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Joined on November 15, 2008

Last Post on July 2, 2014

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moisture in the system

@ July 2, 2014 4:18 PM in major problems with new carrier system

If there is moisture in the system you could have ice forming in the TXV after a period of running.

What kind of unit is being replaced?

@ May 30, 2014 4:29 PM in Help with RTU replacement......

What kind of unit is being replaced?  I believe the Daikin units have the same footprint as some of the old carriers and may not require a curb adapter.  I almost wonder if one contractor is pulling the old curb, reworking the drops and patching the roof and the other contractor is just pulling one unit and setting another right back on the existing curb.  That would be a big difference in price.

Mitsubishi hyper heat

@ May 8, 2014 10:00 PM in Cold Climate Air Source Heat Pumps

We've used the Mitsubishi hyper heat units here in the upper peninsula of michigan. We put them on a stand and use the base pan heater. We used one in a cabin which was intended for use in March through November and it worked well down into the teens. He tried to use it when it was single digits below 0 and it only got the cabin into the 50's. It all depends on heat loss of the structure of course. We just put in our first trane variable speed condensing unit - works great so far but no experience with real cold weather yet.


@ April 12, 2014 1:23 PM in What do you think of when somebody says Hydronics?

Very interesting. Are there issues with cleaning the flat plate between milkings?

you should listen to Gordon

@ April 9, 2014 5:37 PM in Auto fill/back flow preventer. Is it necessary?

I agree with Gordon. If you tee in the return from the heat exchanger to the hot water supply as drawn you have a scald hazard. Hypothetically - 6 yr old grandchild starts washing hands in sink. Water heater decides to turn on pumps. Wood boiler water is at 200 degrees for some reason or flow through domestic side is restricted. 120 degree water enters heat exchanger and leaves at 150. 150 degree water enters tee and proceeds to faucet and grandchild gets scalded. Tempering valve prevents this.

temp of cold water

@ February 15, 2014 6:48 PM in Running Out of Hot Water With a Megastor -40

Does the temperature of your incoming water change during the winter months?  Where I live the cold water temperature is 65 - 70 degrees during the summer and 35 degrees in the winter.  If that is the case you would have less recovery in the winter.

low air temp

@ November 29, 2013 6:24 PM in Indoor Pool HVAC

That's part of the reason for the energy usage - typically dehumidifers are sized with the expectation that the air temp will be something like 2 degrees warmer than the pool water to control the evaporation rate.  I would guess the unit is running all the time.  As far as the split condenser - that is an option to provide cooling should the room be too hot.  There is also a reheat coil in the unit itself.  If the dehumidifier hasn't been serviced regularly it would be a good idea to make sure all the coils are clean and the refrigeration system is properly charged and operating correctly.  I probably can't help you much more but to say be careful - we dotted all the i's and crossed the t's and still had a very unpleasant situation with a similar residential indoor pool that was not being run as designed.

room temp

@ November 29, 2013 5:47 PM in Indoor Pool HVAC

What temp do they keep the room at? What area of the country are you in?

i wouldn't

@ November 29, 2013 1:58 PM in Indoor Pool HVAC

That doesn't sound like a cheaper method to me - with the current unit the heat you remove from the evaporator coil ends up either in the pool water or back in the room depending on what unit you have. With the mini split you would be running two compressors to do the same work. Do you know how they are running the system right now? Are they running the room temperature higher than the pool water temperature? Do they cover the pool when not in use? Those things make a huge difference in the amount of energy used.

be careful

@ November 29, 2013 1:05 PM in Indoor Pool HVAC

Be careful - ductless mini splits have a dumidification mode but they have no ability to reheat like a pool dehumidification unit does. Pool dehumidifiers are expensive to run - but if they don't like the $800 / month to run it they surely won't like the $xxx,xxx.xx in damage not having a proper dehumidification / ventilation system can cause. Everything matters with these - pool temperature, air temperature, air pressures relative to living spaces, etc and improper systems can lead to massive mold and rot issues in the home.

CHS boiler

@ May 23, 2013 9:45 PM in Time to choose a boiler

I put a CHS85 in my own house last year. It's a good boiler - nice control and display, versatile piping,runs quiet. No problems with it at all.


@ April 17, 2013 5:45 PM in I hope I am not beating a dead horse.

I agree with you with one caveat and it involves systems that were engineered and installed with higher water temperatures in mind.  I thought they didn't exist until we got involved with a weatherization program for some subsidized apartment buildings built in the early 80's.  The original systems were installed exactly to the original spec and on design day required 180 degree water and ran with an 18 degree temp drop.  In that situation you need the bigger boiler pump.
On a side note - with these firetube boilers with low heat exchanger water side head loss - how cool would it be to have a system with a single pump (no primary secondary) that had a setpoint for minimum flow rate and then used delta T to control above that rate.  


@ April 17, 2013 4:48 PM in I hope I am not beating a dead horse.

I think what JDB is getting at is that using a Delta T pump in and of itself will not help a boiler short cyling problem when dealing with a small zone.  Slowing down the zone flow to achieve a higher Delta T causes the total BTU output of the zone to drop as he showed in his calculations.  Obviously it has other advantages as regards water temperature return to facilitate higher running efficiencies but it does not result in higher BTU output from the zone.

grundfos 40-120

@ November 28, 2012 1:23 PM in Grundfos Magna - which mode?

It is a 40-120.  The system has some long marginally sized pipe runs to the furthest radiators.  I left the pump in the proportional pressure mode as per the manual.  I guess I'm just trying to understand why that would be better in my situation.  Constant pressure makes more sense to me.

Grundfos Magna - which mode?

@ November 27, 2012 9:15 PM in Grundfos Magna - which mode?

I just installed a grundfos magna on a cast iron radiator system with TRV's and outdoor reset.  I am just curious what mode others have used in in this situation and with what results.  The other times I've used the magna were on apartment buildings with zone valves - I left it in the auto-adapt mode and it worked fine.


@ October 26, 2012 8:29 PM in WEIL MCLEAN ULTRA

Is it natural gas or propane?  Was a combustion test done on startup?


@ September 28, 2012 11:47 AM in New Mod-Con system - wife not happy

Is there a new thermostat on the system?  Sometimes the old stat was out of calibration and the home was warmer than the setting.

chiller control

@ September 16, 2011 9:10 PM in How would you

13 x 19 printer

@ August 10, 2011 8:23 PM in Is it me or is Wiring diagrams getting smaller in print???

We have started printing wiring diagrams on 13 x 19 paper - the printers aren't that expensive and it really helps.

@ February 24, 2009 1:55 PM in seals going out 6 months in heating system

We saw a system that had ongoing seal problems - it turned out the pH in the system was very high. When that was fixed the seal problem went away.

It happens

@ February 8, 2009 8:34 PM in LIne Set Frost in Winter

Dangerous No. It's simple the refrigerant migrating. The difference between the compressor crankcase heater or winding temperature and the indoor coil temperature as the heating cycles of the furnace changes can make the refrigerant move all on its own. Refrigeration's cool.

Gas input

@ December 21, 2008 8:17 PM in Sucky Mod Con Efficiency.... (ME)

Mark - has the boiler input changed significantly? It would seem to me like a fouled heat exchanger would lead to less air flow at the same blower RPM and thus a lower firing rate.
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