need help with designing new system

dobro23

just asking for a little advice and guidance in a boiler install that i will do in a few weeks. I am a heating professional, work for an HVAC company, and do most of the boiler installs with 1 other technician and an apprentice. the current heating system is a peerless jo 5 with domestic coil and an electric 50 gal water heater piped in parallel. ( dont ask why!) there is a #30 extrol tank serving the system now so i don't "think" it has a particularly large water volume. we estimate the heating load of the house to be about 135K BTUH. the actual fuel consumption points closer to 150K but it is an old house. in either case the jo 5 is oversized and we plan to replace it with a peerless wbv 04 with a hydraulic separator and an 80 gallon indirect water heater wired for priority. there are currently 6 heating zones. 2 are 3/4 copper fin tube and the others are a mixture of cast iron radiators and sun-rad radiators. the supply and return of these zones is 1-1/4 copper and the branches of most of the tees leading to the radiators is 1/2 copper. most of these zones have circulators similar to B+G 100's although i cant tell exactly what they are. they are piped in direct return and reverse return configs and have both regular tees and monoflo tees depending on the radiators they are serving. i also think there may be 2 or 3 kickspace heaters in the kitchen but that hasn't been determined. so my questions are simple. how do i size the header and hydraulic separator? what type of circ do i need on the boiler side of the system? is a 007 big enough? are 1-1/4 steel headers with 1" branches for circs big enough or should i go to 1-1/2? how about the hydraulic separator? the boiler net is about 158k btw. is there anything that i am overlooking? the pics attached are of what's existing and may be helpful. thank you all in advance!

delta T

How big is the house? Your estimated heat loss of 135k sounds.....high. I wouldn't touch something like this unless a real heat loss was done. Unless this house is very old and VERY leaky and 5000 sq ft +. You need to know room by room, what each rad is going to need temp wise, and flow wise, what boiler is appropriate, and then your other questions can be ansewered

Danny Scully

Is the job sold already?

dobro23

the job is sold but i am the installer not the salesman. an actual room by room heat load was done and thats where the 135k is from. 150k was from the actual oil usage but remember there was a domestic coil involved even though they were drawing off both the coil and the electric. the house was built in 1897 and is just over 4600 sq ft.

Jamie Hall

That heating load for that size and date house may not be that far off... see my signature line!

bulldoglax

1/14 headers and taco vr1816 circs for every zone. You can dial in each zone. Also make sure the indirect loop is piped in minimum 1". Depending on state circs have up to 100 rebate.

ChrisJ

Yeah,
My 1860s 1600sqft house needs around 70,000 btu/h when it gets below 0°F and that's coming from my Ecosteam's run times not a heatloss calc.

Old houses aren't new, and they never will be unless totally gutted inside and out and redone and I don't believe that's cost effective.

Rich_49

bulldoglax said:

1/14 headers and taco vr1816 circs for every zone. You can dial in each zone. Also make sure the indirect loop is piped in minimum 1". Depending on state circs have up to 100 rebate.

Why would someone use a VR1816 for a single zone , instead of a single VR1816 and zone valves ?

bulldoglax

That's not a bad idea either. Pumps can be constant pressure if zone valves are used or dialed in on fixed speed if all circs are used to match each zones flow . either way I wouldn't use 007s

Zman

I would not be thinking primary secondary on a cast iron boiler. I just don't see an advantage. The last thing you need is another pump.

If it where me, I would be trying to get my head around how those zones are set up. How long? How much radiation? Are they original or has someone been cobbling? From there you should be able to get a strategy that will work.

As for the pipe size on the boiler side of things goes, 1 1/4" is just big enough if you are doing a reverse return with flow rates based on a 20 degree delta T. If you are going to wing it and just replace the pumps, I would upsize the boiler piping as the flows will be higher than that.

mickey46

i have a 17 year old peerless wbv 04 with water on the floor and a smoking pipe into the main chamber----i need good and reliable help. who should i contact.

ChrisJ

mickey46 said:

i have a 17 year old peerless wbv 04 with water on the floor and a smoking pipe into the main chamber----i need good and reliable help. who should i contact.

We need you to narrow your location in a little more than "Earth".

STEVEusaPA

mickey46 said:

i have a 17 year old peerless wbv 04 with water on the floor and a smoking pipe into the main chamber----i need good and reliable help. who should i contact.

You should start your own thread...and look here:
https://heatinghelp.com/find-a-contractor/

dobro23

i just got notifications that this post is again active. thought i would throw in some pics of the finished job from about 4 years ago.

Intplm.

I always enjoy seeing a job well done. Especially with the before and after pics !!
Nice work !

John Ruhnke

Great Job!! and a huge improvement!

Zman

That is absolutely fantastic!
The @SteveThomas @Joe Mattiello taco guys should buy you a steak diner for showcasing their products.