Blower Door Project Concept

Blower Door Project Concept

Summary

Air infiltration (air leakage) is a significant source of energy loss in older homes. Air infiltration can be reduced significantly by use of caulking, weather-stripping, foam insulation, and other methods which do not require training.

However, finding the source of all air leaks in a home takes time, and the average homeowner doesn’t have a means to find them. We propose to help homeowners by giving them access to a blower door.

What we need

1. A blower door assembly to lend out, used or new, with or without air sensors to lend or rent out
2. The funds to purchase it.
3. A person or agency willing to manage the loans or rentals

The Long Story

Energy Assessment Process

Energuide Energy Assessments are a widely supported and very effective process for upgrading the energy efficiency of older homes. They involve

1. An initial home inspection, when a Certified Energy Advisor visits the home to rate its energy efficiency. The advisor surveys windows, doors, insulation and other properties of the home, measures its volume, and performs an air infiltration test using a blower door. This is a fabric apparatus with a large adjustable volume fan in the middle, which sits in the opening of an open exterior door. It blows air out of the house, so that exterior air will flow in through any leaks in the wall assembly.

The blower door apparatus includes inside and outside pressure sensors, and an airflow sensor. The Energy Advisor enters readings fromthese instruments into a software package, along with the building volume, to show a rate of air exchange – a measure of how ‘leaky’ the home is.

With the blower door running, the Energy Advisor tours the house with the owner, pointing out areas with the most air coming in. Sometime later, the Energy Advisor provides the homeowner with the energy rating of the house.

1. The homeowner later installsweather-stripping, caulking, foam insulation and other means to seal up the air leaks as well as they can. They will typically do other upgrades such as new windows, furnace, heat pumps, etc.
2. Usually months later, after all upgrades are done, the Energy Advisor returns. The blower door is installed again and a new air exchange rate calculated. This final test establishes the energy rating of the home, and determines its eligibility for grants and incentive payments.

The problem

The problem with this process is that there may beleaks remaining which the homeowner could remedy, but he/she doesn’t know where they are.The brief tour with the Energy Advisor is not long enough to show them all.

Also, the homeowner has no way to check whether his efforts to seal up the air leaks have been effective. The second test in step 3 ‘seals his fate’ and there is no second chance without repeating the second test at a typical cost of $300.00.

The solution

BCSEA Victoria (at the suggestion of member Jack Meredith) proposes to acquire a blower door to lend out to homeowners during the period between the two inspections. They could leave it running for as long as they wish - probably hours – as they findair infiltration, seal it, and check the results around their home.

The blower door they borrow would not require the air pressure sensors the Energy Advisors use – it only needs to maintain negative pressure inside the house as the homeowner does his work.

Benefits

Homes which are sealed properly use less energy and are more comfortable without drafts. They have higher energy ratings. Energy ratings are beginning to be included in real estate listings, so they could have increased value.

Cost

A fully equipped new blower door (with all sensors) is about $4,000 according to Peter Sundberg of City Green. He also said that they are quite sturdy and last a long time.

This concept could start with a used blower door, without the sensors, possibly for $1,000 - $2,000. Possible sources: or

Current availability

We have not been able to find a blower door available through normal retail channels. We have not found one at an equipment rental company in the CRD area. Some people borrow them from Energy Advisors, but this relies on personal goodwill and acquaintance. We wish to have a more generally available program.

Proposed Availability

Although the door would more likely be used by someone in the energy assessment process, it could be used productively by anyone who wishes to make their house more comfortable and energy efficient.

Management

Some person or agency would have to manage rentals of the blower door. It should be available at a low cost which would only serve to ensure it is returned after a reasonable period – perhaps two days. A damage deposit would have to be collected and refunded.

Options:

1. Peter Sundberg of City Green offered to manage the rental. Their office is downtown and open normal working hours.
2. A BCSEA Victoria volunteer could manage it, perhaps delivering the door and helping the homeowner set it up and showing how to look for leaks. It could be free for use by BCSEA members, and a donation to the Chapter for others.
3. Perhaps an equipment rental company such as Saanich Rentals, GWG Rentals, or WesternOne could be persuaded to add a blower door to their rental inventory. They have all the systems in place to manage equipment rentals.

Publicity

City Green Energy Advisors could inform homeowners of the loan/rental program, and BCSEA could publicise it to our Victoria contact list. We could also show it at community events where we have a display table, both to explain what it does, and to encourage its use.

Training

The blower door is simple to set up and operate, and finding leaks is straightforward- using a smoke source (smoke pencil or incense stick) or just waving a hand along the wall will detect them. We would not be including the air sensors or computer software, so that complexity is avoided.

There are many videos on YouTube which show how to set them up – e.g. ‘Southern California Edison’s Tool Lending Library presents: How to use a blower door’.

Safety

The fan in the blower door is contained in a cage like any household fan, so doesn’t present any particular risk. The house pressure is reduced only slightly, so there is no change to breathing.

Contact

Bruce Mackenzie, Chair, BCSEA Victoria Chapter

Mobile 250 216 7871

Last saved: 2013/01/19 22:22 by: Bruce Mackenzie 1