Total Home Automation

Making my home use less energy

I have a house that is about the size of Al Gore's.  I know he has been getting a lot of grief about how much energy he uses.  Recently he apparently upgraded a lot of systems to "Walk the Talk".  I have looked on the web to see what he has done, but really can't seem to get any really good information.  Maybe I can provide some answers by doing things to my own home though, that others might benefit.

I am in the planning phase for my energy conservation project.  I want it to:

• Save energy
• Ease maintenance
• Have a near term payback
• Be resilient to future upgrades and technology

My general plan is to:

1. Implement a monitoring solution so I can measure performance
2. Switch to geothermal
3. Consider solar thermal and electric
4. Improve insulation and windows
5. Increase automation/conservation

My house is large enough to almost be a commercial property, but small enough not to be - so there are a lot of complexities to how best to balance out my systems, recover energy, etc.  Some of these questions include.....

1. Should I replace my 5 5-ton AC units with a single chilled water plant?
2. If I replace my 5 air handlers with geothermal, should I still use my boiler to supplement heat, or use electric re-heat coils as often recommended by HVAC vendor
3. Geothermal has a slow "Recovery Phase" (that means if you set back your thermostat in the winter, the system can produce enough peak heat in the morning to get back to proper temperature in time for breakfast).  So, does the improved efficiency of geothermal make up for a setback strategy - what is the payback?
4. I can fit a lot of solar thermal on my east facing roof.  Not a perfect direction, but is it worth augmenting my system with some of that heat?
5. I need more insulation in my attic.  I have 2 air handlers and my second floor ducts in that space.  Should I instead insulate the underside of the roof?  What is the real science behind vented and un-vented roofs?
6. If I super insulate the attic, how much tonnage reduction will I have, and how will that effect cycling of my Geothermal system.  If my load is 25 tons during the summer now, and it goes to lets say 20 tons with super insulation, will those larger units cycle excessively?
7. I get most of my energy from Coal (the power plant).  Natural gas is going up in cost.  New power plants will have more natural gas.  There is a high loss rate in electricity distribution, so with increased energy cost will I be better positioned to heat with natural gas or electric (via heat pump)?  What is the cross over point in the business case for this?

If anyone has answers or thoughts please comment.....

Foam Insulation

As an early adopter of technology, I like vendors that know what they are doing.  Having spent a long career as an engineer, I have found too many vendors that use "Rule of Thumb" without understanding the underlying principle of the product they sell.  A good example is HVAC vendors that size a system just on square footage rather than heat load, cubic space, etc.

So, as I set out to find a spray foam vendors, and realized I needed to look more.  Spray foam has been around for a while, but in meeting with vendors at a local home show I was unimpressed.  Most were making superficial comparisons to why they were better than fiberglass and other insulation.  They really did not have a sense of thermal barrier, convection, air barrier, etc. 

So I started searching the web and found Foam Engineers, just outside of Central MO to help with my insulation project.  I picked them because David McClure, who runs the operation, is a professional engineer. 

I was looking at Icynene (0.5 lb/ft3) and InsulStar (2.0 lb/ft3) foam.  The basic Icynene product is the more typical product.  It sprays quickly, hardens quickly, is slightly flexible, has an R value of ~3.6, and can be removed easily by hand.   InsulStar is a much more dense closed cell foam that is more rigid, higher R factor (6.5), structural, and very hard to remove.  They both inhibit moisture, but InsulStar has the full capability as a vapor barrier.

I was tempted to go with InsulStar because I liked the higher R factor and structural component (that floor makes to much noise when walked on).

Another critical decision regarded the depth of insulation.  More R seems better, but there are limits to benefit.  Because foam is a thermal barrier and prevents airflow, it provides a higher degree of thermal resistance.  So R-10 of fiberglass does not perform as well as R-10 of Foam when one consider airflow and other installation factors.  Foam is more like to go in right and is naturally more resilient in application.  Icynene puts out a good data sheet regarding the diminishing return of more foam (Economic thickness of insulation)

Home Energy: Garage Insulation

I have a 4 car garage in my basement.  It is under the laundry room, a bedroom and part of the kitchen.  Generally that part of the house is too cold in the winter, and a bit warmer in the summer.  So, decided it must be the insulation etc over the garage are and under the floor of the 1st floor of the house.

I love the idea of blown in foam insulation.  Partially for R Factor, but also for reducing conductive flow (air moving from hot to cold).  I have allways wanted to use foam in the house, but not had a good retrofit project to try it on.  Now I do.

Over July forth, I had some friends over so we ripped down all the wall board.  There was about 4 inches of batt insulation on top of the wall board, but that space in total with floor joists is about 10-12 inches deep.  The trusses are wood capped with steel truss structure - so air moves around freely.  Essentially we have a sandwich of first floor, 6 inch air gap, 4 inch insulation, wall board, garage ceiling.

Looking more deeply though, there are all sorts of openings throughout the area for air flow, flow into the basement, flow outside, etc.  Basically a giant gap in the house.  Now with the ceiling down, I have scheduled the foam guys to come buy and blow in 5-6 inches of foam.  More on that later.....