Buildings

Published on December 10th, 2015 | by Guest Contributor

18

How To Really Improve Home Energy Efficiency & Comfort

December 10th, 2015 by  

Originally published on LinkedIn.
By Cameron Taylor, CM

On the eve of Thanksgiving this year, I was grateful I had the good fortune of meeting Nate Adams of Energy Smart Home Performance on his home turf in Cleveland, Ohio. Nate is the real deal; you won’t find many people who care about their work and mission as passionately as Nate does.

Nate took me to a house he has retrofitted this year and is now in the punch list stage. It is estimated to be over 100 years old, survived a nearby natural gas plant explosion back in the 1940s, and is within a stone’s throw of Lake Erie.

home energy efficiency

This is a house that if you looked at it from the curb it would bring to mind chilly, drafty interiors with steam radiators everywhere to offset the ever-present, creeping chill of winter by a giant lake. Upon my arrival at the house, it was 45ºF outdoors with a 28ºF dew point. Once inside, I was shown via the digital thermostat that the air temperature was 62ºF, and later found the surrounding wall surfaces showed infrared scan readings in the mid 50s.

By any past experience, I should have felt chilly inside that house. Instead, I was asking where I could hang up my coat. The level of comfort was, for lack of a more apt phrase, “womb-like.” I felt enveloped by warmth in spite of the low set point of the thermostat. Why was this? I was intrigued.

Prior to visiting the Cleveland site, Nate had sent me a vast photo library of the house project, from where it started to where he brought it, so a 6’4″ Texan (me), whose building science thinking is largely advised by his predominant cooling climate, felt comfortable in a northern house at 62ºF. Overall, this was achieved by attention to detail pertaining to envelope air sealing and drastic reduction in duct leakage. In addition, Nate bravely specified a 24 KBTUH Carrier Greenspeed heat pump to replace a steam boiler (estimated at 100 KBTUH). A heat pump! In northern Ohio! At two tons!! That should be blasphemous by conventional thought, but it is painfully obvious to me that good building science merged with good HVAC design makes how it is so often otherwise done actually be the blasphemous offender; i.e. piecemeal commodity hit n’ miss mush.

The Greenspeed system approach is where residential HVAC design needs to go as a whole. It involves a mechanical and control strategy where the system’s capacity can infinitely vary between its maximum rated capacity to a turn down minimum much lower than conventional single speed systems can. Single speed (and to an extent, two-stage) systems are essentially binary control; they are either on or off, operating at full capacity or shut down. A system like Greenspeed has an inverter-driven compressor, variable speed blowers and fans, and electronically controlled expansion valves (EXVs) that together can precisely meter refrigerant and airflow for the actual load on the house at a given time of day. For anyone who understands psychrometrics, this is entirely possible from a psychrometric standpoint; now HVAC technology has caught up to make it possible for a well-suited house.

This approach, along with a building envelope that is well sealed and evenly insulated, can deliver incredible comfort at lower thermostat temperature set points. In Nate’s project house, the system is set to run the indoor blower non-stop. Since Nate made sure the ducts were as air tight as possible, and very well insulated, minimal system loss or house pressurization concerns occur with a continually operating blower. The comfort result is minimal air temperature stratification within the home since the air is always in gentle motion, with the system adding or removing heat and humidity as needed. This result will be much less satisfactory if the building shell is leaky and unevenly insulated, and there is considerable duct leakage. Nate knew this going in and worked very hard to ensure those negative factors were minimized.

Part of Nate’s package to his clients is to monitor the results of the retrofit. Too often, high pressure sales tactics over-promise and vastly under-deliver energy savings and comfort gains, because their approach is “silver bullet” based vs. comprehensive. This leaves customers/clients feeling cheated and distrustful of any future person promising comfort and energy savings.

Nate’s project house is essentially net-zero energy ready, meaning if the client chose to add solar panels and battery storage (such as Tesla’s new Powerwall) in the future, the client’s draw from the electric grid would at times go negative to where he could sell power back to the utility, and where electricity drawn from the grid vs. what is sold back essentially equals the same. On a house of this age in a climate with over 6000 heating degree days, this is an impressive feat.

