Re-fitting old house with new tech.

FrozenJedi

I have a home in SW Minnesota built in 1950, roughly 1500 Sq' . I'm getting ready to finish a couple rooms in the basement and in this process I will be (or would like to) re-fit the old 2 pipe hot water heat, which is a trunk and branch style with a manifold homerun style installation, mainly to gain headroom and be able to put doors where they need to be but also to hopefully gain some efficiency. I have looked through as much as I can of the forums for answers and I'm finally just going to ask my own specific questions, so here goes nothing. in the pics you can see the Shut-off at the supply side, the nipple at the return side, and the fitting I removed which is the second half to the tail and nut union. If my terminology isn't correct I apologize and would ask for corrections. it seems to me that the fitting I removed would have been used to balance the system back in the day and if I'm correct I would accomplish that with my new manifold so I could eliminate that fitting and adapt straight from the rad to pex, yes? if that was correct could I eliminate the shut-off at the rad and install one in at the manifold for each loop or would that be overkill?
I'm going to start with those questions as I'm sure I'll have several more as this project evolves.
thanks for any help or advice you can offer me and if you need more pics just let me know!
Thanks!

FrozenJedi

ok, next questions.
sizing my system, determining GPM, TDH and BTU/h. Here's a pic of the boiler info and I have a Grundfos UPS15-58FC, 3-Speed Circulator running on speed 1. There are 6 rads in the house on the main floor, 5 of which are recessed in exterior 2X4 walls. the total goal here is to
A) get rid of all the low hanging 3/4" iron pipe to make doors, and ceilings easier to frame and hang.

Heat the Basement rooms that I need to frame in and finish. 2 rooms one 10X12 second 12X16 both with new Egress windows.

C) replace the 30" electric baseboard heater in upstairs bathroom with a hot water baseboard. (house was remodeled at some point and that's whats there) this could also be down the road as it is above a room that will not get finished anytime soon.

D)Leave room or have a plan in place for future heat in basement bathroom,hallway, and small tv room. those could be a year or more away but I don't want to have to reinvent the wheel when it comes time to do them.

I'm going to be plumbing in a new Supply to the whole house in this process because the current one comes in where an Egress window will be installed so I'm going to run a new 3/4" pex supply and eventually a Manabloc. That's a different deal but here's the point- I'm going to buy a nice pex clamp tool to do the domestic stuff and I'd like to use the same fittings for everything. Bottom line, is this reasonable, will clamps pass code for rad connections, and am I going to have a huge headache down the road with a leak. I like owning nice tools that do what you want when you want but pex tools get spendy pretty quick and I was comfortable spending the $160 on a decent ratcheting style crimp tool but I don't want to go much more than that or have to buy a second style if I don't have to.

I've considered putting in underfloor electric heat in the bedrooms and have that priced out at about $1500. Where I live we pay $0.50 on the dollar for controlled electric heating devices and get rebates for installing smart Tstats so I thought that would be the quickest/cheapest longterm solution that avoids a serious overhaul of the system. I like the idea of the manifold system and zone actuators, but don't want to get bogged down with all new pumps, controls and the like if thats what it takes.


I know this seems hasty, and you're correct. I have good reason though, I'm working on getting custody of my 2 girls and I need to get the rooms finished up, legal, and inspected ASAP. I know there is alot of info out there on these questions but I need to get it pulled into one place for my own sanity. I'm hoping to roust some brotherhood and get this done the right way and you are all the experts I think a guy needs to do it. I would hire a pro plumber but unfortunately my lawyers got all the plumber money.
as far as my ability to do this, I'm very confident, but I need good advice on the technical side of things. boilers/rad are the only thing in a home I don't have proficiency with so that's why I'm turning to you for help.
Thank you,
FJ

FrozenJedi

Larry Weingarten

Hello, I'm likely one of the least qualified here to answer your questions, but hopefully others will chime in Assuming PEX is the right material, a few thoughts/questions come to mind. It needs to be barrier PEX, so that oxygen isn't getting into the system. I like Uponor or Viega as their fittings are not as restrictive as some other makes. Also, you may find you can get used tools for them on Ebay or Amazon. I have done so and they are much less expensive this way. How were you planning on balancing the system so that you get just the right amount of heat from each emitter? Also, how are you going to keep air out of the system?

