YMMV as our hvac contractor is the bane of our new build, (MULTIPLE deficiencies and poor workmanship, which the GC is barely dealing with)

but, we did HEPA filtration due to hubby severe allergies, and the darn thing was 1k on its own! not looking forward to finding out how much the replacement filters cost...

Were in the cold frigid part of Canada, so were required to have an HRV....we're honestly not sure its working tho, as it doesnt have enough suction to move a kleenex!

...ok, so my post probably wasnt that useful, but thanks for letting me rant!

See this previous thread. Putting makeup air vents too close to the exhaust is incorrect. Your HVAC designer should have suggestions.

I put in an Ideal 700 cfm unit in our last kitchen and strangely there were no requirements for makeup air. The only time the fan was used at full blast--for tripe (ugh!)--I just opened a nearby door.

1,200 cfm is a commercial system.

Unless it is required in your jurisdiction I'd avoid it, unless you run your hood a whole lot more than most of us. For the typical 10-20 minutes a day sort of use just open a window while it's on. You will save a lot of money and avoid huge complexity. The flow of cold air from outside can also be constrained to the kitchen area, where you might well appreciate it anyway.

For many reasons I'd insist on sealed combustion furnaces and water heaters, this eliminates any possibility of backdrafting.

lookintomyeyes83:You are correct, several accessories seem to cost more than an AC unit; I dare not mention the price here.

worthy 1,200 cfm is a commercial system: Its a 60" hood for a 48" gas range; may only ever use outputs exceeding 400 cfm when cooking on the griddle or frying etc.

rwiegand: It is required

I have to admit I missed makeup air code requirement in my design. Met the HVAC guy again yesterday; we have no choice but to install a 1200cfm makeup air unit, however he agreed to my suggestion of installing a makeup air unit in the attic above the laundry room next to the kitchen, with 3 ducts/vents above kitchen cabinets above wall oven and refrigerator. The advantage would be not moving makeup air through the whole house but kitchen to kitchen only; it will only kick in when hood extractor setting is above 400 cfm.

An HRV is required too or a means of bringing fresh air into the home at managed frequencies. We figured we can instead use a timed/damper fan inlet feeding fresh (filtered) air alternating directly into the two furnace plenums, followed by sequentially opening of different zone dampers; sounds complicated and it is a little bit. What happened to the days when one simply opened a window or a door to let fresh air in. The cheapest option no doubt would be to order windows with vents but it's something I will avoid in this home for better humidity and temperature control.

Hi,

Make-up air systems are a good idea and are code-required in our area when vent hood exhaust exceeds 400 cfm. I suggest you consider the pre-engineered systems offered by Fantech: http://www.fantech.net/solutions/residential-kitchens/true-makeup-air-system/

Best wishes for a successful project.

I'm here in Minnesota. We have a large Viking gas range with a grill. We have a 1,200 cfm exhauster on the roof.

We have MUA with electric duct heaters, that we can turn on, if we want to.

There are MUA kits. You HVAC contractor should be able to find a source of supply.

I would love to see the cost/benefit analysis which led to the requirement for makeup air systems in homes. Thousands of dollars to install a system and I've never heard a single anecdote of a case where CO poisoning would have been avoided with a makeup air system. I would imagine those thousands could be better spent myriad of ways to improve a family's safety.

At the end of the day a residential range with commercial power is totally unnecessary, so requiring makeup air is hardly a draconian burden, but when you can just open up a window during those few times you use max exhaust for an extended period it seems like total overkill to me.

What happened to the days when one simply opened a window or a door to let fresh air in

Quantifying the deleterious health effects of tightening modern homes could be shocking. But there's more money to be made and grants received by "fighting" global warming. This all started off with the Peak Oil fake story, then morphed into saving the planet and equalizing underdeveloped countries with developed ones.

@freeoscar: "At the end of the day a residential range with commercial power is totally unnecessary,"

Wow - who died and left you boss? Maybe you 'cook' canned soup.

When you have a hood capable of exhausting xxx cfm, many locales require MUA.

Opening a window is not as effective, and in the Minnesota winter - you may not want 0 degree air.

hmm, I think most of us who have such ranges realize that they are a luxury item. Until 20yrs ago billions of wonderful meals were made at home using ordinarily powered equipment. It's a nice option to have the high power, but hardly necessary for quality home cooking, so I'm not upset about what I consider to be overkill mandates for MUA if you want a luxury item. And as to the latter issue, I'm not saying you shouldn't be allowed to have MUA if that is your preference, but that something as simple as opening a window gets the job done for virtually every scenario, at a savings of thousands of dollars.

