There are a few things to consider here. Blowing insulation into the walls can certainly help if there isn't any or if you know of pockets or voids. Ceiling insulation is very helpful. It wants to be well fitted. how much difference it makes will depend a lot on where you live and how cold or hot it gets. Remember that a lot of heat comes in through the ceiling as well which influences air conditioning costs. These days I would think even in moderate climates cross laying two layers of 6 inch for overall 12 inches of fiberglass would not be extreme. The exterior foam will insulate but it also helps create an air barrier. That turns out to be one of the most costly problems, air leakage. In cold weather or during windy conditions go around feeling for drafts. A sighted person can stick a strip of something like toilet paper onto the end of a wire, something like a straightened out coat hanger or maybe a light ribbon. turn off the furnace fan and move around poking this ribbon around closed doors, windows, electrical outlets, other penetrations like bathroom fans, where the water or electrical panel is located looking for air movement. When you find it figure out how to weather strip or calk. Old windows often weren't well fitted and there can be quite wide gaps between the outside frame and the edge of the hole in the wall. Carefully removing the trim around a window and insulating that space, sometimes half an inch wide all around the window can really help. Spray in foam fills the void well and seals it up. Be careful not to get the stuff that really expands, it can deform the window frame and seize it up. Figure this though, a window 3 by 4 feet is 168 inches around. A half inch void all around represents 84 square inches without insulation. That is like a square over 9 inches by 9 inches. If you have say 10 such windows that is a big open insulation space.
Now consider an exterior door. Say 78 inches by 34 wide, that is 224 inches around. Let us allow a 16th inch gap all around. That is 14 square inches. If you don't have a good seal around that door when it closes it is like having a hole in the wall about three and three quarters inches by three and three quarters inches. One probably doesn't have quite that large a gap but consider all the doors and windows and leaks around penetrations like the telephone and cable television wires or an open chimney flu and it can add up to a bloody great hole just robbing heated or cooled air to the outside which has to be made up if you are going to be comfortable. There are other contrived exhausts like bathroom fans and the dryer vent pulling air from the house which is being made up with outdoor air. It all costs heating or cooling money. As for running circulation fans I really only ever turn mine off when I change the air filter. It is a bit noisy but I get used to that, I never get used to the damn thing coming on and off and of course the circulating air tends not to layer. We have a rather big house though and only the two of us knocking about in it so empty rooms wouldn't otherwise get much ventilation. Probably electricity is too cheap as well. I also rarely remember to turn off the dust filter in my shop and I seem to have a variety of stereo equipment on most of the time. There may be another dimension to your thoughts on mold spores. As water condenses out of the air passing through the humidifier it may be that it is capturing spores and washing them down into the reservoir where they collect for tipping down the drain. Every occasionally I used to dribble an ounce or two of Javex or other bleach into the reservoir just to keep algae from growing. As for the capacity, it only comes down to how often you empty it. My old dehumidifier had a knock-out and a cap over a sump at the bottom of the reservoir which could be removed and either set over a drain or have a hose threaded onto so that the reservoir drained directly into the sewer. The humidistat might not be all that far off when you consider it is sensing air as it passes through the machine. At that point it may well be different from a sensor located and reading ambient humidity at some point remote from the dehumidifier. Consider what would happen if your thermostat was above a heat outlet or even some other heat source. It would not register the same as a thermometer on the front door. As the environment stabilizes I am pretty sure you will find that the dehumidifier will run much less. Often one is better leaving it operate continuously rather than switching it on and off just because it will take a long time to restore stability after extended disuse. So, to recap, defeat air leakage and control the exchange of fresh and ambient air. Insulate to retain the heat you pay for Those are really quite cheap efficiencies. Based on my experience I also recommend a programmable thermostat. Now Janet is in the house so we don't set it back during the day but I have the furnace come on to 21C or about 70F an hour before we get up in the morning. It isn't quite settled in an hour but close enough. In the evening, about 7 p.m. I have it up a degree, nearly 2 degrees F. then at 10:30 it automatically sets back to 16C or about 61F. According to my talking thermostats, the furnace rarely comes on before morning even when it gets as cold as 40 below. It is difficult to know just how much this saves as gas prices have gone up substantially since I installed the programmable thermostat and certainly a lot of my success is the high insulation and air tightness of this building. We also always sleep with our bedroom window open, admittedly