Questions about a having Central Heat installed in San Diego

[wjelmer]

My mom wants central heat installed in there house, so we had multiple HVAC guys come out and give us some quotes.

I thought they were kind of high but both guys she had come out were Trane Installers. Going to get one more quote from a Rheem HVAC guy.

Since were live in San Diego and climates are mild, They recommended XR95 or an XV95 because my mom wants to make sure the system isn't. Is the XV really that much quieter than the XR (and do we need variable speed in san diego)?

One of the installers wanted to go through the attic and one of the installers wanted to go under the house through the crawlspace. We would prefer to run it through the attic because we don't want vents in the hardwood. What do you guys recommend?

Thanks for your help.

Attachment 330521

[dan sw fl]

I would use a Heat Pump.

[jpsmith1cm]

wjelmer.

Your attachment had pricing in it, so I had to remove it per site rules.

[Shophound]

In San Diego, the general rule is that for every mile one travels inland, the daily high temperature increases by one degree. Meaning in summer, if it's 70 along the coast, it can be 85 degrees in El Cajon. I once lived in Linda Vista, El Cajon, and Lakeside, so I know this is more or less true (depends on the season and weather patterns). So, while overall the area can be considered to have "mild" weather, and that is the prevailing pattern, the weather isn't exactly mild during Santa Ana conditions or farther inland in the summer.

What system is best for your mom's place depends on where she lives within the county, what a load calculation specifies for what size the equipment should be, and what is the most economical energy source for heating. If she's out around Alpine, for example, natural gas might not be available, and propane very expensive, meaning a heat pump could be the best choice. On the other hand, someone in Chula Vista may not need much a/c most of the year, but might find natural gas for heating to be more economical than a heat pump. I remember many homes along the coast with no a/c at all, just a natural gas furnace, whether it was a central unit or one in the wall or floor.

[motoguy128]

I think I've heard of some homes where they just install a direct vent gas fireplace. I think the apartment that my wife lived in ther had that. A couple tiems in the winter you'd fire it up on colder evenings. Otherwise indoor heat sources and afternoon solar heat gain provided nearly enough heat most other days since most homes were smaller and just running the oven or stove can heat a small space.

[BaldLoonie]

Wonder if a 95% is worth it in that climate? Before thinking heat pump, investigate electric bills. CA can be salty!

Sis has a house in Carlsbad. No A/C. I know what the hound means. I've been there when it's 50 at the coast and 90 inland.

[dan sw fl]

So maybe "the A/C unit" should draw O.A. from 20 miles West.

Heating .. just have a Large evening Party

[wjelmer]

Thanks for all your responses. Guess I should have given you a few more details.

My parents live in Pacific Beach about a mile from the ocean so we will not be installing AC.
Currently They have a natural gas furnace in the living room. We do not want a heat pump, we would like to go with a Natural Gas Furnace.

My main question is do we need a 95% efficient Variable-speed blower with two-stage heating or will a 80% single stage heater suffice since it does not get that cold? Is the variable speed/two stage really that much quieter than the four speed/single stage?

Also curious why some guys would like to run the vents under the house and some want to go threw the attic? (we would prefer threw the attic.)

[catmanacman]

i would put in the attic also a properly sized single stage 80% furnace would be fine.although the the xr 95 would burn less gas and the xv 95 would burn less gas and less electricity , first thing you need to know is what size you need .i would think a 45000 btu furnace would heat a pretty big house in the mild climate ,and a oversized 2 stage furnace that is always in low fire is a waste of money. as for the noise level its all in the install i do not find a varible speed to be any differnt in sound level if installed properly

[BaldLoonie]

Heat from the floor tends to be more comfy. Your choice. Again I question if you'll ever get economic payback from a 95% as little as it will run. Wanna see payback? Come freeze up here with us!

[Shophound]

If the hardwood floors are off limits for supply and return grill cut-ins, either the attic or furring down sections of ceiling within the house are your other options. If you opt for attic install, be sure to specify that wherever the ceiling is cut open for a supply or return, the gap between the ceiling drywall or plaster and the new duct "boot" is sealed so attic air can't be in contact with house air. You also want all duct joints in the attic sealed with mastic, and if they use flex, all runs need to be kink free, straight as possible, and stretched tightly as possible.

If the furnace itself will be located in the attic, it will need access. If the attic currently does not have an access hatch or door, putting one in can bring in problems that were not there before, since these hatches so often are leaky. Remember, no attic air mixing with house air. You want to keep these separate. Bottom line, any hatch installed needs a way to seal itself against the house when the hatch is closed.

As for the furnace choice, hard to justify a 90%+ in Pacific Beach, IMO. Heating along the SoCal coast is mostly to ward off coastal chill, not because a blizzard is blowing around the house. California Title 24 may dictate what can go in, anyway, as a minimum choice.

[motoguy128]

all runs need to be kink free, straight as possible, and stretched tightly as possible.

Wait you mean you can cut flex?... you don't have to use it in 25' and 50' sections only? Shhh... don't give away all your trade secrets... other contractors might catch on and you'll lose your edge.

[dan sw fl]

If

... in Pacific Beach, IMO. Heating along the SoCal coast is mostly to ward off coastal chill, not because a blizzard is blowing around the house. California Title 24 may dictate what can go in, anyway, as a minimum choice.

All one should need for heat is
___________ four candles IMO.

[wjelmer]

So we decided to go with a Trane 80% unit. Were debating wether we go with a XL80 or a XV80? Is there variable speed worth the money or necessary for the amount were going to use it?

Also I have had 4 estimates and 3 of them are different BTU pumps (40k, 50k and 60k) shouldn't they all becoming up with the same calculation for BTUs?

[Roncool]

You must mean they have a wall furnace in the living room. In your area you have 2 choices . You can cut in a attic furnace or depending on the area and codes you can do a roof top. I would forgo the 90% and go with a 80% VS 2 stage system. I would install a Honeywell wireless T stat so your mom and Dad can control temps in any area of the house with the remote .They can also view outside temps and hum levels from same easy to use stat. I assume you have a attic and it is old school construction so more then likely the attic access hatch will need to be enlarged. You may be right about the AC, however check the temps last year I think you have been in the 90's more then a few days for the past couple of years . Take some of the savings from 90 + % and possibly apply it to AC. We did 2 jobs in that area for friends of people we did jobs in my area and they both went with AC. Rheem is good but the install trumps the brand in most cases .

[Roncool]

So we decided to go with a Trane 80% unit. Were debating wether we go with a XL80 or a XV80? Is there variable speed worth the money or necessary for the amount were going to use it?

Also I have had 4 estimates and 3 of them are different BTU pumps (40k, 50k and 60k) shouldn't they all becoming up with the same calculation for BTUs?

This depends on sf of house and heat loads like windows, insulation things like that. In genseral VS is the way to go . I would under size before I would over size.

[dan sw fl]

So we decided to go with a Trane 80% unit. Were debating wether we go with a XL80 or a XV80? Is there variable speed worth the money or necessary for the amount were going to use it?

Also I have had 4 estimates and 3 of them are different BTU pumps (40k, 50k and 60k) shouldn't they all becoming up with the same calculation for BTUs?

I am not sure you'll ever get a consensus within 10%.
I'll give you 41,000 today and 36,000 tomorrow.
Wednesday .. who knows? 39,999.

Just something I picked up from mitt a few months ago.
However, the something is ... The Lunatic on the Potomac INSANITY.