Prius-life retrofit for extreme cold?

[impr3]

So, I've been living in Vincent the Prius (https://vanlivingforum.com/threads/vincent-the-prius.42464/) for over two years now and I've gotten pretty comfortable with my system. However, I've thus far been living in temperate northern California and will be moving up to snowy Spokane for a year starting next summer. I'm a tad worried about managing the winter there... Thankfully, I have nearly a year to do retrofits so I'm hopeful that I can figure out something that will work. I'm turning to y'all's shared experience for ideas and or critique of my current plans. Plus, I'm hoping this may be useful for someone else in the future as the info currently available online about winter car living is kind of sparse... Once I get to the build stage I'll probably start a separate thread for this retrofit and post photo updates as I go. For now, thanks for any input you can share on the planning stage!

First off, the context. In the past 12 months, the temperature in Spokane has ranged from -23C (-10F) to 38C (101F). I'm using this as an estimate for the temps that this retrofit is going to need to be able to handle. Spokane also gets a lot of snow and ice in the winter which will present their own challenges.

Based on my limited experiences with below 0C (32F) temps in the Prius while living in NorCal, below are the main issues that I've identified that will need to be addressed in the retrofit.
1. Staying warm. Heating and insulation are the main components in this category. I'll also need to keep my electronics and water supply above freezing in addition to keeping myself warm.
2. Avoiding condensation. This will require active ventilation/air exchange with the outside, good air movement inside, dehumidification, and minimizing the temperature difference between inside air and surfaces that it comes into contact with (warm air + cold surface = condensation). Condensation is probably my top priority issue. I can live with getting cold, I've done it before, but the car will quickly become uninhabitable if it gets wet and subsequently moldy...
3. Keeping the increased energy demand powered at low cost. Minimizing power use and adding power sources. I'd like to use ready mode as little as possible since gas is getting expensive!
4. Enabling previously outdoor activities such as cooking to be done in the car.
5. Enabling some use of outdoor space, even in winter. So I don't go stir crazy.
6. Maintaining mobility in icy conditions. This will require tools to get the car ready to go quickly in inclement weather, like an ice scraper, as well as things like chains to ensure the Prius can actually move in a variety of road conditions. These would be relevant even if I weren't living in it, but since it's my home this becomes even more important as I can't just catch a ride "home" from someone with four wheel drive and wait to dig my car out when the snow clears...
7. Adding safety features for if the weather surprises me with a particularly cold snap, traps me away from sources of food and water, or blocks my exhaust pipe with snow.

I've already started planning out a bunch of retrofits to address these issues and will add these in a separate post below once I have them all typed out. In the meantime, if you have experience with cold weather car life and would like to add to this list of issues to address, please reply to this post!

 

[bullfrog !]

My original post in your initial posting still applies. A cheap electric heater run off an inverter will provide dry heat and cut down on engine run time. My understanding of that part of the country is the humidity is often so high it is impossible to vent enough to get completely dried out. Really ideally you need to find a heated garage you can rent or covered storage, even a parking garage would be better than out in the open during heavy snow events. Maybe work out a deal with a local repair garage to stay nights in one of the bays in exchange for the security you would provide by having someone on property. The 2” lift will help some with plowed but slushy roads. A Prius does not do well in snow, so stay in populated areas with public transportation and plowed roads as well as 24 hour restaurants if it gets really bad or if you need to open up the car in cold weather to try to dry it out you can at least stay warm while doing so. Maybe use a piece of flexible exhaust pipe to extend your exhaust to outside the garage or if outside up above snow levels with a 90 degree or more bend that you can temporarily attach up high on your car or something like a folding metal step stool when in heavy snow. A small foldable multipurpose shovel may come in handy. An insulated custom made car cover might work as interior space is limited but would be a real pain in snow to deal with when traveling. Maybe it is time to consider buying a big enough box truck to park the Prius inside of or tow behind and use the Prius to power a well insulated living space in the truck while staying at truck stops! There are some here and on YouTube that have stayed year round in that area you may want to contact.

