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SWEI

SWEI

Joined on November 26, 2011

Last Post on July 22, 2014

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One GPM

@ June 29, 2014 1:29 PM in ECM circulators

is clearly in the ecocirc e3 realm.  They're no less expensive than an Alpha or a Stratos, but they draw tiny amounts of power.  Much better to run a pump in the sweet spot of its curve than to bounce of the bottom.

Curious about the plate radiator

@ June 29, 2014 1:17 PM in recent job

looks like a Myson -- mounted under the other radiator.  Is that fed with steam, or catching condensate on the way down?

Indirect calls

@ June 29, 2014 12:54 PM in Water Tank Temperature After Shower

on all the mod/cons I have used force the boiler to a preset water temp, then shut off once the DHW hits the preset temp.  The smarter ones use a thermistor in the tank to increase response to a droop and reduce overshoot.  With external controls we can take them to the next level -- firing the boiler to the lowest temp which will achieve the needed recovery.  Combine that with some intelligent setpoint management and we see far fewer ignitions.

Sensible and latent loads

@ June 28, 2014 10:48 AM in Cooling load, heating load, sizing equipment

are calculated separately.  I'm not sure where the "80% to 90%" numbers came from, but maybe that works in Chicago.  There is more than one way to remove humidity.  I'm sure Rich's guy is familiar with all this.

The complete lack of cluefulness demonstrated on your heating load makes me question the whole deal.

SMART indirect temperature sensors

@ June 28, 2014 10:33 AM in Water Tank Temperature After Shower

Are located roughly in the middle of the tank, or at least the bottom of the sensor well is.

It sounds as though your contractor did replace the tank aquastat with the 12k thermistor (that's how the boiler sees the tank temp you presumably read from the boiler display.)

Floor zone

@ June 26, 2014 10:06 AM in need electrical help

is this by any chance a radiant floor?  Why did you select the BWF?

Did anyone do a heat loss calc for this job?

We call it an apron

@ June 25, 2014 2:04 PM in Thermal break at overhead doors

and you just described nicely what I was trying to convey.  Separate the part of the slab that is under (and just outside) the door from the main interior portion.  Heat it or not -- your choice -- but keep it isolated at least a bit.

Personally, I'd run it at least 18" past the door and set it up for a separate snowmelt zone as ice described in his original reply.  It's really, really nice not to have to chip away at the door closure after a cold night.

Can you tie the apron to the main slab

@ June 25, 2014 12:18 PM in Thermal break at overhead doors

with a bunch of #7 bar that bridges the thermal break?  Heat transfer is all about area, and that might do the trick.

Codes vary

@ June 24, 2014 10:22 PM in Main Lobby in hotels

depending on jurisdiction.  Here in the US, we have an assumed occupant load of 15 square feet per person for lobbies.

Fermentation

@ June 24, 2014 5:53 PM in The history of the toilet

is quite sensitive to foreign critters.  The neat thing about beer and wine is that almost anything undesirable that grows alters both smell and taste in an obvious way.  So if it smells OK and tastes OK, it usually is OK.

Energy Costs

@ June 23, 2014 10:36 PM in Need help rating these radiators.

Every year, a larger portion of our domestic electricity is produced from natural gas.  When the power company burns gas, it only converts 50-60% of the available BTUs into electricity.  An additional 20-25% is lost in distribution.  Net net is that you are lucky to see 40% of the BTUs that are burned delivered to your premises.

A properly functioning commercial steam boiler will convert about 85% of those BTUs into heat.

Don't be lulled into complacency by the power company PR.

For this size and complexity of project

@ June 23, 2014 10:22 PM in Need help rating these radiators.

You really do need some professional expertise.  The sizing of A/C versus heating loads is one area, as mentioned above.  Occupancy patterns make a significant impact.  If the sanctuary is used once per week, mostly uninsulated, and constitutes the bulk of the total facility load (quite common in older churches) that skews things significantly, and in a manner which standard equipment sizing programs will not account for.  Air distribution in high-ceiling rooms is in itself an art form, and one which the Asian split makers have not generally addressed.  There are ways to do it (by pairing their short-duct evaporators with special nozzles) but it's not common knowledge amongst the installer base.

