Thanks for the info regarding the volume requirements, the 1.5 gpm/ton did seem rather low to me as well. I have been looking for a curve or equation based on factors such as source water temperature and even ambient external temperature and insulation efficiency but so far no luck. As for the cooling by spraying with water, I'm not clear as to why you suggest that it is not a good idea. It is exposed to the elements after all (e.g. rain). My biggest concern would be scaling due to the content left behind after evaporation but maybe there is a way around that (e.g. descaling or reducing/removing hardness, I have considered looking into a softener system to make use of my existing sand point for household use and reduce or eliminate the need for city water but am not sure if that would remove enough)? As for the sand point, you should not be mislead by the pictures or experience of the Muskoka's and assume that all of northern ontario is exposed rock, not to mention the fact that I am not in the Muskoka area. In fact, as I mentioned in my previous post, we have a significant water source at about 10 feet below the surface and myself and a number of my neighbors have sand points into this water (which is primarily used to water lawns and gardens), with my own at about 16 feet deep on a 2" pipe. The soil is rather sandy and boulders do not appear to be an issue though i am sure an occasional one could be hit which would result in abandoning that hole. The bigger issue, as verified by a local installer, would likely come again from the same issue I pointed out above, namely hard water build-up, though this time it would occur in the exchanger itself, leading to reduced efficiencies and emminent failure if it cannot be controlled. This variable itself will likely make the project a no-go, again however leaving the question of how effectively a softener system would work around this and provide a controlled heating/cooling fluid, and then at what cost. On a slightly different topic, in a closed loop vertical system, what is the typical bore size for the wells? In other words, how much separation is there between the supply and return tubes? This post was edited by Dave_Gillingham on Wed, Feb 12, 14 at 19:11

tigerdunes - I have learned a lot from reading your postings on this forum and I appreciate your inputs. Your minimum specs list has already been very useful (though a lot of sales people really struggle to find answers about some of the items on that list), and IâÂÂm leaning now toward the XL15i instead of the $660 more expensive XL16i. I still havenâÂÂt completely ruled out Carrier and Rheem, but a neighbor has had a 4-ton Trane XL14i for over three years and I like the way it does not seem to have collected very many of the evergreen needles that are everywhere around here. I am curious though just why the XL16i has so much trouble with dehumidification, and whether that is important to our well-shaded house just outside of Seattle. We havenâÂÂt bothered to run our heat pump in cooling mode for at least the last decade, so I remain mostly concerned with heating performance and expect to use very little cooling. Also, is the XL16i any less reliable that the XL15i, or is it just (as I understand from other forum postings) that it is more complex to hook up and hence more prone to improper installation? I am also puzzled when I compare ARI heating performance of the XL15i and XL16i. At 47 degrees their ARI heat capacity and COP are identical, and at 17 degrees the 15i has only 1% more heat capacity. The 16i has the better 17 degree COP, 2.86 versus 2.82, but it falls down on HSPF to 8.50 versus 9.00 for the 15i. This seems to imply that the 16i spends more time in defrost mode, but I do not understand why. Returning of your spec list, I assume âÂÂstaged backup heat stripsâ refers to the capability to selectively turn on part instead of all of the backup heat? Our old heat pump has this feature, but I have yet to find a sales person who can tell be whether modern systems can do this. One issue is not really relevant until our new heat pump is being installed, but opinions about it are so amusingly diverse I cannot resist asking. Our power utility offers an extra rebate if we install a lockout control. What should it control? We have a lockout set at 32 degrees on our old heat pump and I understood it prevents the backup heat from coming unless the outdoor temperatures is below 32 degrees. The âÂÂenergy expertâ I talked to at our power company agreed, but said the lockout should also turn off the heat pump compressor at 32 degrees to âÂÂprevent a spike in our electric bill.â I recognize efficiency is down at that temperature, but unless there is a lot of icing up it still seems to make sense to run the compressor. Sale personnel were about evenly split whether the lockout should turn off the compressor. Is there any clear answer on this?

You've probably never been in a home with properly sized ductwork. Don't feel bad, it's estimated that as much as 3/4 of the heating and cooling systems in the US are oversized. 2 stage and modulating furnaces are better, but I've lived in a home with both, and both can be very comfortable and the single stage equipment doesn't make it feel more dry that I can tell. BUt you are correct, multistage cna reduce the sense of dryness you might get with a less than ideal system. THe RH of hot air is lower than cooler air, but cool air can make things feel drafty. That's why radiant heat is popular. You essentially have very, very low air velocities and much of the heat energy is indirect infrared heat which make you feel warmer, similar to direct sunlight. Keep in mind too, that unless you have an outdoor rest control for hte boiler or to sped up or slow the circulator, most hydronic air handlers are single stage for heating. So the heat is no different than a furnace. Worse, as you reduce BTU's to the coil, the airflow speed is usually ocnstant, so air temps get cooler. My point being, that a properly designed and installed furnace won;t make it feel dry even if single stage. But yes, oversized furnaces and those with restricted airflow can. Vairble capacity will always make the system more comfortable, but it will cost more. Radiant heat overall is superior, but the installed cost is much, much higher. That's why it fell out of favor. Same reason drywall took over the market and plaster disapeared. ITs' primarily a matter of cost. It's also why stone and brick homes aren't built anymore and concrete homes are the minority.

I have HEPA air filters in multiple rooms of my house but it is still very dusty. I thought it was because the windows were open earlier in the year, because this is a dusty environment (Sierra Nevada mountains) but the windows have been closed for a month. There isn't forced air here, so it isn't the ducts. I vacuumed an entire bag's worth of dirt out of the carpets the first two months I lived here with a brand new Miele vacuum. I fixed the dryer vent which leaked. The dust still appears overnight! Help! I like the idea of a filter before the box fan although I am going to have to come up with something more attractive than duct tape to make that work in my bedroom!