Fair enough,
rrtechno. You’re neither my enemy, nor you mine. It obvious we are both concerned about energy and taking steps to curb energy consumption. We each operate in different worlds. You are building an efficient box filled with status quo single function technology and applications. I do super-efficient shells involving synergistic tech and apps creating a multifunctional interactive integrated home to deliver greater benefit often for less cost than ordinary construction. I’ll get to you
rrtechno at the end of this post.
Let's start again. This post is intended for total rehab and new construction in the design and budget stage, not for while in construction. I will not willy-nilly address one’s sole desire unless it is directly aligned with this post’s intent. I am happy to do that through DM. And since I have been proven right a new way of thinking is required, I cannot be more clear when I say the truly energy efficient homes which are born from treating one’s home as single system as compared to a mere well insulated box containing single function technologies.
Everyone is missing a profound point to which I have stated repeatedly. An efficient home, the truly remarkable ones, must be designed as a single interactive thing. Seeming unrelated items or systems working together for the betterment of a single home. The thermal envelope is also special for it must be designed synergistically to react and adapt to the total heat/cool energy picture. Without synergy, the best one can HOPE for is an insulated box containing many unrelated non-interactive single function technologies.
Synergy is not just about the materials; it involves the entire process, including installation speed and labor.
The mediocre has been proven time and again to be staggeringly parasitic in nature. This post is how to eliminate and avoid waste, not continue with status quo. In order to get where one desires and achieve remarkable repeatable results one has to first learn to challenge status quo and cease traditional thinking in favor of following a synergistic program.
What is synergism: “
Interaction of discrete conditions such that the total effect is greater than the sum of the individual effects.” More than the sum of its part, if you will.
The following example is one of hundreds; thousand’s even, as to how one can achieve a far greater effect from a single thing common to status quo. Everyone knows sheetrock, generally speaking. First, the science. I have written the following more than a dozen times on this and other posts.
The btu/hr sizing formula: btu/hr = area (sf) x U (1/R-value) x Td (diff of inside & out temp, positive number) was expressly devised for use by entire HVAC and insulation industry.
The R-Value rating system established as a by-product of WWII is applicable to ONLY 1 method of heat transport through direct contact of materials. Approved coefficients or multipliers to the above formula span nearly 200,000 variations, all spawn from the base formula.
Every known material, including all building materials (windows and doors included) has it’s unique U value. R-value (resistance to heat flow) is the inverse of U, conductance of heat flow. To calculate R its 1/U converted back to U as 1/R. One half-inch thick sheet rock has an R-Value of R-0.45. A 5/8” wallboard is R-0.5625.
So, how does one effect lower energy bill with sheetrock? By thinking synergistically.
Sheetrock of itself does not contribute much R-value but everything helps. The greatest benefit of sheetrock is its mass relative to occupied space. So how mass does mass fit into the energy picture? Higher mass has a higher thermal storage capacity than low mass items, like stud or SIP houses. The thermal mass has a coefficient value that may be added to the above formula, thus: btu/hr = area (sf) x U (1/r) x Td (inside vs. out temp) x TM (thermal mass coeff). Thermal mass typically has a relative value of 0.5 – 1. The greater the mass, the lower the coefficient. There are exceptions to that rule, see below.
If a stud or SIP house with standard sheetrock, the formula is as:
- Btu/hr = area (sf) x U (1/r) x Td (inside vs. out temp) x 1 (TM)
A TM value of 1 does not change the btu/hr result. Installation also involves synergy. Ordinarily the perimeter of a modest sized home for either building system types requires a solid day with 4 or more hangers while applying installation synergy the hanging of double sheetrock layers is reduced to about 4 hours with a crew of 4 sheetrock hangers.
Adding 2x layers gypsum, stud or SIP now has greater thermal mass, the formula may be:
- Btu/hr = area (sf) x U (1/r) x Td (inside vs. out temp) x 0.5 (TM)
Regardless of the other variables in the formula, it’s easy to see the TM value may effectively reduce heating and cooling system size requirements by 50%. Note adding R-1 due to the sheetrock will not cause the significant reduction, achieved by the increased mass. If I wanted to just add R-1 I would buy Sherwin Williams insulating paint.
Does the above formula mean one can attain the same reduction with an ICF homes? NO.
To reduce heating and cooling size requirements it is necessary to located thermal mass inside the climate-controlled space. This is unlike ICFs that encase concrete inside foam panels outside the interior space. If its 0 deg F outdoors and 70 inside, then somewhere inside the ICF thermal mass its 35 degrees. In the latter case, sometimes mass can work against a desired intent. Concrete has an R-value of R- 0.2 per inch thickness.
