Ventilation Air In SIP Construction

[lumbee]

I'm building a home using structural insulated panels. According to all the reports that I read, a home built using sip construction, if built right, is tight and requires outside air for ventilation. According to the North Carolina building code you need .35 ACH. What would be the best way to introduce outside air and how much air would be required? Could I use an exhaust fan only and assume outside air is coming in thru infiltration? Would I include a heat/energy recovery ventilator? If so, would it stand alone or connect to hvac unit? What manufacturer makes a heat/energy recovery ventilator for residential use?

 

[tombmech]

1st, If the structure is heated and air conditioned, then you need to bring the outside air through the unit (assuming you don't want a separate, dedicated make-up air unit). Otherwise, you're destroying the integrity of your environmental control.

2nd, You can't really count on infiltration anyway. "Tight" construction means a lack of infiltration.

3rd, In order to ensure that outside air is really ventilating the house, you must include some form of exhaust. A mechanically driven exhaust is the most positive, although pressure reliefs will work, too. It depends on the amount of outside air brought in through the unit.

Lastly, technically speaking, ASHRAE bases their ventilation standard on the number of occupants, not air changes.

 

[GMcD]

For a tightly built SIP house, look at the Lifebreath or Venmar brand (and there are other brands) of heat recovery ventilators to provide proper ventilation to the house. While the Codes may require a minimum of 0.35 ACH, there's notjhing wrong with using 0.5 or even 0.75 ACh depending on your comfort and health desires. Remember, the Codes are just a "minimum" standard.