We use solid concrete ones on larger heatpumps. Some of the big ones weigh 400lbs.
The side they put towards the wall is the side that needs room to swing open for cleaning; condensing unit photos. Not cool IMO.
Read, read, read!
There is plenty of space on all sides of the unit for service and cleaning. We were careful to make sure the service panel (to the left of where the lineset comes in) had plenty of clearance. How much space do you need? Was not going to install the unit in the middle of the side yard, and there wasn't much of an option to move it either. Anyone else want to find something to nitpick about? (Jimmy did make a valid point about the pad with a heavier unit like the 20i -- I do appreciate the feedback. But the unit is fine and stable on the current pad.)
Originally Posted by sarge
By the way, the panels don't swing open. Not a Lennox. Although I was strongly considering the XP21. Chose the 20i for several reasons, including: 1. preferred the aluminum coil and EEV of the TAM8 over copper coil and generic TXV used in the CBX32MV for years, 2. could do side return with the TAM8 -- height was an issue and the Lennox would have been a tight fit, and 3. wanted the dual Climatuff compressors for better dehumidification and staging. I like the longer runtimes achieved with the 2 ton compressor, whereas with the Lennox or any other unloading scroll system I would be at ~3 ton capacity on low. Manual J called for 3.7 tons/1601 cfm to maintain 72 F db/50% RH. The 4 ton 20i was a great match providing ~46,100 btuh cooling @ 1600 cfm. The system has been working well in both cooling and heating modes so far. I really like the features of the ComfortLink II communicating system: tells you superheat, EEV position (/500 steps), coil temperature, DAT, ESP, blower RPM, and much more...
Last edited by RyanHughes; 10-15-2012 at 11:07 PM.
i *personally* must take exception with the color, i don't think the contractor matched the color scheme of your basement correctly. they must be unliscenced/nonunion/daylaborers from home depot. there's ansi regulations regarding color choice, clearly violated here. a real pro like me would never make such a *pft* obvious mistake.
nice job Ryann.
you can take credit for hiring a company
who takes pride in their work.
maybe a nice cool sage green would be more
of a complimentary color match.
The cure of the part should not be attempted without the cure of the whole. ~Plato
Thanks La. The basement carpet is a darker green shade, so I guess the air handler does match its surroundings quite nicely.
Like the bottom/side return setup. Guess that's pretty close to ok:
Originally Posted by RyanHughes
It'll be interesting to see how much it runs at 4t, or if that's overkill/missed opportunity to get a lower low. You able to see run graphs?
Total static on high stage (1600 CFM) was around .55" with clean MERV 10 filter (.15 on low - 800 CFM).
Which makes more sense to you?
- turning your thermostat back and being uncomfortable. Maybe saving 5-10%
- leaving your thermostat where everyone is comfortable. Saving 30-70%
DO THE NUMBERS! Step on a HOMESCALE.
What is comfort? Well, it AIN'T just TEMPERATURE!
Energy Obese? An audit is the next step - go to BPI.org
, or RESNET
, and find an auditor near you.
No runtime graphs, but from my experience thus far, when the outdoor temperature is 45 deg or above, the 2 ton compressor handles the heating with long cycles. Lower temperatures, the 4 ton compressor is likely to engage for roughly 8-10 minutes to help out. It hasn't gotten nearly as cold as it can be yet (lows have been mid-upper 30s). So I suspect the 4 ton compressor will be used more often in Jan/Feb when it's real cold. Heat loss was about 45k, give or take, which is the high compressor ARI capacity. 15 kW of electric heat that hasn't needed to be used yet. System was sized by the Manual J results, and the actual capacity of the 4 ton 20i matched the home's load quite closely, but part of me does now think a 3 ton would have performed adequately at least close to design temperatures. I didn't want to go smaller because I wanted to ensure I could maintain 72 all summer and 70 all winter. But seeing the 2-stage operation in action, you realize the low stage compressor, by running its long cycles, really reduces the calls to high stage needed -- even at fairly cool/warm ambient temps. I've been happy with the improved comfort over the previous system it replaced... it'll be interesting to see how it does this winter and next spring/summer (summer use this year was limited).
Originally Posted by tedkidd
How big is the house and what are your design temps?
The way the refrigerant lines are run into the air handler would make me want to punch the installer in the nose if I was the service person that ever needs to work on the heat package, especially if It needs to be removed...
3030 sq ft conditioned space (~600 of which being a partially below grade basement). Design temps were 91 deg outdoor for clg (although these past few summers we've had plenty of days above that) and 17 deg outdoor for htg. Indoor design was 70 deg winter and 72/50% summer. Total load was 3.7 tons and total cfm requred per Manual J was 1600 and that's what the system was set up for rather than the 1400 cfm. Luckily the home has a good duct system capable of delivering this much air, didn't need to change much of that except modify the return setup in the basement. Hard balanced system with no manual dampers, but very minor temp differences between rooms -- 2 floor house. Overall system works great summer and winter satisfying the temp/humidity set point and doesn't short cycle. FYI total net capacity of the 4 ton 20i heat pump is closer to 3.8 tons at ARI conditions.
Originally Posted by 54regcab
Agreed, they should have been run directly out to the left side and up. While there is more room to service them than the picture shows, removing the heater package could be challenging and may require some bending...
Originally Posted by mark beiser
Only during times when stage 2 kicks in are you getting any benefit from the oversized high end system. A single stage 2.5 ton would have would have worked just as good, and yielded the same electric bills. The only difference is you wouldn't have the reserve capacity to hold the 72 degree setpoint during outdoor design tempatures.
Originally Posted by RyanHughes
3.7 tons cooling load sounds high for 2400sqft above ground @ 91 outdoor temp. Either somebody fudged/miscalculated the cooling load or you really do have a leaky house. I'm at 800sqft per ton on my own house (2 tons, 1600sqft) and it will keep it 75F indoors when it's 100F outside. Typical 1999 construction, not super tight but not a sieve either. People tend to turn thier thermostats down to 72 to compensate for humidity issues, if the AC is running wide open to hold 72 it's too cold for most people.
I too question the low static values, did you take the readings with a wet coil?