There is a little more to it than that. Three phase equipment, especially in residential-y sizes is more expensive - primarily because it is less common. Some of the components are also more costly but I think the price difference is largely due to the lack of economy-of-scale in production. It's just less common so the price has to be higher.
This is just a guess - but if forced to make one I would guesstimate that the total lifecycle cost of three phase equipment would be about 20% than the same thing in single phase.
BUT . . . . far more important to life-cycle costs are:
1. Absolutely Accurate equipment size - to precisely match the heat load and gain.
2. Impeccable Installation practices and execution.
3. Adequate and timely maintenance.
Any other factor is a far-distant fourth or lower.
PHM
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I got a quote for HVAC. They gave me a quote for single phase. Then I told him that i have 3 phase power. They wrote back and said this "upgrade the condenser and heat kit to 240volt 3 phase for $XXX".
I though when we bought a system , it would come in either single phase or 3 phase. No need extra upgrade. Is it right? Can some professionals help me understand this?
Thanks.
lvdummies.
