Comments on: An HRV System Overview http://sustainable.cchrc-research.org/2008/09/an-hrv-system-overview/ Are you Sustain Able? Thu, 17 Jun 2010 19:06:48 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: tjomi http://sustainable.cchrc-research.org/2008/09/an-hrv-system-overview/comment-page-1/#comment-3325 tjomi Mon, 01 Mar 2010 09:30:20 +0000 http://sustainable.cchrc-research.org/?p=167#comment-3325 how to design an effective hrv system how to design an effective hrv system

]]> By: jaye-bird http://sustainable.cchrc-research.org/2008/09/an-hrv-system-overview/comment-page-1/#comment-2659 jaye-bird Fri, 20 Nov 2009 22:58:49 +0000 http://sustainable.cchrc-research.org/?p=167#comment-2659 I was wondering if you can control the hunidity in a house with an HRV system? I was wondering if you can control the hunidity in a house with an HRV system?

]]> By: Anthony L. http://sustainable.cchrc-research.org/2008/09/an-hrv-system-overview/comment-page-1/#comment-2552 Anthony L. Mon, 02 Nov 2009 23:58:06 +0000 http://sustainable.cchrc-research.org/?p=167#comment-2552 How come my HRV unit only blows cold air? How come my HRV unit only blows cold air?

]]> By: kelly white http://sustainable.cchrc-research.org/2008/09/an-hrv-system-overview/comment-page-1/#comment-1185 kelly white Sun, 08 Mar 2009 00:56:07 +0000 http://sustainable.cchrc-research.org/?p=167#comment-1185 I would like to know how one would go about installing a hrv unit in a house with a boiler system. Thank you. I would like to know how one would go about installing a hrv unit in a house with a boiler system. Thank you.

]]> By: ibenesch http://sustainable.cchrc-research.org/2008/09/an-hrv-system-overview/comment-page-1/#comment-204 ibenesch Fri, 19 Sep 2008 19:58:42 +0000 http://sustainable.cchrc-research.org/?p=167#comment-204 Colin, Good question. A good illustration of this scenario would be a 1600sf house I built two years ago that blower door tested at .07 natural air exchanges per hour. In this instance the boiler was part of the house, but had it's own room with make up air and was meticulously sealed to isolate it. This is not always the case. More and more homes are coming up with really low numbers like this - the REMOTE wall construction systems being a good case in point, so it should be addressed. One popular solution in the past has been to cut a hole in the wall in an area where it best meets demand, and use a cold trap arrangement as you would for a boiler. Not the prettiest fix, but effective. Typically a pipe would come in at about waist level and then turn up and travel 4 feet or so to within 6 inches of the ceiling. Theoretically, the cold air would stay down low until enough negative pressure created a demand to draw it up the pipe and into the room. One drawback here was that any slight pressure differential could induce cold air to come in..ie opening an exterior door, or an improperly balanced forced air furnace. I talked with Bill Reynolds again at Solutions to Healthy Breathing and he suggested a better option. Say, as you mentioned, you have a high cfm range fan in the kitchen. Somewhere on an exterior wall, preferably in the vicinity of of the fan, you would cut a 6 inch hole and insert a duct from inside to outside. You can place your grilles of choice on both sides of the wall. Inside the duct you would install an inline backdraft damper facing inwards. If the negative pressure gets too big, then the damper is sensitive enough that it can open and supply the needed air, otherwise it stays closed. I have bought these dampers before at Holaday Parks....I remember they ran about $20. I haven't checked, but Ferguson may carry them as well. Incidentally, those dampers work really well for sealing outgoing exhaust ducts such as dryer vents, bath fans, and range hoods. Just make sure they are facing the proper direction when you install them. Colin,
Good question. A good illustration of this scenario would be a 1600sf house I built two years ago that blower door tested at .07 natural air exchanges per hour. In this instance the boiler was part of the house, but had it’s own room with make up air and was meticulously sealed to isolate it. This is not always the case. More and more homes are coming up with really low numbers like this – the REMOTE wall construction systems being a good case in point, so it should be addressed. One popular solution in the past has been to cut a hole in the wall in an area where it best meets demand, and use a cold trap arrangement as you would for a boiler. Not the prettiest fix, but effective. Typically a pipe would come in at about waist level and then turn up and travel 4 feet or so to within 6 inches of the ceiling. Theoretically, the cold air would stay down low until enough negative pressure created a demand to draw it up the pipe and into the room. One drawback here was that any slight pressure differential could induce cold air to come in..ie opening an exterior door, or an improperly balanced forced air furnace.
I talked with Bill Reynolds again at Solutions to Healthy Breathing and he suggested a better option. Say, as you mentioned, you have a high cfm range fan in the kitchen. Somewhere on an exterior wall, preferably in the vicinity of of the fan, you would cut a 6 inch hole and insert a duct from inside to outside. You can place your grilles of choice on both sides of the wall. Inside the duct you would install an inline backdraft damper facing inwards. If the negative pressure gets too big, then the damper is sensitive enough that it can open and supply the needed air, otherwise it stays closed. I have bought these dampers before at Holaday Parks….I remember they ran about $20. I haven’t checked, but Ferguson may carry them as well. Incidentally, those dampers work really well for sealing outgoing exhaust ducts such as dryer vents, bath fans, and range hoods. Just make sure they are facing the proper direction when you install them.

]]> By: Colin Craven http://sustainable.cchrc-research.org/2008/09/an-hrv-system-overview/comment-page-1/#comment-192 Colin Craven Thu, 18 Sep 2008 17:43:57 +0000 http://sustainable.cchrc-research.org/?p=167#comment-192 Hey Ilya, I like the overview, and you reminded me of some thoughts I've had. If the goal of a HRV is to maintain pressure around neutral for the home, how does one integrate a range/oven fan in keeping balance in the home? Is a cold air intake for the combustion units of the house sufficient to provide supply air for those type of exhaust-only units? Hey Ilya,

I like the overview, and you reminded me of some thoughts I’ve had.

If the goal of a HRV is to maintain pressure around neutral for the home, how does one integrate a range/oven fan in keeping balance in the home? Is a cold air intake for the combustion units of the house sufficient to provide supply air for those type of exhaust-only units?

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