Do it Yourself: Re: [DIY] Just an after thought:

13 January 2013

Re: [DIY] Just an after thought:

it is indeed a problem when a structure is totally sealed tight. the solution in a commercial building and in larger homes is to bring in outside air thru the hvac system to supplement the stale air in the building, while exhausting the same amount of stale return air from the building. healthier but at a cost, due to having to treat the outside air to bring it to the conditions of the interior air, and having to upsize the hvac system to handle the additional load. here in the south, that requires adding dehumidification systems for summer and humidification systems for the cooler months and some means of controlling these additional systems. increasingly this is done with electronic systems thru a computer, requiring more $ to operate at highest efficiency. many times the savings from a high efficiency hvac system can be lost in operating costs and maintenance. monitoring of air quality is a good field to get into due to the additional requirements being mandated by the government!

From: subprong <subprong@gmail.com>
To: DoIt_Yourself@yahoogroups.com
Sent: Saturday, January 12, 2013 6:52 PM
Subject: Re: [DIY] Just an after thought:

Not sure if it's the same episode but I saw an episode on a multi story house where they pumped in colored air/smoke. They basically stood outside to watch for leaks. Sure enough you'd see this smokey air come out through little crevices. Then they patched them up. As usual another simple idea to find problem areas (at least to some).

On Sat, Jan 12, 2013 at 4:49 PM, Dale S <dalu@hbcomm.net> wrote:

While watching an episode of "This Old House" last night I noticed they now have a new structural integrity test that they can run on a completed home. In this instance an exhaust fan was installed in the front doorway and the CFM of the exhaust air was measured to determine how draft tight the overall structure was. This was a large three story home with a full basement and they drew less than 2,000 cfm which is pretty low. This tells me that the natural flow of fresh air through that house with all the windows and doors shut in the fall and winter months would be like living in a walk-in refrigerator with a furnace. There seemed to be some implications that this might become a standard test on future homes to determine FHA saleability. I begin to wonder whether cooking and heating with gas would even be safe or whether the build up of CO and depletion of oxygen might become a problem. A local family was very nearly killed a few years ago when a forced draft furnace created enough back draft to fill the house with smoke and co from the smoldering embers in a fireplace, and a gas fired water heater.

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Dale in the Flatlands.