Manablock is used for DHW plumbing. It may be used for heating, but I haven't seen it. I'd find out what manifold is right for your needs. Folks here can answer that. Also, this is likely a closed system, so you need provision for thermal expansion (which you may already have). I might suggest that you post a drawing/schematic of how you want to plumb this and let the experts critique it. Include as much detail as possible, so we can see all the valves, vents, drains, etc. Also, the place to start with all this is knowing what the heat loss from each room is. That will affect sizing. I believe Slant Fin has a sizing calculator on this site. Hope that helps!

Yours, Larry

FrozenJedi

Hi Larry, thanks for posting!
I may have mixed up the two projects when I described them so I'll try and clarify here.
The domestic water and Manabloc project will be separate from the heating project but occurring at basically the same time or at least in quick succession. The only cross over between them would be the choice of PEX tool, but I'm not going to let a couple hundred bucks get in the way of following good advice and using a more reliable connection so I'm all ears for some input there.
The barrier/non barrier PEX issue is also pretty clear to me so that may push me more towards the pex-al-pex on the heating project and eliminate any worry about leaks or issues down the road.
As far as balancing the heating loops , it seems like the flow controls on manifolds like the Caleffi's (which I'm leaning towards) would do that and also offer the option of zoning different rooms with their own actuators.
OH! and the expansion tank that is in place now is a 30G galvanized unit that is dated 8-22-49. It's about 14" diameter and 5 1/2' long and hangs over where the hallway will be. I drained the system down and got roughly 50G out of it. Basic calculations I've done say that I can replace it with a #30 extrol but I'll wait to make that choice when I get some more detailed info.

I hope that clears up any confusion from my end, If not, I'm at your disposal until I get this deal done.
Thanks!

Gordy

You need to do a comprehensive heat loss room by room first.

This will help you decide pex sizing, pump sizing, flow rates, and emitter sizing.

Home running is a good decision. Consider trvs for that standing iron.

I think I would review operating costs for electric in floor heat. Sometimes rates are so high that it offsets any upfront cost reductions in short order.

FrozenJedi

I'm working on the calculations as we speak. the Slant/fin App is really nice, big thumbs up to them. and thanks to Larry for the suggestion.
I totally agree about the TRV's. any insight you have there would be awesome.

hot_rod

These Idronics issues have plenty of good design info. Issue 4 &5 are on manifolds and zoning including TRVs and delta P circulators.

https://www.caleffi.com/usa/en-us/technical-magazine

FrozenJedi

Outstanding! thank you Hot Rod!
I'm a trainer in the construction field as well. Nice to have a pro weigh in on my project, thank you.

FrozenJedi

OK, I have the calculations done for the main floor and the 2 rooms I'd like to finish. can anyone tell me how to figure the BTU rating for the old sunrad's I have? I'm guessing that's going to be the next step.

FrozenJedi

That app is really easy to use by the way. highly recommended!
If i heat just these 2 rooms in the basement the BTU loss for the room directly above drops 3000 BTU. and the master bedroom upstairs drops from 2188 to 748. I think I may have some oversized rads pretty soon. I'm getting excited.

Gordy

Emitter over sizing lets you run lower water temps. That's good except you have a ci boiler which limits how low you can go.

Usually emitters end up oversized from initial designed, and or envelope improvements reducing heat loss over the years.

So instead 170 average water temp you may be able to get down to 150 as an example. If you had a condensing boiler you could go even lower if the radiation was oversized enough to allow it.

Gordy

Idronics is a very good learning tool. You may get so wrapped up in it once you start your project could fall behind

FrozenJedi

Hey Gordy,
Thanks for the post and you are right, Idronics is a very good read.


my initial concern with putting trv's in is, the style of rads I have are recessed and the supply and returns are on the bottom leaving little room to work and without removing the new floors unable to pull them from their cavities in the wall. would the trapped heat or proximity of the trv's to the rad cause the boiler to short cycle?

I attached the PDF below that shows the system I've had in mind all along. figure 5-13 on page 17. Now I just need to figure out how to get from here to there. Thanks again to Hot Rod for pointing me towards idronics, invaluable info there.

Rich_49

Many TRVs can be ordered with remote sensing capability