Quantifying the deleterious health effects of tightening modern homes could be shocking. But there's more money to be made and grants received by "fighting" global warming. This all started off with the Peak Oil fake story, then morphed into saving the planet and equalizing underdeveloped countries with developed ones.

Ok you lost me or maybe all this rain in SW FL is getting to me. Want to explain what you're meaning?

freeoscar: Opening a window would work, but will not pass code; wish it was that easy. I remember back in NJ, I replaced a recirculating hood with an OTR microwave with a powerful extended exhaust. One winter evening when the fireplace was burning, DW switched the exhaust to full speed and our entire living room filled with smoke when air sucked in from the fireplace, smoke alarm went off etc. Don't want to see repeat of a similar incident here; besides it will not pass code in my new construction.

A further call to the HVAC guy helped me get closer to our goal; MUA selection is down to a choice between two units, the Fantech and Electro Industries. Changed my mind about where to install since the Electro unit has status and warning lights, filter change lights etc. and it would remain hidden in the attic; instead we are going back to installing in Mechanical Room and feeding air into return air ducts. For HRV they will install a 100 CFM fan running 24x7 (initially) feeding into furnace before the filter. I think that about covers it.

Makeup air and ERV/HRVs should be separate systems. I am not sure how easily they can be combined but maybe the HVAC engineer can offer more input.

Makeup air system examples

1. Fantech
2. Electromn
3. Broan
4. CCB innovations

HRV/ERV system

1. Zehnder
2. Fantech
3. Broan

Good luck!

We have a Fantech MUA system but usually just crack the window next to the stove.

FWIW very happy with Zehnder HRV.

We have a 1200 cfm fan above our gas range with grill in our new house. We open a window when we turn the fan on. No MUA system. Even in Syracuse in the winter the cold air is rarely a problem. HVAC contractor proposed a system and I declined. Building inspector didnt catch it. I know that doesnt help you, but that's my experience.

homepro01

Makeup
air and ERV/HRVs should be separate systems. I am not sure how easily
they can be combined but maybe the HVAC engineer can offer more input.

Not actually combined; MUA will feed into return air duct while HRV would feed into inlet system.

schreibdave

We
have a 1200 cfm fan above our gas range with grill in our new house.
We open a window when we turn the fan on. No MUA system. Even in
Syracuse in the winter the cold air is rarely a problem. HVAC
contractor proposed a system and I declined. Building inspector didnt
catch it. I know that doesnt help you, but that's my experience. OMG would love that but the county will catch it if/when requesting mechanical permit (unless it was part of building permit)

I may be overreacting but the quote I received last night seems rather high but I guess there is lots of sheet metal ducting. zones, dampers and controls to be built. HVAC installers are extremely busy in this area and most are not prepared to give you time of day, especially for what appears to be a large and complex system; may have to bite crow and accept it; working out to around $8/sf for everything installed.

Nice thing about an indoor grill and big honking exhaust fan is that my wife doesnt have to call me in from the yard when dinner is ready. I can smell it!

PineBaron,

The quote was for your whole house HVAC system not the MUA unit right?

In a way, right. The basic quote covered two 2-stage 80,000 btu furnaces, all ductwork, gas lines, electronic dampers (for 3 zones for one system and 2 zones for the second), 4 programmable thermostats. Options priced in addition were two 4 ton AC units, 2 on demand hot water naturag gas heaters, cost of AC coils/wiring, installation cost of MUA unit I would purchase & provide. I arrived at the total cost by adding everything up, basic quote + all options (including cost of MUA I'd purchase). This morning I requested the HVAC guy provide a detailed cost breakdown by material, labor etc. of his basic quote; who knows it may all make sense then.

HVAC Guy/Company upset since I asked for a breakdown of the estimate, says he can't provide it and rather not do the job; I think these guys have way too much work and have no time for people who ask too many questions. Am I asking for too much?

HVAC is among the most complex systems of a home. Good contractors are rare and in demand. I don't think a breakdown is out of the ordinary depending on the level of detail expected. I thought PineBaron might prefer variable speed heat pumps and might consider reaching out to contractors beginning to include these higher quality systems.

