We're in for a heat pump PR debacle right now: the cheapest heat pumps that qualify for a federal IRA incentive are HORRIBLE at dehumidification.

The only viable fix is a requirement for a dehumidification mode and probably reheat dehumidification from @ENERGYSTAR standards. The curse is this will take multiple years to implement, in the meantime many thousands of people will get sick and their homes are likely to become unhealthy and moisture damaged. Both are like cancer patients - you are in remission, never cured.

PSA: Early adopter language about electrification is repulsive to the mainstream.

There's too much early adopter language right now, to finish by 2050 we need to be hitting mainstream #ASAP.

#electrifyeverything If you can replace what you're saying with "vegan" or "crossfit", change your language.

Do you remember the Sick Building Syndrome in the 1970s?

It came from buildings getting too wet and not having enough outdoor air piped in.

With the IRA heat pump incentives rolling out, we're almost certain to see a resurgence of it.

A 🧵 Old school air conditioners ran very cold indoor coils that act like sponges and suck the humidity out of the air.

As we've pushed for higher efficiencies, the tradeoff is that we get more cooling, but less dehumidification like the chart shows.

$7500 for an installed ducted heat pump @rewiringamerica ?!?!

The equipment alone costs more than that!

Stop setting up inflated expectations. You’re fucking those of us in the field. There’s no way to recover from this, consumers think we’re scamming them. Everything in this document sets up expectations we can’t even begin to meet. Free?!?! Seriously?!?!

I’m fucking pissed. You are making it impossible to create goodwill.

Stop this shit. It’s a pattern. You’re hurting not helping.

content.rewiringamerica.org/reports/Rewiri…

Good insulation is expensive. Let's do a quick exercise on why. A 🧵

Let's think of a flat 1200 sf attic/loft, could be a 1200 square foot ranch or 2400 sf two story home. This isn't spray foaming the roof deck which is the other main option. 1 To air seal, you really want to remove all existing insulation to expose air sealing opportunities.

Every time we do this, we find surprises.

Cost: $1.25-2.00/square foot, $1500-$2400

2

Some wonder why we don't advocate more for external wall insulation (wrapping a new wall around the outside of a house). This is why.

A 🧵

https://twitter.com/AdrianHiel/status/1571829859315220482

Our last house was a beautiful 1835 home outside Cleveland Ohio, I figured it would be $70K-100K to do external insulation on.

How much did it save? It modeled $250/year. That would be closer to $500/year now, but that's a 140-200 year payback.

That's not uncommon.

Ugh.

2

The Dangers of Cliffs, a 🧵

We have a major concern with the heat pump tax incentives in the IRA: they create a cliff that could be very problematic.

I'll illustrate with a system we put in in two of our AirBnbs, the Daikin Fit, and give a potential solution. 1 Let's talk benefits of the Fit:

The Fit has roughly half the wholesale cost of the Carrier Infinity GreenSpeed heat pump we've been using almost exclusively for a decade.

It's a next gen product that has full output to 5F, which is better than the GreenSpeed. 2

Andy nails our thoughts on incentives well in this tweet (and thread.)

I’m overall quite positive about IRA, but have already heard about the “market freeze” in our Electrify Everything group, and NY/CA saw a sugar crash this year. Implementation details will matter.

https://twitter.com/AndyJFrank/status/1555486211887841282

It looks as if the tax credit money is retroactive into 2022, if so that’s good and can prevent the freeze. (Selfishly we installed two heat pumps this year.)

It doesn’t look like the rules are particularly onerous either, 30% of the entire job up to $1200/$2000.

It's fun seeing your first house back on the market. I bought it at 23. Shouldn't have frankly, we paid for the pleasure of spending 2000 hours working on it.

All the light fixtures are still there and we took it from near-foreclosure to really pretty.

zillow.com/homedetails/22… Knowing what I know now I would have done the insulation much differently, and we didn't touch the HVAC, what you see is new.

We really like taking old houses that have a lot of deferred maintenance and bringing them back to life.

Here’s a look at how much energy heat pump water heaters can save.

It’s often 2/3-3/4. Look at October-March vs May.

I’m annoyed how loud they are in the wrong applications, but you can’t deny the usage reduction. Here is our Ohio home. Note 60-80 kWH per month, I usually see 150-300/month for resistance. Roughly 75-150 kWH/mo/person.

This is HUGE for residential rooftop solar. Much higher equipment requirements and interconnection times are large factors in why the US pays 2-3X what the rest of the world does.

