Hydronic system questions( Circulator, Heat exchanger )

[BKB]

So I did something very unusual for me. I threw together a heating system having no clue what I was doing, and made no effort to learn. I was shocked when it didn't seem to work as good as I thought it should. Im now trying to educate myself and looking for some ideas.

What I have

EFM PK450-44222 11700net BTU Waste Oil Boiler 180'F
Taco 007-F4 circulator
4 Zone valves
Unit is on a shelf 8' off the ground
Antifreeze to 0'F

What its doing

I have a 64 x 40 x 16 pole barn that uses a EFM Waste Oil Furnace as its main source of heat. When I built it I installed 1" insulated pex from the house to the barn. The barn has 3 rooms that I ran Slantfin 30 baseboard as supplemental heat. Mancave has two 8' units, bathroom has a 2' unit, craft room has one 8' unit. The craft room is the only one that works well, the other rooms are below the boiler and seem to have reduced flow.

The math

Man Cave 216 foot of 3/4 pex including the 16' of slantfin 14.4 head
Craft Room 192 foot of 3/4 pex including the 8' of slantfin 13 head
bathroom 154 foot of 3/4 pex including the 2' of slantfin 10.75 head
House 475 foot of 1' pex 28.5 head

The Questions

So I see now my 007 Taco is way out of range in every possible way. Can I still get away with using a single circulator pump for all 4 zones? If not do they make a 2 speed pump that can run a lower head on 3 zones and ramp up for the House?

For the house im limited by the 1" pex so I guess around 8 GPM. The air to water heat exchanger is very large to try and keep my duct work restrictions to a minimum. Im looking at 22" x 30" 230,000 BTU at 27.5 GPM, What would the actual BTU be at the flow I would have? I need around 80,000 BTU for my 15 year old house. I have a heat pump with electric backup plus oil furnace back up. For the most part the pex is all long sweeps with limited use of 90's, so head pressures im sure are calculated higher then actual. Pictures will be added.

Thanks
Brian

 

[yeldogt]

So you are heating the house as well ? What's the overall heat loads ?

So the house is on one 1" loop -- somehow (slab) using 1" pipe?

Is this radiant -- or did you just use PEX to pipe the baseboard. Did you use slatfin's table to calculate the needed length for output

 

[BKB]

Ok, ill try to word things differently.

Boiler is located in the barn and is supplemental heat to the man cave, bathroom, craft room. Everything in the barn is slantfin 30 and most rooms I simply ran out of wall space. Again this is supplemental heat, the barn is 55-60'F forced hot air, other rooms have mini split or electric back up as well.

The house has a heat pump with electric backup and oil furnace back up. The idea is to remove the oil furnace back up as its a restriction in the duct work and I have to throttle back CFM because of it. A water to air exchanger will take its place and I will need around 8 GPM to give me around 70-80k BTU. I would then have the heat pump go into emergency heat around 26'F turning on the circulator to waste oil boiler. Im running 1" pex from the barn to the house. I plan to re calculate my head pressures using PEX specific software to see if its accurate. My main question is how to address the different head pressures of the 4 zones. Using as few pumps as possible type of thing.

 

[BKB]

I think running two taco in series will work right. Replace my one 007 with an 00?? for the barn 3 zones and add a 00?? in series for the house loop to double my head. It would require little mods to my current set up and use a cheap simple pump.

Ran the #s one last time not using software so tell me if this is better. Getting some very different numbers from these calculators.

House 1" pex 20% Glycol 180'F 8 GPM 3.58 per 100ft plus 11.5 feet for evey 90' and .9 feet for every coupler. I now get 17.9 head.

Barn 3/4 Pex 3.45 per 100ft 10.8 feet per 90' .9 feet per coupler
Man cave 10.8 head
craft room 8.6
bath 6

 

[BKB]

So ran the math a few different times and settled with these #s. I found two different charts that came within a few % of each other, I averaged them and pretty sure I have a plan.

House 1" with feet added for all fittings, 20% glycol, 180'F 45.5 Head
Man Cave 25
Craft room 21
Bathroom 17

Taco 0011 to replace the 007 that is in now. And add a second 0011 in series to the house. The two pump is series should keep flow at 8GPM but double the head 48 head. Im still learning and do need to look at other pumps but Taco makes it very easy to figure out.

 

[fitter30]

House is 475' so thats 950' of pipe? Is the pipe insulated and what was used? Btu loss for your house piping could be a big loss.
Facts About Insulation Requirements for Plastic Piping - Insulation Institute (this is a pfd)
Man cave ,bath and craft room one zone or more? 30% prop glycol doesn't freeze solid till -18* and the 30% minimum is what most want for inhibitors. With such long pipe runs and a cast boiler it will have to piped primary/ secondary loops because the boiler can't take cold water returning to it.

 

[BKB]

All run pex numbers are total length including radiators. Boiler is an EFM 1/4 welded steel. PEX to house is 3 wrap insulated badger 190ft one way from house to far side of barn, rest of the pex is un insulated in the basement and barn.

 

[fitter30]

1" pex is normally rated at 7.5 gpm @ 4' a second. With 30% glycol 7.5 gpm 71800 btu's
8 gpm 30% 76640 btu's.

 

[BKB]

Replaced the Taco 007 with a Grundfos 26-99 set on med. This fixed all the issues I had with the barn slant fin. Wish I would have known about the high output slant fin, With such little wall space I could have used them in the man cave and bathroom. So once I hook up the house circuit I will purchase another 26-99 or an equivalent on high setting and add it in series for the high head. Any preference on where to add the second pump in series? I could add it in the basement to pump back to the barn or on the back of the boiler after the other pump. The plan will be to use all 3 speeds on the circulator on the boiler using either mechanical relay logic or a plc. Not happy they way Grundfos molded the switch right into the motor wiring cover, it makes it a tad more difficult. It might not be worth the effort but might save some electricity and reduce the stress on the pump when only one zone valve is open. Any thoughts?

 

[fitter30]

Is your 26-99 pump a alpha 2 pump it has a auto setting.

 

[BKB]

No its the older 3 speed switch style