Hi Vittorious, Anything we can do to reduce fossil fuel usage is ok in my book. If the space isn`t being used and the barrel are free.. then you may as well put it to good use. Here are some of the limitations so you don`t expect too much from them :) The effectiveness will depend on how much of the barrel surface area gets direct sun. If the six barrels are in a straight line you`ll have around 56ft2 to work with. The heat transfer from the barrels to the greenhouse is governed by their surface area and temperature difference. So assuming you have 113ft2 barrel surface (excl the tops and bottoms),water at 70F (magically no losses)and a greenhouse at 50F. Your barrels lose 2260btu/hr(662w)and the water temp in the barrels will drop by 0.82F to 69.18F 662w to make a dent in an hours worth of greenhouse losses :) You now have slightly cooler water so the following hours transfer will be less than 662w. Thats the simplified version, in practice you`d have radiant loss and losses to the ground to consider. Plus the water in the barrels wouldn`t all be at a uniform temperature and winter daytime air temp will rob more heat than is stored. Another variable is the thin boundary air layer on the barrel surface. It will be warmer(relatively)than the greenhouse air due to the flow of heat so theres less temperature differential driving the heat transfer from the barrel surface to the air :) If it doesn`t cost anything, you`ve nothing to lose and may gain "something"

I'm pretty positive not. There are only 11 units; only 9 resident families (one's a duplex; one's empty). There's no room in the units to be installing devices; it's pretty tight. My big question isn't really "what's causing this?" bcs I'm pretty sure the plumber will figure it out. (I think it's a check-valve that has gone bad; we had the same problem 10 years ago when the plumber put in new water heaters & put the valve in backwards. He fixed that--but this problem is SO much like it, that's my theory--a failing check valve) But I'm just wondering--does it really matter whether you turn the shower diverter down AFTER you turn off the faucet at the handles, or BEFORE? I always thought it didn't matter, and I'd like to confirm it.

Poor or incompletely pollinated fruit are often distorted either inside or outside or both. Common signs are cat facing, zippering, puffy, fused, hollow, etc. Dave

A few issues... Refrigerant piping. I prefer to keep refrigerant piping as straight as possible with as few bends as possible. The more bends you put slow the flow. If there is to be a bend it should be a sweeping bend, not 90 degree. Given how your house was built, where the line set exits the structure, to flip the condenser the other way may not have made this situation any better. (I wouldn't install the unit in front of a window. --- so it is what it is. Either that or run a new line set from a better location, that will increase costs as you may have to relocate electrical service too.) I believe the access panel to this unit is on the back side opposite the Lennox logo you don't show in the pictures. So placing this back end toward the structure limits serviceable access as well. -- not a good idea. If you had 3 feet from structure only then so as to provide ample room to service it. All these things are "design related things" that at some point may impact the life of this unit. Dirt kills air conditioners. It permiates the coil after years and years of yard guys blowing crap into it... or due to constraints of not being able to get in and clean it properly. The best way to aleviate these problems? build a bigger concrete slab to place it on, position it further from the structure. I prefer 2 feet if possible... from 'anything else' all around the unit. The unit not only needs to breathe, it also needs to be serviced and serviced well. That said: there are controls in a Inverter type AC that does a better job at things that causes more trouble with traditional AC that don't have these controls. (Oil return to the compressor) I service the Katy, Texas area.