Convert condensor to heat pump hydronic system

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Morrelli

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Hope everyone had a nice Thanksgiving! Looking for professional opinions. My current HVAC system is hydronic with air handlers ( two units, upper and lower levels) using a navien combi fired by LP for DHW and heat source. I have two 22 year old condensers for AC, one a 5ton and one a 2 ton, again upper and lower using mentioned air handlers. What I'm trying to accomplish is replacing the 5 and 2ton AC units with inverter heat pumps as solar is cheaper than LP. I have been told I can utilize the existing lines sets with proper cleaning and others have said no. The lineset runs are considerable but very intact. I've also resorted to the fact that I'll likely need to replace air handlers to match heat pumps. With inverter heat pumps couldn't I eliminate the hydronic heat and use the matched air handlers to heat and cool? Old air handlers are suntherms. As it is now, when there is a priority call for DHW on the combi boiler, the hydronic heat loop is secondary and this means no heating of the home while DHW call is happening. Not a huge issue, but is noticable at times. It very rarely gets below 30F where I am and summers can be hot enough so that without solar, cooling costs would be near 1k a month at times. So anyway, thats what I have. I'm not rich, but ill save for good quality. Any thoughts if it was your place? What would you do for the most long term savings, (retiring soon and dont plan on moving) I would add I have a 10kw solar setup with 26kw in backup battery. I pay about 3 bucks a gallon for LP and living in the overpriced screwed up state of California I'd rather utilize the solar if at all possible. Thanks in advance for any comments.
 

Fitter30

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All condensing combi boiler side are 95% efficient when return water is below 140° above 87% the colder the better. Line sets have to be the correct size and both lines possibly have to be insulated. Line length might be a problem because of the variable refrigerant flow or if a unit had more than one compressor failure. 10 kw =41 amps then have to account for the inverter 97%, unit run times and hours of sun that the panels are putting the out 100% Consider a energy audit from your electric company that includes a blower door test. With new windows, doors ,insulation and roof might lower the tonage the equipment.
 
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Fitter30

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Sounds like a reasonable route may just be updating existing condensors to more modern units?
The higher the seer rating the sharper the service person has to be and the company they work for has to be committed to training and tools. There are fed tax rebates , might be state and electric company for upgrades for house and equipment.
www.seerenergysavings.com
 

John Gayewski

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Have you considered leaving your system as is and adding a supplemental electric heat system? This would probably be the most practical. You could add either radiant electric to the flooring or electric baseboard heat that would take most of the load being as your in California.
 
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