 

[impr3]

My original post in your initial posting still applies. A cheap electric heater run off an inverter will provide dry heat and cut down on engine run time. My understanding of that part of the country is the humidity is often so high it is impossible to vent enough to get completely dried out. Really ideally you need to find a heated garage you can rent or covered storage, even a parking garage would be better than out in the open during heavy snow events. Maybe work out a deal with a local repair garage to stay nights in one of the bays in exchange for the security you would provide by having someone on property. The 2” lift will help some with plowed but slushy roads. A Prius does not do well in snow, so stay in populated areas with public transportation and plowed roads as well as 24 hour restaurants if it gets really bad or if you need to open up the car in cold weather to try to dry it out you can at least stay warm while doing so. Maybe use a piece of flexible exhaust pipe to extend your exhaust to outside the garage or if outside up above snow levels with a 90 degree or more bend that you can temporarily attach up high on your car or something like a folding metal step stool when in heavy snow. A small foldable multipurpose shovel may come in handy. An insulated custom made car cover might work as interior space is limited but would be a real pain in snow to deal with when traveling. Maybe it is time to consider buying a big enough box truck to park the Prius inside of or tow behind and use the Prius to power a well insulated living space in the truck while staying at truck stops! There are some here and on YouTube that have stayed year round in that area you may want to contact.

Thanks for your reply to this thread and to my original one several years back! I remember your prior comment and have actually been looking at 12v heaters as a way to reduce how much time the car needs to run in Ready Mode. I haven't had to pull the trigger on this purchase yet in NorCal since I almost never need to run the car for heating, but it's on my to-do list for the retrofit .

As to humidity, thankfully Spokane is pretty much high desert so things shouldn't get nearly so wet as they would out west so long as I keep a good handle on condensation and managing my own body's moisture. The vent that I'm looking at advertises 100CFMs which is nearly a full air change per minute for something as small as a Prius so I'm hoping I'll have plenty of room to play around with running it at a slower speed or only intermittently and still have enough air turnover to remove the moisture that I produce. We'll see...

All that said, I have been seriously considering trying to rent garage space. I hadn't thought about offering a shop security and I love the idea! I'll definitely ask around once I get there.

Regarding a lift, I think you might have been the one who turned me on to that idea originally as well. I installed the lift kit from OffRoadPrius about a year ago and it was well worth the rather high price tag!

I hadn't thought about the exhaust extension either. I'm adding that to my to-do list. I'm picturing basically an exhaust snorkel .

As to alternatives, I have looked at a friend's van conversion that they're interested in selling but it would cost $20k that I don't have... Plus, it doesn't have the climate control/power generation benefits of the Prius (or the excellent MPG!).

 

[Happy Camper]

You have a good battery setup with the house batteries and the jump start capability. That said, you might consider buying a lithium jump starter for that just in case for the very cold temps. They are very small and really do the trick if for some reason your batteries can't handle the cold.

 

[bullfrog !]

Just to be clear, you can use up to a 1500 watt inverter ( which changes 12 volt DC to 120 volt AC ) with simple connections to the 12 volt starter battery and therefore not only is the smaller inverter cheaper to buy but also to install. You can also attach an up to 3,000 watt inverter to the larger battery but it is much more expensive. The cheap ceramic heaters ( usually less than $40 ) usually have a low setting that uses 700 watts and a high setting that used 1,500 watts so the smaller cheaper inverter works and since the smaller battery is charged by the bigger battery recharging only occurs when the larger battery reaches it’s lower level of charge reducing run times in order to heat the vehicle. Last time I checked the 12 volt heaters were much more expensive and circulated less air than the 120 volt ceramic heaters. The Prius is worth keeping in my opinion if nothing else for the fact it is about as economical as a purpose built Honda generator to produce electrical power. It is one of the few vehicles that can support an air conditioner while parked. I had thought about towing one behind a motor home as not only for cheap transportation but as an electrical power source for the motor home after modifying the Prius with an inverter. As far as humidity there are desiccant crystals you can buy and use to collect the humidity inside the vehicle but you do need to dry them out after they have done their thing.

 

[Happy Camper]

I looked up a few lower wattage heaters and found this worked for some van dwellers. It's small, and might allow you to use a smaller inverter if space is an issue.

Amazon Basics 500-Watt Ceramic Small Space Personal Mini Heater - Blue https://a.co/d/6Klv7k0

You might also consider an electric blanket, mattress pad, or throw blanket.

 

[RonDean]

I lived on a houseboat in Newport Oregon and that was about as moist as you could ask for. Because I had AC shore power I I kept a couple Eva-dry Dehumidifiers going. I don't know if you could utilize your Prius & a power inverter to run one, but I'm thinking it should work. I see they are on Amazon for about $15. I've seen YT videos saying you can get disposable dehumidifiers at $stores, although I have never seen them.

 

[abnorm]

I've seen YT videos saying you can get disposable dehumidifiers at $stores, although I have never seen them.

