Showing posts with label Air Conditioning. Show all posts
Showing posts with label Air Conditioning. Show all posts

October 03, 2025

Ventilation plan implemented for High Holy Days (Activity Report)

THIS YEAR, with the incidence of Covid-19 infections at a moderate level and a predicted high temp of 78° for Rosh Hashanah, we implemented a particular plan to provide reasonably healthful air for attendees at our High Holy Day services. 

Below the jump, that plan is outlined for future reference.…

September 19, 2025

Duct smoke detectors installed in sanctuary HVAC system (Activity Report)

ALTHOUGH I HAD provisionally concluded that duct smoke detectors were not required in our sanctuary, as described HERE, I nonetheless looked for an opportunity to get an authoritative opinion. That opportunity presented itself exactly one week ago, when Tom Nasrollahi, a mechanical (HVAC) engineer, made a site visit as a consultant on our main-floor restroom renovation project.

One of the new duct smoke detectors

Unhesitatingly, Tom replied that these devices were indeed required in our sanctuary, according to code. 

He explained that even though each of the sanctuary’s two systems has its own thermostat and each one by itself has a small enough blower to be exempt, they must together be treated as one overall system because they both participate in conditioning the same space. The system’s cubic feet per minute (CFM) for the total space is what counts.

Happily, a pair of detectors was installed yesterday. They were placed just upstream of the air filter before the blower intake (see photo). 

Thus we have made a capital improvement (betterment) that addresses a life-safety risk, which is of course the highest priority use for our precious funds.

(How did it come about that the installer of our replacement heating system in 2017 did not include these devices at that time? Maybe I don’t want to know.…)

July 10, 2025

Duct smoke detectors: required in the sanctuary’s HVAC system? (Background Report)

A DUCT SMOKE DETECTOR is an HVAC-system device that can prevent flames and smoke from being spread or fanned by the system. In the event of smoke, the detector sends a signal to shut down the fan. Its presence is required by code in most circumstances. Normally the determination is made by city building department officials when a permit is applied for. 

The HVAC contractor Jessy Perets told me that our sanctuary’s HVAC system lacks duct smoke detectors. He also pointed out that our twin HVAC units were installed in a visibly low-budget manner, apparently without a building permit. Which has led me to wonder whether or not a pair of duct smoke detectors were technically required in our case. 

For a fire safety measure, the fact of requirement (if it indeed exists) would argue for installation after the fact (which would cost $1,275 as quoted by one contractor). Conversely, if our case is an allowable exception, that would argue for leaving things as they are. At its June meeting, the board adopted that approach and asked the B&G Committee to find out whether duct smoke detectors are required by code in our sanctuary. 

I have a provisional answer, which I lay out below the jump.…

June 11, 2025

Proposed HVAC system for Social Hall (Speculation)

AN EXPERIENCED H.V.A.C. CONTRACTOR submitted today a proposal for a two-stage HVAC system for the Social Hall. The installed cost of a ventilation system would be $28,000. Later, we could add heating and A/C for another $21,600, plus the cost of electrical work. Subtotal: roughly $50K

I asked for this bid because the Ad-Hoc Committee on Capital Priorities recently named such ventilation one of its top five items:

“The Social Hall should once again become an integral part of Mishkon’s life. [It] needs new ventilation and heating.”

Below the jump, I describe the elements of the vendor’s proposal and discuss them, including related options.…

March 11, 2025

HVAC units in school building free up reserve funds (Condition Report)

ACCORDING TO OUR JANUARY 2019 Property Condition Assessment (PCA), our school building’s HVAC units (= furnace, A/C fan coil, and rooftop A/C condenser) were likely to need replacement by 2024. So for more than a year, I have been bracing for an equipment failure any day now.

Below the jump, I recount the ironic tale of how I learned this past week that we can expect many more years of life from our HVAC equipment in that school building.…

June 27, 2024

Ventilation and air conditioning in the rabbi’s office

OUR RABBI MAY WELL be the biggest beneficiary of the security windows that were installed in December. I’m not talking about protection from potential attacks. I mean on a more tangible, everyday basis!

(As usual, click/tap on an image to enlarge it.)

Below the jump, this post explains why I say so.…

November 09, 2023

Toward a more comfortable and healthful school building

THIS POST UPDATES one that I wrote in September. I'm still trying to arrange for improvements to be done in late December, during the preschool break. The present focus is on improving the HVAC system’s air flow throughout the building.

September 13, 2023

Improving HVAC in the school building

THERE’S A LOT of room for improvement in the HVAC system of our school/office building. Thermal-comfort levels are good but not great. Our hospital-grade filter is reducing the risk of airborne disease, but it is taxing the air-supply blower. Running more than 45 hours per week, this HVAC system is much more heavily used than the one in the sanctuary. That’s why in July, when a preschool parent expressed interest in funding a system upgrade, it became my personal highest-priority new project for Mishkon. (This one is moving slowly, however, because I’m still heavily involved in old projects.)

A return-air register for mounting in a door
(As usual, click/tap on an image to enlarge it.)

Below the jump, I discuss the prospects for improvement. This work would be done in late December, during the preschool break.…

August 22, 2023

About the thermostats

WE HAVE THREE thermostats, all of which are the same model: a Honeywell Wifi 9000 Color Touchscreen. For the manual and online support, go HERE.


Below the jump, this post explains some features of our thermal comfort control system.…

August 12, 2023

About our air conditioning systems

Yesterday I spent the morning with Nathan Delgado, a service technician from Acme Heating & Air conditioning, with whom Mishkon has a service contract. 


Below the jump, this post describes what I learned from the experience.

March 16, 2023

Utilities Costs: Electricity and Water

BECAUSE I DON'T have ready access to our utility bills and usage records, I’m attentive when they do come my way. Recently, for a training project, I was given spreadsheets of what Mishkon spent on electricity and water (combined) during the past year. 

Below the jump, I briefly discuss the spreadsheets that I received from our bookkeeper.

February 25, 2023

HVAC (Mechanical heating/cooling system) in the sanctuary (Background Report)

WHAT’S THE CONFIGURATION of the heating/cooling system in our sanctuary?

This post gives you a basic picture, through verbal description and photos.…

February 10, 2023

Change the school building’s air filter every 2 months

After exactly 2 months, the hospital-grade furnace filter in our school building was caked with dust. (Happily, it was changed this week, on 2/9/23.)

Old filter on the bottom; new one on top, for comparison.
(As usual, click/tap on an image to enlarge it.)

So this is a brief note just to say: Hooray for routine maintenance! 👏


January 22, 2023

Tips for good ventilation and thermal comfort in our school building

PICTURE A HALLWAY that’s lined with doorways. You might think that in a proper hallway, all those doors should be closed. A nice and neat look, yes?

Yet that is not how our school building was designed to function! 

This post discusses our building’s characteristics, and how best to work with them.…