Hi, great info / discussions in your forum, congrats.

May be you can volunteer some advice for us. We live in Albuquerque, NM. We are considering replacing our old swamp cooler (about 5500 CFM, roofmounted) with either an advanced evaporative cooler, such as the Oasys or the Coolerado, or going to refrigerated air.

The current swamp cooler works fine for us, (we are cool) but we are trying to tackle to concerns, 1) allergens 2) environment, in no particular order.

So we called so far 5 vendors, two were NATE certified, one from a big box store. I armed myself with info, before and during this process. First, I am disappointed none of these vendors ran a heat calc, not even the 75% NATE certified. While I believe their experience may serve their estimates well, I think it would not hurt check the numbers a bit.

See, we have a 3ton (80000 BTU) Carrier furnace (9200 weathermaker, 96% AFUE, 1 speed). This is still a bit young -8 years old. Our 1968 house is adequately insulated, although we are going to upgrade that (ceiling has 12ft fiberglass), Im not sure about the R-specs of the walls). We measured the usable square footage (room by room), came up with about 1700sqft. It has three bedrooms, a den, small office, two baths and an open living/kit/dining room. We had installed renewal by andersen double pane windows, got 9 windows. The attic ductwork seems fairly good, thoroughly insulated with fiberglass, and no noticeable leaks. There are 13 vents, and return lines (floor level vents) in most of the rooms, except bathrooms and our den.

OK - so the consensus seems that our furnace blower may be a bit undersized for our house. Most of the vendors raised an eyebrow when they inspected the cabinet size, and pointed out that we need a 4ton blower. They just seem to 'know'.

We run two good hepa-air filtration systems in the house, these are standalone-mobile (Austin & Whirpool), and seem to move air well in the zones we want to filter air. The filters will degrade fast with the humidity added by the swamp coolers (evap), so that's why we look to the new - lower humidity machines mentioned above. The catch is that the Oasys is a 3ton system (the claim is 60 SEER) and the Coolerado is about $8,000 installed, may be 5ton, i dont remember now.

Anyhow, I ask the vendors about a heat-calc, and they were reluctant to go into the effort (1hr??). We are having two more vendors come.

At the electrical panel, we may need to replace the main breaker (50W) to something more appropriate, along with the wire to the pole. The panel can handle, it is rated to more than that. We would need to tend a 220v line up for a compressor or a Coolerado, as the other 220 breakers are used to capacity by drier & range.

What we would like to know is, if we could just place a 3-ton system for our cooling needs (we dont feel we need to be at 72 all the time, BTW) and run it near peak efficiency. Then we can decide whether to go with a Carrier compatible compressor until we need to replace our furnace with at least a 2 speed one with same blower.

Everybody is giving us 4ton compressors, except two vendors, all told us to replace out furnace with a 80% efficient (or better.. Trane, Carrier). Im afraid the eventual heat calc may suggest we need a 3.7ton system or so. I couldnt access the only heat-calc tool I saw a few months ago online, but ey, maybe you could chip in some advice we are missing here.

Thanks in advance!!

mia