For those unhappy with makeup air requirements for vent hoods, the best path is to stay below 400CFM. Why put your health or future inhabitants health at risk when it's not necessary? I would say the same thing about avoiding gas ranges and choosing induction instead. For those recommending against life safety building codes, be aware of negatively influencing the safety and health of others.

Our latest house is so tight and vent hood so strong (1000 CFM) that the energy rater fears backdrafting the tankless water heater (so called sealed combustion), let alone the gas dryer... ugh. That's with a code approved makeup air system. If it proves to be true, we will need to add a fan to the makeup air duct at significant expense. I liked the rater's comment that we should have dumped the makeup air supply duct directly onto the cook, instead of the heating and cooling ductwork, that way the homeowners might better feel the effects of their decisions.

Effective measures for stovetop pollutants should include vent hood capture area. The lower and wider, the better. First deal with the manure then don't suck is a good Lstiburek overview of the house as a system with some good thoughts on makeup air and vent hood capture efficiency towards the bottom of the article.

I don't find breakouts of equipment/parts/labor to be useful. More helpful to get 2 or 3 bids with comparable equipment.

I will say this is so easy. We have a vent stack on our roof. The MUA comes in with a 10" duct. There are two 50K heaters. The duct comes into our kitchen, behind the range.

The heaters are manual - a double pole, double throw, switch, with an off in the center. The axial fan is on a fan speed switch - so we can decide how much MUA we want.

Stan Z: That is the route I'm having to take; getting another formal bid and I'll have to sign if comparable.

After having met a couple of good HVAC contractors (waiting for second bid), we have a good feeling on what the final design will look like, only slightly different from what the HVAC guys initially perceived; basically two systems each with a 4 ton AC and 80k BTU furnace, one system with two zones for main living and master and the second system with three zones for 2 x two bedrooms (front and rear each) and a zone for the gym/media room; additional thermostat damper control for bedrooms. MUA: 1200 CFM variable speed/temperature MUA with 20KW heater.

For those unhappy with makeup air requirements for vent hoods, the best path is to stay below 400CFM. Why put your health or future inhabitants health at risk when it's not necessary?

Where I am in FL, we have to stay below 600 CFM to not need MUA.

Springtime Builders

I thought PineBaron might
prefer variable speed heat pumps and might consider reaching out to
contractors beginning to include these higher quality systems.

A whole house air filteration system and HRV is definitely on the cards with installation; it will surely avoid me having to cart around the portable air cleaner I used in our previous gym/media room.

Here in WA:

400CFM: No MUA

600CFM: MUA

>600CFM: Heated MUA

Thank you all for your positive advice and suggestions, it is appreciated.

During our kitchen renovation we installed a new range vent it was rated for up to about 600 CFM. During installation our contractor jumpered it for a max of 400 CFM just in case the inspector asked, but he didn't even seem to care during the final inspection. We then had our contractor reset the jumpers so it would be able to hit the max CFM, and we just open a door or window if we do set the fan on high. However, its a 6 speed fan and we seldom ever go higher than 3.

Bruce

Bruce in Northern Virginia: That is certainly an attractive idea however I don't want to risk a failed inspection.

Town inspector on our new house didnt catch that we had a 1200 cfm hood either.

Well, in my case I just didn't see the value in doing all of those things. I was initially excited at the prospect of taking the opportunity to upgrade to a very tight house when we did our gut/expansion. But the more I looked into it, it became very complicated and expensive for undefinable benefits. In the end, we just did things by the book - all new insulation, windows, doors, HVAC, siding to code and not much beyond that (a higher efficiency A/C and Furnace which were relative no-brainers after gov't rebates, and zoning more for comfort than savings). And I'm happy with that. We more than doubled the volume of our house, have way more window coverage, and our heating and cooling bills are actually less than they had been previously (which was an admittedly leaky 60yr old home). Nothing fancy needed, no special contractors, no special materials which may not age as well as predicted, no difficult to service equipment or difficult to diagnose problems should they occur. The house is remarkably comfortable, which was a challenge given that it's an expanded split so there are all kinds of different levels and environments in the house.

Obviously everyone has their own priorities, but I wanted comfort, manageable utility bills, and reasonable upfront and servicing costs, and we have that.

^^^^ it sounds like you did about 90% of it already! You shouldn't need "exotic" in order to have an efficient and healthy home.