Retrofitting older house with modern HVAC system?

Nessism1

Nessism1

Joined
May 30, 2022
Messages
1,594
Location
Torrance, CA
My house, built in 1952, has one wall heater, and one (non functional) manual wall heater unit back by the bedrooms.

The main house heater is a great unit, but it is a simple radiant heat unit. The house gets cold in the winter, but not unbearable, considering So. Calif.

A friend had his similar house retrofit with a ducted forced air heating/cooling unit, located up in his attic. My guess, with modern costs, a similar unit would cost $30k.

Another friend suggested a mini-split unit install. Has anyone around here have experience with these units? I'm guessing that 5 in-room units, along with the required plumbing would be enough for my small home.

Please share your thoughts.
 
Grandson just got an estimate for retrofit on a one story approx 1000 sq ft older house with basement for about 14K. Goodman natural gas furn with electric AC unit with duct work. $15K. I assume most to all duct work will be run up from basement. Not sure you can get this reasonable a deal in California.
 
HVAC companies do this all the time around me. They install a central or a dual system in the attic and /or the basement, run ducts through closets or stud pockets (beware of that it’s a cause of mold). They are heat pumps and can add supplemental heat in the winter. My parents retrofit a unico high velocity system in their 1920s home. That uses small diameter PVC pipes.

That said, HVAC companies doing this are amongst the biggest thieves of all tradespeople. They can’t justify a labor price, lie about pulling permits, etc. you may be better served doing mini splits (which are more efficient), DIY. I bought all high quality US made tools and was still thousands ahead on the first unit I DIY installed in my house. The excuses the HVAC techs made, on a balloon frame home where I could put a scope up the wall, were obnoxious. Mine get used as supplemental to the hydronic system that I have and love, mod-con boiler with indirect hot water. I use the split to keep the house overall cooler, and just boost a bit in spots where the family is on the coldest days. Works great.

I believe @The Critic installed a split in CA as a booster in his home.
 
Last edited:
My HVAC system involves this heater and open windows...

747ac536-38f7-454b-b3a3-98f1f851ad0b.webp
 
No way in hell I'm spending that much. Get a mini split. The ones that are meant to be installer easy are known to be bad. I think they're called pre charged or something like that. Mitsubishi mini splits are surprisingly bulletproof and had one installed in mexico and after 11 years it's been solid. It's the top brand down there for reliability since mini splits and window units are most common. Homes aren't made to be ducted over there.
 
Pablo said:
You really don't need any kind of heater in coastal so cal.
Click to expand...
True, but it's all about comfort level.

Are you okay with 62F inside your house, and a $200/month heating bill? Clearly, this is related to insulation in the house. With my house, even with the main wall heater running often, the heat doesn't get into the back bedrooms all that much. No biggie, just add more blankets. Clearly, I need more insulation, but the lack of heating capacity is clear.
 
Nessism1 said:
True, but it's all about comfort level.

Are you okay with 62F inside your house, and a $200/month heating bill? Clearly, this is related to insulation in the house. With my house, even with the main wall heater running often, the heat doesn't get into the back bedrooms all that much. No biggie, just add more blankets. Clearly, I need more insulation, but the lack of heating capacity is clear.
Click to expand...
I agree on the mini split and see if power company will rebate
 
I have a Mr Cool mini split, 1.5 ton. Love the thing. Did it myself for $2300. The most obnoxious thing about it is its huge outside condensor and the lineset.

AC contractors are crooks for how much they get for doing the same thing. It's one hole in the wall, one supply wire, and one breaker!
 
Go mini-split and make sure to get an "inverter". Do not over size the AC part. With an inverter, you have less chance of over sizing as the units can throttle themselves back with a variable speed compressor. This will reduce short cycling and help on humidity/mold. I installed a 60,000 btu ACiQ (Carrier) 96% two stage furnace and a 2.5 ton CENTRAL air unit (AC only/no heatpump, I wish now I went w/heatpump $800 more) inverter unit with A-Coil box unit. $5,500 delivered from HVAC Direct dot com. The condenser is horizontal like the common mini-split condenser. Since the neighbors bedroom window is 5 ft away and code would not allow a conventional AC unit that close to any bedroom. You don't hear a thing running and no loud engagement of the AC unit, it slowly ramps up at 53 decibels. The only way I know it's running is the grass/weeds moving from the condenser fan.

