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Engineer ambushes salesman, or “what do we do about HVAC?”

Nate G | Posted in Mechanicals on

So at this point, I have done a Manual J load calc for my house that puts the heat load at around 20,000 BTUs. I know that I want an electric heat pump so I can eventually go net zero. I *think* that I want it to be the Bryant Evolution 280a, which has the highest HSPF (13) that I’ve been able to find in a ducted heat pump. Seems simple enough, right? “Quote me an installation for this unit.”

But so far I have been unsuccessful in getting any HVAC companies to bid. Not one. Four salesmen have come by, and no bids. Zero.

I reeeeeally try to avoid being the nightmare engineer customer, but none of them want to install what I’m requesting without some explanation, which inevitably reveals that they have no product knowledge for anything besides gas furnaces, let alone how to size a unit properly. One guy told me that a heat pump simply wouldn’t work, full stop (climate zone 4/5). Another one didn’t know that heat pumps came in non-minisplit configuration. Another didn’t recommend heat pumps because he said the supply air temperatures would be uncomfortably low (what is this, 1995?). Yet another insisted on quoting mini-splits and initially specified a 12k BTU heat in every bedroom before I protested (never actually got the quote). All of them have estimated grossly inaccurate heat and cooling loads ranging from 40-90k BTUs for my house.

Today’s salesman was actually interested in why my Manual J calculation was so different from what his crude app said. We went over his app’s output line-by-line and I was able to point out the exact errors built into it. For example: hardcoding an outside temperature of 0 degrees instead of something appropriate for the climate (18); only going up to R-30 for attic insulation; using a u-value of 0.96 for double-pane windows instead of something reasonable or letting you input a value (my windows are U-0.26). I could go on. I doubt I’ll get a quote from him–same as the last three.

What’s to be done about this craziness? Am I going to have to become a licensed HVAC professional myself just to install a freakin’ heat pump?

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  1. GBA Editor
    Martin Holladay | | #1

    I feel your pain.

    SOS call to the HVAC industry -- to Carrier, Lennox, Bryant, Mitsubishi, everybody -- your industry is in crisis. If you cannot address the catastrophic ignorance among your installers, your ships will soon sink.

  2. Expert Member
    Dana Dorsett | | #2

    A 2 ton Carrier Greenspeed can hit an HSPF of 13 with the right air handler, and cover a 20K load down to low positive single digits F outside. The capacity of any GreenSpeed compressor & air handler combination at any given design temperature can be estimated from their online tool:

    (Click on the "Heating Capacities" tab, then select the compressor and air handler options in the lower left boxes.)

    No matter what the nameplate HSPF says, the modulation range of these puppies are limited, only 2.5:1 turn-down. Oversizing with 3 ton system for a ~20K load would RUIN it's as-used efficiency.

    Quotes I've seen for GreenSpeeds have usually driven me into the arms of Fujitsu & Mitsubishi. A single 1.5 ton Fujitsu 18RLFCD mini-duct unit can probably handle your whole load if you're zone 4 (what's your 99% design temp?) and it has a HUGE modulation range.

  3. Nate G | | #3

    Okay, I got a quote from company #5! $16,000 + tax. An utterly ridiculous number. The wholesale cost on this equipment is like $3,500; what's wrong with these clowns!?!

    Dana/USER-1004076: I'm in New Mexico, in CZ5b but within a mile of the boundary with CZ4b. My 99% temperature is 18f.

    I originally started out looking at the 18RLFCD, in fact. But the SEER, EER, and HSPF numbers are lower than the Bryant (though for this price difference, it hardly matters). The big problem is ductwork. It wouldn't work at all with my existing high-static duct system. I'd need to build all new ducts in a dropped ceiling in the main hallway, and if you think it was hard to get bids for the Bryant heat hump, you should see people's faces when I proposed that project. They looked at me like I was on fire. And I'd still need a second unit--a ductless--to serve the main room due to the geometry of the house. This means having a multi-split outdoor unit which further lowers efficiency, or a second outdoor unit, which will fill up my electrical panel and leave no room for a feed-in breaker for a solar PV array, and also reduces efficiency by having a redundant outdoor unit.

    At this point I feel like I might as well buy and install a Chilltrix. All-internal refrigerants, the distribution story is easy with their air handlers, and it has better efficiency to boot.

