heat loses and deign day below the point

clammy

Well here in north jersey we have hit if not went below our design day at least for me .Being i have a mod con and can check my boiler output i found it funny that i kept my home at 70 and watch my boiler modulate to low fire for over 2 days .My input was down to about my miniun fire to mid so i kinda really only was inputing at the most about 40 mbtu.Kept the house pretty toasty.Had one home drop in temp the heatlose was done but older HO had by mistake turned her ac fan on it took over 30 hours to get her home back to 70.The boiler was sized corectly but that big temp drop and strong winds put a hurting on alot of homes which where sized tight and never had any futher weather sealing or insulation.Wondering if anyone else has ran into this in the north jersey area with those extremely hi winds sunday and monday peace and good luck clammy

JStar

I have a few customers that can't raise their house above 65F. Those high winds are just forcing cold air into the house. And, if you set your thermostat back, you don't stand a chance.

Brp814

We received a call for a furnace not being able to get the house above 65 degrees. This is near Cranbury NJ. The furnace is a 50K BTU, but it is in an attic, spaghetti like flex duct all over the place, and 12ft ceilings with the registers in the ceiling. The house also sits on a slab. Supply temp was 85 degrees, but the attic was 25 degrees. Furnace is doing all it can, he had heat though.

KC_Jones

A good friend of mine has 3k sq ft and heat pumps only. He hasn't been able to get above 63 with a steady 69 set point all day and night.

icesailor

Brp814 said:

We received a call for a furnace not being able to get the house above 65 degrees. This is near Cranbury NJ. The furnace is a 50K BTU, but it is in an attic, spaghetti like flex duct all over the place, and 12ft ceilings with the registers in the ceiling. The house also sits on a slab. Supply temp was 85 degrees, but the attic was 25 degrees. Furnace is doing all it can, he had heat though.

Go up in the attic and see what the temperature in that unconditioned space is. Take a infra-red heat gun and shoot the ceiling temperatures in the heated spaces, then check the ceilings in closets.

Codes want the flex duct held up off the floor. I guess so that you have even heat loss around the entire circumference of the R-6 or less insulated flex duct. And if it is older, the covering is probably split off and there is no insulation around the vinyl tube. For heating, outlet grills belong near the floor, not in the ceiling. Where they belong for cooling. Your friend has a AC system trying to heat his house under AC rules. The same as when AC is put under a house and the supply and return are in the floor. The only heating circulation is across the ceiling from the supply to the return in the ceiling.

If the ducting is accessible, get up there and insulate with fiberglass blankets and cover over it. It works for the cooling too. The insulating will pay for itself. R-19 X 23" works well.

SlamDunk

or , apply some psychology by reminding them that 65 on a 100 degree, humid august day is damn nice!

Gordy

Just go outside for a while then come back in.

Mark N

The design day for the part of New Jersey that I live in is 10 degrees. The day you need your heating system the most it can't keep up. I think they might need to rethink their design day temps, zero might have been a better choice.

bmwpowere36m3

In my area of CT the design day temp is 7*… it's been pretty cold, but I don't think there's been a day where it was 7* or less for the entire day.

Jamie Hall

I have no idea what my design day it -- northwestern Connecticut -- but we've had three days in a row when it didn't get above 5,and the coldest was -11 with a 35 knot steady wind (gusts to 50). Cedric managed, at about a 70% duty cycle

Gordy

Unless the boiler is running 100% your not maxed out. If it ain't keeping set point it's an emitter sizing issue, or swt.

On the other hand if it is running 100% and SWT is maxed out.......go outside and come back in.

Jamie Hall

Gordy said:

Unless the boiler is running 100% your not maxed out. If it ain't keeping set point it's an emitter sizing issue, or swt.

On the other hand if it is running 100% and SWT is maxed out.......go outside and come back in.

Oh no -- Cedric managed to keep the building right at the set point -- even recovered from a 3 degree setback. No problem. Makes me wonder a little just what the system could do. Not that I really want to find out, thank you.

bmwpowere36m3

Jamie Hall said:

I have no idea what my design day it -- northwestern Connecticut -- but we've had three days in a row when it didn't get above 5,and the coldest was -11 with a 35 knot steady wind (gusts to 50). Cedric managed, at about a 70% duty cycle

Hartford is 6* and Windsor Locks is 8*…. no northwest towns listed. Kingston, NY is 2* and Springfield, MA is 0*.