We are trying to help you be careful with your congregants' money.

You're in luck!

@ June 23, 2014 6:38 PM in Need help rating these radiators.

Dave works in your area and will not steer you wrong.

For an intermittently-occupied minimally insulated building (like a sanctuary) nothing can touch steam for quick recovery.  You really can have the best of all worlds with a properly designed (and controlled) hybrid system.

Properly implemented geo-exchange is a beautiful thing, but modern inverter-driven air source heat pumps often represent a better bargain (unless you happen have a large body of water or free-flowing stream on site.)

Who's designing the geothermal system?

@ June 23, 2014 6:04 PM in Need help rating these radiators.

there is sophisticated software for this, sometimes even free from the manufacturers.  Sizing of coils is critical and depends on heat loss/gain as well as latent (dehumidification) loads.

The ratings depend on temperature

@ June 23, 2014 12:55 PM in Need help rating these radiators.

Unless there have been some envelope upgrades, it's quite likely you will not be able to heat the building on a design day with a heat pump and the existing radiation.

http://usboiler.net/library/USBoilerReport/heatinghelper/offline/download.pdf has a lot of useful info.  Note in particular the derating of EDR for temperature on p. 37 and remember that the vast majority of heat pumps can't supply water hotter than about 130ºF.

Radiant Cooling

@ June 23, 2014 11:56 AM in Whole house de-humidifier

Start here http://www.uponorpro.com/~/media/Extranet/Files/manuals/Nonoptimized/RCDM_Manual_RC03_0513_52020red.aspx?sc_lang=en&version=051720130958

Have you tried Dahl Brothers?

@ June 21, 2014 8:11 PM in No end of aggravation

More configurations than you can imagine, and well made.

Larger diameters

@ June 21, 2014 11:50 AM in Aquatherm piping

can feel a bit like wrestling anacondas at times.  We borrowed one of the early clampy-jig things from our rep and decided it was not worth the money they wanted for it at the time.  Several newer designs have come along -- this one looks like it would be much easier to use overhead than what we had http://www.mcelroy.com/ppr/socket/opt_machine.htm

We opted out of the butt fusion by subbing out the handful of 6" connections on the job.  Bought a full set of tooling up through 63mm (2") and am happy playing there, with occasional forays up to 125mm (4") as needed.

Sourcing is a challenge, but then in our remote location that is nearly always the case.  I have at least seven supply house branches who are one day UPS away and stock Aquatherm.  Sometimes it can take a couple of calls to find the right fusion outlet.  Specialty items like pump flanges are special order, but Webstone flanges usually work better on most jobs anyway.

Again in the Main Wall

@ June 20, 2014 11:40 AM in Aquatherm piping

Aquatherm is our preferred choice for sizes over 1" nominal for both hydronic  heat/cooling and DHW.  If the largest pipe in the job is 1", we specify  ProPEX for everything.  On larger jobs, it's still easier to use PEX for the small stuff and transition around ~9 GPM to Aquatherm.  The  flexibility and cost of saddle welding are tough to beat.  Watch out for the transition fittings -- over 1" they get spendy fast.

One more

@ June 20, 2014 11:39 AM in I finally bought a brick

Just another brick in the hod.

I'm curious

@ June 20, 2014 11:28 AM in Oil to Gas conversion

what kind of excess air numbers the Midco LNB is producing.  We see near-perfect combustion from that type of burner in other applications.

I've posted about it here a few times

@ June 20, 2014 11:16 AM in Aquatherm piping

I'll repeat one of them here:

Aquatherm
is our preferred choice for sizes over 1" nominal for both hydronic
heat/cooling and DHW.  If the largest pipe in the job is 1", we specify
ProPEX for everything.  On larger jobs, it's still easier to use PEX for
the small stuff and transition around ~9 GPM to Aquatherm.  The
flexibility and cost of saddle welding are tough to beat.  Watch out for
the transition fittings -- over 1" they get spendy fast.







I'll shoot you an email with my cell number if you want more details.
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