Air-Source Heat Pumps (ASHP) performance and price data?
An update to our question:
First, thanks for the answers, and especially for the link to look up performance.
The Mitsubishi City-Multi S-Series in our spec is rated for a HSPF of 8.7, which seems to be at the lower end of the efficiency range. We do understand the importance of reliability and we do have someone good to install it, but the install cost is above our budget, and we’re wondering whether it’s worth looking for a more efficient system that might end up costing less (but may require a costly re-design!).
Anyone have any perspective on whether the City Multi is a good choice, or given that efficiency is really important to us to get to net-zero, whether we should really look for a more efficient system?
Thanks!
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We’re trying to determine the best mini split ASHP to get for the net zero energy house we’re building and are having trouble finding data comparing the alternatives (so far we’ve considered the Mitsubishi City Multi R-series and Mr. Slim series, and Daikin).
In particular, it would be really useful to find a table or spreadsheet (ideally based on real world performance) comparing the performance (COPs) of various systems at various temperatures. Does this exist anywhere?
Also, to make a fair comparison, we’ll need to know the comparative pricing of these systems as well (e.g. if a system performs 10% better but is 50% more expensive, it’s probably not worth it). Is there any pricing info on these systems anywhere on the web??
Thanks for any links!
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Replies
In choosing HVAC equipment, one thing to keep in mind is who will be installing it. The HVAC guys typically will have a favorite, based not on performance but on ease of installation and reliability. Gathering this information should be part of your due diligence when choosing a brand. These high tech units are pretty new and still changing fast, and you don't want to be stuck with something no one will work on.
To find an installer, call the local wholesaler for recommendations. They know who has actually been trained and has some installations under their belt.
Karen,
I agree with Kevin -- it's important to choose a local contractor who can service what's installed.
The necessary research to choose your minisplit is no different from choosing any other building materials. You can find specifications on the Web sites of all the major manufacturers; you can contact local contractors for pricing; and you can use your telephone to find out which brands are serviced locally.
It's pretty straightforward to search for systems using the AHRI Directory. Here's the link for the directory of air-source mini-splits and mullti-split heat pumps - http://www.ahridirectory.org/ahridirectory/pages/vsmshp/defaultSearch.aspx
From there you can search any way you like. For instance, if I wanted to look at high performance mini-splits for a small, super-insulated house, I would search for systems with rated capacities between 10,000-14,000 Btu/hr (@ 47F), with a minimum capacity at 17F of ~6,000 Btu/hr, and an HSPF of at least 10.0. The directory comes back with just 32 results.
As for price - many of these systems are available from web-based "wholesalers". For pricing reference, I search for the online "wholesale" price for a system, then double that price to get a rough idea of the "installed" price from a local HVAC contractor. Once I have things narrowed down, then I can get a firm price quote from a local installer.
Beyond that, I echo Kevin & Martin's suggestions with the following addition - the HVAC guys favorite unit may also be based on profit margin or a cozy relationship with a particular wholesale distributor.
Thanks for that link, John, very helpful.
Thanks for the answers, and especially for the link.
The Mitsubishi City-Multi S-Series in our spec is rated for a HSPF of 8.7, which seems to be at the lower end of the efficiency range. We do understand the importance of reliability and we do have someone good to install it, but it's pricey, and we're wondering whether it's worth looking for a more efficient system that might end up costing less (but may require a costly re-design!).
Anyone have any perspective on whether the City Multi is a good choice, or given that efficiency is really important to us to get to net-zero, that we should really look for a more efficient system?
Thanks!
The City-Multi S-Series is available in a 40,000Btu/hr or 54,000Btu/hr version (nominal heating capacity at 47F) and can serve up to 8 indoor units. You don't mention where you're located or any details about the house, so it's REALLY hard to say whether or not it's a good choice.
I have several of the mitsu mini splits, SEER 26 units, and I would think the only drawback to them is the multiple outside condensers, as they are generally cheaper than the city multi. There is online some data RE COP and HSPF, though not in spreadsheet form