Is the QuFresh compliant with code?
Yes, it meets all codes including ICC, Energy Star, ASHRAE 62.2, California Energy Commission Title 24. It is also HVI Certified, and UL listed.
How noisy is it?
The QuFresh utilizes fans that meet the ENERGY STAR criteria and one of those criteria is a limit on how loud the fan can be. The QuFresh is very quiet (0.3-1.6 sones) sitting on a table top, let alone in an attic, basement, or joist space. The resident will never notice it running.
Where can this be installed?
Wherever you prefer. The QuFresh can be installed in any configuration and comes ready with built on
How can you say that bringing in hot, humid outside air is good for a building?
With the energy code requiring tighter and tighter residential units, the homes just don’t breathe like they used to, trapping pollutants inside so any fresh air coming in is a good thing. But we agree that hot, humid air can be detrimental to the comfort of the residents and the durability of the building. That is why we designed the QuFresh with the ability to test the humidity and temperature of the incoming air. The resident/owner can set the max and min temperatures as well as the max humidity and if the air is outside of those selected bands, it temporarily shuts the device off until the air returns to the preferred settings.
Will this cause condensation?
No. The unit is fully insulated and has door and take-off gaskets.
What size fans can I get this in?
One, but thanks to the variable speed motor, one will work for most residential units. The QuFresh is able to deliver between 30 and 130 cfm in 10 cfm increments. Running continuously, the 130 cfm is enough outside air for a 7500,sqft 5 bedroom house to be compliant with the 2012 IRC and ASHRAE 62.2-2010.
Do I need a special thermostat to use this product?
The QuFresh is independent of the heating/cooling system so you are free to use whatever thermostat you prefer.
Will I need to increase my breaker panel?
No. The energy stat fan pulls at .20″ SP from 10.1 watts (30 CFM) to 33.6 watts (130 CFM).
How much voltage does this need? Does it get it from the air handling unit?
The QuFresh comes with easy wiring access for 120v / 60Hz. Being an independent system, it will need to be connected to house power.
How much will this increase the homeowner’s energy bill?
The key to remember here is that the 2012 IRC mandates outdoor air being brought in so homes built under their guidelines will have outdoor air regardless. The advantage the QuFresh presents is to be able to prevent air coming in that is too hot, too cold, or too humid (based on setting preferences), so this means that a home built with the QuFresh will have a lower utility bill than a home without it that is built under the 2012 IRC or later.
Do I need to filter the air?
No. It is not a requirement in many states or codes but we recommend installing one. We have them in MERV 8 and MERV 13. They are 10″x10″x2″ (nominal). There is a “slot” in the unit for this filter.
If one is installed we recommend that it be checked at the same time the filter for the HVAC system is checked. Depending on the outdoor conditions it may need more frequent changing.
Can a system that provides outdoor air through a supply fan not directly connected to the dwelling unit’s air handler meet code.
Yes, there are many places in and out of code that detail that it is acceptable to have a stand alone fan provide outdoor air. The 2009 IMC Code Commentary for section 403.1 states, “The components of a mechanical system can be dedicated for space ventilation or can be part of an HVAC system that serves the space.” While the 2009 IRC does not address outdoor air, the 2012 does and provides us with this guidance under M1507.3.1: “The whole house system shall consist of one or more supply or exhaust fans, or a combination of such, and associated ducts and controls. Local exhaust or supply fans are permitted to serve as such a system.” Additionally, both of the above codes reference ASHRAE Standard 62.1 (commercial buildings) or 62.2 (residential buildings). The ASHRAE 62.2-2010 User Manual for section 4.2 clearly enhances this stance by explicitly stating “Supply ventilation can be provided through dedicated supply fans or through the central HVAC system air handler.”
Whether you have a commercial or residential building, the experts all agree that a supply fan, such as the QuFresh, can be completely separated from the HVAC system, though it is also acceptable if it is.
If a supply fan providing outdoor air is designed and installed for continuous use but has an off switch or controls that allows the system to run intermittently, do we have to alter our design and controls to deal with intermittent usage?
Not at all. If the system is designed to the appropriate flow rates for your occupiable space, then it is fully in compliance and nothing else needs to be done. Manual override controls are actually a mandatory component but nothing details how the override must operate, so a system that can shut off when the outside temperature or humidity is outside a range of owner defined limits is considered as part of the manual override controls.
The 2009 IMC Commentary states that “The ventilation system shall be designed to supply the required rate of ventilation air continuously during the period the building is occupied, except as otherwise stated in other provisions of the code.”D The 2012 IRC item M1507.3 agrees that design is the key component by detailing “Whole-house mechanical ventilation shall be designed in accordance with sections M1507.3.1 through M1507.3.3.”E
This might seem to contradict code and ASHRAE, both of which have an exception that discusses a factor that is multiplied to the airflow rate if operating intermittentlyF, but the key is that the system is a continuously operating system that has specific manual override controls. 2012 IRC, section M1507.3.2 says “The whole-house mechanical ventilation shall be provided with controls that enable manual override,”G and ASHRAE 62.2 User Manual dictates “The occupant must be able to modify the settings or override the system if he or she chooses. While the standard requires the whole-building ventilation system the occupant has the option of not choosing not to operate the system.”H
To ensure that this understanding of continuous operation with override controls for possible intermittent use was accurate, a Technical Opinion was requested from the International Code Council. Chad Holland, Senior Technical Staff, responded with “If the system meets the ventilation airflow rates indicated in Table 1507.3.3(1) <IRC 2012> then it would appear to meet the requirements in the code. It should be noted that while the code states that manual override controls must be provided there is nothing in the code which states what the manual override is supposed to do.”I
The Fresh Air Machine should be designed under the assumption that it will operate continuously but in addition to an on-off setting, the Fresh Air Machine is equipped with an Eco-Saver mode that will override the system operation if the outside air is too hot, too cold, or too humid based on the owner’s inputs.
Is there an energy penalty associated with providing outdoor air to dwelling unit and how does this impact the Energy Code?
There is a small energy penalty when providing outdoor air to a dwelling unit but it is a minor element that can be further minimalized through the use of Energy Recovery and/or manual override controls that limit the outdoor brought in when the outdoor air is too hot, too cold, or too humid.
The majority of new buildings built follow a performance path calculator which does not factor in these impacts as it is not referenced until the 2012 IECC, but it is not considered to be significant. As an example, the energy efficiency modeling software, REM/Rate, which is used by the Home Energy Rating System industry and can model total energy usage with and without an outdoor air ventilation system was used to examine a 1653 sqft dwelling unit with 4 bedrooms in Dallas, TX. The estimated total energy with outside air introduced by the air handling unit was 89.9 MMBtu/yr while without it was only 87.2, a 3% increase. It is important to note though that most builders achieve performance scores above code based on good design and efficiency measures mandated by a competitive marketplace. This example house achieved a HERS 71 and the 2009 IECC is roughly a HERS 87 in the same climate zone, so this house is already 18% better than code before the 3% alteration from the addition of outdoor air.
The impact of additional energy generated to operate the fan or Air Handling Unit can be offset by including manual override controls and allowing the system to operate intermittently. Care must be taken when running the outside air to/near a furnace as the manufactures have minimum return air temperature requirements (typically 55°F)J therefore having a controller that limits the air being brought in based on the temperature is a large benefit in these situations.