Improve this and the math goes from "meh" to "wow!"

https://twitter.com/ramez/status/1523366716809523201

Solar installers in Germany and Australia are paying good wages and making good money while installing at roughly half the cost.

I am NOT a proponent for hurting profits. There are large red tape gains to be made.

Wish this was true for our sector!

Story Time - Advocating apolitically for #electrifyeverything

A thread. 🧵

Pulled from the Electrify Everything group. bit.ly/ElectrifyEvery… I arrived in Des Moines last night for the Momentum Is Building conference.
I grabbed a cab and naturally we got to chatting. I LOVE cab drivers because they are full of so much local information. 2

Thread 🧵

20 kWH of battery goes a long way.

Beyond the heat pump usage, I needed 14.4 kWH of resistance to get through a very cold night here, at design temp 10F.

This is usage from my house last night. Bosch heat pump set to 2 tons max. 5 kw backup on the air handler. This is measured with an Emporia Vue energy monitor.

A heat pump uses about 1 kWH per hour per ton when running at 100% as mine has.

I’ve watched a number of client homes, 20-50 kWH is enough to load shift all of them so far to make up for resistance usage on cold days.

Electrification in US climate zones 1-4 is pretty straightforward. Often insulation upgrades aren’t strictly required.

In climate zones 5-8 it’s much trickier. Shell upgrades are often required to keep operating costs down.

~50% of resi gas use is in 5-8. At present insulation upgrades don’t result in predictable resale value increases.

Until this changes, don’t expect scale in retrofits. 150-200k/year maximum.

The solution is simple: publish energy use at resale.

My 2016 article still holds: bit.ly/EUIonGTM

First experiences with induction are really important.

Here's a recent review of our Ohio house, note their experience. What if there were thousands of homes like this? How fast could #electrifyeverything spread? @Airbnb could help a lot with a new class: bit.ly/AirBnbElectrify

This is what code enforcement looks like.

2015/2018/2021 IECC (insulation codes) are all good enough.

But they’re not enforced, and it’s gonna be TOUGH.

But some are looking for opportunities like this fellow. It’s really tough to fudge leakage tests, so it’s a key tool.

Although duct leakage in northern homes with ducts in heated space doesn’t matter all that much. While home air leakage does.

Down south with ducts in attics, both duct and home leakage matter.

THREAD:

Homes as thermal batteries aka resilience.

This house dropped 20 degrees in 8 hours in similar 30-40F temps during the Hurricane Sandy outage in 2012. It took 2 days to recover.

Post project it took 26 hours to drop 10 degrees.

@lloydalter This is a ~2000 sf 1950s Cape Cod in Cleveland Heights.

Full case study on the insulation and air sealing project we did here. It was about $20K and was focused in the attics of this house (it has 4, or was it 5?)

bit.ly/1959CapeCaseSt…

Tight well insulated homes perform well, exhibit A:

This 5000 sf new home in Cleveland with an 80kbtu 98% furnace and 4 ton heat pump is only at 67% capacity at 8F. That’s about 53kbtu/18kw output.

A 4 ton heat pump would be appropriate here. For a huge house! As we discuss resilience, air tightness is important. This house clocked a 1025 cfm50 blower door or about 1 ACH50.

THREAD:

As painful as it is to watch what's going on in Texas, the residential solution basically looks like what we should be doing anyway:

-Tighter, more efficient homes
-Smaller, more efficient HVAC
-Batteries
-More local generation like community solar

Hard to sell tho! The fact of the matter is we humans don't change until the pain of not changing is greater than the pain of changing.

In residential resiliency creating a comfortable, healthy, and efficient home is a great deal of work. Work that few contractors are good at selling or doing.

A Heat Pump Policy Thread:

What if we paid resi HVAC manufacturers ~$400 per AC they manufacture if they make all of their production heat pumps?

Currently US OEMs make ~5M ACs and ~3M heat pumps. What if they were all heat pumps?

This might only cost ~$10 billion over 4 yrs We think of residential electrification in "Two Clocks".

The first is getting to where 100% of installs involve a heat pump. Doing that by 2030 is REALLY HARD.

The second is running through all inventory, which will take ~20 years.

THREAD:

48% of US residential fossil gas use is from 9 cold (or cold-ish) states. This is a major #electrifyeverything challenge.

Source: eia.gov/dnav/ng/ng_con…

HT @JuliePi31415926

@buildingdecarb heads up I wanted to look at this two ways. First, raw usage by state, then usage per person.

Note that CA and TX are WAAAAYYYY less than the others.

You can tell that PA and MO are a bit mild too.

NJ should be mild (mainly climate zone 4), but isn't, poor buildings?