    Allow me to once again pine for a simple $800 120v plug-in 3000 BTU mini-split with decent efficiency that's DIY-able with pre-charged and evacuated linesets and quick-connect fittings. Sell 'em direct to the consumer at Home Depot and the like. I'd put one of those suckers in every room and be done with it.

  4. Mike M | | #4

    I have had the EXACT same issue with doing my home addition and upgrades. I have had 3 HVAC companies flat out refuse to use the calculations I've come up with and oversize the hell out of them. I keep getting quotes for 5+ tons, yet I tell them I was able to cool close to 2/3 of my home this last summer with two window units at 1 1/2 tons. Not only did it cost about $20 less a month than my 5 ton unit did, but I also kept the temperatures close to 6 degrees cooler and the humidity was 20% lower.

    I decided to finally bite the bullet and go with a split system and do it myself. I was able to save nearly $4000 just on the quoted equipment costs alone.

    Now the issue I've run into is that since I've purchased the equipment, no-one wants to do the pressure test, vacuum, and charge before commissioning because they can't get enough money out of the deal.

  5. Nate G | | #5

    I feel like life is pushing me in the direction of starting a company selling truly DIY-able mini-splits. Mr Cool has a DIY-friendly product that's close, but it's not good enough (too expensive, too much capacity, needs hardwiring).

  6. Steve Knapp CZ 3A Georgia | | #6

    I was wondering how difficult DIY would be. That led me to a site with a few reviews of DIYable mini splits and an accompanying This Old House video. Based on the video, it looks like a very straightforward process as long as you can pressure test and evacuate the coolant line.

  7. John Clark | | #7


    Deaf ears sir, deaf ears !

  8. Expert Member
    Dana Dorsett | | #8

    If you oversize the Bryant it's as-used HSPF will not be nearly as good as the 18RLFCD, despite the test numbers, but you're right that it probably isn't going to work with the pre-existing ducting.

    About 18 months ago I saw a proposal for 4 ton GreenSpeed + new ducts + 1-ton Daikin mini-split quoted at about $40K (for a total load of about 2.5 tons.) They didn't get the contract. The home owner pushed back, asking for a Manual-J to rationalize the sizing- they quoted $2K to run the Manual-J, and they didn't get that contract either. They ended up with a (still oversized) multi-split solution for about $15K, after paying an engineer <$1K to run the numbers. The $25K difference is enough to buy into a community-solar project large enough to cover most of the power use, despite the lower efficiency. (The house is in the woods, not suitable for site-solar.)

    With a cooperative HVAC company it's possible to DIY-mostly a mini-split and have the contractor commission it in such a way that the manufacturer's warranty is still valid. You can understand why the contractor wouldn't apply their own warranty on something that they only did the final pump down/charge/test on, but it can be well under a grand in most markets- basically a service call that includes a bit of actual service. Most people don't have the interest in owning the right tools and educating themselves enough to do the whole thing, and most first-tier manufacturer's won't warranty DIY installs, insisting on installation & commissioning by a licensed & trained pro to be covered.

  9. Stephen E | | #9

    Never Install a mini split by yourself. Waranties are invalid, against the law in most areas and there is way cheaper ways to be more efficient.

  10. Charlie Sullivan | | #10

    Some of you are going to think I'm crazy to say this, but I think a Chiltrix air-source hydronic heat pump is a much better candidate for a DIY installation than a minisplit. Most importantly, the refrigerant loop is all inside the box, so there's no need to make refrigerant line connections or to test, evacuate or charge the system. And the package also includes a variable-speed pump for hydronic distribution.

    The design of the hydronic distribution system is maybe not not something that should be DIY, but an engineer who does those designs regularly could lay it out pretty quickly and easily, and then a DIYer could run pre-insulated PEX and connect it up.

  11. Mike M | | #11

    I would check with the manufacturer on the warranty. The only thing I was told by Mitsubishi I lost by not buying/installing from their Diamond dealer were the extended warranties, and this was only because they were not installing it.

  12. Anon3 | | #12

    DIY mini split is the way to go.

  13. Nate G | | #13

    FWIW, to close the loop on this, I eventually found a knowledgeable HVAC guy who was willing to work with me on the tech and design side. His crew installed an appropriately-sized quad-zone LG multi-split system in my house for a little under $10k and I couldn't be happier with it. It heats perfectly fine in the dead of winter and upgrading from swamp cooling to air conditioning has been lovely. The bedroom units are a bit larger than necessary because we couldn't find any air handlers small enough for the very low bedroom loads, but it's been fine anyway.

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