not a lot in really cold weather but with the bedroom door closed. I was skeptical at first, wondering how much energy it takes to raise the ambient temperature of the building structure and the contents but it seems to work and I suppose that some of that energy cost is offset by the inertia of the building and contents cooling off. We don't air condition although there are always a couple or three weeks in the year it would be nice. We can usually turn the furnace off about the first week in May and back on about the first week in September but this year we have had it off a couple of days only, it was on last night but looks like maybe we won't need it tonight. if we get good enough sun during the day our daily solar gains might mean that last night is the last this season but they are calling for cool cloudy days over this coming week-end. This year may be a little longer heating season than most, so much for global warming! That about taps my knowledge on the subject. Hope it gives you some ideas. Dale leavens. ----- Original Message ----- From: Scott Howell To: [email protected] Sent: Tuesday, May 12, 2009 7:28 AM Subject: Re: [BlindHandyMan] more on humidity Dale, You make some excellent points and I think your summary of an expensive bathroom fan is probably on target. There is no heat exchanger/recovery system in this. I think I slightly offended the woman when I said it was a high-priced fan ducted to the outdoors. grin You make some interesting statements I'd like to elaborate on a bit or maybe more ask questions. See this is one of those issues I've been dealing with and until I moved my office to the lower basement, I really didn't think much about the humidity etc. I knew it was there because the place smelled musty which is apparently dead mold spores in the carpet, yuck. In any event I have some expensive instruments and protecting them and the other stuff down here is very important and I can't move my operations back upstairs for a lot of reasons. So, I guess the humidifier is the best choice although I wonder if 45 pints would be sufficient or if I should go up to a 65 pint unit. THe basement is odd in that this is a split-level house so there is no door at the top of the stairs. I think this unit is doing a reasonable job. I have found that setting it's humidistat to 65% will keep the humidity at around 50%, so that indicates to me the unit is not very accurate and the hygrometer is probably not perfect itself and thus the sum total is no more musty smell and that's a good thing. THe one thing I did do right is I had the gent who installed my new heat pump, put in a return and outlet in another area of the basement. THe previous owners had a vent in a closet, which made no sense so I had that sealed and a defuser put into the main family room area. Now you say you run your furnace fan all year. I leave it running when the AC is on, off when the windows are open, and off during the Winter. The reason off in the WInter is because heat pumps suck so bad, the air at 65 degrees even on a real low speed makes the house feel cold. However, perhaps I should be running it regardless of whether or not the heat or AC is on and just turn it off when the windows are open. There are days where we have neither AC or heat on, but windows closed. Perhaps that would be the time to still run the fan. I think my concern was the possible $20 to $30 additional cost per month to run the dehumidifier and that is a lot considering the cost of electricity here. I do need to get the specs and try to calculate the cost of running this unit. I know it will certainly ad to the electric bill, but folks I have talked to around here who have used dehumidifiers made in the last couple of years say the increase was not that bad. And I guess in the end the additional expense is going to be worth it. I don't know how much of this piffle the sales lady talked about the humidifier pulling mold spores in and tossing them back out really matters. I mean there is likely mold in here in any event and all but short of sealing my house and having a decontamination chamber at each door, I'll likely have some mold. Now sorry, I did get a little off track in my extensive prattle and I suspect Dale that yes, they anticipate a leaky home, which in reality would bring humidity into the home. I don't know if the system is a completely bad idea, but for $1,500 on sale to $2,200 regular price, it can't be worth it. If just installing a fan that vented outdoors would solve my problem, that would be very easy, but I sure don't want to extract heat or cool air from the home and dump it outside, that would just make no sense at all. Thanks for the great feedback and any ideas, I'm open to suggestions. I keep my house at 65 degrees F in the WInter because it would cost me to much to heat the damned thing to 70, which would please my wife to no end. I often think that perhaps adding more insulation to the attic would be a wise move and any recommendations on the best insulation appreciated. And I have often toyed with the idea of blowing more insulation in the walls, but that probably would be an expense and I'm not sure if that would make sense. I had new siding put on and they did put 3/4 thick foam (that stiff stuff) on before the siding and I think that did help. I'm willing to consider any ideas to make the home more efficient since I know that was not the builders idea. Of course getting rid of the heat pump would be the best move, but then I'm down to oil or propane, since natural gas is not available. tnx, [Non-text portions of this message have been removed]
