Mitsubishi Non-Hyper Heat vs. Hyper Heat Heat Pump (Central PA)
sibanez
| Posted in General Questions on
Recently purchased a house built in 1962 in Central Pennsylvania. It’s a Cape Cod style house with a kickout on the second floor. When I purchased the house, I knew that the AC system and oil furnace would need to be eventually replaced because they are older units from 1995. House is roughly 1600sqf above grade.
There is no option for natural gas due to the location of the house.
I’m now looking at heat pumps to replace everything. Based on recommendations from a friend in Boston, I’m looking at Mitsubishi units. Looks like I can get a 18 SEER/12.5 EER/13.6 HSPF unit installed for $10.9K. The unit that’s being proposed is a SVZ-KP30/SUZ-KA30.
The other option is a PUZ-HAC30/PVAA30 Hyperheat system for $13.2K. The Hyperheat is good to below 0, which we’ll never see here in Central PA.
Along with the install, we will have a new return ran from the air handler to the first floor and reconnect the returns in the upstairs area, which should put it at 1100 cubic feet of return air.
Thoughts on the two units or any experience?
The HVAC company swears the non-Hyper Heat option with backup electric heat strips will work wellq and the cost won’t equal the Hyperheat system. Another HVAC company swore that I would need dual-fuel (oil+heat pump) to keep the house comfortable.
Thoughts? I’d really like to avoid more oil if possible and love the 365 use of a heat pump. We are in 17011 (near Harrisburg/Maryland) if that matters.
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Replies
No need to guess what you need to carry the house through the winter. Right off the batt, I can tell you that the HVAC installer that wants oil backup doesn't know what they are talking about. There are people with heat pumps in climate zone 7 that heat the house without any electric resistance heater backup, never mind oil furnace.
First run through the calculations in the link bellow and figure out what your current heat load is. If you have oil fill data, the calculations are pretty straight forward:
https://www.greenbuildingadvisor.com/article/out-with-the-old-in-with-the-new
Once you have that, you can look at your design temperature and which units can carry the place. In most cases you get better efficiency out of a hyper heat unit plus they can be sized smaller than a non-hyper heat. The best is to search through here:
https://ashp.neep.org/#!/product_list/
Select "single zone centrally ducted" and adjust the sliders to match your heat load from the earlier calculation.
My guess something like this would be in the ballpark with a bit of resistance backup:
https://ashp.neep.org/#!/product/31992
Or go for the 2 or 2.5 ton unit with no backup heat:
https://ashp.neep.org/#!/product/34582
This is a hyper heat version of the SUZ units which is cheaper than the PUZ series that are light commercial units.
Thank you, this is very helpful. I don't have full logs of oil, but will try to pull together a comp. Appreciate the guidance.
> below 0, which we’ll never see here in Central PA
Every place in central PA that I checked has experienced temperatures well below 0F. For that matter, well below -13F. The UZ-KA30's listed minimum outdoor temperature is 14F. Can someone point to Mitsubishi info that says that occasionally operating this unit well below listed minimum is harmless and the unit will keep producing heat? Or is the plan to provide 100% backup heat?
For the UZ-KA30s, they would install backup heat strips. HVAC installer swears that the additional electrical cost won't offset the extra cost of a Hyper Heat system. The Hyper Heat system costs roughly $3600 more and would not have backup heat. We are planning to stay in this house for another 4 years max.
This is the first time I've ever dealt with HVAC before and there appears to be a huge learning curve. I did start at degreedays.net and pulled data for the past 36 months.
For 2019, with a HDD of 68, the most heating required is 47.9 back in March 2019. There was a four day period where the average was 43.7.
> We are planning to stay in this house for another 4 years max.
Then unless something's broken, I wouldn't touch a thing.
I agree
For the SVZ series, the price difference between a hyper heat or non hyper heat outdoor unit is about $1000, the indoor unit is the same in both cases. Moving up to the PUZ+PVA does increase the cost a fair bit, the $3600 is in the ballpark.
In your case, there is no reason to go with the light commercial unit, the residential hyper heat will work fine.
The cost difference is low enough that by avoiding the cost of resistence backup and associated wiring, it is pretty much a wash. Where you can save money is by getting a right sized unit, each additional ton of capacity is about $1000 extra for the SVZ series.
Any idea why a company wouldn't offer the SVZ hyper heat? Is it relatively new to market?
I'm going to have to push back a bit, since they are the only Mitsubishi installer in the area. It seems like the SVZ they recommend works really well, until it gets too cold.
This is a newer offering. For a long time if you wanted a hyper heat system with a furnace type air handler your only option was the a multizone outdoor unit or the P series.
If you have a Carrier dealer near you, their Greenspeed or the rebadged Midea units are also a good option. Both can do full heat without resistance backup down to 5F.
https://ashp.neep.org/#!/product/33268
https://ashp.neep.org/#!/product/29479
To my way of thinking oil does not seem like a good choice for backup heat. Could you really trust an oil furnace to work when you need it most given how infrequently it will run? Never having owned one it seems like they tend to require more maintenance than other fuels plus the liability of storing hundreds of gallons of oil in a rusty old tank in or around your house.
You do have an interesting question. How many years will it take to recover the cost of the hyper heat upgrade over electric backup non hyper heat unit? Short of computer modeling your house with your weather using your fuel costs and guesses at inflation it seem unanswerable.
If you want to model try BEopt
https://www.nrel.gov/buildings/beopt.html
Walta