The house I live in has an existing oil-based boiler for both heat and hot water. The hot water tank (50 gallons) will likely need to be replaced in the next few years as it is more than 10 years old, probably approaching 15. I am on well water without a water softener, and I assume that the previous owners never did any sort of maintenance with the current hot water tank. (A neighbor mentioned that there is some sacrificial part that can be replaced every so often to extend the life of the tank.)
I keep reading that the hybrid heat pump water heaters are incredibly efficient, and I hate having to burn oil during the warmer months just to heat my showers. My plumber tells me that it's a really efficient system and that I should keep it intact as long as I can. He also seems a bit old school in his opinion and preferences, as he scoffs at the idea that I would eventually like to replace the whole boiler and system with a heat pump system instead.
Is there a good place to learn about how my existing system works, and any way to compare to possible savings (or pitfalls) of switching to a new system? Are there other options, such as tankless hot water heaters, that I should consider? I gather that recovery time with a hybrid heat pump water heater will be much slower than the existing system, so should I also calculate for a larger system (65 or 80 gallons)? Two adults live here full time but we frequently host guests and family gatherings, and we sometimes need enough hot water for 10 or so adults to shower. There are three full bathrooms in the house and one day we may add a fourth.
This is true if you are pulling the heat from outside of the house. If it pulls from inside, and you are needing to heat your home, it can only be %100 efficient since it's a closed system. Depending on where you live, though, the extra cooling is more of a positive than a negative, though.
I wonder if anyone makes a heat pump water heater that can pull from both outside or inside.
I almost built that for my last house but ended up moving before I could. It wouldn't need much, just an extra pipe with a baffle and a door that opens internally.
You need to be licensed to work with refrigerant, though, right?
No refrigerant. Just a stream of cold air coming from a vent on the unit.
Well, there's probably a refrigerant in there somewhere. But it's not like HVAC system with a refrigerant line and a compressor outside. It's all contained within the unit, and cold air just pours out. You can direct that using ducts.
Ah, so that's like the 50% solution. You can choose to exhaust cold air outside, but still pull warm air from inside either way.
If there were two refrigerant loops, you could choose between pulling heat from outside/exhausting "cold" outside, and pulling heat from inside/exhausting "cold" inside.
I dont have it in me to try to calculate what efficiency gains you'd get for that trouble, though.