Just turned on my HVAC system

When it comes to addressing climate change upgrading existing homes to be more efficient is essential. For too long it's been an obsession with building brand new energy efficient homes, which has a massive carbon footprint compared to upgrading already built homes.

 

I'm so hungry for the day when we're all being honest about climate change and working together to reduce personal carbon emissions and it's not just another dog whistle "attack the libs" with hatred issue. Of course the fact that all the world's governments & military seem to be owned & operated by the fossil fuel industry is a whole other calamity to deal with.

 

What are your low and high temp like?
We don't turn on our heat unless outside temp drops to 20s and daytime high don't reach 40s which is usually some time in Nov.

Posted via the PriusChat mobile app.

 

Wow! 95 high is a killer for me. We don't have HVAC at our house, just oil boiler heating. But during summer time about two weeks when the day temp gets above 85F, I have to turn on the window AC.

So far our nighttime lows have been in the upper 20s, but daytime highs are still above 40. We have no heat turned on yet. But had to fill the tank in preparation. At $5/gallon, it costs more than $1300. We will need to fill it twice for the heating season from November to April.

 

For those of us in milder climates zones who don't have an equivalent reference point, what would be a normal no-HVAC span in your zone, absent your improvements and active solar heat gain management?

Here, where probably a majority of dwellings still lack AC, it wouldn't be unusual for people to have heat off for 4 to 5 months straight. Our heating season ended late last spring, then returned Friday. Though an increasing portion of dwellings are getting some sort of AC, which would have been heavily used just 9 days ago.

Yes, lack of efforts to upgrade existing homes is a huge hole that demands far more attention.

But the obsession with making new homes energy efficient is essential, and probably not strong enough. They ought to be even more efficient. As the homelessness crisis demonstrates, it isn't like we don't need more housing. The new units are going to remain in use much longer than many old units.

 

Yeah, I had a contractor set up to install a heat pump... but it made no sense to just install a single unit since our house is heated by a single-zone oil boiler central heating system. I got an estimate for converting the entire heating system to a muti-zone heat pump system. I got an estimate for installing two outside units with 5 inside zone units to heat the entire home with electricity. But... it was way more than a single heat pump installation. I decided to wait a bit until next year to take an advantage of the recent Inflation Reduction Act which may give me up to a $14,000 rebate for this major improvement,

 

Of all my improvements (including added floor and ceiling insulation, sealing air infiltration leaks, lighting and appliance updates, upgraded patio slider door, an exterior shade to reduce summer heat gain through that door, better management of other solar heat gain, solar panels shading the roof, etc.), the ductless heat pump in the largest living space produced the largest savings (not including the solar production). The heat pump water heater was second.

A second ductless heat pump added to the other end of the house late this spring will displace additional electric heating and bring some more energy savings, especially in the coldest weather, but is unlikely to provide enough additional energy savings to ever pay for itself. Though it will produce more comfort, especially in the summer. As we age and become less able to tolerate temperature extremes, summer is also getting increasingly warm. We are getting more occasions where the overnight temperatures are too high for a window exhaust fan to sufficiently cool the house by dawn, or wildfire smoke makes that cooling method very undesirable.

 

How are you heating the areas without a heat pump? For our house, it is absolutely necessary to have the entire house converted. The problem is that the main large open area where we spend most of the time is where the thermostat for the heater is. If we just install a single zone heat pump there and use it as a main source of heating, then the rest of the house gets no heat. If I relocate the thermostat out of the main area to heat the rest of the house, then the main area will also get heated by the oil boiler thus the heat pump will never turn on. The only way to alleviate this problem is to reroute the heating plumbing pipes to make our oil boiler heating to multi-zone. The cost of conversion on the existing oil heating zones plus a single-zone heat pump is about equal to installing multi-zone heat pumps to heat the entire house.

 

From his description earlier this year, yes, it really is necessary for his house. A single zone wouldn't work, won't cover enough of the space, and a partial conversion was going to very problematic, causing interoperability problems between the two systems.

I hope the new incentives do enable a full conversion of that house.

 

I had a contractor come to check on the conversion of our oil-boiler-connected hot water heater to an electric heat pump hot water heater. If the conversion was possible, we qualified for a free installation and free heat pump hot water heater. Unfortunately, it was determined our system was not compatible with the conversion. From our records, I know we use almost 300 gals of oil just for hot water during the non-heating season (May to Oct). I think the efficiency of the hot water heater part improves during wintertime when the boiler is on for the heating. But if I could convert to the heat pump water heater, it would have cut down our oil use by at least by a third.

Without this conversion, unfortunately, even if I get to install a whole-house multizone heat pump system, I can't get rid of the oil boiler. And it is likely that the reduction in oil consumption is only going to be about 33% less than the current level. Not the ideal situation.

 

I agree more improvement in existing homes is needed.
Older homes are not, however, being ignored.

At the same time we were building our energy efficient house, a 1907 house was being updated to Net Zero.
Minneapolis Net Zero Victorian - SALA Architects

There are also incentives for rental units. This particular one is in MN, however I have heard of others.
https://mn.gov/commerce-stat/pdfs/success-story-multifamily-south-minneapolis.pdf

Improving old homes isn’t as ‘sexy’ as new homes, but it is critical and is being done at some level.

 

Guessing you have forced air for heating and cooling. Many homes that don't have central cooling use hydronic for heat. With no duct work in place, mini-split systems are the most economical way of adding AC or heat pumps. Then the home's floor plan dictates the number of indoor units for even heating and cooling.

Multiple zones can lead to more energy saving by reducing the load in areas of the house not in use.

 

Which is more effort than setting a thermostat, and letting the system handle everything. Zones can be set up with any system. My hydronic one has 3. But if the situation means mini-split is the only viable solution, then having multiple zones isn't an additional cost.