While some building folks have opined that energy audits are less than essential, I am admittedly biased. It is what I do. But it raises an interesting question: how could one do the work on a house and ensure air quality, warmth, comfort and moisture control without an audit? What minimum provisions would a builder need to make?
This is an important question and not just in an attempt to kneecap my business. Air quality, warmth, comfort and moisture control are the essentials of a healthy home. Answering the question of how to address these without an audit gets at how to do the same in new construction. Those answers will be with the industry for as long as we are building houses.
The first concern would be safety. Safety means several things: air quality, carbon monoxide, gas leaks, fire hazards, moisture, heating system safety, asbestos, lead paint. There are a lot of concerns. Second would be sealing all the big thermal bypasses and last would be cost effectively improving insulation as feasible. How would one approach all of these without an audit assessment of each area? Hit each of the above and err on the side of safety and caution.
Air Quality
There’s an awful lot of debate about ventilation for air quality these days. The no audit/no brainer answer: add a ventilation system, set it to meet ASHRAE 62.2 and go eat a sandwich.
Aggggh! Technical Mumbo Jumbo
It may be changing but currently ASHRAE 62.2 is 7.5 CFM (cubic feet per minute) per occupant plus 1% of the building’s living space (sq ft) plus it assumes that all mechanical systems are properly ventilated.
So if 3 people lived in a 2000 sq ft house, the 62.2 ventilation standard would be 42.5 CFM (2000 * 1% + 7.5 * 3)
End of Warning: Tech Talk
The slightly more truthful answer: tighten the building envelope, test periodically with a blower door to direct the air sealing then add mechanical ventilation.
Carbon Monoxide
Add at least one hard-wired, battery back-up carbon monoxide alarm in the combustion air zone (or CAZ) and preferably one per floor.
Gas Leaks
If the house has gas appliances, the fuel lines should be inspected by a licensed gas technician and inspected regularly
Fire Hazards
Make sure you’re following building code standards for ignition barriers, recessed light cans, chimneys and foam insulation.
Moisture
This can take many forms but the general goal is that moisture and humidity levels are well controlled before tightening the enclosure. Less energy in the building means less drying which in the wrong circumstances can mean more mold.
Whatever moisture control measures is needed would be done. This can mean bathroom fans, gutters, concrete sealant, oven hoods, etc.
Heating Systems
Since we’re tightening without testing the CAZ, we need to make sure the heating system won’t backdraft into the house. This means either installing a sealed combustion system or adding a makeup air kit to your atmospheric system. All this means is that your heating system won’t be using interior air for combustion.
Sealing the Big Holes
Very easy. Print out a copy of the Energy Star Thermal Bypass checklist and send it with a couple guys armed with foam sealant and caulking guns.
Insulation
Improve the insulation to high performance levels. This could mean IECC 2012 or more roughly to Building Science’s 10/20/40/60 levels (R-10 subslab, R-20 basement wall, R-40 building walls, R-60 attic). Basement and crawlspaces are generally easy to access and work in. Likewise with attics. Walls are a judgement call; if the return on investment works or the homeowner commits to improving their home, awesome.
Improvements without Audits
Tens of thousands of insulators and HVAC companies improve the efficiency of buildings every day without an energy audit. Understanding the issues and how to avoid health and safety pitfalls can help make your house safe and warm.