This went into my daughter's new to her 1884 farmhouse in St Paul MN. My wife's co workers friend husband works for a large HVAC as an installer and he did 90% of the install since I was wiring the whole house after stripping all the knob & tube. 2) 8 inch duct runs to the 2nd floor and 2) 6 inch added runs to the first floor to get the correct ducting flow CFM for the furnac/AC. Plus a new main trunk run and drop down intake with a 20x25x 5 inch filter pod. All for $3,700, included the 50 ft copper lineset. Total $9,200 where I was bidded $17,000 to $19,000 by HVAC companies. I did myself, full complete plumbing, full redo of all her electrical from the mast. All my work, of all the trades was permited against my daughters enitial wishes, as I told her you will get about $8,000+ more on resale that the house had full permited work, as many in her area are not. I am glad I did, because the city forced me to redo ALL the plumbing from stack at the floor entry and I found 5 large "venting run" galv pipe holes hidden in the walls. The inspector said that's why we force you to do it, we see it every day in 1930/40 plumbing.

Added note: My daughters 1st floor as two of the floor return vents like you posted, but bigger. Those are her main return vents Also if you do go conventional ducting and you have a second floor, you have the option and within code at least in Minneapolis/Stpaul to use floor/ceiling air returns so you don't have to run ducting returns in the walls/closets. It is a simple square hole in your floor/ceiling with a square are of for hers was a 8 inch pipe area in 2 spots. Would cost tons more to run ducts as there was just enough room to only run feeder ducts to the upstairs.
.
 
Last edited:
Go mini-split. I have one in my garage, and it's been running almost 24/7 since 2017. Made by Fujitsu. This thing is unbelievable ! It gets a break in the spring and the fall. I shut it down., and clean it. The outdoor unit is mounted on the north side of the house, then ducted all the way to the south side. Has to be an 80' run, easy. Has a drain hose that dumps into washing machine drain. I do maintain it, using that no-rinse evap spray on the inside, but I still use a garden hose on a light spray to get that stuff off. It just goes down the drain, not the wall. Cleaning filters is important to keep it clean. Also clean the outdoor unit the same way.
 
Last edited:
Nessism1 said:
My house, built in 1952, has one wall heater, and one (non functional) manual wall heater unit back by the bedrooms.

The main house heater is a great unit, but it is a simple radiant heat unit. The house gets cold in the winter, but not unbearable, considering So. Calif.

A friend had his similar house retrofit with a ducted forced air heating/cooling unit, located up in his attic. My guess, with modern costs, a similar unit would cost $30k.

Another friend suggested a mini-split unit install. Has anyone around here have experience with these units? I'm guessing that 5 in-room units, along with the required plumbing would be enough for my small home.

Please share your thoughts.
Click to expand...
Hire a designer.

Contact this guy and maybe he'll have a West Coast referral.

https://www.energyvanguard.com/hvac-design/hvac-load-calculations/
 
Nessism1 said:
My house, built in 1952, has one wall heater, and one (non functional) manual wall heater unit back by the bedrooms.

The main house heater is a great unit, but it is a simple radiant heat unit. The house gets cold in the winter, but not unbearable, considering So. Calif.

A friend had his similar house retrofit with a ducted forced air heating/cooling unit, located up in his attic. My guess, with modern costs, a similar unit would cost $30k.

Another friend suggested a mini-split unit install. Has anyone around here have experience with these units? I'm guessing that 5 in-room units, along with the required plumbing would be enough for my small home.

Please share your thoughts.
Click to expand...
Caulk and weather strip. See if you need more insulation in the attic. Just get a portable plug in heater. Your welcome.
 
I had 2 Daiken mini splits installed (with 2 separate compressors) for $15k.

If the house wasn't so nice I probably would have sawzalled the wall and threw an AC unit into each room and saved $14k. :D
 
You must log in or register to reply here.

Similar threads

W
Garage heat options
2
Replies
20
Views
1K
WA1DH
Number_35
  • Locked
Plumbing in a window AC Unit to simulate central air
2 3
Replies
57
Views
5K
Bladecutter
A
Cost to Heat and Cool our New Home = CHEAP
2 3
Replies
59
Views
5K
Donald
Nick1994
  • Locked
Saved $2,100 - HVAC
2 3 4
Replies
65
Views
6K
Astro14
BeerCan
Natural gas vs firewood/coal
2
Replies
32
Views
3K
benjy
Back
Top Bottom