garage) and the run is a perfectly straight shot.  I'll run another pair for the hot tub later.

Scott - how long to ship if I were to place a pex order?    I will probably be doing the underground pex in two weekends as I take Thanksgiving week off every year and will have plenty of time that week.   I'll probably do my inside run as well at that time.

Thanks again guys for the advice.   

kc

[Scott7m]

Yes it would be ok to use un insulated pex inside as long as you put some type of insulation on it, foam wrap or something.

As far as a hole in your foundation, it's just part of it.  You have to get your tile into the dry zone of your home, stopping it outside would only let water get inside and ruin your insulation. 

Just be advised when looking at pipe, not all of it is the same or remotely close tp the same quality. 

Orders on specific lengths of pipe usually ship next day and arrive in 2-3 business days after that via ups

[kc]

Scott where are you located in area code 606?   I am in Bullitt county and if aren't too far east it might be worth a drive and just pick up what I need...

kc

[Scott7m]

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