Like Damp rid.................a salt in a waxed cup.........they're OK in a closet

 

[onethoughtatatime]

Hi @impr3 wishing you the best for the northern winter.

Number 2 point about condensation, I am sure you will be aware of priuschat, the experts there have much valuable information. One thing I've been reading about recently is about how the heating and AC systems work. Like you, I don't like using "ready" mode much if at all. However, there is some very useful information about how the AC compressor is a variable speed model and can use phase 3 HV power up to 2500w but as low as 250w (I seem to remember).

There are various modes the AC works on depending on the mode (for instance window defrost mode from cold can use one of the two (gen 2) anaemic heaters).. Anyway, I digress, because the AC unit is essentially a dehumidifier, it can provide cooling capability or heating (from the anaemic heaters or motor engine in my gen 2). Essentially, it dries out the air.

Now you don't see this factoid posted often in relation to prius car camping but I would wager if you use the AC with the lowest heat setting but not MAX COLD, and lowest fan setting that would mitigate some of the moisture buildup and not use a huge amount of HV battery and therefore fuel. I haven't tried it yet. Anyway, it's an idea

Another thought for warmth might be installing (and upgrading) a chinese diesel heater in a prius if you don't want to use "ready" mode. They are more efficient in regards to fuel usage from my calculations for heat compared to the car AC and is another option because they can be had in the US/Canada/UK etc very cheaply. From what I can tell, prius' generally use the engine block for heat and not the AC like they do in sticks and bricks.

Hobbit, of prius fame, has a page where they tapped into the AC blower unit for cooling with prius off for air cooling. It involves mucking around with that ECU/unit and so I am reluctant to do that. I would have thought tapping into the HV battery blower would have been easier as it vents directly outside and the intake is centrally mounted (for a gen2 anyway).

Like you, moisture build up is my main gripe with such a small space. In the past I've used window socks in smaller vehicles with the window down and I've got some but they don't work in the rain..

 

[maki2]

Dehumidifiers create heat to remove moisture from the air. So get a small one with a drain hose and use some of the battery power to run it as well as the heater. Solve both issues at the same time.

 

[onethoughtatatime]

Sorry, I wasn't very clear in my post. The prius AC which runs when on 'ready' mode is a dehumidifier and can run all night long fairly efficiently.

 

[maki2]

Sorry, I wasn't very clear in my post. The prius AC which runs when on 'ready' mode is a dehumidifier and can run all night long fairly efficiently.

If it is running in ready mode is that the same as turning on heating mode?

I believe the goal would be heating as well as dehumidification, both happening at the same time so things do not get soggy in high humidity condition weather such as freezing temperatures with a high wind chill factor plus rain, which is exactly what the weather was early this morning in Quartzsite AZ

 

[onethoughtatatime]

If it is running in ready mode is that the same as turning on heating mode?

I believe the goal would be heating as well as dehumidification, both happening at the same time so things do not get soggy in high humidity condition weather such as freezing temperatures with a high wind chill factor plus rain, which is exactly what the weather was early this morning in Quartzsite AZ

"Ready" mode is the prius term for all on. They have different terms than everyone else I guess. So, the car is on but in park. However, the motor cycles on periodically but is turned off most of the time running the AC off the bigger battery. You can stay in "ready" mode indefinately and people have powered their homes this way in emergencies. I heard somewhere that Toyota started putting inverters in their cars after the Fukushima tragedy because people were adding them anyway and using them to survive during the aftermath.

So, you can run any level of heat or cooling but also dehumifying as well when in "ready" mode.

 

[maki2]

It is easier to understand by the explanation of the Prius heat pump system on this webpage. However I have no idea if all of the Prius that predate and post date this 2017 model in the discussion have the same equipment for their heating and cooling system. That would take further research by model and year to find out.
https://www.greencarreports.com/new...p-work-in-a-toyota-prius-prime-plug-in-hybrid

 

[camperdan]

Thanks for your reply to this thread and to my original one several years back! I remember your prior comment and have actually been looking at 12v heaters as a way to reduce how much time the car needs to run in Ready Mode. I haven't had to pull the trigger on this purchase yet in NorCal since I almost never need to run the car for heating, but it's on my to-do list for the retrofit .

As to humidity, thankfully Spokane is pretty much high desert so things shouldn't get nearly so wet as they would out west so long as I keep a good handle on condensation and managing my own body's moisture. The vent that I'm looking at advertises 100CFMs which is nearly a full air change per minute for something as small as a Prius so I'm hoping I'll have plenty of room to play around with running it at a slower speed or only intermittently and still have enough air turnover to remove the moisture that I produce. We'll see...

