I work with a C.A.O. here in Ohio under the W.A.P. now that D.O.E. requires implementing ASHRAE 62.2 2010 as of PY 13 and 62.2 2013 in PY 14 my concern is accomplishing this correctly.
The required mechanical venting calculation is pretty much cut and dry with the availability of calculating programs thru R.E.D. and alike. So now I have my required cfm, do I really want to install an exhaust fan system in every home, no, not with depressurization limits, questionable infiltrating air quality source and so on.
How about a in line supply air system in the return duct to the furnace, maybe, is it a central return system if so where is it located in a hallway ceiling or on the wall in the living room ? On a branched return system, I might be wrong here but,wouldn't the path of least resistance for the in line supply air be over the heat exchanger? If that is true, wouldn't there be some kind of thermo shock to the heat exchanger having 20 or 30 degree or colder air blowing over it for any period of time then the burners lighting off, resulting in a premature failure of exchanger from expansion/contraction or possible excessive condensation?
I'm not up to speed on the other options such as ERV, HRV just the basic concept, that is next on the to do list.
I understand Wisconsin's W.A.P. has been doing this, ASHRAE 62.2,since 2005 so I,m just looking to start a conversation with anyone, especially associated with W.A.P. and familiar with the limited Health and Safety funds available, on how they approach and implement this standard, or any studies done on the energy, efficiency or comfort level penalty, along with the other side of the coin, improved heath via fewer E.R./ Urgent Care / Hospital reports of lower respiratory/health issues.
A big THANK YOU to everybody responding ! The wealth of untapped knowledge and experience in this field is mind boggling and I urge all of us newbees (only 5yrs here) to utilize this site and others like it to get that knowledge and experience flowing. I really don't want to over think this ASHRAE 62.2, preferring to use the KISS (Keep It Simple Stupid) approach, but air sealing has a proven track record in WAP, now this ventilation is something I am directly bring into and installing into this structure and in my mind that's a different game. I have more questions to the replies but limited time, but one quick question on the calculations that I stated was "cut and dry". I have a unit with two baths,each having spot ventilation to some degree, over 35cfm,my original calculation calls for whole house ventilation at let's say 47 cfm now my strategy is to install a 50cfm fan in the common bath,as most folks are doing,I need to go back and refigure the required ventilation because I'm taking the existing spot ventilation in the common bath out of the calculation thus increasing the required ventilation. Thanks again for the insightfull replies
In your recent post, Billy, it sounds like you are talking about adjusting the whole-building flow as the local "appendix A" deficit changes, but with the new fan the required flow shouldn't increase; it should have been reduced if the new fan is running 50 cfm continuous in the bath. That could take care of both the spot ventilation (if at least 20 cfm continuous) and the whole-building. That seems like a reasonable WAP retrofit, particularly if the duct to outside (and the wiring) already exist.
Regarding the search for an optimal solution, one I have seen is a range hood that plugs in. When "off", it quietly moves 40 cfm, then kicks up to 130 or so when on. This would then eliminate the entire kitchen deficit (which, with no operable window, could be one quarter of 100, or 25, cfm) from the whole-building flow requirement. If the range is on an outside wall, the vent is less than a foot long, and the 5.3.1 "readily accessible override control" is the power cord.
I've been involved in WAP primarily in Michigan, and dislike the idea of putting air into the HVAC return; as Dale pointed out, it tends to pressurize the house and push air and moisture into the walls. It also costs a lot of money to run a furnace fan year round (particularly if not ECM, and no AC). Using the RED calculator and conservative estimates of load (say 350 watts intermittent) it can cost over a hundred dollars a year in additional electric cost. Compare that to a Panasonic Whisper at 10-15 watts ($10-15 per year, continuous), and no blowing cold air when the controller calls for ventilation but the thermostat is satisfied.