So I'd venture to say somewhere in the 0-8* range. I'm in Fairfield County.

Harvey Ramer

This cold weather makes people more conducive to ideas of real heat.

The actual low temp wouldn't have been a problem for most people, but if you were on the business end of that wind.... It just mercilessly permeated every structure in it's path.

icesailor

"" I would suspect those with gas that have properly sized boilers are in a bit of trouble at design with 40 kt. winds. That's a very unique situation.

But, those with oil, as costly as it may be, are never in such a problem. The nature of the beast is that they always have the reserve. ""

And the oil companies can never drop the pump pressures when their load is so high, they can't maintain service. So they pump air and LPG to try to keep gas pressures up to a minimum acceptable pressure. Downsizing all the heating equipment on their reduced output pressure systems.

All those 40,000 loads with 40,000 boilers, suddenly have 35,000 BTU boilers. And the "Experts" who have been convincing everyone that smaller is cheaper and more "efficient" never get the blow back that the unsuspecting installers get. They never hear about a cold house.

Harvey Ramer

You bring up a good point about LPG, Ice.

Basically, if you want to run a boiler on LPG, it is best to have the tank buried. Helps keep a stable pressure.

clammy

It many not have to do with a tighly sized boiler but more to do with old leaky windows .Went back tuesday and just knew it wasn t right that the heat could keep up system been in for 8 years or so not issues .Ended up nosing about and found 3 windows that where not closed properly and had at least a 1/8 to 1/4 gap on the top straighten then out and caulked up a couple of other windows in her kitchen which she had towels covering that air was blasting in and she was good to go.My last computer which is dead had her heat lose on it was done with a design day of 10 outside it s usually what i use in my area and she was the first that i had not keep up .Did a home directly around the corner 80 mbtu munchkin over 2800 sq ft better insulation package no issues in close to 10 years and if there where this guy would be screaming for sure .Thanks for all ur insight peace and good luck clammy

icesailor

Harvey Ramer said:

You bring up a good point about LPG, Ice.

Basically, if you want to run a boiler on LPG, it is best to have the tank buried. Helps keep a stable pressure.

Something to consider with LPG tanks is that if you bury them, you are using the ground as a radiator, like a heat sink. The ground is warmer than the air. If the load is too high for one tank, the vaporization can freeze the ground around the tank and slow the process down. If you have a high energy user and it goes off when no one is around (like during the night) but starts right up in the AM when re-set, think that it might be shutting down because it isn't vaporizing because of frost in the ground. From the tank. I know of a job like that that had 3- 1,000+ buried tanks. The ground was totally frozen. It was at a golf club where they had to keep the heat on during the winter because some members might come to play. It was a couple of winters before it was figured out. Under the conditions, using liquid on the boiler wasn't an option.

I had restaurants with three big stand-up tanks that would heavily frost up and the pressure would drop. Adding another tank was just enough to keep the vaporization going and the pressure up.

MikeG

I'm in NW Ohio. The last couple of days it was down to -9* at night around 0* during the day. Normal avg is 36* Hi and 15* Lo. I have a Munchkin 80M on LPG running 160* SWT to mostly copper BB and a small floor and ceiling radiant zone. That radiant zone is both ceiling and floor in a utility room. Best room in the house. Coat and boots are warm and dry in the morning. Luckily the wind was not too bad. Boiler running steady. I keep tstats at 68. House dropped to 66* overnight but once temps came up outside a few degrees recovered nicely. Design temp is 0* but I figured 10* when I installed the boiler. No ODR on this boiler, so it does short cycle in milder weather. Indirect is not set on priority so there has been short periods where everything is running. Return temps have been right around 20-25* Delta T. It does condense. Overall I've been happy with the setup. I would do it a little differently now. I would go with a boiler with a lower end output. Tomorrow night it is suppose to hit -15*. I do know that the wind and wind direction really affects the infiltration on my house so I'll see how things look Friday morning.

Gordy

Nothing better than ceiling, and floor radiant. I have 4 rooms with both.