I would gladly log data, and share it, but I am not sure what is of interest. I live in Orlando, so it is a cooling environment. I do not mind buying a data logger (or having one sent to me). A recommended model would be great.

Duct Test:

Main House (10 ft tall attic, R15ish – old batts on attic floor they need adjustment/repair in some spots.

New 3.5 Ton, 16 Seer AC & Heat Pump – 3rd Gen Nest

Actual Sq Ft: 1950. CFM-50:2937
Doors Open: 0.0 Doors Closed: -0.27
Individual rooms generally had a dP of 3-5
Bathroom dP was -0.8

In-Law – separate 1 bedroom building, flat roof, unknown R-value

Old 2.0 Ton Unknown Seer AC

Actual Sq Ft: 750 CRM-50: 1350

Doors Open: 3.4 Doors Closed: 2.0
Bedroom: -18.21

What I have don:
I have replaced the main home’s AC.
I have replaced all bulbs with LEDs

My plans were:
1) Fix Ducts
2) Seal & insulate Canned lights and other such leaks.
3) Add blow in – R39 total
4) Install 8K PV solar and hybrid hot water
5) Tint windows, then replace later

What I might do:
a) Radiant Barrier
b) The house has multiple ridge vents at different elevations. I am thinking of closing off the lower elevations to bring in more air from the soffits. At first it would be with a simple cover, and log if there is a temp decrease.

Any other suggestions on what to do or order of what to do would be wonderful.

I am putting in an 8K Solar PV system which should generate about 1300kW per month. I have a no-AC month @ around 900kW/month and a full cooling June bill of 2100kW/month.

I am hoping that I do enough improvements that I eventually become a net-zero home @ 1300kW/month.

Best Regards,

Greg

A favorite diagnostic test is to pressurize the home with a blower door, then use smoke to see if air is leaving registers which can only be going outdoors showing their is duct leakage to outdoors. If a sensitive flow hood is used, the leakage can actually be measured and a subjective sense of the duct leakage to outdoors can be uncovered.

Below, is a new wrinkle that works in houses with ducts entirely inside the living space. In those cases, the “duct” going back to the furnace is the bedroom (when the door is closed) and the undercut in the door. The duct leakage path to outdoors is mostly the exhaust fan duct and the pocket door leading to the ensuite bathroom.

It might be assumed that duct leakage to outdoors is a non issue when ducts are entirely within the living space but that is not the case the moment a bedroom door is closed. Close the bedroom door with blower door running (airhandler off); any register flow you detect with smoke must caused by duct leakage going outdoors. I have worked on a method to quantify this exactly but got bogged down and it remains unfinished. This might be worth working out as diagnostic tool. Simply take the house to say +25 Pa with the blower door and measure the register flows, pressure drops at door ways to get a good idea of how the system is performing.

Another method would/could be LBL’s Delta Q process which we have working but have not seen any interest in.

Greg