Perhaps what attracts me the most about this house, in addition to its amazing comfort at minimal energy demand, is that it proves this is where we need to focus our attention to reduce dependency on fossil fuels and improve outdoor air quality. So often our media outlets go on at length about what I call “boutique” new house projects, where from the ground up the owner is opting for a super-tight, super-insulated building shell with right-sized HVAC, triple pane windows, etc. That’s nice if you’re building new, but opportunities for our nation’s existing housing stock to be retrofitted to perform like Nate’s project house are boundless, and essential if we are to transform our society from one dependent on geopolitically volatile (think Middle East and terrorism) and environmentally degrading finite fuel sources to a sustainable, renewable base.


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  • Roger Lambert

    How much did the revamp cost? $50,000? Can the average homeowner afford this sort of thing? And if not, how can we help finance it?

    • Nate Adams

      The full project for a brand new HVAC system and complete Home Performance job was just under $40K. The house was only $40K. So this one is unusual. Not many projects are as comprehensive as this one.

      The math worked well on this project because my client was dumping a $500/mo real estate tax bill for a $50/mo one. The objectives were extreme comfort and low operating costs. When he sells his current house he will come out substantially ahead cash wise.

      My projects are typically closer to half that, which sounds like a lot, but with reasonable energy savings often come out in the $100/mo range. That’s affordable for many households. I find our process works down to about $75K/yr household income. Far better than most, albeit there is more work to be done.

      Financing still stinks, efficiency is not yet valued, if Energy Use Intensity (EUI) in kBTU per square foot per year, was put into mortgage calculations, it could increase the value of higher performance homes enough to make financing a lot easier. That’s a whole ‘nother can of worms though…

    • TedKidd

      The point of this article is to help people understand what is possible. That you don’t have to make walls 8″ thick to have a great performing home, not define what everyone must do to their homes.

      This particular job was designed to fit the needs, objectives and budget of this specific homeowner. Ultimately he’ll have an amazing home for under $100k.

      What may not be clear is the underlying design process is the average homeowner CAN implement this process because it is NOT about stuffing prescriptive improvements down their throats. It is about gaining thorough understanding of problems, helping develop affordable budget, and designing improvement plans tailored to these client criteria.

      So yes, the average homeowner can afford this sort of thing.

  • phineasjw

    Air sealing is far and away the most important first step in any home insulation project. It’s so often and easily overlooked. I’m sure Nate did a pro-job.

    And, it’d also be wonderful if Nate altered the laws of physics to make 62 degrees with mid-50s surfaces “comfortable” to the average person who’s not looking to remain huddled in a ball under blankets in a Herculean effort to keep the oceans from boiling — but I doubt it. Spend a night in that house under warm blankets, then get up in the morning and walk around in your pajamas or underwear and tell me that 62 degrees feels “womb-like”. 🙂

    Still, wish there were more details and pictures about the steps he took to insulate and air seal the house. No doubt he did a great job. I’m doing the same in my 1950s attic at the moment — sealing all the wall top plates and plumbing penetrations.

    • sault

      With the system constantly operating, it is 62F over the whole house, not just next to the thermostat. Plus, humidity control can make 62F feel a bit warmer. But yes, he was probably in a sweater and at least kept his socks on while they either walked or did some sort of physical activity during the entire tour of the house. If someone was just watching a movie on the couch for a few hours or just getting out of the bed in the morning, I imagine 62F might be a little chilly.

      • Nate Adams

        These clients like it cool. This is their real life set point. That said, few clients like it this cold, most prefer around 70. I’ll look like a hero for energy consumption in winter. In summer they prefer the same temp, I won’t look like a hero then…

    • Riely Rumfort

      I’m never all that cold at 62, our thermostats usually 65 from 8pm to 6am, and I’m up til 2am most nights in a T-shirt and khakis.
      Man-up 😛

    • Roger

      Yes, this guy obviously doesn’t have a wife. If I had my Thermostat set at 62 that would end in a quick divorce.

      • Adrian

        Wait ’till menopause. 62 will be FAR too warm. For about 10 minutes, after which 82 will be too cold.

    • rockyredneck

      By using radiant heat, you can get comfort at considerably lower temperatures. I like in floor heating the best. It works by heating objects rather than air.
      Air sealing is certainly the best and cheapest start, followed by increasing attic insulation. Be careful to provide ventilation or dehumidification enough to prevent creating a mold box.
      Replacing windows, increasing wall thickness, and replacing heating equipment is very costly and in many cases does not increase efficiency enough to warrant. If you are replacing ugly, badly damaged or obsolete and unsafe, however, the economics are totally different

    • Nate Adams

      This will be a case study in the near future. The new website should be done by fall. Here’s the basic list:

      1. HVAC – New 2 ton Carrier GreenSpeed heat pump and duct system. (When I arrived there was a spot on the floor where the boiler used to be, my client was pretty committed to forced air…) It also has a small 70 cfm HRV.

