Controlling Airflow in Existing Dwellings

The new concept of "controlling airflow" is discussed with a Savings-to-Investment Ratio (SIR) calculated. Controlling airflow includes 1) air sealing to red...

Views: 114

Comment

You need to be a member of Home Energy Pros to add comments!

Join Home Energy Pros

Comment by Rick Karg on June 26, 2014 at 9:04am

David, I am the guy who put together and narrated the video.I am sorry you missed the section in the video about increased heating load resulting from ventilation, which was 6.4 therms (slide 9). I did mention the increased cooling load, but did not include it in the SIR calculation because of the location; Portland, Maine, where cooling is a minor issue. If you use this analysis in a heating/cooling climate, both the heating and cooling load increases from ventilation should be included in the SIR equation numerator. The RED Calc Free Advanced Infiltration tool reports both heating and cooling loads.

Regarding maintenance, you are correct, I did not include any maintenance costs. If these were included they would be subtracted from the numerator as a recurring annual cost and would lower the SIR value. I ignored these costs because we don't have a good idea of what they are. Of course, there will be some homeowner work involved, such as cleaning the ventilation fan blades, etc. We hope to get a better idea of maintenance costs for ventilation systems within the next five years or so.

It is best practice to add ventilation to each room using ductwork, as you suggest, but it is not required by the ASHRAE 62.2 standard. I assumed a high quality exhaust fan installed in a centrally located bathroom would provide local and whole-building ventilation (this complies with ASHRAE 62.2). If the ventilation system is more complex, the cost of installation would increase. This would, of course, impact the SIR value. A ventilation system that distributes fresh air evenly throughout a home is preferred. However, it is common that this best-practice solution will not fit into the project budget, especially for the folks working within the low-income weatherization program.

Comment by David Eakin on June 26, 2014 at 8:20am

You did not add the (other) expected yearly running costs for the ventilation unit (additional air conditioning costs for heat/coll/dehumidify, any replacement parts/service, etc.) in the initial SIR computation; you only talk to the fan electrical costs. Also note: if the structure does not already have duct work (a very common occurrence in older buildings) the additional ventilation duct work costs make this proposal very costly, and assuming a single exhaust fan will provide adequate ventilation to each individual occupied room - especially with closed doors - without dedicated duct work is problematic regardless of what the ASHRAE prescriptions preach. It is the reason why paired supplies/returns are the best way to deliver conditioned air to each occupied room vs. central supplies/returns.

Videos

  • Add Videos
  • View All

Latest Activity

Home Energy Magazine's blog post was featured
6 hours ago
Profile IconEfficiency First California and Kevin Daly joined Home Energy Pros
17 hours ago
Kevin Daly joined allen p tanner's group
Thumbnail

Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
22 hours ago
Bryan Gabriel replied to Larry Nissman's discussion Strange IR Image
"Is this a close up or broad view?"
23 hours ago
Home Energy Magazine posted a blog post
yesterday
Ashique Ibrahim posted a status
"Hello everyone.Please suggest a software to carry out analysis of energy auditing."
yesterday
Ashique Ibrahim posted a status
"Hello guys. I am student im doing my project on emergy auditing and benchmarrking. Please suggest the best software to do the analysis."
yesterday
Adin Maynard replied to Adin Maynard's discussion 2x DG-700 manometers for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Yes, one is still available ."
Monday

Home Energy Pros

Welcome to Home Energy Pros – the unique digital community by and for those who work in the home energy performance arena.

Home Energy Pros was founded by the developers of Home Energy Saver Pro (supported by the U.S. Department of Energy) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network. Please honor our Guidelines

© 2017   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service