I am going to call the contractor who I feel will do the best job on our new HVAC system. He has given me a quote on the following Tempstar system and doing some duct mods.
Tempstar two-stage 96% communicating gas furnace
two-stage 17 SEER Heat Pump
Observer communicating thermostat
4" Filter system
I am going to have him send me the AHRI for whatever coil is to be used to make sure it gets the numbers he stated.
Is there anything else as far as the system goes that I should ask him about? Outside temp sensor, humdity on demand ect.
He has done all the required calculations, just want to make sure I don't overlook anything on this big expense.
Keep in mind the AHRI numbers only mean that the equipment was matched at an industry design criteria. If the system is not installed and commissioned properly the numbers mean nothing as far as performance and longevity of equipment. Have your installer benchmark the equipment with pressures, temperatures, airflow etc. to verify that the equipment is performing as designed, and if they won't keep looking.
Originally Posted by rk05
Should be a nice system. You're in a very good area in terms of climate for dual fuel.
For dual fuel you absolutely need a thermsotat designed for it with an outdoor sensor and the ability ot set lockout temepratures for each heat source. IN most cases, you balance point will be between 30-40F on natural gas and 0-20F on propane. You will probably lock out the furnace above about 45-50F (lower for propane... LO should be at the thermal balance point where the heat pump cna no longer keep up (probably 30F) and then let the system decide which to use below that.
Dehumidify on demand, IMO should be standard for all equipment everywhere in all climates. With this feature the thermostat signals the furnace to slow down the vairable speed blower by 15-20% for increase humidity reduction when needed. It's needed the most on cloudy days and evenings during lower solar heat gain situations. Also when you have a lot of occupancy or are cooking or bathing.
You said he did all the load calculations. We often like to double check those on here. GIEGO... garbage in equals garbage out. If he uses the wrong desing temperatures or "pads" the numbers somehow, you'll still get an oversized system that will use more energy and not be as comfortable. You don;t want ot oversize, even with a heat pump. Better slightly undersized than too big. Manual J alreayd have a margin of error built in.
This contractor was the only one who did both a room by room load and manual D plus gave me all the data. He also ran it twice based off two different design temps so I feel pretty comfortable with it.
Does anyone know much about the Tempstar tstat? Should I ask for a IAQ for the dehumidifie feature?
I haven't had any experience with the Obsever thermostat but I did read all specs and manuals. It will control humidity just as well as an IAQ.
Brent, thanks those are the type of things I'm looking for.
Does Tempstar have an aluminum coil or do they only make just one?
What was the model number of the coil they quoted?
They did not give any coil number yet. Before I sign anything I am going to have them send me all model #'s for all the equipment.
+ the AHRI # so you know it's a matched system.
Originally Posted by rk05
then it's easier to find documentation on
It's Not Rocket Science, But It is SCIENCE
with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE
Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities