In summary, what would be the major difference between these 3 setups?
Setup #1
- 3 ton blower
- 3 ton coil
- 3 ton condenser
Setup #2
- 3 ton blower
-4 ton blower (okay)
- 4 ton coil
- 3 ton condenser
Setup #3
- Reduce the heat-gain/heat-loss
- 3 ton blower
- 3 ton coil
- 2.5 ton condenser
Rumor has it that Setup #2 "may" fish out more cooling during the very hot days. Reason for going with Setup #2 is that 3 ton blower is existing and can only accommodate a 3 ton condenser. So to "turbo" charge the system, a 4 ton coil can be used to give it some extra BTUH's of cooling. How about choosing #3?
Step #3 if correctly sized will deliver better efficiency.
# 2 depending on climate conditions, in a dry climate operating costs should be less than #1.
Even in an average humidity climate zone, you may be able to keep your
3-ton evaporator coil and use a humidistat to energize a fan relay switching to a 350-cfm speed for higher humidity and dropping back to higher 400 to 450-cfm per ton of cooling. With other load calc reducing options, maybe even use a 2.5-ton condenser
----------------------- True or False? Would the operating cost be significantly different? Which would cost more to run? 3 ton furnace with blower is fairly new and coil and condenser would be brand new rated at up to 15 SEER. Would appreciate any feedback.
------------------------- In a Dry Climate using a larger Evaporator Coil and larger Airhandler to move more CFM per Ton of cooling, this will increase the ratio of Sensible BTUH to Latent. Example: 2-ton condenser at 95-F outdoor temperature, indoor airhandler at 800-cfm with a return air 67-F wet bulb with a total capacity of
23,000-btuh and 16,500-btuh sensible . Increase the airflow to 900-cfm at 67-F indoor wet bulb and the system now delivers 18,300 BTUH.
Example: if the Manual S needed 18,000-btuh sensible, by increasing the airflow 100-cfm in an average or higher humidity climate by using a humidistat controlled fan relay to change speeds, it could make the difference between a 2.5-ton or using a lower amp draw, lower initial cost 2-ton condenser. - udarrell