A single layer of ½ inch sheetrock is not statistically attributable mass to a stick house, a second layer on the perimeters walls in another matter. Gypsum subfloor is better still. Ceiling getting the idea. In all my projects, I use 2 layers of Fire-X 5/8 in wallboard because Fire-X more dense than standard sheetrock. Ok. You got the energy picture for sheetrock, let’s see some benefits of synergism.
Unlike what was once a thing to hang pictures… Synergism, synergistic benefit as for the case of multi-layer sheetrock now looks likes this: Greater resistance to storms and quakes, smaller heating and cooling systems - including smaller input (electrical or other energy source) and output distribution systems all which means lower installation cost, faster, less costly installation, improved affordability of upgrading plant efficiency; vastly improved sound control, radically improved fire resistance (especially for the SIP homes due to melting foams which can cause premature load failure in a working fire), Smaller HAVAC loads mean smaller less expensive alternative energy (solar, wind, etc.) system and all that related hardware, and on and on.
In the case of single sheet wallboard, you pay for it and that’s all you get. If the extra synergy achieved is worth the investment, go for it. Understand there will be savings that can handily cover the cost of extra sheetrock. Adding sheetrock is not a code violation, rather it exceeds code. Sheetrock is the easiest way to add significant inconspicuous thermal mass to any home.
Referring back to smaller Btu requirements: Thermal mass stores heat (or cool) potential within the conditioned climate. This mass absorbs or releases heat when neighboring space air temperatures rise or fall relative to the thermal energy stored in the This synergistic interaction increases “Off” time duration between “On” run cycles as dictated by the room thermostat. Simply put, the temperatures swings are amazing small and smooth, no more dramatic swings in space temperature.
Mass inside the conditioned space will work extremely better only if doing one ultra-low mass improvement to the perimeter walls. Where and how to do that thing I’ll get into in another feature. It’s vitally important to know that adding thermal mass along with the latter permit the effective TM result to go sharply lower so as to pay for the ultra low mass item further reducing heat/cool plant size. I’ll get to that later. You all have enough to chew on. And this is but one of potentially thousands of things involving synergy.
Why do I say abandon status quo [thinking]?
- When has your sheetrock guy told you to add more sheetrock to reduce your heating equipment size and save energy?
- Did your builder ever offer more sheetrock in order to cut back on all the extra voids, pockets, channels, and special framing needs to accommodate ducting, or that mechanical room?
- Has your mechanical guy ever volunteered a ½ priced system, if you add extra sheetrock?
The modern trade world is all based on an installer mentality. They don’t say anything because they either don’t know or they protect a special agenda!
I have written extensively about the various home energy consuming categories within average homes and general percentages for each; even how compute and remedy lesser consuming sectors. All over this forum I have responded to energy and service questions and only the few with whom I interact on this particular post take issue with that I present.
Mr. rrtechno,
I also agree SIPs are a great construction system. Among the various companies I own, one is a SIP installation contracting company, another does SIP designs and engineering among other things. SIPs are good, but everything has its place. They do not satisfy all building needs everywhere. To fully exploit the full potential of Stud and SIPs there are two more things necessary to optimize thermal performance vastly beyond expectations. No, it’s not adding more insulation. I haven’t any clue what, how, or where you are building though you demand of me - give nothing.
I am extending you an open invitation. You will be required to sign an NDA and non-compete agreement. DM or email me your SIP type/composition and where you are building. I’ll also need composite floor, wall, and roof/ceiling configurations to guide you accordingly. And I’ll tell you preciously what needs done to realign your desires to accommodate this tech. My offer stands; otherwise I’ll hear no more from you on the matter.
As an aside: Just how long did it take to assemble just the SIP portion? I ask because the picture in post
//www.city-data.com/forum/archi...onth-heat.html that home was under roof papered with shingles started, siding near complete, windows/doors installed, and halfway done with interior perimeter sheetrock – all from the sill plate up in a single day. Inside two days all the interior partitions were finished framing. Yes, you heard right, homes in the US are built backwards. Oh yea, much of the perimeter electric was install, too.
Synergy is not just about the materials; it involves the entire process, including installation speed and labor.
I have tried to insert spreadsheets and pictures into these quick post replies without success. It is not my fault readers are not getting what has been expressly stated aor reading between the lines of the many formulas and what and how they work. If I must go to another forum or start a new one with the necessary means to display a picture explaining a thousand words, I may just have too.
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