Sorting Out What Will Live In My Mechanical Closet (SOWWLIMMC?)

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DoctorLem

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Greetings and thank you for taking a look at my post.​

Apologies in advance for my asking of any relatively elementary questions.​


I have be working on a complete rebuild of my house for the past 5 years, which has left me in a completely open, new construction status/blank slate for HVAC.

I am planning on radiant heat throughout the house, with eventual solar thermal and lofty dreams of geotherm and wood fired boiler in the future, and a few other experimental features.

The Basics:


- All 2x6 exterior wall construction, 2x12 vaulted rafters

-1576 sqft first floor

-560 sqft second floor (2132 sqft total), vaulted ceilings 7-10'

-2" closed cell spray foam on all wall and interior ceiling surfaces, augmented with fiberglass.

-Isolated cold deck standing seam roof (plywood layer directly on rafters, 30# felt, 2x3 sleepers, then second layer of ply as roof deck; free vents from outside of soffits, no air flow within structure.

-Rain screen style steel (or maybe Hardee) siding, bug screen vented top and bottom

-Portland, OR Climate zone 8a, if that applied to this conversation

What I'm planning on:


-1st floor: 1/2" O2 barrier Uponor PEX, 8" on center, cast in gyp-crete, 23/32 OSB, Floating rubber-backed carpet squares, circuits are all 150' or less with separate circuits per room (this is 40% installed)

-2nd floor: 1/2" O2 PEX, same layout, but with staple-up aluminum transfer plates. (7) 150' +/- circuits. 5" spacing in bathroom

-Electric backup heat in all spaces (for both quick heat rise per zone and boiler failure.

-Future eventuality of zone controlling room by room via manifold soleniods. I have a plan for a PLC controller that will limit electric heat and manage boiler/valves/recircs.

-NTI Combi Boiler, for heating and domestic.

-Storage tank on heating circuit return, with coil(s) for preheating domestic water/adding solar thermal/Geo/Wood/Thermal mass

-I have a 3 yard void under the fireplace. I'm planning on foam isolating and casting PEX circuits in a 6 ton block of concrete to utilized that space for thermal mass to charge from rooftop solar

-I have site specific design for a rocket-mass style firebox, under the stairs (internal center of the structure). This may also have heating coils built in to transfer directly to thermal mass or into storage tank for dom/heating preheat.

-HRV to service bathroom exhaust and provide air exchange. Hoping to not have to add powered fans, if possible.

So, here's the ask...


I feel a bit overwhelmed in getting the specifics sorted out for equipment needed! I have been doing research for years to try to understand thermal transfer physics and all, and most of my research avails to amazingly differing opinions on what works and what doesn't.

So, any advice about any and all talking points above would be greatly appreciated. Forum links, contractors that could consult, personal experience, BTU calculators or software, really anything.

I did pick up "Heating with Renewable Energy" by John Siegenthaler P.E. at the beginning of this half decade rabbit hole, which has been helpful, yet also above my understanding.

I am a commercial/industrial electrician, and have installed a lot of HVAC control with Siemens and JCI, which is the lions pride of my knowing enough to be dangerous in the realm. Side note, I'm not a Doctor, that's just a nickname that stuck decades ago.

Thank you kindly for your time!
 

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Fitter30

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For your roof you don't need a second layer i put 30# felt 1x4 ladder screwed to the trust through the shingle roof with 26 gauge barn siding with vented cap. Air flows up and out saved at least 1 ton of cooling. Water has twice the thermal mass as concrete. Any flooring other than ceramic / stone should check with manufacturer for radiate compatibility. 15 years ago worked on architectural company building brought in to see how to fix it .Vacuum tube solar on the roof ,a chiller for chilled beams, water thermal mass tank, ERV to help control RH because of the chilled beams and a rooftop unit for added cooling. 50° overcast day 160° solar. Used air handlers for hot water heat. Customer took about half of are control and mechanical recommendations. Worked for a company that was very progressive with one engineer and for 5 years he tried reinvented the wheel a lot. Jobs went bad. Most efficient system by far geo that makes dhw. Least efficient wood. Your plan is banking on electric everything needed to operate pumps ,valves and controls. So if have power failures generator will be needed.
Your plan of using different sources of energy might sound good but there wouldn't be enough payback to make all of it happen. You can use a plc to control zoning but there are commercially made zone controllers that do outdoor reset , dhw priority and operate zone valves.
 

DoctorLem

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For your roof you don't need a second layer i put 30# felt 1x4 ladder screwed to the trust through the shingle roof with 26 gauge barn siding with vented cap. Air flows up and out saved at least 1 ton of cooling. Water has twice the thermal mass as concrete. Any flooring other than ceramic / stone should check with manufacturer for radiate compatibility. 15 years ago worked on architectural company building brought in to see how to fix it .Vacuum tube solar on the roof ,a chiller for chilled beams, water thermal mass tank, ERV to help control RH because of the chilled beams and a rooftop unit for added cooling. 50° overcast day 160° solar. Used air handlers for hot water heat. Customer took about half of are control and mechanical recommendations. Worked for a company that was very progressive with one engineer and for 5 years he tried reinvented the wheel a lot. Jobs went bad. Most efficient system by far geo that makes dhw. Least efficient wood. Your plan is banking on electric everything needed to operate pumps ,valves and controls. So if have power failures generator will be needed.
Your plan of using different sources of energy might sound good but there wouldn't be enough payback to make all of it happen. You can use a plc to control zoning but there are commercially made zone controllers that do outdoor reset , dhw priority and operate zone valves.
Thanks Fitter!

These are all great talking points.

I know that the PLC is over the top. That project is an eventual progression and pet project, primarily for fun, but also for remote monitoring of system status and other points (like water sensors on the crawl, elec heat priority, ext) I like controls.

I agree that the 2nd layer of ply is (was) not needed. My engineer told me that he'd have to change my drawings and I'd have to revise my permit to use the breathable mesh/sleepers venting system I was proposing, but another layer of ply worked out with standing seam. The city didn't like my wanting of using barn metal.

As far as ROI for the other heat sources, kinda same pet projects for proof of concept on a slow trajectory. I don't want to waste time or money, but I'm curious about application. I figured it might keep 70 year old me busy at home in a few decades.

I've made 2 solar heating projects out of reclaimed items that have worked unexpectedly well, which fuels some of this. One being a headting system for a 1000 gal lap pool for a geriatric dog (that worked too well initially), The other being a heating system with (3) 4x8' flat plate collectors, a glass lined WH tank and tube in tube heat exchanger (all scavenged) that has been heating my father's 30x40 shop for the last 10 years in Upstate NY.

I'm always open to suggestions on my current project tho.

Thank you for taking the time for response!
 
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