As a case study Comfort Advisors Energy Upgrades (CAEU) completed an upgrade on a 1300 square foot Costa Mesa home, that has a crawlspace, which was built in 1961. The home had the original furnace in a closet, asbestos ducts and a small amount of insulation in the attic that had a lot of rat feces in it.
Our first measure was to have the asbestos ducts removed by AQHI, a company that is licensed to remove, transport and dispose of hazardous material.
Then we removed the insulation, vacuumed and sanitized the attic. After cleaning the attic, our HVAC crew came in and installed a new Bryant furnace with a manual fan, R6 Mylar flexible ducts and a NEST Learning Thermostat. A deck was created in the attic to access the furnace and we also built a catwalk beyond the furnace, so that the homeowner could maintain a radio antenna that is mounted in the attic.
This same day we had an electrician come in and install two continuous ventilation fans, which constantly exhaust air from the house and are a combustion safety precaution. Installation of a Carbon Monoxide alarm is another safety measure that we install during each upgrade.
The next stage was sealing the attic floor. We had a blower door available to quantify the measures as they were implemented. The outcomes are listed below:
4534 cfm - Building leakage (leakage) when the attic deck was clean
4387 cfm – Leakage after sealing foam was applied to attic penetrations
3292 cfm - Leakage after CanCoverIts were sealed around 25 recessed light cans
2845 cfm – Leakage after R38 of cellulose was blown onto the attic deck
CAEU is one of the few companies on the West Coast that utilizes CanCoverIts to cover recessed cans. Rather than use sheet metal around the cans that do not limit access to attic air (dirty, hot or cold) we use an insulated cover that reduces recessed can leakage, yet still allows them to be insulated and ventilated safely.
Duct leakage is a crucial part of each upgrade we complete. In more than 2 years of testing ducts, the average leakage that we have found in homes is approximately 32%. Please note that asbestos ducts are not supposed to be pressure tested so we utilized an Energy Upgrade California approved vintage default table. We came up with the data below as we tested the duct leakage:
28% duct leakage – Asbestos ducts, as prescribed by Energy Upgrade CA vintage default table
8.5% duct leakage – After new Mylar flexible ducts were installed
2.5% duct leakage – After sealing of boots that are cut into the walls or ceiling
By lowering the building leakage, minimizing the duct leakage and blowing in R38 of cellulose insulation, this Costa Mesa homeowner will have a very comfortable residence 365 days a year. They also now have a furnace fan to circulate the air in the home as desired, especially on days that are unusually hot.
Please feel free to contact us if you have any questions regarding this home performance upgrade or to schedule an appointment to see how you can make your home more comfortable and energy efficient.
