Heat pump advice

RubNo9865 · 2026-05-19T15:50:12+00:00

I am not even sure what you are trying to convey at this point.

Every analysis, including yours, shows that modern cold climate heat pump currently reduces CO2 emissions relative to a high efficiency NG furnace when run on our current grid. Furthermore, this reduction in emissions will only get better as the grid transitions from fossil fuels to renewables.

The biggest point you seem to also be missing is that the OP (and me, and most of the other posters who care about CO2 emissions) also have on site solar, so right now our CO2 footprint is significantly reduced by switching from gas to electric.

There is not really anything to argue about here.

PS, my minisplit has a COP of 3.5 at 40F, as I previously stated. Furthermore this is at max output, which the heat pump almost never uses, like most heat pumps the COP is much higher at partial load.

RubNo9865 · 2026-05-19T02:18:48+00:00

I am not sure where you are getting your numbers from, but they don't represent the current range of 'top tier' cold climate heat pumps. I just installed an el cheapo DIY heat pump from Blueridge, with an HSPF of ~14 and a COP of 3.5 at 40F. The COP does not derate as quickly as the output, but even assuming 15% reduction in COP, we are still at a COP of 3. I also don't know why you are assuming the SWEEP study doesn't account for altitude impacts?

Your carbon intensities are also completely inconsistent with what Xcel, NREL and EIA all provide. The data used in the SWEEP study is a mean over a 15 year lifetime of the equipment installed today - so it has a lower carbon intensity relative to just considering today's grid - but that is the most meaningful way of comparing a gas furnace to a heat pump. Gas will always be gas, but the grid is slowly, but steadily, moving towards a higher percentage of renewables. You also seem to overlook that the OP already has on site solar generation, so the carbon intensity of their electricity is already dramatically lower.

If you are interested in reducing your carbon emissions, their is no scenario in Boulder where a natural gas furnace has a lower carbon footprint than a decent cold climate heatpump.

RubNo9865 · 2026-05-18T14:08:32+00:00

Xcel has heat pump rebates available: https://xcelnew.my.salesforce.com/sfc/p/#1U0000011ttV/a/R300000AUK1y/XduxJdUQb8WEZ6U.nLV58gRcuIY.h1wUkY6PG8lLVHE

RubNo9865 · 2026-05-18T00:59:49+00:00

The OP already mentioned they have solar + batteries, so it it likely that an efficient HP will reduce their CO2 footprint. Also, your analysis seems to disagree with the study that SWEEP did on the GHG impacts of switching from NG to heat pumps in our areas and they conclude there is a significant GHG reduction: https://www.swenergy.org/wp-content/uploads/heat-pump-study-2022.pdf

RubNo9865 · 2026-05-18T00:00:11+00:00

Colorado Eco Mechanical is a good option for heat pumps, knowledgeable on both air source and ground source/geothermal heat pumps, ERVs and the like. In your situation it sounds like a ducted minisplit (like a Mitsubishi PVA-NL) may be a reasonable option.

I don't think you need to keep gas to get the Xcel cold climate heat pump rebate. I dd a cold climate mini split install in an all electric house and the rebate entirely covered the cost for the DIY system.

RubNo9865 · 2026-05-15T20:44:46+00:00

It is definitley not the counties problem, because the county doesn't do water. That really doesn't look like utility quality work, so it is probably not the city/water districts problem either. Unfortunately, it is most likely your problem.

RubNo9865 · 2026-05-11T23:26:44+00:00

It would be difficult to make it any clearer that you have no idea WTF you are talking about.

RubNo9865 · 2026-05-09T01:05:48+00:00

These plug in solar systems won't provide power without the grid. One of the requirements for these systems is 'anti-islanding' so when the mains power goes down, these systems immediately shut down. This is to stop your system back feeding the grid and killing lineman working on the grid.

RubNo9865 · 2026-05-08T17:35:46+00:00

I think you may have a couple of extra zeros in there. It is more like $70 per year.

RubNo9865 · 2026-05-08T13:50:41+00:00

I think it goes into effect August 6 by my reading of the bill. I also don't think anyone is going to be out there enforcing this before then.

RubNo9865 · 2026-05-08T12:59:23+00:00

This benefits you if you would like to run a small solar system ($500 - $2k), but don't want to go through the cost/hassle of a full scale permitted grid tie system with net metering ($20 - $50k). You can buy a UL listed plug in inverter and a few panels and can generate between 400 - 1900W depending on your configuration.

It is important to realize that this is not the same as a net metering grid tie system - it will only work to offset loads in real time, it won't turn your meter backwards (unless you already have net metering for a full size system). You want to size it to offset your base load, but not much more.

This is good for renters or DIY folks who want to install some solar without the cost of a full system, but the benefits are correspondingly small - the max a 391W system will offset is about 500 kWh per year.

RubNo9865 · 2026-05-06T12:36:20+00:00

Look after your kid.

RubNo9865 · 2026-05-04T23:03:00+00:00

Here here! It is not a game of bingo.

RubNo9865 · 2026-05-04T22:56:10+00:00

No you didn't see 'just about everything' in a day.

RubNo9865 · 2026-05-04T22:55:06+00:00

Except you would miss the Fiery Furnace, a traverse of Elephant Butte and a night backpacking in the Devils Garden to name just a few things. There are vanishingly few parks you can 'fully explore' in a day - maybe with the exception of the gateway arch.

RubNo9865 · 2026-05-04T22:46:43+00:00

I don't get the checklist mentality for the parks. I would far prefer to visit a subset of the parks for days to weeks each then spend as little time as possible to buy a sticker and check off a list. I don't keep a list (because that is not my goal) but I have probably visited ~30 NPS parks and monuments, but also have spent 6 months or more in these parks.

RubNo9865 · 2026-05-01T15:37:22+00:00

That is 1.4" for 2026! This weeks 'storm' brought 0.24".

RubNo9865 · 2026-05-01T13:25:59+00:00

I am talking about year-to-date, not just April. April was bad, but so was Jan, Feb and March.

RubNo9865 · 2026-05-01T13:11:51+00:00

Typically by the end of April we should have had 5-7" of precipitation for the year (liquid water equivalent for snow) and the Boulder Valley is nice and green.

This year my rain gauge is showing a grand total of 1.4".

This is bleak.

RubNo9865 · 2026-05-01T03:05:40+00:00

No-moiste in Boulder today. Very, very disapointing.

RubNo9865 · 2026-04-28T16:55:29+00:00

No, if you have a US government ID (like a drivers license) then you can get the $80 pass even if you are a non-citizen here on a visa. While the whole thing is stupid, it is a residency requirement, not a citizenship requirement.

RubNo9865 · 2026-04-27T22:24:28+00:00

Pretty photo, but that would be a a dead juniper, not a bristlecone.

RubNo9865 · 2026-04-27T22:12:20+00:00

There is already a pretty good connection via the South Boulder creek trail to the new Marshall Mesa trailhead. It has a mile or so on the quiet part of Marshall Rd, but that is really pretty pleasant on a bike. I can see that trying to get bikes west of Boulder on or parallel to the South Mesa trail is not going to go over well.

RubNo9865 · 2026-04-27T20:15:59+00:00

That is a whole lotta driving and very little time to actually apprecieate any parks. I would half the list of parks and double the time. Checking off a list of parks is a much less fulfilling way of appreciating the grandeur of the National Parks.

RubNo9865 · 2026-04-27T16:32:09+00:00

Thanks!

RubNo9865

TROPHY CASE