      2. Attic – Removed all insulation. Ductwork went in upper attic and was foamed. Two part closed cell spray foam was used to air seal. Foamed rear knee wall. R-60 cellulose blown on top. Double ceiling made air sealing results disappointing.

      3. Walls – Dense packed with cellulose. Odd construction, some double walls.

      4. Basement – 2″ spray foam on all exterior walls to reduce moisture intrusion and warm up the basement/first floor floor. This is part of the good surface temperatures.

  • neroden

    This is a solid job, but based on what I learned from _The Super Insulated Retrofit Book_ (1981), it *isn’t even insulated as well as it should be* — mid-50s is colder than the interior walls should be. The air sealing is the first step and it seems that this was done right, but it sounds like the R-values in the walls are lower than desirable.

    The usual issue, and I’m guessing this was the issue here, is that the walls aren’t thick enough to add additional insulation. Which is why _The Super Insulated Retrofit Book_ recommends increasing the depth of the walls, on the exterior of the house, to add insulation. With this type of siding, that’s a surprisingly small job (though it’s effectively impossible with stone or brick siding).

    People have no idea what you can get from insulation. It’s spectacular.

    • Brooks Bridges

      Just not practical some old houses. Making walls thicker would be an unthinkable project for our 1920 house.

      We opted for getting Icynene foam blown into walls via 3 holes per 16″ between joists. Big advantage is this also does a fantastic job air sealing. Balloon construction – could run tape measure from basement, up two floors and into attic. Same foam in attic roof but much thicker-.

      Then two guys for a day with good foam in cans and caulk gun. Done with blower door running, infrared camera to show air leaks. New furnace and A/C. Amazed at leaks they found in what appeared to be perfect foam job.

      Also laid down thick poly on crawl space floor and sealed to walls so moisture wouldn’t wreck things. Also run a small humidfier. Paid $400 for a 2 tank foam kit and foamed basement/crawl space walls.

      Gas for heating is 1/2 even though we now use attic for wife’s studio. Electric down 1/3.

      Foam for walls – $7000, foam for attic, $5000 with $2000 rebater from electric company. Caulk job $1200. New 2-ton Ac does whole house – 2000 sq feet. Forget furnace rating but it also does whole house. Guessing under $20K for whole business – people spend that on a new kitchen. But they never expect a “payback” from new kitchen. In our case wife was renting a studio for $300 a month so now we save that with her using attic.

      We’re in our 60’s – 70’s and keep it 69 when up, 67 at night. Still put on a sweater and socks frequently.

      • Nate Adams

        Awesome story and example! BTW you might try turning up the heat, you may find it’s a small cost penalty.

        $20K is a good number, and I love hearing that the air sealing was done with a blower door and IR camera! That is shockingly rare.

        Efficiency is a spectrum. Going deep doesn’t fit many budgets, getting remarkable results fits many more. Thanks for sharing!

    • Nate Adams

      Neroden, have you sold any of those jobs? At what cost? What closing ratio? This is a retired blue collar client, it’s a real market solution.

      Would it be good to superinsulate? Of course! How many homes are done that way? Not that many. There are less than 10 Passive Houses in Cleveland. I did that many projects last year barely trundling along.

  • Mike333

    So, the home was essentially re-habbed. Because to seal all the duct work you’d have to open up all the walls.

    • Brooks Bridges

      Not necessarily. I have a 1920 house and ducts are in the attic (sealed, conditioned space) and in the basement/crawlspace – also sealed.

      Air comes out of floor vents downstairs (heating) , out of ceiling vents second floor (cooling)

    • Nate Adams

      I totally missed this repost. The first floor ducts were done from the basement. For the second floor we removed the chimney and ran the ductwork to the attic. To reduce leakage, we spray foamed the snot out of the ducts up there. Total system leakage was a pretty good 163 cfm25, but leakage to outdoors was a very good 51 cfm25. This would pass 2015 energy code.

      The rest of the rehab was pretty minor, paint, refinished floors. Bathroom reno and light kitchen reno.

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