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.