All that said, I have been seriously considering trying to rent garage space. I hadn't thought about offering a shop security and I love the idea! I'll definitely ask around once I get there.

Regarding a lift, I think you might have been the one who turned me on to that idea origin

ally as well. I installed the lift kit from OffRoadPrius about a year ago and it was well worth the rather high price tag!

I hadn't thought about the exhaust extension either. I'm adding that to my to-do list. I'm picturing basically an exhaust snorkel .

As to alternatives, I have looked at a friend's van conversion that they're interested in selling but it would cost $20k that I don't have... Plus, it doesn't have the climate control/power generation benefits of the Prius (or the excellent MPG!).

As a 20-year full-timer that has moved with the seasons within AZ, I admit I am biased a bit. So....first question is ' why are you staying in Spokane? Job...family...cost of travel. If it is JOB, can you do it remotely from a more climate friendly spot?
Clearly, I do not know your situation. Maybe you could fill us in. Nothing wrong with living out of a Prius.....but climate challenges may not be that necessary. Just want to be helpful.

 

[impr3]

Hi @impr3 wishing you the best for the northern winter.

Number 2 point about condensation, I am sure you will be aware of priuschat, the experts there have much valuable information. One thing I've been reading about recently is about how the heating and AC systems work. Like you, I don't like using "ready" mode much if at all. However, there is some very useful information about how the AC compressor is a variable speed model and can use phase 3 HV power up to 2500w but as low as 250w (I seem to remember).

There are various modes the AC works on depending on the mode (for instance window defrost mode from cold can use one of the two (gen 2) anaemic heaters).. Anyway, I digress, because the AC unit is essentially a dehumidifier, it can provide cooling capability or heating (from the anaemic heaters or motor engine in my gen 2). Essentially, it dries out the air.

Now you don't see this factoid posted often in relation to prius car camping but I would wager if you use the AC with the lowest heat setting but not MAX COLD, and lowest fan setting that would mitigate some of the moisture buildup and not use a huge amount of HV battery and therefore fuel. I haven't tried it yet. Anyway, it's an idea

Another thought for warmth might be installing (and upgrading) a chinese diesel heater in a prius if you don't want to use "ready" mode. They are more efficient in regards to fuel usage from my calculations for heat compared to the car AC and is another option because they can be had in the US/Canada/UK etc very cheaply. From what I can tell, prius' generally use the engine block for heat and not the AC like they do in sticks and bricks.

Hobbit, of prius fame, has a page where they tapped into the AC blower unit for cooling with prius off for air cooling. It involves mucking around with that ECU/unit and so I am reluctant to do that. I would have thought tapping into the HV battery blower would have been easier as it vents directly outside and the intake is centrally mounted (for a gen2 anyway).

Like you, moisture build up is my main gripe with such a small space. In the past I've used window socks in smaller vehicles with the window down and I've got some but they don't work in the rain..

Thank you for this detailed post! I had not thought about the dehumidification function of the Prius climate control and suspect I will end up taking advantage of that when things get too extreme for my other systems to handle!

 

[impr3]

As a 20-year full-timer that has moved with the seasons within AZ, I admit I am biased a bit. So....first question is ' why are you staying in Spokane? Job...family...cost of travel. If it is JOB, can you do it remotely from a more climate friendly spot?
Clearly, I do not know your situation. Maybe you could fill us in. Nothing wrong with living out of a Prius.....but climate challenges may not be that necessary. Just want to be helpful.

Sadly, the job can't be done remotely or elsewhere. It's a really amazing apprenticeship opportunity that will just be one year and then I'll be coming home to NorCal .

 

[impr3]

Thank you everyone for your replies! I have read through every post in detail, including the ones from while I've been MIA these last few months. I'm a tad hurried at the moment as I move to Spokane in just over a week and the Prius is still completely gutted with all the trim and headliner removed as I work on installing the insulation and extra electrical infrastructure. Because of that, I haven't had a chance to reply to each of you directly and just wanted to say a group thank you!

I probably won't have a chance to post a proper update here until after I'm done with the build due to lack of time. However, I am recording most of the building prices and slowly uploading those to YouTube. I'm a tad behind on uploading the videos relative to where I am in the build, but they should be trickling in over the next few weeks.

Videos posting here: https://youtube.com/@cobbmountainroots?si=ipAYgJqVjj6wCn54

Thanks again everyone!