Willowside Project, Day 10, part 2

OK, I'm back from getting the dimensions of Doe's house, enter all the information into EnergyPro, and do an initial calculation. It looks like the house as it is has a HERS of 147, which means that the model predicts that it will use about one and a half times as much energy as a 'reference home', which is this exact same home if it was built to today's energy code requirements and has by definition a HERS of 100. 147 is not too bad but way above what we want. Let's see if we can get it below 100.

I enter a selection of possible energy improvements into the software and recalculate. Great! There's a possibility of cutting Doe's energy use in half if all the improvements are done. I have a screenshot of the EnergyPro run showing the percentage reduction in energy use that we will get from each of the measures: air sealing the house, adding ceiling insulation to R38, insulating the floor, a new 95% furnace with R8 ducts and 13 SEER AC, and a new high efficiency water heater.

All of these together add up to a significant amount financially for most homeowners, as high as $20,000. But one of the strong reasons I want to suggest installing high efficiency condensing furnace and water heater is that condensing units draw their combustion air from outside. The combustion air vents in the doors and closet ceiling can be sealed up and there would no longer be all the air quality and heat loss problems that come from combustion appliances in an indoor closet.  EnergyPro may model the percentage savings of the improved house but it can't show the increased comfort, how the HVAC system no longer constantly cycles on and off, how all the rooms are now an even temperature, how the owners are no longer breathing air from the crawlspace, and that there is no longer any possibility of carbon monoxide entering the house from the water heater's poor venting. All powerful reasons to do this whole package.

Plus, entering the Energy Upgrade California program should get the owners a $3500 check after the work is done and using our local property assessed program, the Sonoma County Energy Independence Program, means that John and Jane can finance the cost with only a few hundred in fees up front.  If we can cut their utility bills in half (which currently average nearly $300/month), then their savings of $1800/year should cover the payments on the assessment and in 10 years, it's paid off.  Sounds like this project is a win/win.

A few quick numbers from government research papers:
40%+ of inside air comes from the crawlspace because warm air rises, drawing in crawlspace air through all the little holes in floors, also known as the Stack Effect. (anybody know the cite?);
30%+ average duct leakage in the US, though my guess is it's in the 20s in California;
Far more people die of Carbon Monoxide poisoning in the US than are struck by lightning and CO causes 15,000 to 20,000 ER visits per year.

The recommendations going into my report:
Air sealing the ceiling, the floor, adjusting doors and replacing weatherstripping as needed to reach the minimum target of 1962 cfm50 (it's 3110 right now so that seems reachable);
Insulating the floor to R19;
Replacing the recessed ceiling fixtures or building boxes over them;
Blowing loose fill fiberglass into the attic to reach R38;
Replacing the FAU with a 95% condensing unit of much smaller size, with R8 ducts properly sized and sealed;
Replace the DHW with a 90%+ condensing unit and insulating all how water pipes;
Deal with the flooding issues in the crawlspace and cover the soil with a 12 mil vapor barrier.

Caution: numbers alert. FYI and if you are interested, 1962 cfm50 is the minimum that BPI currently allows without requiring mechanical ventilation, which is 70% of 0.35 natural air changes per hour with an n factor of 22.

Next, the report.

Surprising results

Just did an audit on a VERY high end home up on the ridge above San Rafael, above the ferry building.  Built in 1913 for a well heeled ship's Captain.  Wild layout but was ready for a remodel, something the new owners were doing.  A brand new high efficiency furnace system was already installed with all new ducts and they looked *beautiful* from the outside.  Very neat and clean, beautifully finished and taped, we expected very low duct leakage. So we sealed up all the registers we could find and pressurized the duct system.  Surprise!  It was off the charts high.  First thought: perhaps the manometer was hooked up wrong or was on the wrong setting.  Nope.  Then perhaps we missed a register and that was why we couldn't pressurize the system.  After crawling all through the house; attic, upstairs, downstairs, basement, crawlspace, we couldn't find any open registers.

Next: get out the smoke generator so we could blow theatrical smoke in to the duct system and perhaps we could then see where it was blowing out.  Running around the house while the smoke generator was sending smoke in to the duct system, the whole place was slowly getting smoky.  Everywhere.  After working on this simple duct pressure test for 2 hours and going over everything multiple times, we finally had to face the fact that this beautiful duct and furnace system leaked like a SIEVE!  I mean huge leakage.  We had the duct pressure fan up to max and still barely were able to get a number of CFM leakage.  Ready? Over 1100 CFM25.  Perhaps that doesn't mean anything to you but we were expecting around 100 CFM from a new, correctly installed system and we got over 1100.  1100 CFM is another way of saying that the duct leakage was around 50%, meaning half, HALF, of the heat put out by the furnace was lost to the outdoors before it ever got inside.  And in a brand new system, no less.  I was floored.  Part of the report will emphasize that the contractor MUST get the HVAC sub-contractor back out there to do his own test and fix the system.  It won't be easy and there may be some metaphoric blood spilled but the owner has the right to a correctly installed system.

What an example of a beautiful façade hiding a lousy system.  Note to self: put aside your snap assumptions until the data is in with the real story.