16 SEER with only 8.7 HSPF? Someone sold you a system on "efficiency", but forgot to tell you that it was only efficient in cooling mode at mild temperatures. 8.7 HSPF was acomplished by several 10 SEER systems. If you havent made your purchase, spend some time doing some homework.
I believe that's what the mktg lit says for it... 3 ton Lennox XP16 which is a 2-speed. Not sure where to get the official stats. I think the only thing better in that line is the XP19 and that I can't afford unless I give up my 3-zoning which is necessary. I do have 20 KW heatstrip backup. Any other recommendation in the Lennox line...all dealers who bid were Lennox.
I don't remember 10 SEER systems having an HSPF of 8.7. Most 13 SEER are below that, typically around 8.2-8.5. What I remember on 10 SEER systems was about 7.7 to 8.2 HSPF. I am going to do a little searching to see if I am wrong.
Originally Posted by docholiday
Originally Posted by stockgal2
The need for a 20kw heat strip backup makes me question whether your HP is sized correctly. Assuming a 3 ton is correct, then I would ask installing dealer about (2) 10kw heat strip modules and have them staged. according to heat loss demand.
In my opinion, the best procedure with a heat pump is to leave the house set at one temperature. If you dont do this then I suggest getting a thermostat that allows you to lock out the resistance heating strips.
Originally Posted by dn0121
The XP16 in a 3 ton, depending on the match, will only give you between 6.7 and 8.2 HSPF... The EER's are only 10.90 and 11.20 at best. The SEER, as if it were important can only pull a 14.2.
Dont let them call this a 16 SEER, high effeiciency machine.
The XP19 is only slightly better on SEER, and maybe even a smidge better on EERand overall average of HSPF , but there is a significant cost difference to gain that little.
Choice is either Lennox XP14 which is "up to 16 SEER & up to 9.5 HPSF", or their XP16 w/2-stage scroll compressor "up to 16 SEER & up to 8.7HPSF" both using 410.
Since I am in semi-mild winter climate with very discounted winter elec rates (8 months of discounted rates), and very very hot summers w/no discounted rate, the XP16 gives me the cost savings when elec rates and burden on system is the worst and giving the 2-stage feature to be able to draw less a/c power instead of full power all the time -- more savings.
So far the installers questioned between the two as well as Lennox tech preferred the 2-stage feature since again it helps w/summer rates and that the 8.7 HPSF is fine for a heat pump. They all agreed the XP19 doesn't give enough adddl bang for the addl buck.
Post model numbers of condenser and air handler for efficiency and performance ratings.
Originally Posted by stockgal2
I measured the supply air temperature (just after the coil) of my Goodman 3 ton 14 SEER (12 EER, 9 HSPF) last night using a Fluke meter w/calibrated t-couple:
47 degrees outside
68 degrees inside
68 thermostat setpoint
95.7 air handler temp from heat pump
Bump stat to 70
136 degrees (aux heat kicked in)
96 degree air handler temp after aux heat kicks off and temp stabilzes
Bump stat to 72
150 degrees (aux heat must be in 2 stages, 5 kw per stage)
99.5 degree air handler temp after aux heat kicks off and temp stabilizes
72 degree room temp, about 1/2 hour of total run time
Is your coil ON TOP of your blower? Should be below the blower. Otherwise, you aren't allowing the heat pump to raise the temperature as well as it should.
Originally Posted by gary_g
Temperature rise @240V, 1200 CFM:
4.8KW=13, 7.2KW=19, 9.6KW=25, 14.4KW=38, 19.2KW=50
The difference between your two aux heat numbers (150 and 136) makes me think that you've got 14.4KW strips. I also think that you might have picked up some radiant heat from the elements/coil. Can you measure it immediately after a turn (perhaps a bypass humidifier duct)?
Lennox models are
Heat pump: XP16-036 3 ton 16 SEER 2-stage scroll compressor
Blower coil w/var speed: CBX32MV-036
Heat strip: 20KW
"up to" is no different than a commercial for a car where "prices start at". Neither one of them will come into play in the real world. I'm merely suggesting you look for yourself.
Understood, that's why i said "up to" as they do. I don't have any literature yet for any other details than what Lennox says on their mktg. Thx