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Thread ID: 85346	2007-12-07 07:53:00	humidity	Thomas01 (317)	PC World Chat

Post ID	Timestamp	Content	User
618726	2007-12-07 22:05:00	Check this thread (pressf1.pcworld.co.nz)out Thomas. There is some good info there. We've had an HRV for several years now - very happy with it. The deal is that it draws in air from your roofspace, filters it and pushes it out via the roof vents and out your windows (which SHOULD be left slightly open for optimum results). In it's travels through the vent to the window, it picks up moisture that would otherwise be cooling your house. An additional benefit is that it seems to pick up and expel dust that would otherwise settle. A positive airflow away from the house. Just having your windows open, you are dependant on a breeze - and it's no fun with your windows open in the winter!! All, as you say, temperature controlled (so the house is warmer in the winter and cooler in the summer)....	johcar (6283)
618727	2007-12-08 01:57:00	Well I'm certainly getting lots of information. But one aspect still puzzles me. Why are so many American sites pushing Humidifiers instead. They seem very concerned about the health effects of dry air and instead offer devices to RAISE the humidity level. Also why 60 years ago did we use bowls of water in front of our heaters to raise the humidity level if that was the wrong thing to do? I am also still puzzled by the lack of drainage or collection units if the air is being dried. It MUST go somewhere. Tom	Thomas01 (317)
618728	2007-12-08 02:28:00	Well I'm certainly getting lots of information . But one aspect still puzzles me . Why are so many American sites pushing Humidifiers instead . They seem very concerned about the health effects of dry air and instead offer devices to RAISE the humidity level . Could be the Search criteria you're using . . . . Could be the sites are based in the mid-West where it is a lot drier than the coastal areas . . . Could be just the latest American fad . . . Also why 60 years ago did we use bowls of water in front of our heaters to raise the humidity level if that was the wrong thing to do?Because houses were a lot drier back then, with drafts a fact of life due to the more basic building materials being used back then . . . I am also still puzzled by the lack of drainage or collection units if the air is being dried . It MUST go somewhere . TomIf you're wondering about the DVS/HRV systems - the air in the roofspace is drier than that inside the house (inside you have humans breathing, showers running, pots boiling on the stove etc) - this ex-roofspace air picks up moisture as it passes through the house back to the great outdoors, removing much of it from the interior living space of the house . This makes it easier to keep the interior temperature of the house at an even level . When you turn a heater on, it's the moisture in the air that gets heated first, which is why in a damp house it takes much more heating effort to get the air temperature up (similar to using a fan heater in a bathroom - when you get out of the shower, the net effect is that you cool down, rather than the expected warm feeling on your skin - the warm air from the heater is going for the lowest entropy item first - the water on your skin) . No, I don't work for HRV or DVS . :D	johcar (6283)
618729	2007-12-08 02:33:00	Now I remember. It is HRV whereas the one on Fair Go was DVS and even then I think they were the victims of a ruthless operator rather than DVS themselves. I still have reservations about the idea of the system but my wife hates steamed up windows. The salesman did produce letters complementing them on the installation and to my surprise the letters had the addresses on them! So not a typical scam. I must admit the idea of a football sized hole in the ceiling and a cheap fan appeals. But the HRV system has an outlet for each room (4 outlets for us), ducting to feed them, a filter system and fairly sophisticated control system. So all in all not too bad for the price really which was somewhat over $2000.00 But I really cannot see how it can remove moisture if there is no drainage system or even a bucket to catch the moisture. Anyway the Americans seem to think removing moisture is the wrong thing to do. Still very puzzled. Tom We had the HRV system installed in our old bungalow. We also had underfloor insulation installed as well. Together they have made a HUGE difference to the warmth and dryness of our house - also great for cooling on the humid Auckland nights.	winmacguy (3367)
618730	2007-12-08 02:49:00	I still have reservations about the idea of the system but my wife hates steamed up windows . The salesman did produce letters complementing them on the installation and to my surprise the letters had the addresses on them! I could write you some letters too and put addresses on them . I'm also a believer in fixing the cause rather than the symptoms . Why do you have steamed up windows? We don't . Any time of year .	pctek (84)
618731	2007-12-08 03:01:00	I could write you some letters too and put addresses on them . I'm also a believer in fixing the cause rather than the symptoms . Why do you have steamed up windows? We don't . Any time of year . Ahh, but you have a fireplace pctek (open fire?) which is a good ventilation system in and of itself, whether there's a fire burning in the grate or not! :thumbs:	johcar (6283)
618732	2007-12-08 03:56:00	, the net effect is that you cool down, rather than the expected warm feeling on your skin - the warm air from the heater is going for the lowest entropy item first - the water on your skin) . No, I don't work for HRV or DVS . :D Now I know why I have been puzzled all along . It's this entropy thing . Might have known it would get involved somewhere . I passed the heat engine exams with flying colours 50 years ago but must admit still didn't really understand entropy . Gave me nightmares it did . Tom	Thomas01 (317)
618733	2007-12-08 04:02:00	Whats a crock, The air in your house doesn't need filtering, There is nothing wrong with it. If you do think its harmful, I suggest you go outside immediatly and board up the house. Of course you won't, The air is fine. If you want fresh air, crack a window open.	Metla (12)
618734	2007-12-08 20:00:00	Ahh, but you have a fireplace pctek (open fire?) which is a good ventilation system in and of itself, whether there's a fire burning in the grate or not! :thumbs: I have a woodburner. Yes, the modern trend is to put polystyrene in the walls, uner the floor, install aluminium windows and basically seal the thing up. Wrap anything tightly in glad wrap and watch it sweat. My house does not have anything under the floor. The windows are wood framed. We sit here toasty and warm all winter and not a drop of wetness anywhere.	pctek (84)
618735	2007-12-08 20:37:00	Thomas, I am really puzzled by your memories of placing "a bowl of water in front of our heaters (particularly gas) to improve the humidity". I could understand that with a radiant style electric heater cos they dry the air to an uncomfortable level, but gas? Portable gas heaters (is that what you were talking about) seem to pump out huge amounts of moisture. There is a hut on the Heaphy (Saxon) that has (or had?) gas heaters. I read in the hut book that some people used the gas heater in the evening, then came out of the bunk room in the morning to find ice all over the floor and walls as a result of the condensation freezing. Needless to say, ice on the floor ain't safe. Are you sure about your memories? Or was it mains gas, which may behave differently, coming from coke rather than LPG?	John H (8)
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