Search found 21 matches

by 3rdcoast
Tue May 09, 2017 7:29 pm
Forum: Superheat/Subcooling
Topic: Goodman superheat chart versus fromula
Replies: 19
Views: 702

Re: Goodman superheat chart versus fromula

Wow, that took a little time to set up that chart.. Thanks Thanks to EXCEL that only takes a few minutes to set up, the reason I made a spreadsheet was to have the ability to add other brand charts I find in the future. My Ruud dealer is now carrying a piston air handler for some of the 14 SEER mat...
by 3rdcoast
Fri May 05, 2017 3:36 pm
Forum: Superheat/Subcooling
Topic: Goodman superheat chart versus fromula
Replies: 19
Views: 702

Goodman superheat chart versus fromula

Installed a goodman 14 SEER straight cool the other day, (R410A). Since 14 SEER is entry level now, Goodman and many other brands are using pistons on the 14 SEER stuff. Was charging the unit by the chart in the unit, and decided to check the number versus the superheat formula developed earlier by ...
by 3rdcoast
Sat Oct 15, 2016 8:00 pm
Forum: Applied Electronics/Electricity
Topic: Contactor Chattering? We Can Fix That...
Replies: 22
Views: 1243

Re: Contactor Chattering? We Can Fix That...

The attached document talks about series impedance and shunt capacitance in control circuits for contactors. If you look at the tables provided at our low control voltage of 24 volt the shunt capacitance distance is ignored because the series impedance limiting distance is shorter. At higher control...
by 3rdcoast
Sat Oct 15, 2016 10:24 am
Forum: Applied Electronics/Electricity
Topic: Contactor Chattering? We Can Fix That...
Replies: 22
Views: 1243

Re: Contactor Chattering? We Can Fix That...

If your unit that has the control transformer in it operates off of 240 volt instead of 208 (usually not the case on 3 phase) move the transformer tap to the 208 tap and your control voltage will start out higher. Use a small 24 volt control relay at the outdoor unit and have it control a contactor ...
by 3rdcoast
Mon Feb 15, 2016 8:08 pm
Forum: Combustion
Topic: Flue Pipe Sizing
Replies: 59
Views: 2102

Re: Flue Pipe Sizing

I would assume you have tested it in all three modes, furnace only, water heater only, and both and all is well? I would agree that the charts have extra margin built in, but one thing that helps yours is the straight pipe to the roof with no offsets. If you start reading the manual and counting all...
by 3rdcoast
Wed Feb 10, 2016 9:44 pm
Forum: Combustion
Topic: Flue Pipe Sizing
Replies: 59
Views: 2102

Re: Flue Pipe Sizing

With the 4 inch pipe in the wall you can get the medicine cabinet in and your wife will be happy. If your wife is happy, you might be happy. :mrgreen: If the combined vent does not work, a redneck repair would be to add a normally open valve with 24 volt coil to the water heater control gas outlet. ...
by 3rdcoast
Wed Feb 10, 2016 11:08 am
Forum: Combustion
Topic: Flue Pipe Sizing
Replies: 59
Views: 2102

Re: Flue Pipe Sizing

If I'm moving the HWH a little I could just as easily move it directly under the vertical stack for a straight shot out. Thinking out loud... But then that would mess the configuration with the straight through on the tee with the furnace (fan). Anyway the HWH can be moved. My wife wanted space alo...
by 3rdcoast
Wed Feb 10, 2016 9:59 am
Forum: Combustion
Topic: Flue Pipe Sizing
Replies: 59
Views: 2102

Re: Flue Pipe Sizing

using the GAMA tables to size the common vent you need the vent height from the outlet of the highest appliance to the cap of the vent. You want to use a 4 inch pipe to clear your medicine cabinet, you have a 40k btu natural draft water heater with a 3 inch outlet and a 88k btu fan assist furnace wi...
by 3rdcoast
Tue Feb 09, 2016 10:41 pm
Forum: Combustion
Topic: Flue Pipe Sizing
Replies: 59
Views: 2102

Re: Flue Pipe Sizing

I picked up a 4" tee single wall. The basement is conditioned space. Did I goof? I also got 4" single wall for both the HWH and furnace. Planned on twisting the HWH also Using single wall connectors raises your minimum vent height to meet 128k to 28 feet with no extra margin. The single w...

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